NUCLEAR

TECHNOLOGY
REVIEW
2009

@
NUCLEAR TECHNOLOGY REVIEW 2009
 The following States are Members of the International Atomic Energy Agency:

AFGHANISTAN GHANA NIGERIA

ALBANIA GREECE NORWAY
ALGERIA GUATEMALA OMAN
ANGOLA HAITI PAKISTAN
ARGENTINA HOLY SEE PALAU
ARMENIA HONDURAS PANAMA
AUSTRALIA HUNGARY PARAGUAY
AUSTRIA ICELAND PERU
AZERBAIJAN INDIA PHILIPPINES
BAHRAIN INDONESIA POLAND
BANGLADESH IRAN, ISLAMIC REPUBLIC OF PORTUGAL
BELARUS IRAQ QATAR
BELGIUM IRELAND REPUBLIC OF MOLDOVA
BELIZE ISRAEL ROMANIA
BENIN ITALY RUSSIAN FEDERATION
BOLIVIA JAMAICA SAUDI ARABIA
BOSNIA AND HERZEGOVINA JAPAN SENEGAL
BOTSWANA JORDAN SERBIA
BRAZIL KAZAKHSTAN SEYCHELLES
BULGARIA KENYA SIERRA LEONE
BURKINA FASO KOREA, REPUBLIC OF SINGAPORE
BURUNDI KUWAIT SLOVAKIA
CAMEROON KYRGYZSTAN SLOVENIA
CANADA LATVIA SOUTH AFRICA
CENTRAL AFRICAN  LEBANON SPAIN
REPUBLIC LESOTHO SRI LANKA
CHAD LIBERIA SUDAN
CHILE LIBYAN ARAB JAMAHIRIYA SWEDEN
CHINA LIECHTENSTEIN SWITZERLAND
COLOMBIA LITHUANIA SYRIAN ARAB REPUBLIC
CONGO LUXEMBOURG TAJIKISTAN
COSTA RICA MADAGASCAR THAILAND
CÔTE D’IVOIRE MALAWI THE FORMER YUGOSLAV 
CROATIA MALAYSIA REPUBLIC OF MACEDONIA
CUBA MALI TUNISIA
CYPRUS MALTA TURKEY
CZECH REPUBLIC MARSHALL ISLANDS UGANDA
DEMOCRATIC REPUBLIC  MAURITANIA UKRAINE
OF THE CONGO MAURITIUS UNITED ARAB EMIRATES
DENMARK MEXICO UNITED KINGDOM OF 
DOMINICAN REPUBLIC MONACO GREAT BRITAIN AND 
ECUADOR MONGOLIA NORTHERN IRELAND
EGYPT MONTENEGRO UNITED REPUBLIC 
EL SALVADOR MOROCCO OF TANZANIA
ERITREA MOZAMBIQUE UNITED STATES OF AMERICA
ESTONIA MYANMAR URUGUAY
ETHIOPIA NAMIBIA UZBEKISTAN
FINLAND NEPAL VENEZUELA
FRANCE NETHERLANDS VIETNAM
GABON NEW ZEALAND YEMEN
GEORGIA NICARAGUA ZAMBIA
GERMANY NIGER ZIMBABWE

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The Headquarters of the Agency are situated in Vienna. Its principal objective is “to accelerate and
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 SAFETY xxxxxxx SERIES No. XX

NUCLEAR TECHNOLOGY
REVIEW 2009

INTERNATIONAL ATOMIC ENERGY AGENCY

VIENNA, 2009
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 CONTENTS

EXECUTIVE SUMMARY. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

A. POWER APPLICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

A.1. Nuclear Power Today . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

A.2. Projected Growth for Nuclear Power . . . . . . . . . . . . . . . . . . . . . 7
A.3. Fuel Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
A.3.1. Uranium Resources and Production . . . . . . . . . . . . . . . 8
A.3.2. Conversion, Enrichment and Fuel Fabrication . . . . . . . 9
A.3.3. Back End of the Fuel Cycle . . . . . . . . . . . . . . . . . . . . . . . 10
A.4. Additional Factors Affecting the Future of Nuclear Power . . . 11
A.4.1. Economics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
A.4.2. Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
A.4.3. Human Resource Development . . . . . . . . . . . . . . . . . . . 14
A.4.4. Public Acceptance of Nuclear Energy . . . . . . . . . . . . . . 17

B. ADVANCED FISSION AND FUSION . . . . . . . . . . . . . . . . . . . . . . . 19

B.1. Advanced Fission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

B.1.1. Water Cooled Reactors . . . . . . . . . . . . . . . . . . . . . . . . . . 19
B.1.2. Fast Neutron Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
B.1.3. Gas Cooled Reactors . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
B.1.4. INPRO and GIF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
B.2. Fusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

C. ATOMIC AND NUCLEAR DATA . . . . . . . . . . . . . . . . . . . . . . . . . . 23

D. ACCELERATOR AND RESEARCH REACTOR

APPLICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

D.1. Accelerators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
D.2. Research Reactors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

E. NUCLEAR TECHNOLOGIES IN FOOD AND

AGRICULTURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

E.1. Improving Livestock Productivity and Health . . . . . . . . . . . . . 27

E.2. Vaccine Research . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
 E.3. Insect Pest Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
E.3.1. X Ray Irradiation for Insect Sterilization . . . . . . . . . . . 29
E.3.2. SIT against Tsetse Flies . . . . . . . . . . . . . . . . . . . . . . . . . . 29
E.4. Food Quality and Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
E.4.1. Traceability as an Approach to Control Food
Contaminants and Improve Food Safety . . . . . . . . . . . . 30
E.5. Crop Improvement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
E.5.1. Gene Identification and Function Elucidation
using Induced Mutants . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
E.5.2. Integrated Technologies for Enhanced
Mutation Induction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
E.6. Sustainable Land and Water Management . . . . . . . . . . . . . . . . 33
E.6.1. Understanding the Role of Microorganisms 
in Soil Quality and Fertility under Changing Climatic
Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
E.6.2. Stable Isotopic Tracers to Support the Control of GHG
Emissions From Agricultural Lands . . . . . . . . . . . . . . . . 33

F. HUMAN HEALTH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

F.1. Linkages between Nuclear Medicine Imaging and the

Pharmaceutical Industry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
F.2. Application of Nuclear Techniques to Support Nutrition . . . . 35
F.3. Advances in Quantitative Imaging and Internal Dosimetry
for Nuclear Medicine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
F.4. Improvement in Radiation Oncology Applications . . . . . . . . . 36

G. ENVIRONMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

G.1. ‘Hot Particles’ in the Environment . . . . . . . . . . . . . . . . . . . . . . . 38

G.2. On-line Access to Worldwide Marine Radioactivity Data . . . . 38
G.3. Stable Isotope Labelling in Marine Food Web Studies . . . . . . . 40
G.4. Radiotracers to Measure Impacts of Ocean Acidification
on Marine Biodiversity in the Arctic and Mediterranean . . . . 41

H. WATER RESOURCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

I. RADIOISOTOPE PRODUCTION AND AVAILABILITY . . . . . 43

I.1. Security of Supplies of Molybdenum-99 . . . . . . . . . . . . . . . . . . . 46

I.2. Electron Beam Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
 I.3. Radiation Processing in Nanoscience . . . . . . . . . . . . . . . . . . . . . 48

ANNEX I: DEVELOPMENTS IN MUTATION ASSISTED

PLANT BREEDING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
ANNEX II: QUALITY ASSURANCE IN RADIATION
DOSIMETRY: ACHIEVEMENTS AND TRENDS . . . . 63
ANNEX III: ISOTOPES FOR MANAGEMENT OF
TRANSBOUNDARY RIVERS AND AQUIFERS. . . . . 75
ANNEX IV: ADVANCED CONSTRUCTION METHODS FOR
NEW NUCLEAR POWER PLANTS . . . . . . . . . . . . . . . . . 84
ANNEX V: INTERFACING NUCLEAR POWER PLANTS
WITH THE ELECTRIC GRID: THE NEED FOR
RELIABILITY AMID COMPLEXITY . . . . . . . . . . . . . . . 100
ANNEX VI: SEEKING SUSTAINABLE CLIMATE, LAND,
ENERGY AND WATER (CLEW) STRATEGIES . . . . . 116
 EXECUTIVE SUMMARY

The year 2008 was paradoxical for nuclear power. Projections of future
growth were revised upwards, but no new reactors were connected to the grid.
It was the first year since 1955 without at least one new reactor coming on-line.
There were, however, ten construction starts, the most since 1985.
At least until the global financial crisis, cost estimates reported for new
nuclear reactors were often higher than those in previous years, particularly in
regions with less recent experience in new construction. However, growth
targets for nuclear power were raised in the Russian Federation, and similar
considerations were under review in China. India negotiated a safeguards
agreement with the Agency in August, and the Nuclear Suppliers Group subse-
quently exempted India from previous restrictions on nuclear trade, which
should allow India to accelerate its planned expansion of nuclear power.
In the USA, the Nuclear Regulatory Commission (NRC) received
combined licence (COL) applications for 26 new reactors. The US Department
of Energy (USDOE) received 19 ‘Part I applications’ for Federal loan
guarantees to build 21 new reactors.
Nonetheless, current expansion, as well as near term and long term
growth prospects, remain centred in Asia. Of the ten construction starts in
2008, eight were in Asia. Twenty-eight of the 44 reactors under construction at
the end of the year were in Asia, as were 28 of the last 39 new reactors to have
been connected to the grid.
Armenia joined the Russian Federation and Kazakhstan as members of
the International Uranium Enrichment Centre in Angarsk, Siberia. The
Ukrainian Government announced that Ukraine would also join. AREVA and
USEC applied to the USDOE for loan guarantees for the construction of
AREVA’s proposed Eagle Rock Enrichment Facility and USEC’s American
Centrifuge Plant.
Construction of an underground repository for low and medium level
radioactive waste began at the former Konrad iron mine in Germany. The
USDOE submitted a formal application to build and operate the long planned
high level waste repository at Yucca Mountain in Nevada.
The ITER International Fusion Energy Organization formally applied
for a construction permit to build the International Thermonuclear Experi-
mental Reactor (ITER), an experimental fusion reactor, in Cadarache, France.
Water resource management, food security, human health, environmental
protection and the use of radioisotopes and radiation are all areas where
nuclear and isotopic techniques are making valuable contributions to socioeco-
nomic development around the world.

1
 In the food and agriculture area, nuclear techniques are being used,
together with complementary techniques, to enhance livestock productivity as
well as to prevent the spread of dangerous transboundary animal diseases such
as avian flu. As international trade expands, the need to ensure food safety also
grows. Isotopic techniques are being used to trace the origin of foods and to
track the infiltration of contaminants as a means to ensure the quality of food
products.
Nuclear imaging is playing a growing role in the development of new
drugs. Interventions to improve nutrition are increasingly becoming part of
development strategies; the use of stable isotopes to assess key nutritional
aspects, such as body composition, can be part of effective strategies to
counteract later development of chronic diseases. The long sought ‘magic
bullet’, where a truly targeted substance kills cancer cells without damaging
healthy tissue, is progressively, albeit slowly, becoming a reality in therapeutic
nuclear medicine.
In the natural resources management field, nuclear techniques are
helping to assess ‘hot particles’ — a type of radionuclide that can be released to
the environment from a number of sources including weapons testing and
nuclear accidents. Stable isotopes are being used in order to gain a better
understanding of complex food webs and carbon cycling in the marine
environment. Radiotracer tools are being utilized to measure the impacts of
climate change, such as ocean acidification on marine biodiversity. Isotope
methods are increasingly being used to assist in the easy identification of
aquifers with old water and no recharge, or with modern water with significant
recharge, which is important information for effective freshwater management.
Global demand for radioisotope and radiation sources is growing due to
their use in medicine and industry with a corresponding expansion of regional
centres for the production of clinical radiotracers for positron emission
tomography imaging. During the past year, disruptions in the supplies of the
radioisotope molybdenum-99, the source of widely used technetium-99m for
diagnostic imaging, had a negative impact on patient services in nuclear
medicine centres around the world. Governmental support and stronger
cooperation among isotope manufacturers including public–private partner-
ships will be required to ensure that suitable reactors will be engaged in the
irradiation of low enriched uranium targets for molybdenum-99 production in
the future.

2
 A. POWER APPLICATIONS

A.1. Nuclear power today

Worldwide, there were 438 nuclear power reactors in operation at the

end of 2008. No new reactors were connected to the grid in 2008, and
Bohunice-2 was retired at the end of the year in line with Slovakia’s European
Union (EU) accession agreement. Worldwide nuclear generating capacity as
well as nuclear power’s share of global electricity generation remained
essentially unchanged at 372 GW(e) and at 14%, respectively (see Table A-1).
There were ten construction starts in 2008: Fangjiashan-1, Fuqing-1,
Hongyanhe-2, Ningde-1 and -2 and Yangjiang-1 (all 1000 MW(e)) in China,
Novovoronezh 2-1 and Leningrad 2-1 (both 1085 MW(e)) in the Russian
Federation, and Shin-Wolsong-2 (960 MW(e)) and Shin-Kori-3 (1340 MW(e))
in the Republic of Korea. This compares with eight construction starts plus the
resumption of active construction at one reactor in 2007. In 2006, there were
four construction starts plus resumed construction at one reactor.
Current expansion, as well as near term and long term growth prospects,
remain centred in Asia. Of the ten construction starts in 2008, eight were in
Asia. As shown in Table A-1, 28 of the 44 reactors under construction at the
end of the year were in Asia, as were 28 of the last 39 new reactors to have been
connected to the grid. China is considering raising its target for nuclear power’s
share of electricity by 2020. India negotiated a safeguards agreement with the
Agency, and subsequently the Nuclear Suppliers Group exempted India from
previous restrictions on nuclear trade. Less restricted trade should allow India
to accelerate its planned expansion of nuclear power.
Targets were raised in the Russian Federation — to 52–59 GW(e) of
nuclear power capacity by 2020. The Russian Federation also licensed the Kola-
1 nuclear power plant for extended operation through July 2018, i.e. a currently
licensed lifetime of 45 years.
Also in Europe, the United Kingdom published a White Paper in January
2008 that stressed that it was in the public interest for nuclear energy to
continue to form part of the United Kingdom’s low carbon energy mix in order
to help meet carbon reduction targets and ensure secure energy supplies.
Several European utilities expressed interest in building new reactors in the
United Kingdom. Italy announced plans for reestablishing the legal, regulatory
and technical infrastructure necessary to restart its nuclear power programme,
which had been shut down following a referendum in 1987. A bill overturning
the nuclear moratorium was approved by the lower chamber of the Parliament
in early November. In Romania, partners signed an investment agreement to

3
finance construction of Cernavoda-3 and 4. In Bulgaria, partners signed
contracts for the construction of Belene-1 and 2. In Finland, Teollisuuden
Voima Oyj (TVO) applied to the Council of State for approval in principle to
build Olkiluoto-4, and two further applications are being prepared by other
companies. In Switzerland, Atel, Axpo and BKW FMB Energy have submitted
applications to build new nuclear power plants in Niederamt, Beznau and
Gösgen. In Slovakia, Slovenské elektrárne launched a tender for the
resumption of construction at Mochovce-3 and 4.
In Canada, Ontario’s provincial government selected Darlington as the
site for two new reactor units following Ontario Power Generation’s 2006
application for a site preparation licence. Ontario Power Generation was also
granted licences to operate the Darlington and Pickering-B reactors for
another five years, through 2013.
In the USA, the Nuclear Regulatory Commission (NRC) approved ten
power uprates, totalling 2178 MW(th). It approved three licence renewals of 20
years (for a total licensed life of 60 years) bringing the total number of
approved licence renewals at the end of 2008 to 51. Concerning new
construction, the NRC received combined licence (COL) applications for 26
new reactors. The US Department of Energy (USDOE) received 19 ‘Part I
applications’ for Federal loan guarantees to build 21 new reactors. The total
requested was $122 billion, significantly more than the $18.5 billion offered.
Interest in starting new nuclear power programmes remains high. In the
past two years, 55 Member States have expressed, through requests to the
Agency to participate in technical cooperation projects, their interest in
considering the introduction of nuclear power.
The Agency assists interested Member States both in analysing energy
options and in preparing to introduce nuclear power and/or uranium
production. The number of approved technical cooperation (TC) projects on
analysing energy options increased from 29 to 41 for the technical cooperation
project cycle starting in 2009. The number of projects on uranium exploration
and mining increased from 4 to 10, and the number of projects on introducing
nuclear power increased from 13 to 44. The Agency introduced a new service
providing integrated advice to countries considering the introduction of
nuclear power. In 2007 and 2008, ten such missions took place, to Belarus,
Egypt, Jordan, Nigeria, Philippines, Sudan, Thailand, and to members of the
Cooperation Council for the Arab States of the Gulf (three times). The Agency
also provides guidance documents. In 2008, it published Evaluation of the
Status of National Nuclear Infrastructure Development and Financing of New
Nuclear Power Plants to supplement two basic publications in 2007, Considera-
tions to Launch a Nuclear Power Programme and Milestones in the
Development of a National Infrastructure for Nuclear Power.

4
 TABLE A-1. Nuclear power reactors in operation and under construction in the world (as of 31 December 2008)a
Reactors in Reactors under Nuclear electricity Total operating
Operation Construction Supplied in 2008 Experience through 2008
Country
Total Total
No of units No of units TW·h % of Total Years Months
MW(e) MW(e)

Argentina 2 935 1 692 6.9 6.2 60 7

Armenia 1 376 2.2 39.4 34 8
Belgium 7 5 824 43.4 53.8 226 7
Brazil 2 1 766 13.2 3.1 35 3
Bulgaria 2 1 906 2 1 906 14.7 32.9 145 3
Canada 18 12 577 88.3 14.8 564 2
China 11 8 438 11 10 220 65.3 2.2 88 3
Czech Republic 6 3 634 25.0 32.5 104 10
Finland 4 2 696 1 1 600 22.1 29.7 119 4
France 59 63 260 1 1 600 419.8 76.2 1 641 2
Germany 17 20 470 140.9 28.8 734 5
Hungary 4 1 859 13.9 37.2 94 2
India 17 3 782 6 2 910 13.2 2.0 301 4
Iran, Islamic Republic of 1 915
Japan 55 47 278 2 2 191 241.3 24.9 1 386 8
Korea, Republic of 20 17 647 5 5 180 144.3 35.6 319 8
Lithuania 1 1 185 9.1 72.9 42 6
Mexico 2 1 300 9.4 4.0 33 11
Netherlands 1 482 3.9 3.8 64 0
5
6 TABLE A-1. Nuclear power reactors in operation and under construction in the world (as of 31 December 2008)a (cont.)
Reactors in Reactors under Nuclear electricity Total operating
Operation Construction Supplied in 2008 Experience through 2008
Country
Total Total
No of units No of units TW·h % of Total Years Months
MW(e) MW(e)

Pakistan 2 425 1 300 1.7 1.9 45 10

Romania 2 1 300 10.3 17.5 13 11
Russian Federation 31 21 743 8 5 809 152.1 16.9 963 4
Slovakia 4 1 711 15.5 56.4 128 7
Slovenia 1 666 6.0 41.7 27 3
South Africa 2 1 800 12.8 5.3 48 3
Spain 8 7 450 56.5 18.3 261 6
Sweden 10 8 996 61.3 42.0 362 6
Switzerland 5 3 220 26.3 39.2 168 10
Ukraine 15 13 107 2 1 900 84.5 47.4 353 6
United Kingdom 19 10 097 48.2 13.5 1 438 8
United States of America 104 100 683 1 1 165 806.7 19.7 3 395 9
Totalb, c 438 371 562 44 38 988 2 597.8 14 13 475 7
a
Data are from the Agency’s Power Reactor Information System (http://www.iaea.org/pris)
b
The total includes the following data in Taiwan, China:
— 6 units, 4949 MW(e) in operation; 2 units, 2600 MW(e) under construction;
— 39.3 TW·h of nuclear electricity generation, representing 17.5% of the total electricity generated there;
— 164 years, 1 month of total operating experience at the end of 2008.
c
The total operating experience includes also shut down plants in Italy (81 years) and Kazakhstan (25 years, 10 months).
A.2. Projected growth for nuclear power

Each year the IAEA updates its low and high projections for global
growth in nuclear power. In 2008, both the low and high projections were
revised upwards. In the updated low projection, global nuclear power capacity
reaches 473 GW(e) in 2030, compared to a capacity of 372 GW(e) at the end of
2008. In the updated high projection it reaches 748 GW(e).
The International Energy Agency (IEA) also revised its reference
projection for nuclear power in 2030 upwards by about 5%.1 However, at 433
GW(e) of installed nuclear capacity in 2030, the IEA reference scenario is still
below the IAEA low projection. The IEA also published two climate policy
scenarios. The ‘550 policy scenario’, which corresponds to long term stabili-
zation of the atmospheric greenhouse gas (GHG) concentration at 550 parts
per million of CO2, equates to an increase in global temperature of approxi-
mately 3°C. The ‘450 policy scenario’ equates to a rise of around 2°C. In the 550
policy scenario, installed nuclear capacity in 2030 is 533 GW(e). In the 450
policy scenario it is 680 GW(e).
The OECD Nuclear Energy Agency (OECD/NEA) published a Nuclear
Energy Outlook in 2008, which included low and high projections of nuclear
power capacity through 2050.2 For 2030, the projected range is 404–625 GW(e),
somewhat below the IAEA’s. For 2050, the projected range is 580–1400 GW(e).
The US Energy Information Administration also revised its reference
projection for nuclear power in 2030 slightly upwards to 498 GW(e).3 It is thus
slightly higher than the IAEA’s low projection.
All these projections were made before the financial crisis in late 2008. At
the time of writing, no projections had been published that analysed the conse-
quences of the crisis for nuclear power.

1
OECD International Energy Agency, World Energy Outlook 2008, OECD,
Paris (2008).
2
OECD Nuclear Energy Agency, Nuclear Energy Outlook 2008, OECD, Paris
(2008).
3
Energy Information Administration, International Energy Outlook 2008, US
Department of Energy, Washington, DC (2008).

7
A.3. Fuel cycle4

The Global Nuclear Energy Partnership (GNEP), begun in 2007, grew to

25 partners in 2008. GNEP’s Infrastructure Development Working Group
initiated a resource library of references, programmes, tools and pooled
resources to support the sharing of educational resources, the promotion of
technical educational opportunities and the establishment of new training and
education programmes. It also started a number of feasibility studies for GNEP
members considering nuclear energy for the first time. GNEP’s Reliable
Nuclear Fuel Services Working Group completed a survey of the members’
legal and institutional frameworks for the fuel cycle to identify common
challenges. Its subsequent focus is on issues concerned with the back end of the
fuel cycle.

A.3.1. Uranium resources and production

The 22nd edition of the OECD/NEA–IAEA ‘Red Book’5 reported an

increase in uranium resources, reflecting recent growth in exploration activities
worldwide. The increase in reported resources is a continuing trend. Over the
past 14 years (seven Red Book editions), reported remaining uranium
resources have increased by more than 2.4 million tonnes, despite more than
0.5 million tonnes having been mined.
The reported identified resources (5.5 million tonnes natural uranium
(t U)) would last 83 years at the current rate of consumption of about 70 000
tonnes per year. This figure of 83 years can, however, be misleading because all
mineral resource figures change with commodity price developments, and
uranium is no exception. The reported increase in resources from 2005 to 2007
corresponds to 11 years of 2006 uranium demand, a powerful demonstration of
the impact of increased uranium prices on total resource numbers. Moreover,
the reported uranium resource figures presented in the Red Book are only a
part of the already known resources and are not an inventory of the total
amount of recoverable uranium. Examples where uranium resources are
known, but not reported, are Australia, the Russian Federation and the USA.

4
More detailed information on IAEA activities concerning the fuel cycle is
available in relevant sections of the latest IAEA Annual Report (http://www.iaea.org/
Publications/Reports/Anrep2008/) and at http://www.iaea.org/OurWork/ST/NE/NEFW/
index.html.
5
OECD/NEA and IAEA, Uranium 2007: Resources, Production and Demand,
OECD, Paris (2008).

8
 The projected lifetime of reported identified uranium resources of 83
years at the current consumption rate compares favourably to reserves of 30–50
years for other commodities (e.g. copper, zinc, oil and natural gas). However,
demand is projected to grow, and resources in the ground need to be mined.
Existing, committed, planned and prospective uranium production facilities
could satisfy uranium requirements in the Agency’s high projection through
about 2025, provided existing mines are expanded and new ones opened as
planned. Additional uranium demand would have to be met through the estab-
lishment of further mining capacity beyond what is planned. This is expected to
be forthcoming as firm orders for new nuclear build are placed (in the case of
the Agency’s high projection) instilling confidence in uranium producers of
long term rising sales prospects. Some uncertainty about the volume of fresh
uranium needed to meet demand comes from the continued, albeit decreasing,
availability of secondary sources. Today, secondary sources supply about 40%
of demand.
In 2008, Kazakhstan started several new in situ leaching (ISL) operations
and expanded several more ISL operations to their full targeted capacity in line
with the country’s targeted production of 10 000 t U per year in 2010. Many of
the ISL operations have capacities of at least 1000 t U per year. Ground was
broken in 2008 for a new uranium processing plant at Tummalapalle in Andhra
Pradesh, India, with a design capacity of 220 t U per year.

A.3.2. Conversion, enrichment and fuel fabrication

Total global conversion capacity is about 75 000 tonnes of natural

uranium per year for uranium hexafluoride (UF6) and 4500 t U per year for
uranium dioxide (UO2). Current demand is about 70 000 t U per year. AREVA
plans to start construction of its new COMURHEX II conversion facility in
2009, with an initial planned capacity for UF6 conversion of 15 000 t U per year
in 2012.
Total global enrichment capacity is currently about 50 million separative
work units (SWUs) per year compared to a total demand of approximately 45
million SWUs per year. Three new commercial scale enrichment facilities are
under construction, Georges Besse II in France and, in the USA, the American
Centrifuge Plant (ACP) and the National Enrichment Facility (NEF). All use
centrifuge enrichment, and all are scheduled to start operation in 2009.
Georges Besse II and ACP are intended to allow the retirement of existing gas
diffusion enrichment plants. AREVA and USEC applied to the USDOE for
loan guarantees for construction of USEC’s ACP and AREVA’s proposed
Eagle Rock Enrichment Facility. Armenia joined the Russian Federation and
Kazakhstan as members of the International Uranium Enrichment Centre

9
(IUEC) in Angarsk, Siberia, and, in December, the Ukrainian Government
announced that Ukraine would also join.
Total global fuel fabrication capacity is currently about 11 500 t U per
year (enriched uranium) for light water reactor (LWR) fuel and about 4000 t U
per year (natural uranium) for pressurized heavy water reactor (PHWR) fuel.
Total demand is about 12 000 t U per year. Some expansion of current facilities
is under way, for example in China and the Republic of Korea. A new facility to
fabricate mixed oxide (MOX) fuel is under construction at Rokkasho, Japan,
and is scheduled for completion in 2012.

A.3.3. Back end of the fuel cycle

The total amount of spent fuel discharged globally was projected to reach
324 000 tonnes of heavy metal (t HM) by the end of 2008. Of this amount,
about 95 000 t HM have already been reprocessed, 16 000 t HM are currently
stored to be reprocessed and 213 000 t HM are stored in spent fuel storage
pools at reactors or in away-from-reactor (AFR) storage facilities. AFR
storage facilities are being regularly expanded both by adding modules to
existing dry storage facilities and by building new facilities.
Total global reprocessing capacity is about 6000 t HM per year. In the
United Kingdom, the Thorp nuclear fuel reprocessing plant at Sellafield
restarted commercial operations in 2007, three years after it was closed
following a radioactive leak. Tests at the new Rokkasho reprocessing plant
took longer than expected, and commercial operation was postponed until
2009.
Construction of an underground repository for low and medium level
radioactive waste began at the former Konrad iron mine in Germany. It is
scheduled to start accepting waste in early 2014.
Hungary’s Bataapati permanent repository for low and intermediate
level radioactive waste was inaugurated in 2008. Waste will be temporarily
stored in a receiving area until the rock caverns for permanent disposal are
opened in 2010.
The Swedish Nuclear Fuel and Waste Management Company (SKB),
which is responsible for storing Swedish nuclear waste, was granted an
operating licence for expanding the central interim storage facility for spent
nuclear fuel at Oskarshamn from a capacity of 5000 t HM to 8000 t HM.
The USDOE submitted a formal application to the NRC for a licence to
build and operate the long-planned high level waste repository at Yucca
Mountain in Nevada. The repository is designed to hold 70 000 t HM of spent
nuclear fuel, including 7000 t HM of military waste.

10
 Worldwide decommissioning statistics remained unchanged in 2008: ten
power reactors around the world have been completely decommissioned with
their sites released for unconditional use; seventeen reactors have been
partially dismantled and safely enclosed; thirty-two are being dismantled prior
to eventual site release; and thirty-four reactors are undergoing minimum
dismantling prior to long term enclosure.

A.4. Additional factors affecting the future of nuclear power

A.4.1. Economics

The last time the Nuclear Technology Review summarized cost estimates
for new nuclear power plants was in 2006. That summary compared estimates
from seven studies published between 2003 and 2005. Their estimates of
overnight costs ranged from $1200/kW(e) to $2510/kW(e).6
In the past year, the range of estimates has grown at its upper end. Figure
A-1 shows the minimum and maximum values of recent estimates collected by
the Agency from publicly available sources.
There is no definitive explanation of either the increased uncertainty in
cost estimates (i.e. the wider range) or the escalation in cost estimates (i.e. the
higher range) although several possible contributing factors have been
suggested. Moreover, the cost estimates reflected in Figure A-1 were made
before the financial crisis in late 2008. At the time of writing, the impact of the
financial crisis on nuclear power cost estimates was still unclear. This section
therefore summarizes factors that may have contributed to increased cost
estimates and increased uncertainty, but, in the absence of rigorous studies, it
cannot offer a definitive explanation.
This section focuses on overnight costs, but interest during construction
(IDC) is also a major cost component for nuclear reactors. IDC estimates tend
to be more tightly held by financiers, owners and shareholders and are more
project-specific than overnight costs. Thus, it is difficult to assemble a
meaningful graph of total costs (including IDC) comparable to Fig. A-1 for
overnight costs. However, adding IDC can as much as double total project
costs, particularly if factors like the construction time, interest rate or market

6
‘Overnight costs’ exclude interest, finance and escalation costs during construc-
tion — as if the plant were being built overnight. Escalation costs reflect price increases
during construction. They should not be confused with contingency costs, which relate
only to unforeseen work.

11
conditions change adversely in the midst of the project. The importance of IDC
should thus not be overshadowed by this section’s focus on overnight costs.
Uncertainties in cost estimates

One reason for the variation in cost estimates is that different people use
different definitions. Cost components that are sometimes included, and
sometimes excluded, are costs associated with bid evaluation, site selection and
preparation, licensing costs, owner’s and contingency costs, and some financing
costs.
Some variations are due to local differences. Building on a green field site
is generally more expensive than building on a site with existing reactors.
Building in a more seismically active area is more expensive. Labour and
material costs vary, and their impact varies with the localization rate, i.e. the
percentage of plant components that are locally manufactured or procured.
Subsidies and financial guarantees for nuclear power investments are different

6500
6000
5500
Overnight costs ($/kW(e))

5000
4500
4000
3500
3000
2500
2000
1500
1000
500
0
North America Europe Asia
FIG. A-1. Minimum and maximum estimates of overnight costs for new nuclear power
reactors, by region: 2007–2008.

12
in different countries and regions. Regulatory requirements can differ, as can
the predictability of such requirements. Experience usually reduces uncertainty
— a fact that appears to be reflected in Fig. A-1. The region with the most
recent experience in building new reactors, Asia, has the lowest cost estimates
and the least uncertainty. The region with the least recent experience, North
America, has the highest estimates and greatest uncertainty.
Contractual arrangements also affect cost estimates. A turnkey contract
might be more expensive than a cost-plus contract if the vendor prices any
completion risks into the turnkey contract. Exchange rates, expectations about
inflation, and their differential effects on different cost components introduce
additional variability.
Different technologies have different costs. Proven designs may cost less
than first-of-a-kind reactors, and building a first-of-a-kind reactor will likely
cost more than building subsequent reactors of the same design. Different
estimates also incorporate different learning rates in anticipating how costs will
decrease with experience.
Different perspectives can also lead to different estimates. A 2006 report
by the United Kingdom’s Sustainable Development Commission stated that
vendors of reactor systems had a clear market incentive, especially ahead of
contractual commitments, to underestimate costs.7 Utilities may have a
tendency to be more conservative.
Increases in cost estimates

Possible contributors to increased cost estimates for new reactors were

tighter commodity markets and steep increases through much of 2008 in inter-
national prices for steel, cement, energy, and other construction inputs. These
increases also affected cost estimates for other sorts of power plants, but,
because capital costs are higher for nuclear power, it is affected more.8 In late
2008, the rise in most commodity prices reversed9, partly for cyclical reasons
(previous high prices both stimulated additional production capacity and
lowered demand) and partly because of the financial crisis.

7
UNITED KINGDOM SUSTAINABLE DEVELOPMENT COMMISSION,
The Role of Nuclear Power in a Low Carbon Economy — Paper 4: The Economics of
Nuclear Power, prepared by Science and Technology Policy Research (SPRU, University
of Sussex) and NERA Economic Consulting (March 2006).
8
However, on a life cycle basis and in terms of generating costs, nuclear power
plants are affected the least since they have the lowest specific material requirements
per kW h generated.
9
As of November 2008, the benchmark copper price had halved since September
2008 and world steel prices had fallen by almost 80% since July 2008.

13
 The volatility of commodity prices has probably, in and of itself, also
contributed to increased contingency allowances and thus higher cost
estimates. The financial crisis may have had a similar effect.
Cost estimates may also have increased because, over the past few years,
the global nuclear market shifted from a buyers’ to a suppliers’ market, a shift
that generally exerts upward pressure on prices. The order books of vendors
reached a level not seen since the late 1970s. Heavy forging capacity is limited,
and lead times of more than 50 months are commonplace.
Another contributor to higher overall cost estimates may be the fact that
the greater share of those estimates come from Europe and especially North
America, where the lack of recent construction experience relative to Asia and
new reactor designs likely contribute to the higher estimates shown in Fig. A-1.
Finally, as projects get closer to implementation, a greater proportion of
recent cost estimates may reflect the cost conservatism of utilities more than
the appraisal optimism of vendors and the technological optimism of some
government and academic studies.

A.4.2. Safety10

Safety indicators, such as those published by the World Association of

Nuclear Operators (WANO) and reproduced in Figs A-2 and A-3, improved
dramatically in the 1990s. In recent years, in some areas the situation has
stabilized. However, the gap between the best and worst performers is still
large, providing substantial room for continuing improvement.
More detailed safety information and recent developments related to all
nuclear applications are presented in the Agency’s Nuclear Safety Review for
the Year 2008 (GC(53)/INF/2).

A.4.3. Human resource development

Estimates of the human resource requirements associated with any of the

projections discussed in Section A.2 are not readily available. Moreover, data
are scarce on the number of people today with the various skills needed in the
nuclear industry and on the number in relevant education and training
programmes.

10
More detailed information on IAEA activities concerning nuclear safety is
available in relevant sections of the latest Annual Report (http://www.iaea.org/Publica-
tions/Reports/Anrep2008/) and at http://www-ns.iaea.org/.

14
 unplanned scrams per 7000 hours 2.0

1.8

1.5

1.0
1.0
0.9

0.7 0.7
0.5 0.6 0.6 0.6 0.6
0.5

0.0
1990 1995 2000 2001 2002 2003 2004 2005 2006 2007
Stations 369 404 417 428 419 405 428 425 429 425
reporting

FIG. A-2. Unplanned scrams per 7000 hours critical (source: WANO 2007 Performance
Indicators).

Concerns have been expressed in a number of countries about possible

shortages of people with the skills needed by the nuclear power industry. An
OECD/NEA report published in 2000 quantified for the first time the status of
nuclear education in its member countries, noting that in most cases nuclear
education had declined to the extent that expertise and competence in core
accidents per 1 000 000 person-hours worked

5 5.20

3
2.90

1.63 1.65 1.54 1.42 1.30

1 1.21
1.06 0.96

0
1990 1995 2000 2001 2002 2003 2004 2005 2006 2007
Stations 169 192 203 200 203 201 210 208 209 207
reporting

FIG. A-3. Industrial accidents at nuclear power plants per 1 000 000 person-hours worked
(source: WANO 2007 Performance Indicators).

15
nuclear technologies were becoming increasingly difficult to sustain.11
However, the OECD/NEA has also noted that the overall losses of technical
competencies and skills varied from one country to another according to the
strength of the nuclear power programme.12 The paradoxical result is that
concerns about manpower shortages appear to be expressed less often in
countries with faster growing programmes.
Concerns about possible shortages have prompted initiatives by
government and industry to attract students and expand education and training
in nuclear related fields. Where data are available, these initiatives appear to be
successful. Figure A-4 shows the increase in the number of graduates with
nuclear engineering degrees in the USA, largely as a result of the University
Reactor Infrastructure and Education Assistance Programme.
If the higher projections for nuclear power described in Section A.2 are
realized, the success reflected in Fig. A-4 will have to be replicated several
times over. That challenge will be significant, but not unprecedented. The
Agency’s high projection, for example, would require bringing online an

FIG. A-4. Nuclear engineering degrees at US universities (B.S. = Bachelor of Science, M.S.
= Master of Science, Ph.D. = Doctor of Philosophy) (source: OECD Nuclear Energy
Agency, Nuclear Energy Outlook 2008, OECD, Paris (2008)).

11
OECD NUCLEAR ENERGY AGENCY, Nuclear Education and Training:
Cause for Concern? OECD, Paris (2000).
12
OECD NUCLEAR ENERGY AGENCY, Nuclear Energy Outlook 2008,
OECD, Paris (2008).

16
average of 17 new reactors each year, essentially the same as the annual
average of 16 new reactors during the 1970s. Moreover, in the high projection,
nuclear power’s share of global electricity remains nearly constant through
2030, meaning that other electricity sources — and their manpower needs —
would be growing at the same rate as nuclear power. The challenge faced by
nuclear power is not exceptional.

A.4.4. Public acceptance of nuclear energy

The first issue in the Agency’s guidance for countries considering the
introduction of nuclear power13 is labelled “national position”: “The
government should adopt a clear statement of intent to develop a nuclear
power programme and communicate that intent locally, nationally, regionally
and internationally.” Comparable advice might equally be given in countries
that already have nuclear power, and all governments supporting nuclear
power should seek broad national support.
The most common way to find out whether there is broad national
support for nuclear power to match the rising expectations discussed in Section
A.2 is through public opinion surveys. However, these have their weaknesses.
Responses can depend on how a question is phrased, and even experts may
disagree on how some responses should be interpreted. Nonetheless, reputable
techniques exist for eliminating bias from sample selection, from the phrasing
of questions and from the interpretation of results.
Figures A-5 and A-6 present recent trends or, where no time series data
were available, ‘snapshots’ of public acceptance of nuclear energy in countries
already using nuclear power (Fig. A-5) and in a few countries without nuclear
power (Fig. A-6). The value on the vertical scale, the public acceptance index
(PAI), is the average of the surveys reviewed for a given country and year,
normalized to a scale from 0 (complete rejection) to 100 (complete approval).
The PAIs in the countries that already have nuclear power programmes
(Fig. A-5) are generally higher than the PAIs in those that do not (Fig. A-6).
Among the 12 countries with nuclear power programmes shown in Fig.
A-5, public acceptance increased in 2008 in most cases. The two exceptions
were Spain and Germany, which both have nuclear phase-out policies. The

13
INTERNATIONAL ATOMIC ENERGY AGENCY, Milestones in the Devel-
opment of a National Infrastructure for Nuclear Power, IAEA Nuclear Energy Series
No. NG-G-3.1, IAEA, Vienna(2007).

17
PAI Index
90
India
80 USA
Hungary
70 Sweden
Finland
60 Rep. of Korea
UK
50 France
Slovenia
40 Germany
Canada
30 Spain

20
2005 2006 2007 2008

FIG. A-5. Public acceptance in a number of countries using nuclear power.

third country in Fig. A-5 with a phase-out policy, Sweden, shows stronger, more
stable and slightly increasing support for nuclear power.
Of the seven countries without nuclear power programmes shown in Fig.
A-6, five are considering starting or restarting nuclear power programmes:
Egypt, Indonesia, Italy, Poland and Thailand. In these five, the PAIs are above
or close to 50%.
The details of the surveys that were reviewed for Figs A-5 and A-6
contain insights, beyond those revealed in the figures’ aggregate results that
can help design public information programmes for specific situations. For
example, the results for Hungary show a rather fast recovery from the low
levels that public acceptance dropped to following a fuel cleaning accident in

PAI Index
80
Egypt
70
Indonesia
60
Thailand
50 Italy
40 Poland
30 Austria
Cyprus
20

10

0
2005 2006 2007 2008

FIG. A-6. Public acceptance in a number of countries without nuclear power

programmes.

18
2003. This suggests the importance to public acceptance of safe, incident-free
operation of all nuclear facilities.

B. ADVANCED FISSION AND FUSION

B.1. Advanced fission14

B.1.1. Water cooled reactors

All six reactors on which China started construction in 2008 are 1000
MW(e) PWRs, an evolutionary design based on Generation II technology with
modifications. The first Generation III PWR project, based on AP-1000
technology is moving smoothly, with construction starting in 2009.
In Japan, Mitsubishi Heavy Industries has developed a 1700 MW(e)
version of the advanced pressurized water reactor (APWR) for the US market,
the US-APWR, which started the NRC design certification process in 2008.
The European version of the APWR, the EU-APWR, was submitted also in
2008 to be assessed for compliance with the European Utility Requirements.
In the Republic of Korea, construction started in 2008 on the first
advanced power reactor, APR-1400, Shin-Kori 3.
In the Russian Federation, construction started on the first WWER-1200
units in 2008, Novovoronezh 2-1 and Leningrad 2-1. The contractor and site
were changed for the first floating KLT-40S reactors (two reactors of 35 MW(e)
each), on which construction began in 2007. Their target deployment date
shifted from 2010 to 2012.
In 2008, the NRC design certification process was started for a US version
of the European pressurized water reactor (EPR), and an application for a
design certification amendment for the AP-1000 was initiated. New documents
were submitted as part of the pre-application to the NRC for Westinghouse’s
335 MW(e) integral PWR called IRIS.
In Canada, Atomic Energy of Canada Limited (AECL) is developing an
advanced CANDU reactor (ACR) that incorporates very high component

14
More detailed information on IAEA activities concerning advanced fission
reactors is available in relevant sections of the latest Annual Report (http://
www.iaea.org/Publications/Reports/Anrep2008/).

19
standardization and slightly enriched uranium to compensate for the use of
light water as the primary coolant. In 2008, the Canadian Nuclear Safety
Commission started the design review of the ACR-1000.
2.2. India has two 540 MW(e) heavy water reactors (HWRs) in operation. It is
designing an evolutionary 700 MW(e) HWR and an Advanced Heavy Water
Reactor (AHWR), which will use thorium with heavy water moderation, a
boiling light water coolant in vertical pressure tubes, and passive safety systems.

B.1.2. Fast neutron systems

Component installation work was completed in 2008 for the 65 MW(th)

(20 MW(e)) pool-type China Experimental Fast Reactor. Debugging activities
are under way. Two hundred and fifty tonnes of nuclear grade sodium were
shipped to the plant, and filling of the primary and secondary loops took place
in April 2009.
The reactor vault for India’s 500 MW(e) Prototype Fast Breeder Reactor
(PFBR) at Kalpakkam was completed in 2008 and the safety vessel installed in
the vault. The civil construction of the PFBR buildings that are part of the
nuclear island is nearing completion. The thermal baffle, thermal insulation
panels, sodium storage tanks, argon buffer tanks, core catcher and core support
structure have been completed, and the main vessel is nearing completion.
Japan completed the refurbishment of the MONJU reactor and
component testing. Most full system tests were also completed. Nonetheless,
the scheduled restart was postponed from 2008 to 2009. Japan also launched a
national Fast Reactor Cycle Technology Development Project to commer-
cialize fast reactor technology.
In the Russian Federation, construction was completed on the foundation
plates of the reactor compartment and the turbine hall for the BN-800 fast
reactor at Beloyarsk. Commissioning is planned for 2012.
Belgium advanced the design work for the primary system, core design
and plant layout of MYRRHA, a subcritical experimental fast reactor, to make
it compatible with the EC project on an experimental accelerator driven system
(XT-ADS). To test subcriticality monitoring, an experimental facility,
GUINEVERE, is being built, coupling a continuous deuteron accelerator with
a titanium–tritium target installed in a lead cooled, fast subcritical multiplying
system. GUINEVERE is scheduled to be operational in March 2010.

B.1.3. Gas cooled reactors

The helium test facility, commissioned in 2007 for South Africa’s pebble
bed modular reactor (PBMR), made possible the first full scale operating tests

20
on critical components of the reactivity control system, reserve shutdown
system and the fuel handling system. In 2008, the South African National
Nuclear Regulator granted a hot commissioning licence for the Advance
Coater Facility at Pelindaba, allowing the project to start manufacturing fuel
spheres.
In Japan, more rigorous tests of the High Temperature Engineering Test
Reactor (HTTR), of 90 days in total with 50 days at 950qC, are scheduled to
take place before the end of 2009. In 2007, a first 30 day full power test with the
outlet coolant temperature at 850°C was completed, confirming improvements
in the manufacturing of coated fuel particles.
In the USA, the Next Generation Nuclear Plant (NGNP) project reached
a major milestone in 2008 by achieving zero fuel failures during long irradiation
periods (9% burnup) in the advanced test reactor at Idaho National
Laboratory. This is a major accomplishment in demonstrating tristructural–
isotropic (TRISO) fuel safety. The next target is a burnup of 16–18% before
September 2009.
In China, the implementation plan for the demonstration high
temperature gas cooled reactor was approved by the State Council of the
People’s Republic of China. The project license is under review, and
construction is expected to start late next year.

B.1.4. INPRO and GIF

The Agency’s International Project on Innovative Nuclear Reactors and

Fuel Cycles (INPRO) completed an extensive manual on methods to assess
innovative nuclear energy systems, Guidance for the Application of an
Assessment Methodology for Innovative Nuclear Energy Systems, which was
published in early 2009 as IAEA-TECDOC-1575. One joint and six national
assessment studies were completed using INPRO’s methods to identify weak
links in the development chain, i.e. priority areas in each case for further
research and development. INPRO published a report in early 2009 on
Common User Considerations by Developing Countries for Future Nuclear
Power Plants, the drafting of which engaged 26 additional countries beyond
INPRO’s now 30 members. The Russian Government decided to provide, for
the first time, multi-year support to INPRO for 2008–2012.
Through a system of contracts and agreements, the Generation IV Inter-
national Forum (GIF) coordinates research activities on the six next generation
nuclear energy systems selected in 2002 and described in A Technology
Roadmap for Generation IV Nuclear Energy Systems: gas cooled fast reactors
(GFRs), lead cooled fast reactors, molten salt reactors, sodium cooled fast
reactors (SFRs), supercritical water cooled reactors (SCWRs) and very high

21
temperature reactors (VHTRs). In 2008, China signed a ‘system arrangement’
to join in collaborative work on VHTRs. France, Japan and the USA are
harmonizing work on prototype SFRs, including design goals, safety principles,
system configuration, power level, fuel type, cost reductions through
innovation, schedules and target dates for prototypes and associated infrastruc-
tures. Specific projects are under way on system integration, safety and
operation, advanced fuel, balance of plant, and the ‘global actinide cycle inter-
national demonstration’.

B.2. Fusion

In February 2008, the ITER International Fusion Energy Organization

(ITER Organization) formally applied for a construction permit to build the
International Thermonuclear Experimental Reactor (ITER), an experimental
fusion reactor, in Cadarache, France.
In October 2008, fifty years of international fusion research was
commemorated at the 22nd IAEA Fusion Energy Conference (FEC 2008) in
Geneva, Switzerland. FEC 2008 was held on the same premises as the second
United Nations International Conference on the Peaceful Uses of Atomic
Energy in 1958, at which time fusion was first declassified and opened for
public discussion. A record number of over 500 scientific papers were
presented at FEC 2008.
Also at FEC 2008, a cooperation agreement was signed by the Agency
and the ITER Organization. The scope of cooperation includes exchanging
information, analysing fusion’s contribution to future nuclear power scenarios,
training, publications, organization of scientific conferences, research on
plasma physics and modelling, and fusion safety and security. The agreement is
designed to facilitate interactions between ITER parties and other Agency
Member States that are interested in fusion research but are not members of
ITER.
In addition to progress on ITER, fusion laboratories in Belgium, Brazil,
Canada, China, the Czech Republic, the Islamic Republic of Iran, Portugal, the
Russian Federation, Thailand and the United Kingdom are developing a
research network of users of small fusion devices. The Agency participates and,
among other things, coordinates small tokamak research through joint
experiments to promote international collaboration, network planning and the
education of young scientists.

22
 C. ATOMIC AND NUCLEAR DATA

With rising expectations for nuclear power, progress on fusion and a new
generation of fission reactors, a number of papers and talks at the International
Conference on the Physics of Reactors (PHYSOR’08) highlighted the efforts
under way, including at the Agency, to meet the need for new and updated
fission and capture cross section data for actinides, the need to reduce uncer-
tainties, and the need for data required to implement spent fuel recycling.
Issues of plasma–wall interaction in fusion reactors leading to dust
particle formation and related safety issues of tritium retention, pyrophoric
behaviour, handling and inhalation were discussed at a 2008 meeting of the
Subcommittee on Atomic and Molecular Data for Fusion of the International
Fusion Research Council (IFRC). It was recommended that the Agency
initiate multinational coordinated research projects to study the size,
composition and origin of dust and the spectroscopic, collisional and sputtering
data for tungsten as a candidate material for fusion devices (see Fig. C-1 for an
example of how such data are used). Further, in order to quantify the radiation
damage to, and activation of, structural components of new fusion devices,
there is a need to update and extend the Fusion Evaluated Nuclear Data
Library (FENDL) that is used for design studies and benchmarking material
properties relevant to ITER.
As part of the supercomputer support for modelling fusion devices that is
being developed under the European Fusion Development Agreement, a
centre for high performance computing for fusion was inaugurated in May 2009
at the Jülich Supercomputing Centre in Germany.
The direct irradiation of tumour sites in patients, using accelerator-
produced charged particles, provides a high accuracy dose delivered to the
target while sparing surrounding healthy tissue. Two new hadron-therapy
centres will soon become operational in Heidelberg, Germany and Pavia, Italy.
Recognizing the need for accurate data to design and plan patient treatment
facilities, priority is being given to the establishment of coordinated interna-
tional efforts to quantify and recommend updated charged-particle interaction
data for medical applications.

23
 Tungsten and carbon
diverter wall

FIG. C-1. Computer simulation of the temperature profile of the diverter region of a
fusion device. Temperatures range from ~ 200 000 (blue) to 1 000 000 (red) Kelvin, close
to the temperature at the centre of the sun. Calculated with the B2-IRENE computer
model (Research Centre Jülich), this study required voluminous reliable atomic and
molecular data, many of which have been derived and assembled from a series of recent
Agency coordinated research projects.

D. ACCELERATOR AND RESEARCH REACTOR

APPLICATIONS

D.1. Accelerators

In developing countries, one important way to build competence in

nuclear science is through the establishment of an accelerator facility, as well as
its effective use for nuclear education and training, and hands-on experience in
all related applications. To further broaden educational opportunities in
developing regions, the Agency fosters international cooperation to leverage

24
existing expertise and facilities, for example in South Africa, to benefit
potential regional partners, for example Ghana and Nigeria.
Analytical methods developed at synchrotron radiation sources are
increasing the understanding of novel and biological materials. New techniques
developed using smaller conventional X ray sources are now being applied at
synchrotrons like ANKA in Germany and will also be used at the Elettra
facility in Italy. This approach makes use of the superior features of X rays
available from synchrotron radiation and will thus increase analytic sensitivity
and reliability.
Advances in ion beam technology and instrumentation are increasing the
use of focused proton ion beams in biomedical research, particularly on the
effects of radiation on living cells. The world’s first vertical scanning focused
nanobeam for basic research became operational in the United Kingdom in
November 2008. It will provide new data on the radiation sensitivity of
cancerous tumours, on processes that may lead to cancer, and on the risks of
low level exposure to radiation. The new proton nanobeam will, for the first
time, supply researchers with nanometre sized proton beams to target and
irradiate specific locations in human cells with high precision. It will clarify the
interactions between chemotherapeutic drugs and radiation, helping clinicians
to test the efficacy of different cancer treatment strategies.

D.2. Research reactors

A major use of research reactors is to produce radioisotopes. In 2008, the

unavailability of the few large ageing reactors used for isotope production
posed problems and raised concerns about the security of radioisotope supplies
(molybdenum-99 in particular) for vital medical and industrial applications.
The new OPAL Reactor in Australia, which first achieved full power in 2006, is
the only likely immediate addition to existing capacity. A number of national
reactor centres are exploring, with the Agency, possible capacity additions
through increased use of currently underutilized reactors. More information is
provided in Section I on radioisotopes.
The first nuclear research reactor in Morocco, a TRIGA Mark-II type (2
MW), attained first criticality in May 2007; in June it achieved full power and in
September 2007 it completed all required reactor testing. The reactor is located
at the Maâmora Nuclear Research Centre (CENM), approximately 25 km
north of Rabat. It uses LEU fuel and is designed for a planned future upgrade
to 3 MW. The facility will be used for manpower training, isotope production,
analytic services such as neutron activation analysis and non-destructive exami-
nation, and basic research in solid state and reactor physics.

25
 Given the projected decrease in research reactors from 245 today to
between 100 and 150 in 2020, greater international cooperation will be required
to assure broad access to such facilities and their efficient use. To that end, the
Agency has begun establishing a number of regional networks: Eastern
European Research Reactor Initiative (EERRI), Caribbean Research Reactor
Coalition (CRRC), Mediterranean Research Reactor Utilization Network (M-
RRUN), and Baltic Research Reactor Utilization Network (B-RRUN). An
additional Network on Residual Stress and Texture Analysis for Industrial
Partners (STRAINET) is focused on a specific application rather than a region.
These networks will also contribute to upgrading existing facilities, developing
new facilities and improving access to countries without research reactors. The
new Moroccan reactor will be open to both the national and international user
community on a time sharing basis, and will further help regional collaboration,
networking and research reactor coalitions.
The Reduced Enrichment for Research and Test Reactors (RERTR)
Programme, under the Global Threat Reduction Initiative (GTRI), converts
research reactors using high enriched uranium (HEU) fuel to low enriched
uranium (LEU) fuel. By the end of 2008, 62 research reactors around the world
that had been operating with HEU fuel were shut down or converted to LEU
fuel, and another 39 are planned for conversion with existing qualified fuels.
The RERTR Programme celebrated its 30th anniversary during its annual
meeting held in Washington, D.C. in October 2008.
Very high density advanced uranium–molybdenum fuels that still need to
be developed and qualified, will be required for the conversion of an additional
28 research reactors. Work began on such fuels in the early 1990s but
encountered difficulties due to swelling of the reaction layer, which forms
between the fuel and the aluminium matrix during irradiation. These are being
investigated collaboratively by an International Fuel Development Working
Group that includes Argentina, Belgium, Canada, France, Germany, the
Republic of Korea, the Russian Federation and the USA. Substantial progress
has been made on several fronts, but further progress and significant testing are
still necessary to achieve the RERTR Programme goal of delivering a qualified
fuel by the end of 2011.

26
 E. NUCLEAR TECHNOLOGIES IN FOOD AND
AGRICULTURE

E.1. Improving livestock productivity and health

Nuclear and related technologies help improve livestock productivity.

Isotopes of carbon, hydrogen, sulphur, phosphorus or nitrogen are used to
study the conversion and uptake of feed nutrients, and to evaluate the role of
microbes in the rumen of livestock in feed utilization. Ruminants rely on these
microorganisms living in their digestive tract to convert feed components into
useable sources of energy and protein.
Identification and selection for desirable genetic characteristics, e.g.
leaner meat, increased milk production or disease tolerance, can be done
through the direct labelling of DNA. Isotopic labels are used to determine
parentage or trace the origin of products, and help in assisting developing
countries gain access to export markets.
Stable isotopes, as nature’s ‘ecological recorders’, are useful in studying
animal movement. The profiles of carbon-13 and nitrogen-15 can indicate the
origin and breeding habitat of migratory birds, thereby enabling risk
assessment and prediction of the spread of disease (e.g. avian influenza).
Currently the most effective tracers are hydrogen isotopes found in metaboli-
cally inert, seasonally grown tissues, such as feathers and claws. Once the
isotope profile of a particular bird population or ecosystem is established, any
individual provides information on the global migration of that species or from
that reference point. Global grids of hydrogen and oxygen water isotopes are
constructed using the IAEA–World Meteorological Organization (WMO)
Global Network of Isotopes in Precipitation (GNIP) database, and are
compared with the feather profiles of migratory bird species in different
locations to identify where feather growth occurred and thus trace the origin of
migratory birds.15

15
For further information on the IAEA’s work in this area, please visit http://
www-naweb.iaea.org/nafa/aph/index.html

27
 Africa
Middle East 1%
21%

Europe
6%

Asia
72%
FIG. E-1. Geographical distribution of avian influenza (subtype H5N1) outbreaks in
poultry from 2003–2008 (source: World Organisation for Animal Health (OIE)).

E.2. Vaccine research

Inactivation of pathogens by irradiation is revolutionizing vaccine

research. Such treated vaccines stimulate a protective immune response similar
to live pathogens, and are superior to that achievable by heat or chemical
treatment. Irradiation opens up new possibilities for preventing diseases such
as nagana, foot and mouth disease, fascioliasis and neospora in cattle, for which
genetically engineered vaccines have been largely unsuccessful. Recent studies
show that carefully administered doses of irradiation to alter the gene
expression in pathogens have led to enhanced protection.
Good evidence for breed and individual genetic differences in resistance
to infectious diseases provides an alternative means to address animal disease
through the identification of genetic markers associated with such resistance.
These methods involve the use of radiolabelled nucleotides in DNA hybridi-
zation such as DNA characterization, and radiation hybrid (RH) mapping
procedures. The acquisition of genetic information for livestock species is
crucial for harnessing the benefits of genetic variation for economically
important traits. This process is greatly facilitated by the ordering of molecular
markers along the selected chromosomes.
RH maps derived by radiation-fragmentation of chromosomes in hybrid
cell lines can be tested for the presence of DNA markers or by comparative
gene mapping to enable identification of candidate genes for specific traits.
Although considerable progress has been made with bovine genome
sequencing, the same cannot be said for sheep and goats. There is an urgent
need for RH mapping of qualitative trait loci (QTL) correlated to disease
resistance and productivity (milk production, and carcass and wool quality). By

28
investing in these technologies, together with assays using phosphorus-32,
sulphur-35, sulphur-35 methionine, and iodine-125, to monitor productivity and
reproduction, it will be possible to improve performance.

E.3. Insect pest control

E.3.1. X ray irradiation for insect sterilization

Ongoing difficulties in obtaining and shipping isotopic irradiators have

made it more pressing to evaluate X ray radiation as an alternative to gamma
radiation. Work on adapting an RS2400 X ray irradiator for insect sterilization
has advanced with an improved carousel system and new canisters made of
carbon fibre reinforced resin incorporating steel filtration, resulting in an
acceptable dose uniformity ratio (DUR) of less than 1.3. In addition, revising
the control programme permits the selection of a predetermined amount of
energy delivered to the insects.
Bioassays have been used to evaluate the relative effectiveness of both
the X ray irradiation and gamma radiation systems on the quality of insects that
are the target of the sterile insect technique (SIT). Fruit fly pupae of the same
age were irradiated at the same nominal doses in either the X ray machine or a
gamma irradiator and then assessed under the same conditions for comparative
adult emergence, survival and sterility rates. Field cage tests on mating compet-
itiveness between males treated with gamma rays and X rays were also carried
out to assess the treatment differences under simulated field conditions.
Dosimetric procedures conducted after treatment determined actual doses
received by the pupae.16 Preliminary data for Bactrocera cucurbitae (melon fly),
Ceratitis capitata (Mediterranean fruit fly) and Anastrepha fraterculus (South
American fruit fly), representing significant fruit fly pests in Asia, Africa and
the Americas, on the level of residual fertility and normal adult emergence and
behaviour suggest that there are no differences between gamma rays and X
rays in each of the three species.

E.3.2. SIT against tsetse flies

Efforts to support African Member States with the transfer of SIT against
tsetse flies are being pursued for priority areas. These include Ethiopia
(Glossina pallidipes), KwaZulu-Natal in South Africa and Mozambique (G.

16
For information on and access to the database on insect sterilization, please
visit http://www-naweb.iaea.org/nafa/ipc/index.html.

29
austeni and G. brevipalpis), and Senegal, where the government has a
programme that aims at eliminating G. palpalis from the Niayes region located
north-east of Dakar, which has a high livestock density.
In Senegal, entomological baseline data collection, which has allowed the
development of accurate tsetse distribution maps with the aid of modern
spatial tools, mathematical modelling and population genetics, has shown that
the tsetse population in the Niayes region is completely isolated from the
remainder of the tsetse belt. This offers an opportunity to create a sustainable
tsetse free zone. Surveys show that SIT will be an essential component of an
integrated approach; trial releases with sterile flies originating from Burkina
Faso are planned for early 2009.

E.4. Food quality and safety

E.4.1. Traceability as an approach to control food contaminants and improve

food safety

The use of agrochemicals such as pesticides and veterinary drugs is vital

for agricultural production, especially given the need for increased productivity
to respond to the current global food crisis. However, residues of these
substances in food, and other natural and environmental contaminants such as
mycotoxins and persistent organic pollutants, present risks to human health
and may create barriers to agricultural trade. Global factors such as climate
change and changing crop and livestock production practices also exacerbate
food contamination problems.
Control of these hazards requires a holistic approach addressing the
entire food production chain, which depends on the application of guidelines to
minimize risks and feedback mechanisms to ensure the effectiveness of
controls. An essential element of this approach is the ability to trace food
products to their source — traceability — in order to facilitate corrective
actions when contamination is detected. Isotopic techniques offer distinct
advantages in this field and — when used in combination with conventional
technology — can be applied to provide both robust traceability mechanisms
and monitoring methodology for contaminants in food. Even where food safety
is not a primary issue, the capacity to establish food origin and authenticity
through the application of stable isotope ratio techniques may be important to
exporting countries since there may be considerable added value to
commodities from specific regions. Isotopic techniques can uniquely be used to
examine environmental factors leading to contamination of food commodities,
which is of growing importance given predicted rates of climate change.

30
 Techniques for the comparative measurement of stable isotopes such as
strontium have proven excellent tools for tracing the origin of a variety of food
products. The relative abundances of strontium isotopes in plants are governed
by the isotopic composition of strontium in the environment in which the plant
grows. The strontium isotope ratios measured in the plant provide a ‘finger-
print’ of the place of origin. This has been demonstrated for both plant (for
example, asparagus) and animal products, where the strontium isotope profile
in milk is related to the locale where the cattle grazed. Other isotope ratios
such as hydrogen/deuterium/tritium, nitrogen-14/nitrogen-15, carbon-13/
carbon-12, and oxygen-18/oxygen-16 can be used in the same way, or to provide
complementary data.

E.5. Crop improvement

Induced mutants with desirable characteristics play an important role in

boosting the production of various food crops.17 In recent years, rapid develop-
ments in molecular biology have led to the availability in the public domain of
information relating to the genetic make-up of living organisms. In this
‘genomics era’, scientists are deciphering the genetic code of more and more
organisms, including crops.
Of particular value is the application of methods that advance natural
mutation, enhancing or suppressing genetic traits in order to produce improved
crop varieties. Emphasis on mutation induction is shifting from the traditional
broadening of the genetic base of crops for breeding to include molecular
biology research, which has resulted in a considerable increase in scientific
work involving induced crop mutagenesis.
The current trend for enhancing efficiency levels in mutation induction
assisted breeding is to strategically integrate relevant aspects of novel biotech-
nologies in the processes. Two such strategies, one dealing with the rapid identi-
fication of the mutated parts of the genetic make-up for upstream research, and
the other dealing with the seamless integration of biotechnologies in the
generation and identification of mutants, are reviewed below.

17
Additional information is available in relevant sections of the latest
Annual Report (http://www.iaea.org/Publications/Reports/Anrep2008/), or at http://
www.iaea.org/About/Policy/GC/GC53/Agenda/index.html.

31
E.5.1. Gene identification and function elucidation using induced mutants

The traditional strategy for induced mutation in crop improvement,

known as ‘forward genetics’, involved the reconstruction of the roles of genes
on the basis of observation of the modified characteristics of the mutants. With
the availability of molecular biology information, it is becoming commonplace
to work backwards, starting from the studies of the modifications at the
molecular level and relating these modifications to altered characteristics in
crops.
This newer strategy, known as ‘reverse genetics’, relies on the availability
of populations of well characterized mutant stocks of major crops, e.g. rice,
maize, barley and wheat. Protocols have been developed that permit significant
scaling up of procedures to permit the simultaneous querying of thousands of
mutants for mutations in target regions of the genetic make-up. Reverse
genetics has become a critical tool in gene discovery and function elucidation.

E.5.2. Integrated technologies for enhanced mutation induction

Major aims in enhancing the efficiency of the routine application of

mutation induction have included the generation of large mutant populations
and the identification of the desired mutants in the shortest possible time.
Advances in cellular and tissue biology, especially those that exploit the ability
of each individual cell to give rise to a whole plant (a phenomenon known as
‘totipotency’) are permitting the rapid generation of large populations of
mutants.
Tens of thousands of mutants can be grown under aseptic conditions in
laboratory test tubes and, once DNA has been extracted from them, either
tested for certain traits (e.g. resistance to a disease toxin, tolerance to salt) in
the test tube, or queried for mutations in pre-determined parts of the genetic
make-up using neutral molecular biology tools. Either way, the size of the
population that gets evaluated in the field is significantly reduced. This saves
time, as well as human and financial resources. Current research trends involve
the assemblage of these tools for major crops into technology packages,
enhancing the efficiency of mutation induction assisted breeding.

32
E.6. Sustainable land and water management

E.6.1. Understanding the role of microorganisms in soil quality and fertility

under changing climatic conditions18

Microbial communities play a major role in soil fertility through the

decomposition of crop residues, livestock manure and soil organic matter.
These microbes are often affected by variations in rainfall and temperature
patterns caused by climate change. Recent advances in the use of stable
isotopes like carbon-13, nitrogen-15 and oxygen-18 as biomarkers to charac-
terize microbial communities and their interactions with soil nutrient and
organic matter processes, known as stable isotope probing (SIP), are important
for soil–water–nutrient management.
SIP helps to understand the interactions between soil microbial commu-
nities, and their specific functions in soil carbon sequestration, soil organic
matter stabilization, soil fertility and soil resilience, as well as the soil
productive capacity for sustainable intensification of cropping and livestock
production.
SIP involves the introduction of a stable isotope labelled substrate into a
soil microbial community to see the fate of the substrate. This allows direct
observations of substrate assimilation to be made in minimally disturbed
communities of microorganisms. Microorganisms that are actively involved in
specific metabolic processes can be identified under conditions that approach
those occurring in situ.

E.6.2. Stable isotopic tracers to support the control of GHG emissions from
agricultural lands

Nitrogen losses from chemical fertilizers, wastewater irrigation and

manure can lead to water pollution. This can be minimized by best farm
management practices through appropriate nitrogen fertilizer applications and
by using riparian zones or permanently wet swales in the gullies of agricultural
hill slopes to remove nitrates from surface and subsurface runoff. Nitrates
moving through riparian and wet swales are subject to a soil microbial process
that converts nitrates to nitrous oxide (N2O) and dinitrogen (N2). Nitrous oxide
is a long-lasting greenhouse gas and potential ozone depleting gas. Recently,
nitrogen-15 enriched nitrates have been successfully used to quantify not only

18
Please see http://www-naweb.iaea.org/nafa/swmn/index.html for further IAEA
work on soil and water management.

33
nitrate removal, but also N2O and N2 generation rates from permanently wet
swales in agricultural catchments. With the use of nitrogen-15, wet swales have
been found to be a source of N2O emissions when NO3- nitrate concentrations
are unlimited, but can effectively function as a N2O sink when NO3- levels are
low. These findings provide a balanced solution for the use of wet swales,
between water quality goals (NO3- removal) and greenhouse gas emission
controls (minimizing N2O emissions) through the use of engineered bypass
flows to regulate nitrate loadings to wet swales during high flow events. This
enhances retention time as well as nitrate-limiting conditions without creating
N2O emissions. Without the use of nitrogen-15, agricultural planners and
resource managers would not be able to differentiate N2O and N2 emissions
from NO3- removal.

F. HUMAN HEALTH

F.1. Linkages between nuclear medicine imaging and the pharmaceutical

industry

Imaging is increasingly used as a biomarker to assess new drug devel-

opment. With clinical trials for drug development being undertaken more and
more in developing countries, innovative approaches to the development of
new pharmaceuticals are of key importance.
Imaging has a fundamental role in drug discovery and early development
of clinical applications. In this regard, fluorodeoxyglucose (FDG), as well as
positron emission tomography (PET) combined with computed tomography
(CT), are effective not only for the diagnosis and staging of diseases but also for
monitoring and quantifying treatment benefits. In drug development, this could
translate into identifying and stratifying patients who are eligible for a clinical
trial and then quantifying the results of treatment. The convergence of stratifi-
cation and diagnosis, or quantification of treatment benefits in research as well
as in clinical treatment is an important new development that has potentially
great benefits for both the pharmaceutical industry and, ultimately, patients.19

19
For frequently asked questions on PET and associated technologies, please see
http://www-naweb.iaea.org/nahu/nm/faqanswers.asp#pet.

34
F.2. Application of nuclear techniques to support nutrition

The increasing prevalence of non-communicable diseases is leading to

major health challenges. Industrialized countries as well as countries in
transition are grappling with an increasing constellation of diseases including
type 2 diabetes and cardiovascular disease. In contrast, developing countries
are confronted by the coexistence of undernutrition and overnutrition. This is
arguably the most important issue on the global health agenda and is further
complicated by the HIV/AIDS crisis in many countries.
The most vulnerable population groups are pregnant and lactating
women and their young infants. Recent technical developments have focused
on addressing a missing link in infant nutrition and health, i.e. body
composition assessment to better understand the quality of growth during
infancy and its link with later development of chronic diseases. Nuclear
techniques offer the much needed tools to assess body composition, in
particular in the assessment of total body water by stable isotope techniques
and bone mass by dual energy X-ray absorptiometry. These techniques offer
the highest available standard of body composition assessment and are thus
used to validate alternative techniques such as bioelectrical impedance
analysis.
Early in life, the structure and function of the body determines both short
and longer term health outcomes. The ‘windows of opportunity’ during which
the biology of physical growth and health status can be influenced by nutrition
(either positively or negatively) include crucial times of rapid growth and during
development of the foetus, as well as during the infant's first two years of life.
Nutrition interventions during these ‘windows’ provide the best opportunity for
the prevention of longer-term consequences of early undernutrition, including
those deriving from intrauterine growth restriction and stunting. There is an
urgent need to develop effective strategies to intervene during this crucial time
to counteract the later development of chronic diseases. 20

20
To assist Member States in determining nutritional levels, a Vitamin A Tracer
Task Force was initiated by the IAEA, USAID, HarvestPlus and ILSI to prepare
documents on the appropriate use of vitamin A tracer (stable isotope) methodology and
a handbook on vitamin A tracer dilution methods to assess the status and to evaluate
intervention programmes.

35
F.3. Advances in quantitative imaging and internal dosimetry for nuclear
medicine

The long-sought quest for a ‘magic bullet’, where an accurately targeted

substance kills cancer cells without damaging healthy tissue, is progressively,
albeit slowly, becoming a reality in therapeutic nuclear medicine. The principle
has been successfully demonstrated for over 50 years using the radioisotope
iodine-131 for the treatment of various thyroid diseases. Today, more sophisti-
cated substances have been bioengineered to target a wider range of diseases.
A few of them are approved for clinical use, while many more are currently
being tested in clinical trials, some with the direct involvement of the Agency.
A key aspect in evaluating the efficacy of these new radiolabelled compounds
is to quantify the distribution and determine the radiation absorbed dose
delivered to the disease site, but also to critical healthy tissue.
Nuclear medicine images typically are used for either detection tasks,
such as identifying perfusion defects, or quantitative tasks, such as calculating
left ventricular ejection fraction, standardized uptake values, or organ
absorbed dose.21 Over the past 15 years there has been a great deal of progress
in the development of methods for accurately quantifying nuclear medicine
images. However, propagation of these methods into clinics has been slow and
as yet there are no standardized methods for quantifying single photon
emission computed tomography (SPECT) or PET data.
Obtaining images that are suitable for quantitative tasks often requires
additional processing compared to those used for visual interpretation. This
additional processing frequently results in improved resolution and contrast
and reduced artefacts (Fig. F-1). These improvements in the image can often,
but not always, translate directly to improved performance of detection tasks.
Another advantage of using such images is that they may provide improved
measurement consistency for the field, minimizing variability across imaging
centres, imaging equipment, scan protocols and patients.

F.4. Improvement in radiation oncology applications

Combined modality therapy (surgery, radiotherapy, chemotherapy,

targeted drug treatment) improves survival in most common cancers. Advances
in external beam radiotherapy have increased the accuracy requirements for
dose delivery to patients. The three-dimensional conformal radiotherapy (3D-

21
Additional information is available at http://www.iaea.org/About/Policy/GC/
GC53/Agenda/index.html.

36
CRT) approach is regarded as the standard in most indications of curative
radiotherapy, and in many centres a substantial number of patients are treated
with intensity modulated radiation therapy (IMRT).
Volumetric modulated arc therapy, combined tomography-therapy
innovations, dose-individualized stereotactic body radiotherapy, and four
dimensional image-guided radiotherapy (IGRT) (which expands the target
volume to encompass the range of tumour motion) are being introduced into
clinical practice. They enable the highest conformity and superior critical-
structure sparing when the dose to adjacent normal tissue is minimized.
Improved software for recording and verifying quality systems has become
available to improve the process in clinical radiotherapy.
Increasingly, proton centres are being established to develop normal
tissue-sparing high precision applications. In most cases, more evidence is
needed to prove the superiority of these approaches compared to conventional
radiotherapy.
In addition, information technology has brought about changes in the
working methods in radiation oncology. Worldwide, the introduction of
nationwide registries of case records and electronic patient files at the hospital
level is developing rapidly.22

FIG. F-1. Iodine-123 metaiodobenzylguanidine (I-123 MIBG): transaxial section of

upper abdomen in patient with recurring phaeochromocytoma. The left image shows the
original SPECT image. The right image is corrected using CT acquired data on tissue
density. This type of SPECT image correction can provide better diagnostic information
and serve to more accurately quantify the uptake of the radiopharmaceutical (courtesy of
the University of Pisa Medical School, Italy).

22
At the IAEA’s international conference on Advances in Radiation Oncology,
held in April 2009, the Agency encouraged the world’s leading manufacturers of
radiation oncology equipment to produce more robust, less costly and portable
radiation oncology equipment, for use in poor and rural settings.

37
 G. ENVIRONMENT

G.1. ‘Hot particles’ in the environment

When assessing radiation doses and the impact of radiation on the

environment, released radioactive particles play an important role. ‘Hot
particles’ are small, radioactive objects containing a significant number of
radionuclides with sometimes very high radioactivity. Originating from several
possible sources including nuclear weapons tests, releases from the nuclear fuel
cycle, and accidents involving nuclear material, hot particles contain consid-
erably higher radioactivity levels than the bulk material or the population of
other particles dispersed from these sources.
The properties and environmental behaviour of the particle-bound radio-
nuclides are governed by their composition and the matrix structure, both
factors being source term related and release scenario dependent (Figs G-1 and
G-2). Mobility, environmental behaviour, bioavailability, and ecological and
health effects of the radionuclides are basically determined by the properties of
the particles such as microstructure, chemical composition and speciation.
Although little information is presently available on the impact of hot particles
on the environment, this will become more important as new techniques
become available to characterize such particles.
Due to their small size, often in the range of a few micrometres and below,
airborne hot particles are difficult to isolate. A new simple method has been
developed for the manual manipulation and isolation of single particles in the
size range of 1 μm and above using a light microscope and for even smaller ones
directly within a scanning electron microscope (Fig. G-1). Once isolated, a
particle can be examined using a variety of techniques which can be applied on a
microscopic scale such as scanning electron microscopy, alpha particle detection,
laser ablation inductively coupled plasma mass spectrometry (ICP–MS) and
other mass spectrometry techniques, as well as X ray microtomography.

G.2. On-line access to worldwide marine radioactivity data

Containing over 110 000 data entries, the main objective of the Marine
Information System (MARIS) (http://maris.iaea.org) is to provide easy access
to marine radioactivity data. Furthermore, MARIS is an international

38
FIG. G-1. Scanning electron microscopy (SEM) (left), and light microscope (right)
micrographs of a sand grain illustrating the shape and coverage of the particle with
depleted uranium originating from a munition storage fire in Al-Doha, Kuwait. Scale: 500
μm (from LIND, O., Characterization of radioactive particles in the environment using
advanced techniques, Thesis, Norway (2006)).

FIG. G-2. Microscopic X ray absorption tomography of an oxidized fuel particle released
during the fire that followed the explosion in the Chernobyl reactor accident. 3-D
rendering of tomographic slices showing the surface of the particle (left) and computer-
ized (virtual) slicing of the 3-D image, exposing its heterogeneous inner structure (right).
Particle width: about 300 μm (from SALBU, B., et al., “μ-XAS tomography and
μ-XANES for characterization of fuel particles”, ESRF Highlights 1999, European
Synchrotron Research Facility, Grenoble (2000)).

39
reference source on radionuclide levels and trends in the marine environment,
against which any further contributions from eventual releases to the marine
environment can be evaluated. MARIS has provided policymakers in coastal
regions with improved data for decision making.
MARIS contains past and present radioactivity data on the most
significant anthropogenic and natural radionuclides in the world’s oceans and
seas, in deep basins, coastal zones and seawater, as well as in particulate matter,
sediment and marine biota. These data originate from published scientific
papers, reports and databases developed within institutes or scientific
programmes in Member States.
The data in MARIS are used in baseline studies for the evaluation of
levels, inventories and trends of radionuclides in the marine environment; for
environmental impact assessments; and for the assessment of doses from
marine exposure pathways. Together with oceanographic data, MARIS data
are used to better characterize ocean currents, water column processes and
sediment dynamics, and to study the fate of contaminants in the marine
environment using radionuclides as analogues. MARIS data are also used to
validate regional and global scale circulation and dispersion models which are
useful, for example, for the prediction of climate change and ocean acidifi-
cation.

G.3. Stable isotope labelling in marine food web studies

Stable carbon isotope compositions are widely used to study the sources
of organic carbon in ecosystems and their use in the food web. Understanding
the transfer of carbon and nutrients between the environment and marine
organisms is key to enhancing knowledge on biogeochemical cycles and
ecosystem functioning. The deliberate addition of a tracer such as a carbon-13
labelled compound under controlled conditions, and its tracking through the
various components, provides valuable information. This can reveal which
pathways are significant for identifying the role of important organisms within
the ecosystem. Figure G-3 sketches the delta carbon-13 (G13C) distribution in
the environment. Through the analysis of lipid biomarkers characteristic of
certain groups of organisms and the presence of isotope-signatures in these
substances, it is now possible to resolve species-specific interactions using
stable isotopes at the molecular level. In combination with mathematical
modelling, such data may also be used to estimate the production and turnover
rates of photosynthetic products from different marine organisms. The Agency
is helping Member States to trace the transfer of carbon-13 labelled and non-
labelled compounds through marine food chains, such as corals, plankton and
bacteria based on the analysis of isotopic ratios of specific compounds by gas

40
chromatography–isotope ratio mass spectrometry (GC–IRMS). The
application of this newly developed nuclear technology would contribute to a
better understanding of food web interactions and carbon cycling in the marine
environment.

G.4. Radiotracers to measure impacts of ocean acidification on marine

biodiversity in the Arctic and Mediterranean

Modelling studies have clearly identified that polar regions are particu-
larly susceptible to the combined climate change effects of increasing
temperature and ocean acidification. To better predict their impacts on marine
biodiversity, the Agency has developed portable experimental facilities to
study ocean acidification. This is being used with the calcium-45 isotope to
measure rates of calcification in sea butterflies and cockles from the Arctic that
are key foods of resident whales, walruses and seabirds. Under experimental
exposures that replicate the acidified conditions predicted in the future for
Arctic waters, the Agency has supported Member States in their determina-
tions of appreciable reductions in calcification rates in sea butterflies by factors
that are similar to those already measured for reef-building corals.
The Agency is helping Member States to carry out radiotracer studies on
commercial fish, cuttlefish and octopus of the Mediterranean Sea to determine

atmospheric CO2
(urban area) atmospheric CO2
-7.8 to -12 ‰ (rural area)
anthropogenic -7.8 ‰
CO2 -26 ‰
C3 plants
-27 ‰ CAM plants
C4 plants -10 to -28 ‰
-13 ‰

seagrasses phytoplankton -22 ‰

-10 ‰ macroalgae zooplankton -20 ‰
-15 ‰
fossil fuels
vertebrates -17 ‰
DIC 0 ‰
DOC -23 ‰
organic
matter
CH4 CO2
coal natural gas petroleum -75‰
-25 ‰ -40 ‰ -30 ‰
bacteria
methanogenic bacteria
sediment -22 ‰

FIG. G-3. Sketch of G13C distribution in the environment (modified after Tolosa, Oceanis
30 2 (2004). 239–259). (CAM: crassulacean acid metabolism; DIC: dissolved inorganic
carbon; DOC: dissolved organic carbon.)

41
impacts of ocean acidification on their early life stages. This will further
contribute to understanding and predicting to what extent ocean acidification
will alter marine resources and the socioeconomic impact of these alterations.

H. WATER RESOURCES

In addition to population and economic growth, climate variability and

change are significant drivers of stress on freshwater resources. Nearly one in
three people on earth depends upon water from rivers that are fed by glaciers
and snow melt. Increased variability and vulnerability of river flows in a
warmer climate (due to increased melt-flows and changes in precipitation
patterns) will drive a need for changes in water use and management practices.
As development drives the need for greater renewable and non-renewable
energy production, water for energy will also be an important consideration in
water resources planning. Management responses to increased demands for
freshwater resources would likely include a greater dependence on already
stressed groundwater resources.
Yet there is a significant gap in our understanding of the distribution and
renewability of groundwater resources. One notable effort in improving
groundwater assessment is the Worldwide Hydrogeological Mapping and
Assessment Programme (WHYMAP) (http://www.whymap.org/). This collabo-
rative effort between the Agency’s water resources programme, UNESCO’s
International Hydrological Programme (IHP), the German Federal Institute
for Geosciences and Natural Resources (BGR), the International Association
of Hydrogeologists and others was initiated in 1999 with the objective of
collecting, collating, and visualizing hydrogeological and groundwater
information on a global scale. The groundwater resources map (Fig. H-1),
which was presented in 2008 at the 33rd International Geological Congress in
Oslo, describes three main types of groundwater occurrences: in major basins
with regional aquifers (shades of blue); in areas with complex hydrogeological
structure (shades of green); and in areas with local and shallow aquifers (shades
of brown). The shading of each colour represents the groundwater renewal or
recharge rates. A regional groundwater resources map for southern Asia is
shown in Fig. H-2.
Isotope methods help to easily identify aquifers which contain old water
(and no or negligible recharge) and those with modern water (and significant
recharge.)23 When old groundwater is used for irrigation or for domestic or

42
industrial water supply, it is described as ‘mining’ as the extracted groundwater
will not be replaced naturally under current climate conditions. Such aquifers
need to be managed much more carefully than aquifers that receive modern
recharge. Mining of aquifers occurs in many countries around the world.
The availability of sound assessments of water resources, including
groundwater, will help to substantially increase water availability. National
assessments will improve the ability of countries to better use their regionally
shared resources through improved strategic action programmes. The Agency
is planning to launch a partnership to leverage its technical strengths and
complement the mandates and activities of other agencies, such as the World
Bank, UNDP and WMO, in order to develop a model scientific approach for
water resources assessment that may be replicated in many Member States.
This partnership effort, I-WAVE (IAEA-Water Availability Enhancement),
will establish a comprehensive approach for water resources assessment,
including surface and groundwater resources, as well as help develop better
strategies for adaptation to climate change.

I. RADIOISOTOPE PRODUCTION AND AVAILABILITY

The global demand for radioisotope and radiation sources is increasing as

a result of their use in medicine and industry. The 6th International Conference
on Isotopes held in May 2008 in Seoul, the Republic of Korea, underlined the
high demand for further developments and international cooperation. A World
Council on Isotopes (WCI) is being developed to provide an appropriate forum
for all stakeholders to facilitate the sustainable and safe production and
application of radioisotopes.
The production capacity of radioisotopes using cyclotrons has increased.
The number of regional centres for the production of clinical radiotracers for
PET imaging is also growing. In response to growing demand for fluorodeoxy-
glucose (FDG), tabletop cyclotrons (~7.5 MeV), together with advanced
radiotracer synthesis modules based on microfluidics, are under development
and are expected to be adopted by major hospitals worldwide. In addition, as

23
Additional information is available in relevant sections of the latest IAEA
Annual Report (http://www.iaea.org/Publications/Reports/Anrp2008).

43
44

FIG. H-1. Groundwater resources of the world, WHYMAP (1:50 000 000 scale). Blue areas are groundwater systems in major basins; green
areas represent groundwater systems with complex hydrogeological structure; and brown areas represent locations with local and shallow
aquifer systems. The shades of the three main colours reflect groundwater renewal (recharge) rates.
some PET tracers have a higher specificity for imaging cancer, they are increas-
ingly preferred over FDG, which also accumulates in sites of infection.
The growth in the number of PET and PET-CT centres has increased the
utility of generator based PET tracers for superior imaging. For example,
gallium-68, prepared from germanium-68, is used for the diagnostic imaging of
cancer, and rubidium-82, prepared from strontium-82, is used for myocardial
perfusion imaging.
Radionuclide therapy is experiencing a growth due to advances in
targeting based on molecular nuclear medicine principles. Correspondingly, the
demand for therapeutic radionuclides is expected to grow significantly. An
electrochemical generator methodology developed for the preparation of high
purity yttrium-90 (facilitated through an Agency coordinated research project)
is expected to increase the availability of yttrium-90 based on a process
amenable to remote safe operation in a module. Lutetium-177 is projected to
become as important as iodine-131, and several countries have already begun
or are planning medium to large scale production of this radioisotope.

FIG. H-2. Detail of a 1:25 000 000 scale groundwater resources map showing southern
Asia. Blue areas are groundwater systems in major basins; green areas represent ground-
water systems with complex hydrogeological structure; and brown areas represent
locations with local and shallow aquifer systems. The shades of the three main colours
reflect groundwater renewal (recharge) rates.

45
I.1. Security of supplies of molybdenum-99

During the past year, disruptions in the supplies of the radioisotope

molybdenum-99 — the source of widely used technetium-99m for diagnostic
imaging — caused delays in patient services in nuclear medicine centres around
the world. Molybdenum-99 requirements (about 450 000 GBq per week) are
normally met by irradiation in five reactors located in Belgium, Canada,
France, Netherlands and South Africa, and processing by four industrial
facilities. More than 95% of all molybdenum-99 is produced using HEU
targets. In January 2009, the US National Academy of Sciences, under Congres-
sional mandate, released the report of a feasibility study on using LEU
targets.24
The limited numbers of reactors that produce molybdenum-99 are all
aged and due for maintenance shutdowns, which has led to problems in more
than one production site. In August 2008, one reactor restart (in Petten,
Netherlands) following a maintenance shutdown was delayed because of an
unexpected technical problem. This occurred concurrently with the scheduled
maintenance shutdown of two other reactors in Europe, as well as a radio-
logical incident in a processing facility, leading to significant molybdenum-99
shortages in Europe and other regions. Concerns about the security of supplies
of molybdenum-99 and other reactor based radioisotopes were compounded
by the May 2008 termination of the MAPLE reactor project in Canada, and the
realization that no new reactors are likely to start production until at least 2015.
The earliest additional large scale source of molybdenum-99 will likely
come from the Australian Nuclear Science and Technology Organisation
(ANSTO). In the USA, the University of Missouri Research Reactor (MURR)
has made considerable progress in preparatory planning and exploring
resources for becoming a domestic US producer with a target of meeting
30–50% of demand, although it would take three to four years after approvals
to be established. Two other new facilities are being installed, in Egypt
(supplied by INVAP, Argentina) and in Pakistan (supplied by Isotope Technol-
ogies, Germany), for the production of molybdenum-99, but exact production
plans are yet to be announced.
There is an urgent need to expand geographically well distributed reactor
irradiation capacity as well as to increase the number of processing facilities for
the production of molybdenum-99. Governmental support and stronger
cooperation among isotope manufacturers, including public–private partner-

24
http://www.nap.edu/catalog.php?record_id=12569.

46
ships, will be required to ensure that suitable reactors will be engaged to
irradiate LEU targets for molybdenum-99 production.

I.2. Electron beam processing

High-current electron beam (EB) accelerators are used in diverse

industries to enhance the physical and chemical properties of materials
(Fig. I-1) and to reduce undesirable contaminants. There are more than 1400
high current EB units in commercial use providing billions of euros of added
value to numerous products. This is in addition to the nearly 1000 low current
accelerators used for research purposes.
With the advent of high-energy (5–10 MeV) and high power (up to about
700 kW) EB accelerators, conversion of electron beam power to X radiation is
now a commercially viable alternative to the industrial use of gamma rays.
Figure I-2 shows containers that are capable of holding food products, such as
cartons of ground beef or boxes of medical disposables, ready to be conveyed
before two metre high water cooled tantalum X ray targets.
While the use of low energy (less than 500 keV) EB accelerators for the
curing of inks, coatings and adhesives for the elimination of volatile organic
compounds is growing, there is a need for mobile EB facilities for applications
such as industrial wastewater treatment, seed disinfestation, and air deodor-
izing. An emerging area for low energy electron beam accelerators is surface
decontamination, e.g. for PET bottles and packaging for aseptic filling.

WIRE
CABLE
TUBING SURFACE
(33%) CURING
(32%)

SERVICE
(7%)
SHRINK
FILM (17%)
OTHER (6%)
TYRES (5%)

FIG. I-1. Typical pattern of industrial electron beam accelerator end-use markets. The
bulk of the use is for cables, heat shrinkables and surface treatment (over 80%), while
applications for medical devices and food products are envisaged to increase in the future.

47
I.3. Radiation processing in nanoscience

Radiation technologies can be used for the creation and characterization

of new materials at the nanoscale. Radiation techniques are essential to
nanotechnology because the beam can be focused into a few nanometres and
scanned with high speed. A new technology has been demonstrated in the
Netherlands: multiple electron beam mask-less lithography, which uses up to
13 000 parallel electron beams to directly write electronic circuit patterns on
wafers, eliminating the need for masks. This technique couples very high
resolution and depth of field of the electron beam with high throughput,
providing a cost effective way of making the next generation of chips.
Low energy ion beam lithography works in a similar manner to electron
beam lithography, with advantages such as minimal scattering and nearly
uniform energy loss along the trajectory. A new method was recently
developed using a variable size aperture which shapes the beam spot on the

FIG. I-2. Containers with materials (e.g. medical disposables, food products) moving for
processing by X rays from 5–7.5 MeV electron beams.

48
sample. By combining different sizes of the aperture with different positions of
the sample, complex structures can be exposed in a short time. A heavy ion
beam with acceleration energy of more than 1 MeV can be used for fabrication
of ion-track membranes from polymers and in turn used as a template for the
synthesis of microstructures and nanostructures in the form of wires. Magnetic,
conducting and superconducting nanowires and nanotubules, single or in array,
have been manufactured this way. As well as in the electronics industry,
electron beam and ion beam technologies are used as tools for investigating
physical phenomena at nanoscale dimensions to support research in physics,
nanophotonics, nanobiotechnology and nanobiomedicine.

49
 Annex I

DEVELOPMENTS IN MUTATION ASSISTED

PLANT BREEDING

I-1. Introduction

Spontaneous mutation, the naturally occurring heritable change to

genetic material which played a pivotal role in biological evolution and formed
the basis for speciation and domestication of both crops and animals, can be
artificially induced and supports the maintenance of biodiversity. Since the
discovery of X ray and other forms of radiation at the end of the 19th century
and the ensuing demonstration of the ability of these forms of nuclear energy
to alter genetic material, scientists have routinely used different types of
ionizing radiation to create variants of crops [I-1].
There have been more than 2700 officially released mutant varieties from
170 different plant species in more than 60 countries throughout the world
(Fig. I-1) that not only increase biodiversity, but also provide breeding material
for conventional plant breeding, thus directly contributing to the conservation
and use of plant genetic resources. Hundreds of millions of hectares of higher
yielding or more disease resistant crops have been developed annually through
induced mutations and released to smallholders. These mutant varieties
enhance rural income, improve human nutrition and contribute to environmen-
tally sustainable food security in the world. Close to 90% of these officially

182 60
45

Asia
Australia&Pacific
Europe
897 Latin America
1555
North America
Africa

10
FIG. I-1. Number of mutant varieties developed in different regions of the world (FAO/
IAEA Mutant Varieties and Genetic Stock Database http://mvgs.iaea.org/).

51
 2%
10%

physical
chemical
other

88%
FIG. I-2. Comparative use of different types of mutagens. The majority of mutant varieties
are developed through irradiation (e.g. fast neutrons, X rays, and more than 64% through
gamma irradiation).

released mutant varieties were produced using radiation (Fig. I-2) and
contribute billions of dollars of additional income to farmers annually [I-2].25
Since the early 1980s, there has been a surge in the applications of
recombinant DNA technologies in the quest for answers to several biological
questions in health, agriculture and industry. This has brought about an unprec-
edented escalation in the volume of information on the ‘building blocks’ of
heredity (i.e. DNA sequence information), which is now available in the public
domain. The DNA sequences of many organisms including the human
organism (e.g. the human genome project) and several crop species have been
published. This is referred to as the genomics era, a term coined to reflect the
availability of information spanning the total genetic make-up of an organism,
the genome. The next goal in genomic studies is to unlock information
contained in the genomes of humans, animals, and plants, identifying and
ascribing functions to those parts of the genetic make-up; this will have far
reaching scientific implications and commercial potential. At the same time,
various molecular and genomic tools and techniques have been developed and
have substantially transformed the landscape of biological research. Efforts
towards crop improvement have also entered this new era, increasingly using

25
The IAEA, through the Joint FAO/IAEA Division of Nuclear Techniques in Food and
Agricultue, is working in partnership with national agricultural authorities, farmers, and global
research institutes such as the International Rice Research Institute (IRRI) headquartered in the
Philippines, to introduce new mutant varieties of wheat, rice and cassava species, in order to
increase agricultural efficiency, particularly in marginal lands featuring drought and poor soil
fertility.

52
both genomic knowledge and various molecular tools. Coinciding with these
developments, an expansion in the research and application of induced
mutations for crop improvement has also taken place in scientific communities
throughout the world.
Mutation induction continues to contribute to crop improvement, using
physical mutagens such as gamma ray, X ray, fast neutron, and chemical
mutagens such as EMS (ethyl-methane-sulphonate) and sodium azides.
Recently, new physical mutagens, such as ion beam radiation and cosmic rays,
have been proven to be effective for inducing mutations.
Below is an overview of recent developments related to plant mutation
breeding; induced mutations for harnessing genomics resources; bio-/molecular
technologies for enhancing the efficiency of mutation induction and utilization;
and ion beam radiation as a novel mutation induction technique.

I-2. Mutant stocks as gene repositories

Generations of induced mutants have long been driven by plant breeders,

who would then use them directly or indirectly (through further cross-
breeding) in the process of developing new varieties. The plant breeder’s ability
to improve a crop is as good as the available genetic variation, which can be
exploited in cross breeding and other forms of selection. Mutation induction
offers the possibility to induce such variations where the desired genetic
variation is lacking. Since the genomic region critical for a trait, known as the
gene, can be identified by the deductive process of inducing a series of mutants,
identifying which traits have been modified and relating such observed modifi-
cations to changes in genomic regions of such mutants compared to the
‘normal’ types is important. The mutated genomic region that exerts control
over the trait in question is therefore identified as the gene responsible for the
expression of the trait. The mutant genetic resources as one of the outputs of
mutation induction is an indispensable tool not only in plant breeding research
but also in fundamental genetic research activities related to gene discovery
and gene function analyses.
Significant efforts are currently being made not only in the generation of
genetic variations through induced mutations but also in the systematic charac-
terization of the induced mutants for observed phenotypic and genomic
changes and the cataloguing of the variations in searchable databases. Many of
these databases are available to interested parties.
Climate change may well lead to significant losses of genetic diversity
within species critical for food and agriculture. Roughly 20–30% of species
assessed are likely to be at high risk of extinction, if global mean temperature
exceeds 2–3°C above pre-industrial levels. These include crops’ wild relatives,

53
which are essential to increasing agricultural productivity, but also serve as the
foundation for adaptation strategies required for adjusting to abiotic changes
such as heat, drought and salinity as well as pests and diseases. Loss of genetic
diversity would have important negative consequences locally as well as inter-
nationally, because key traits for climate change and variability adaptation may
be lost forever. Mutation induction can help to meet this challenge.
Most national governments have also established germplasm collections
that contain sizable amounts of characterized mutant stocks that are
distributed to plant breeders and geneticists. The United States Department of
Agriculture, Agricultural Research Service (USDA/ARS) runs several
germplasm repositories (GRIN) that also include mutant genetic stocks under
the National Plant Germplasm System (http://www.ars-grin.gov/npgs/
holdings.html) and is considered to be one of the most comprehensive and best
organized collections.26
In addition to these genetic resources with mostly single point mutations,
another type of mutant genetic resource, radiation hybrids (RH), has been
developed for genomic research. RHs are produced by exposing somatic cells
to lethal doses of gamma radiation or X rays, in order to fragment the chromo-
somes. They are then rescued by introduction into host cells, which are subse-
quently fused with suitable recipient cells for the assessment of their
expressions providing unique materials for the establishment of physical maps,
a process known as radiation hybrid mapping. RH maps have been developed
in a number of crops, such as barley, maize, wheat and cotton for gene
discovery and detailed linkage analysis. This may soon lead to the identification
and transfer of genes affecting useful agronomic, quality and stress tolerance
traits.

26
Information in the FAO/IAEA Database of Mutant Variety and Genetic Stock
has been voluntarily contributed by national agricultural research institutes and
breeders such as the Radiation Breeding Institute of Japan and Zhejiang University in
China (an IAEA Collaborating Centre). For the IAEA mutant germplasm repository
(MGR), please see http://mvgs.iaea.org .

54
I-3. Nuclear methodologies: enhancing efficiency through the application of
biomolecular technologies

I-3.1. Novel molecular biology strategies for enhancing the efficiency of

mutation induction techniques

A major bottleneck in the routine application of induced mutagenesis to

both crop improvement and genomic research (through forward and reverse
genetics) remains the drudgery of producing, handling and assaying the
requisite large mutant populations. This is because mutant events usually occur
in low frequencies and detection therefore requires the creation of large
mutant populations. Molecular biology strategies, by permitting the querying of
the genome, provide neutral tools that are independent of environmental or
other extraneous factors for characterizing living organisms. One molecular
biology strategy, reverse genetics—the use of modifications at the molecular
level to predict phenotypes, holds great promise for reducing the number of
putative mutants for expensive field trials or laboratory analysis, since plants
without any alteration in the target gene could be effectively excluded from
those tests.
Recent advances in genomics, especially publicly available genomics
resources, have permitted the use of a high throughput platform such as
‘Targeted Induced Local Lesions in Genomes (TILLING)’ in the rapid
evaluation of mutant stocks for specific genomic sequence alterations.
TILLING is currently being used by many research groups in the identification
of mutation events. In practice, the knowledge of the frequency of induced
mutations in a population allows the calculation of the optimal population size,
avoiding larger populations than necessary to be screened. Therefore, a pre-
test of mutation frequency is helpful before starting whole population
screening. Populations with too low a mutation frequency should be discarded.
In recognition of the utility of this method in high throughput mutation
discovery, many laboratories have set up the TILLING platform and a number
of laboratories also provide TILLING services for specific plants.
Another problem is the need to have the mutated segment in a
homozygous state so that the mutation, usually recessive, could manifest as a
phenotype. Another major difficulty is the inherent problem of chimeras, a
problem that is exacerbated in vegetatively propagated plants. A number of in
vitro techniques have been shown to circumvent or significantly mitigate these
bottlenecks to induced mutations. These include cell suspension cultures
including somatic embryogenesis; doubled haploid production and rapid in
vitro multiplication.

55
I-3.2. Cell and tissue culture

Cellular and tissue biology strategies enhance efficiency of induced

mutation in crops. Related to the problem of production and subsequent
detection of mutation events in homozygous genomes are the confounding
effects of chimeras, especially in vegetatively propagated crops. This problem is
mitigated through several cycles of vegetative regeneration (both in vitro and
in vivo) of the mutagenised vegetative propagule (i.e. plant material used for
the purpose of plant propagation, e.g. any highly meristematic part such as root
and stem ends or buds, but also cuttings, leaf sections, or any number of other
plant parts that could be induced to regenerate whole plants in vitro).
This is also expensive in terms of time and resources and could be circum-
vented through the use of cell suspension cultures as starting materials for
inducing mutations. Cell suspension cultures take advantage of the potential of
each plant cell to regenerate into a whole plant, a phenomenon known as
totipotency. In practice, this involves the production of cell lines from callus
followed by the regeneration of plantlets through somatic embryogenesis.
Typically, single cells and small cell aggregates are cultured; these proliferate
and complete a growth cycle while suspended in a liquid medium. Since this
technique was demonstrated in 1956 with Phaseolus vulgaris, reproducible
protocols have been validated for other plant species [I-10]. This ability to
culture individual plant cells, from which whole plantlets will arise, permits the
treatment of individual cells with mutagens. The resulting plantlets are
genetically similar leading to significant gains in time.
Where protocols for somatic embryogenesis, through cell lines or friable
embryogenic calli, for instance, are not available, plantlets could also be
regenerated but at relatively lowered levels of homozygosity and enhanced
levels of chimeral sectors through in vitro nodal segments. While this is not
optimal, it is still better than using stem cuttings or other tissues for crops that
due to biological or genetic characteristics can only be vegetatively propagated
and for which microspore cultures followed by chromosome doubling are
impracticable. If this route is taken, due consideration must be given to
planning strategies for efficient dissociation of chimeras. Where multi-cellular
meristematic tissues have been used as starting materials for the induction of
mutations, several cycles of regenerations, with M1V4 being the minimum, are
required to dissociate chimeras in order to approximate the homohistont state.

I.3.3. Doubled haploid production

Another bottleneck to induced crop mutations relates to quality and the

inherent recessive nature of mutations. This leads to the masking of the

56
mutation events in the appearance of the mutants by the dominant allele at the
same gene locus. In a heterozygous background therefore, phenotypic manifes-
tations of mutations are practically impossible to detect in the early progenies
necessitating several cycles of crossing the plant with itself in order to produce
homozygous recessives that express the recessive phenotype.
Again, totipotency is exploited in the regeneration of doubled haploids
(DHs), when the chromosome number of gametic cells, i.e. pollens or anthers
and egg cells, is doubled prior to regeneration of a plant [I-6] to mitigate this
problem. This process could be incorporated into induced mutagenesis by the
treatment of these gametic cells prior to regeneration of the doubled haploids.
With spontaneous and/or induced doubling of the haploid chromosomes,
homozygous individuals are produced, availing the researcher of the most
rapid route to attaining homozygosity without having to cross the plant with
itself [I-13]. By facilitating the possibility of targeting either the haploid or
doubled haploid cells for mutation treatment, a mutation is captured in a
homozygous, pure line [I-13]. These mutants are homozygous for all loci
including the mutated segments of the genome being targeted for modification
and subsequent detection. For seed propagated crops, doubled haploid
strategies provide the fastest method for achieving homozygosity, as compared
to self-pollination. The savings in time and cost are significant as recessive
mutations usually are not detectable till the first self-pollination generation or
later generations. Rapid advances in cellular and tissue biology techniques
have resulted in the availability of reproducible DH protocols for over 250
plant species [I-9] covering most plant genera. The Agency has, through its
coordinated research activities, supported the development of easily applicable
DH protocols for many crop species. The DH methodology has been success-
fully used to expedite the pace for generating true breeding mutants in crops
such as barley, wheat, rice. Salt tolerant wheat was produced in China by
combining mutagenesis with anther culture and at the Agency’s laboratories,
DH was also used to generate a semi-dwarf (and hence lodging resistant) rice
mutant from a salt tolerant but uncultivated wild relative of rice [I-3].

I-3.4. Ion beam mutation

Ion beams have been widely used in the research on material surface
modification since the 1970s. Their application for mutation induction was
started with low energy ions in China in the late 1980s and with heavy ions in
Japan in the early 1990s. While ion beam technology has been used for food
crop improvement in China, it has been more extensively used for floriculture
plants in Japan.

57
FIG. I-3. The schematic view of E5B beam line (RRC = RIKEN Ring Cyclotron). See
Table I-1 for examples of heavy ions used in biological research [I-17].

Ion beams as a mutagen are different from other physical mutagens such
as gamma or X rays in that they not only involve energy transfer (as gamma or
X-rays), but also mass deposition and charge exchange; hence could result in
complex DNA damage and changes that are not found when gamma or X-rays
are used (high percentage of double strand breaks and subsequent
chromosome aberrations). Ion beams are produced by particle accelerators, i.e.
cyclotrons. Figure I-3 is a schematic view of the E5B beam line available in the
RIKEN Accelerator Research Facility (RARF) Japan.
Typical ions used for irradiation on biological samples are neon-20,
nitrogen-14, carbon-12, lithium-7, argon-40, iron-56 (Table I-1). They have
different energy levels and linear energy transfer (LET), ionization densities
which correlate to the complexity of DNA damage, and different ranges of
penetration (Fig. I-4). It is possible to modulate the treatment of plant material
with one species of ion at different LETs by passing the ions through a
combination of absorbers – since changes in the LET of ion species occur as
they pass through matter [I-17].

TABLE I-1. HEAVY IONS FOR BIOLOGICAL RESEARCH IN RIKEN

ACCELERATOR RESEARCH FACILITY (RARF) [I-17].

Ion Energy Range in LET

Charge
MeV/u GeV Water (mm) (keV/μm)
12
C 135 1.62 6+ 43 22.5
14
N 135 1.89 7+ 34 26.3
20
Ne 135 2.70 10+ 23 61.1
40
Ar 95 3.80 17+ 8 280.0
56
Fe 90 5.04 24+ 4 624.0

58
 LET (keV/m) BP
600

500 Ne ion

400
BP
300 C ion
200

100

0 10 20 30 40 50
Range in Water (mm)
FIG. I-4. After a beam with sufficient energy penetrates a plantlet and/or plant tissue with
rather low and uniform LET, the LET will then drastically increase towards the end of the
track which is known as the Bragg peak (BP) [I-17].

Studies have shown that the biological effect of ion beam radiation is
dependant on absorption doses and LET values but independent of ion species
[I-17], which means that the treatment of carbon-12 would produce similar
biological effect on rice seeds as neon-20 if the same dose (say 50 Gy) and same
LET (say 30 keV/μm) is applied. DNA double strand breaks are believed to be
the most important consequence of ion beam radiation. Very complex repair
mechanisms have been unveiled but are prone to errors due to double strand
breaks and lead to deletions, insertions, inversions and translocations. Studies
on the mutant gene alleles induced by ion beam radiation showed that most
mutations are deletions and that the size of DNA deletion is LET dependent.
Most complex DNA damage caused by the intricate set of effects of
heavy ion beams (HIB) escapes the repair efforts and thus is described as more
biologically effective and mutagenic than X-rays and gamma rays. A wider
mutation spectrum and less collateral physiological damage (i.e. effect on plant
survival and growth) is commonly reported for ion beam radiation as compared
to other mutagens, which is considered an important advantage.

59
 In China, 23 new rice and wheat mutant varieties have been bred using
ion beam technology and released for large scale commercial production (more
than one million ha per annum). The wheat variety ‘Wanmai 54’ displayed
excellent resistance to head scab disease and rust disease and recorded the
highest yield in the national new wheat variety yield trial (2003–2007), with
yield increases over control variety of 7~10.6%. In Japan, ion beam technology
has been used for generating mutants for a vast number of plant species by
various researchers; for example, a consortium of more than 90 user groups was
established to utilize the ion beam technology available in RARF (Japan). Six
new flower varieties have been developed using this technology and marketed
in Canada, Japan (Fig. I-5), USA, and the EU since 2002.

I-4. Future Perspectives

With the imminent threats posed by global climate change to crop

production and the ever increasing and more sophisticated demands of agricul-
tural products, crop improvement efforts have to be more powerful and precise
in developing new crop varieties. Breeders therefore require tools that permit
achieving subtle changes to the genetic make-up of otherwise superior crop
varieties e.g. high yielding but lacking in specific quality traits, and yet leaving
the genome largely intact in order not to disturb already stacked alleles of
genes. The availability of genomics information in the public domain coupled
with recent advances in molecular and cellular biology techniques have paved
the way for transforming old mutation techniques into state of the art
technology for both crop improvement and basic genomics research.
Development of novel and more efficient genomic tools have become
routine and the pursuit of new physical mutagens continues. Some technologies
are already in place and when integrated into mutation research, they will
greatly increase the efficiency and application of mutation techniques in plant

FIG. I-5: First cultivation in 1998 of new chrysanthemum varieties using ion beams
(courtesy of Dr. A. Takana, ISIMP2008/342).

60
research. For example, the next generation sequencing technologies, e.g. Roche
454 Genome Sequencer-FLX™ and Applied Biosystems SOLiD™ instru-
ments, have the potential to reduce the cost of genome sequencing by several
magnitudes, and simplify the process of mutation detection, the key point in
mutation research and application programmes. In particular, they will enable
the identification of mutant genes underlying important quantitative traits such
as drought tolerance and yield, something that is still very difficult, if not
impossible with traditional means.
Exposure of organisms to outer space conditions such as microgravity,
vacuum, ultra-clean environment, cosmic rays, have allowed some countries,
since the 1960s, to pursue programmes of “space breeding’’. While it is
impractical to run commercial “space breeding” programmes, experiments in a
simulated space environment are being conducted on earth using accelerator
generated mixed high-energy particles that mimic secondary cosmic rays,
including pion, meson, muon, positron, electron, photon and proton radiations.
These may lead to the discovery of new physical mutagens that are more
effective or have unique properties.

I-5. Conclusion

In conclusion, by facilitating the direct querying of target genes for

changes, molecular biology techniques will significantly obviate the need for
field trialling large populations. Additionally, robust; cheap and easy to use
analytical methods will be ‘hooked’ up to these novel methods to enhance
efficiency of the delivery processes. Cellular biology techniques will address the
bottlenecks imposed by the need to rapidly generate large mutant populations
of suitable genetic backgrounds (homozygous for the mutation events, and
devoid of chimeras). New, space age technologies are being developed for
mutation induction. The Agency is working with a network of experts with the
objective of using a set of globally important food crops to validate identified
relevant novel techniques and build these into modular pipelines to serve as
technology packages for induced crop mutations. Thus, mutation assisted plant
breeding will play a crucial role in the generation of ‘designer crop varieties’ to
address the uncertainties of global climate variability and change, and the
challenges of global food insecurity.

61
 REFERENCES TO ANNEX I

[I-1] STADLER, L.J., Mutations in Barley Induced by X-rays and Radium, Science 68
(1928) 186–187.
[I-2] AHLOOWALIA, B.S., MALUSZYNSKI, M., NICHTERLEIN, K., Global
impact of mutation-derived varieties, Euphytica 135 (2004) 187–204.
[I-3] AFZA, R., et al., “A semi-dwarf rice mutant from a tall salt tolerant indica
landrace induced through gametoclonal variation”, Advances in Haploid
Production in Higher Plants (TOUAREV, A., FORSTER, B.P., MOHAN JAIN,
S., Eds). Springer, Dordrecht (2009).
[I-4] CALDWELL, D.G., et al., A structured mutant population for forward and
reverse genetics in barley (Hordeum vulgare L.). Plant J. 40 (2004) 143-150.
[I-5] COOPER, J.L., et al., TILLING to detect induced mutations in soybean, BMC
Plant Biol. 8 (2008) 9.
[I-6] FORSTER, B.P., et al., The resurgence of haploids in higher plants., Trends Plant
Sci. 12 8 (2007) 368-75.
[I-7] GREENE, E.A., et al., Spectrum of chemically induced mutations from a large-
scale reverse-genetic screen in Arabidopsis. Genetics 164 (2003) 731-740.
[I-8] SUZUKI, T., et al., MNU-induced mutant pools and high performance
TILLING enable finding of any gene mutation in rice, Mol Genet Genomics 279
(2008) 213–223.
[I-9] MALUSZYNSKI, M., KASHA, K.J., SZAREJKO, I., Published doubled
haploid protocols in plant species. In: Maluszynski M., Kasha K.J., Forster B.P.,
Szarejko I. (Eds). Doubled Hapolid Production in Crop Plants: A Manual.
Kluwer Academic Publishers, Dordrecht, The Netherlands (2003) 309–335.
[I-10] NICKELL, L.G., The continuous submerged cultivation of plant tissue as single
cells, Proc. Nat. Acad. Sci. U.S.A. 42 (1956) 848-850.
[I-11] SATO, Y., et al., Mutant Selection from Progeny of Gamma-ray-irradiated Rice
by DNA Heteroduplex Cleavage using Brassica Petiole Extract, Breeding,
Science 56 (2006) 179-183.
[I-12] SLADE, A.J., et al., A reverse genetic, Nontransgenic approach to wheat crop
improvement by TILLING, Nat Biotechnol. 23(2005) 75–81.
[I-13] SZAREJKO, I., FORSTER, B.P., Doubled haploidy and induced mutation,
Euphytica 158(3) (2007) 359-370.
[I-14] TILL, B.J., et al., Discovery of induced point mutations in maize genes by
TILLING, BMC Plant Biol. 4 (2004) 12.
[I-15] TILL, B.J., et al., Discovery of chemically induced mutations in rice by
TILLING, BMC Plant Biol. 7 (2007) 19.
[I-16] TRIQUES, K., et al., Characterization of Arabidopsis thaliana mismatch specific
endonucleases: application to mutation discovery by TILLING in pea, Plant J. 51
(2007) 1116-25.
[I-17] KAZAMA, Y., et al., LET-dependent effects of heavy-ion beam irradiation in
Arabidopsis thaliana. Plant Biotechnol 25 (2008) 113-117.

62
 Annex II

QUALITY ASSURANCE IN RADIATION DOSIMETRY:

ACHIEVEMENTS AND TRENDS

II-1. Introduction

Dosimetry is the science of measuring radiation dosage. The absorbed

dose of radiation is measured in a unit called ‘gray’ (Gy). Radiation dosage
measurements and ensuring they are as accurate as possible are important if
the benefits of the application of nuclear technology in health care are to be
harnessed. Radioactive processes and radiation are utilized in many health
related technologies, and the requirement for quality assurance (QA) and
accuracy in dosimetry depends upon the specific needs of the particular appli-
cations.
In the case of delivering radiation to a patient as part of a treatment
regime, accuracy is vital. The goal of a radiotherapeutic procedure is to deliver
the dose required to eradicate a tumour while at the same time minimizing the
radiation exposure to healthy tissue. Delivering too much radiation can result
in serious complications that could harm the patient’s quality of life. On the
other hand, delivering too little radiation to malignant tissue can ultimately
result in the death of the patient as a consequence of the disease.
Dosimetry is also an important component in diagnostic medicine. In this
case, the primary driver for accuracy is the need to balance the quality of an
image with the amount of radiation exposure. By preventing unnecessary
repetitions of imaging procedures, the cumulative dose to the patient is
minimized, while still providing the information necessary to diagnose and
monitor disease.
The use of radiation in hospitals, industry, laboratories and nuclear power
plants also necessitates consideration of the potential radiation exposure to
workers in the course of carrying out their duties. The level of accuracy
required in dosimetry for the measurement of occupational dose is lower than
that needed for patient dosimetry; however, traceability of measurements at a
defined level of uncertainty is still important. Dosimetry is an essential
component of all radiation safety and protection programmes designed to
monitor and achieve the safe use of radiation.
There are industrial applications of nuclear technology that require
radiation to be delivered at high doses. Some irradiated products may be used
directly by consumers, as in the examples of irradiated food or sterilized
medical products. Optimisation of irradiation delivery is important as the

63
health and safety of individuals are at risk if the dose delivered to the product is
inadequate to achieve the proper effect. Alternatively, if the dose is too high,
resources will be wasted resulting in economic consequences. Hence the level
of accuracy required in industrial processing dosimetry applications is
determined by the economics of the radiation process and the processor’s need
to ensure that their product meets health and safety standards.
Requirements for safe and optimal use of radiation vary depending on
the dosimetric accuracy required. Developing and implementing an
appropriate QA programme will ensure fulfilment of these requirements. The
main components of such QA programmes include traceability of radiation
measurements through accurate calibration of instrumentation, training of
staff, dosimetry audits and the establishment of quality control and radiation
safety procedures.
Recent achievements and trends relating to dosimetry and QA of
measurement standards, radiotherapy, diagnostic radiology, internal dosimetry,
and radiation protection are described in the following sections.

II-2. Measurement standards

Reliable measurements are fundamental in dosimetry, and strategies

have been developed to provide confidence using the traceability principle. The
idea of traceability is that the result of a measurement, no matter where it is
made, can be related to a national or international measurement standard, and
this relationship is documented. The Bureau International des Poids et

30
25
20
15
D NMI / (mGy/Gy)

10
5
0
-5
-10
-15
-20
-25
-30
ARPANSA

IAEA
ENEA

CNEA
METAS

VNIIFTRI
NMi

MKEH

LNE-LNHB

ININ

IRD

NIST
PTB
BEV

NRC

N.B. Black squares indicate results that are more than 10 years old.

FIG. II-1. This figure, adapted from Ref. [II-2], shows an example of an international
dosimetry comparison. It depicts the degree of equivalence between national dosimetry
standards (x axis) with respect to the BIPM reference value y axis). The degree of equiva-
lence to the Agency reference dosimetry system is also given.

64
Mesures (BIMP) ensures worldwide unification of physical measurements in
radiation dosimetry [II-1] with the active participation of national dosimetry
laboratories27 which have their own measurement standards. Reference
standards are maintained permanently at the BIPM and are used as a
benchmark for comparison of national dosimetry standards [II-2]. This bench-
marking has allowed some national laboratories to improve their standards as
well as prompted the dosimetry community to strive for improved accuracy.
For example, development of primary standards for the absorbed dose to water
for high-energy photon and electron beams [II-3 and II-4] in the past few years,
and improvements in radiation dosimetry concepts have reduced the
uncertainty in the dosimetry of radiotherapy beams. The concept of dosimetry
comparisons is now widely accepted and recognized as an important element of
QA programmes and also recommended in recent ISO and IEC guides [II-5]
and ICRU Report 76 [II-6]. It can also be used as a tool to demonstrate the
calibrations and measurement capabilities of national calibration laboratories
and to seek accreditation.

II-3. Dosimetry in radiotherapy

Radiotherapy involves delivering large amounts of radiation to specific

targets within the human body. A high degree of accuracy, reliability and repro-
ducibility is necessary for safe and effective radiation treatment of cancer
patients. This ensures confidence in both the dose delivered to the tumour, as
well as to the nearby healthy organs and tissues, thereby maximizing tumour
control and minimizing adverse radiation effects. QA programmes have
increasingly important roles as radiotherapy technology becomes more
complex. Equipment designs are evolving and more complex treatment
techniques are being implemented. For example, conformal radiotherapy is
now widely available; this modality enables higher doses to be delivered to the
tumour and therefore should increase the cure rates. Intensity modulated
radiotherapy (IMRT) is a similar technique, which is built upon conformal
radiotherapy but takes the concept further by using a multileaf collimator
(MLC) to deliver a series of smaller concisely targeted fields of radiation. For
the application of these small fields dosimetry errors can be considerably larger
than with conventional beams mostly due to two reasons; (i) the reference

27
A network of Secondary Standards Dosimetry Laboratories, known as the
IAEA/WHO Network of Secondary Standards Dosimetry Laboratories (SSDLs) was
established jointly with WHO in 1976. At present this network includes 80 laboratories
in 67 Member States.

65
conditions recommended by existing dosimetry codes of practice cannot be
established in more complex machines and (ii) absorbed dose to water
measurements in composite fields are not standardized and reference
conditions are not yet defined. To address these problems, an international
working group has been established by the Agency in cooperation with the
American Association of Physicists in Medicine (AAPM) to develop recom-
mendations for reference dosimetry of small and non-standard fields. 28
New technologies, such as IMRT, intensity modulated arc therapies
(IMAT), volumetric intensity modulated arc therapy (VMAT), together with
other newer radiation delivery platforms, such as TomoTherapy and
CyberKnife, all require complex QA and verification methods for dosimetry. In
light of these technologies, new QA devices such as two dimensional (2-D)
array detectors, 3-D based detectors, radiochromic film, and thermolumi-
nescent dosimeter (TLD) sheets, are becoming available and the dosimetry
verification techniques in radiotherapy are evolving accordingly. Gel dosimetry
is also used to verify complex 3-D dose distributions; however, it is not yet
widely used. In the past few years a new technology has been emerging in some
countries with hospital based facilities employing proton and light ion beams
for radiotherapy. The advantage of using these radiations is that they allow for
greater control of radiation dose distribution, thus enabling higher doses to
tumours and lower doses to healthy tissue. Similarly to photon and electron
beam treatment, planning of this high precision conformal therapy requires
accurate dosimetry and beam calibration in order to ensure exact delivery of
the prescribed dose. A major obstacle to establishing such dosimetry stems
from the fact that these are different types of radiation, and primary dosimetry
standards for proton and light ion beams do not currently exist. Current
practice utilizes ionization chambers with cobalt-60 calibration coefficients,
recognized as the most practical and reliable reference instrument for
dosimetry of proton and light ion beams. The recent report from the Interna-
tional Commission on Radiation Units and Measurements (ICRU) on proton
therapy [II-7] has recommended the use of IAEA Technical Reports Series No.
398 [II-4] in practical dosimetry. The ICRU report has also adopted the most
recent developments in the field of ionization chamber dosimetry for these
beams.

28
This included providing training opportunities for about 100 medical physicists,
from across the world, educational programmes on the use of these technologies
through IAEA workshops and courses organized in collaboration with the Abdus Salam
International Centre for Theoretical Physics, the AAPM and the European Federation
of Organizations for Medical Physics.

66
 One notable method for verifying the dose delivered to patients is by
using direct measurements taken while patients are being treated, i.e. in vivo
dosimetry (see patient setup in Fig. II-2). In vivo dosimetry provides insight
into the accuracy and precision of the treatment delivery, detection of
systematic errors and helps in the prevention of radiation accidents. Although
such measurements may not prevent a single dose misadministration, they will
minimize the possibility of escalating problems across many treatments or
patients. Point detectors (1-D) used for in vivo dosimetry utilize various solid
state detectors (semiconductor diodes, MOSFET, TLD, OSL) and are
generally considered useful for patients treated with uniform intensity beams,
in particular in radiotherapy centres where on-line electronic verification of
treatment set-up parameters (through records and verify systems29) are not
available. However, some issues are arising because point detectors are not
suitable in non-uniform radiation fields with rapid dose gradients, such as those
relevant to IMRT. To verify the IMRT dose delivery, 2 D in vivo dosimetry
methods are being developed based on the electronic portal imaging device
(EPID) attachments for treatment machines. EPID dosimetry is used in
advanced academic radiotherapy centres but at this time it is not commercially
available. The newest methodology for 3D in vivo dosimetry is under devel-
opment, based on the reconstruction of the dose distribution from EPID
measurements and patient images taken during the treatment using on-board
imaging devices.
To ensure quality care, it is generally recognized that there is a continual
need for national and international comparisons and audit programmes for
radiotherapy dosimetry such as those conducted by the IAEA/WHO [II-8],
Radiological Physics Centre (RPC) in USA [II-9] and other national and inter-
national organizations [II-10]. TLD auditing programmes have significantly
improved the compliance rate among participating radiotherapy centres with
regard to dosimetric accuracy. Other current dosimetry auditing programmes
used for the verification of treatment planning and dose delivery, including
those developed by the Agency [II-11] and RPC [II-12], are based on solid
(anthropomorphic and semi-anthropomorphic) phantoms because of the
multidimensional dosimetric aspects necessary in these techniques. They are
used for a variety of dosimetric situations, including dose measurements in
advanced conformal radiotherapy techniques and IMRT. The experience

29
Records and Verify (R&V) systems are interfaced with linear accelerators and
are used to verify treatment parameters.

67
FIG II-2. Set-up for in vivo dosimetry during cancer patient treatment with a radiation
beam. The dose delivered to the tumour during treatment is derived from measurements
with a radiation detector placed on a patient’s skin during irradiation and compared to the
planned dose.

gained in external audits for complex techniques, such as IMRT, has shown that
careful attention must still be given to basic aspects of dosimetry.

II-4. Dosimetry in X ray diagnostic radiology

Radiology is an area of medicine which has witnessed significant

technologic developments in recent years including the advancement of new
imaging techniques such as digital radiology, interventional radiology and
computed tomography (CT) in order to improve and enhance patient care.
However, while these developments have undoubtedly conferred benefits to a
large number of patients, they have also raised concerns for the quality and
safety of practices because the use of radiation for medical diagnostic examina-
tions is a significant source of human-made radiation exposure. Therefore, the
impact of these technical developments has to be quantified through
measurement with the use of appropriate and internationally recognized
dosimetry protocols and standards.
Diagnostic dosimetry measurements vary from the use of simple dose
indicators used to provide information on the general magnitude of the
radiation dose delivered to a patient, to more detailed and complex estimations

68
of the dose, including estimations of the dose to particular organs for typical
patient models. Dose indicators play a pivotal role in the control of patient dose
as they allow trends to be identified and prompt corrective action on a local
level through the use of optimization processes. Accurate determination of
organ based radiation dosimetry provides useful information regarding biolog-
ically relevant radiation tissue damage and aids in the statistical estimation of
risks to the population. Population risks are particularly important for low to
medium dose usage of radiation as this comprises the majority of examinations
performed in diagnostic radiology. Research is therefore being actively
conducted on the development of methodologies for more accurate patient
specific models and organ specific dosimetry. This work is most active and
notable in computed tomography and interventional radiology, where consid-
erable patient exposure can occur.
Standardization of dosimetry and calibration protocols is clearly central
to the effectiveness of dosimetric measurement necessary in diagnostic
radiology. This has recently been addressed in publications by the ICRU
(Report 74) [II-13] and by an IAEA Code of Practice (Technical Reports
Series No. 457) [II-14]. These complementary documents set out standards for
the measurement of the diverse range of dosimetric quantities necessary to
tackle the challenges of the rapidly changing and expanding environment of
diagnostic radiology. Many laboratories have commenced development of a
standardized set of reference beam qualities and some countries have started
providing calibration services to hospitals.
Dosimetry audits and comparison are not fully developed in this field.
More work is needed by the international community to set-up external
dosimetry audits and comparisons to reach the same level as in radiotherapy
dosimetry.

II-5. Internal dosimetry

In nuclear medicine imaging, patients are injected with radiopharmaceu-

ticals and then imaged with radiation detecting cameras. Distribution of
isotopes in the body presents the need for internal dosimetry, which currently is
most often based on standard reference tables published in medical internal
radiation dose (MIRD) pamphlets. These tables give the average absorbed
dose to the main human organs for any specified amount of injected radioac-
tivity. The tables were calculated in computationally intensive simulations for a
reference man (with an average weight, height and radioactivity distribution).
The tables also provide a rough estimate of the dose distribution for all
commonly used radiopharmaceuticals in nuclear medicine. This method for

69
calculating radiation dose can be used as an estimate of the resulting organ
doses for most diagnostic procedures.
The impetus for more accurate and patient-specific dosimetry comes
mainly from an increased availability and use of therapeutic radiopharmaceu-
ticals [II-15]. Such treatments deliver high doses of radiation to specific targets,
with the intent of providing a curative or palliative effect however the resulting
radiation dose absorbed by both the target and healthy organs is several orders
of magnitude higher than what is received from a diagnostic scan. The demand
for more accurate and possibly patient specific internal dosimetry has grown
accordingly. This demand is partially being met by developments in the
methodology by which the patient specific dose is calculated, and also by
computer-based tools available for the implementation of the improved
methods. Dedicated software packages exist to aid in patient-specific dosimetry
calculations.
The tools for calculating absorbed doses have become more sophisti-
cated, covering the whole spectrum from estimating the whole-body dose to
evaluating the specific radiation energy deposited in single cells. These
important tools are however partially based upon assumptions and depend on
user calculation and input of the true radioactivity distribution for individual
patients in order to perform accurate dose calculations. Accurate quantifi-
cation of the radioactivity distribution within the patient is thus essential for
internal dosimetry (see Fig. II-3). Methods to track the radioactivity distri-
bution in patients over time can include measurement with an external probe;
measuring the amount of radioactivity in blood samples; and also includes
efforts to quantitate the images from gamma camera scans [II-17]. All these
methods are currently being refined with the involvement of the Agency.
As the methods and tools for more precise internal dosimetry are
developed, it is important that medical physicists and other health profes-
sionals are continuously updated and trained so that the shortage of profes-
sionals with adequate skills in internal dosimetry does not lead to an
unnecessary delay in the clinical use of novel and promising therapeutic radiop-
harmaceuticals.
Workers in different nuclear applications are potentially occupationally
exposed due to intakes of radionuclides while working with unsealed sources of
radiation. From the source activity measured the intake of radionuclide is
assessed and the committed effective dose is calculated. New detection
methods, metabolic and dosimetric models are currently under development to
better represent the transfer of radionuclides and exposure process in the
human body.

70
II-6. Dosimetry in radiation protection

Radiation protection is an essential infrastructure element in the use of

radiation-based technologies in medicine, industry, agriculture, space exploi-
tation, education and research. Radiation protection measurements require a
dependable level of accuracy as they can have serious implications and can
significantly influence practices. This is particularly true for applications related
to health and safety of individuals and the public. Radiation fields can be very
complex, depending on the practice and type of radiation involved. The wide
range of ionizing radiation applications requires a wide range of instruments
for characterizing various radiations and their intensities.

2 CVKGPV
D 2 CVKGPV
D

5 EQWV # 2 J 2 # J 5 EQWV # 2 J 2 # J

FIG. II-3. X ray and gamma camera images of a patient with ovarian cancer being exper-
imentally treated with the alpha particle emitter astatine-211 labelled to a molecule that
targets the cancer cells. In addition to alpha particles, astatine-211 also emits photons that
can be detected by a gamma camera. The three panels on the left show the distribution 1
hour after the radiopharmaceutical was infused into the peritoneal cavity. The X ray
image on the far left was acquired simultaneously with the gamma camera images of the
front (AP) and the back (PA) of the patient. The three panels on the right show the distri-
bution 5 hours after the infusion. When combined and analysed, these images provide
information on the radiation absorbed dose to tumour and critical healthy tissue. The
information is used to predict the therapeutic and toxic effects of this treatment (courtesy
of University of Gothenburg, Sweden).

71
 External dosimetry is necessary for workplaces where there is medical or
industrial use of ionizing radiation. This primarily involves using detectors and
dosimeters for measurement of photons, neutrons and beta radiation for area
monitoring and personal dosimetry. More traditional personal film dosimetry
systems are being gradually replaced by solid state detectors thermolumines-
cence (TL), radiophotoluminescence dosimeters (RPL,) and optically
stimulated luminescence (OSL) and electronic dosimeters. Rapid development
of medical applications of radiation, mainly interventional radiology, requires
new approaches in monitoring medical staff. Comparisons of dosimetry
systems for monitoring of occupational doses have been organized by the
European Union and the Agency. These types of exercises are widely accepted
as an efficient tool for harmonization of dosimetry approaches and quality
assurance of services provided to end users. Radiation protection also faces
challenges in addressing problems associated with radiation produced by high
energy accelerators, nuclear power installations, and radiation received on
aircraft or during space missions, and requires the use of a broad range of
techniques for measurement of photons, electrons, neutrons, protons and other
charged particles as well as techniques in computational dosimetry. Behaviour
of many dosimetry systems in such radiations is still not very well known.
Assurance of the quality of measurements is achieved through joint benchmark
exercises organized in facilities that can provide these types of radiations.
Complex workplace radiation fields have been established at the European
Organization for Nuclear Research (CERN) [II-16] and other high energy
accelerator facilities, in nuclear installations, neutron calibration facilities and
also in some radiotherapy facilities worldwide. Extensive research in this area
is still required.
Another concern in radiation protection is environmental dosimetry.
Environmental dosimetry is a field which aims to describe the distribution of
natural and artificial radiation sources in the environment and assess the
resultant doses to the general public and other species. It involves various
active (ionization chambers, proportional and Geiger–Mueller counters, and
spectrometers) and passive (TLD, OSL) dosimetry techniques used to assess
short time and long time variations of radiation levels. Environmental
dosimetry systems are linked to national networks thus providing continuous
monitoring and early warning of nuclear accidents with local or transboundary
implications. While the environmental dosimeters are calibrated at the
laboratory, once used in the field they may lose traceability due to differences
in radiation fields encountered during calibration and in the environment. Field
comparisons play an important role during quality assurance of environmental
measurements. The natural environmental radiation stations and underground
testing laboratories, developed in the frame of the EU research programme,

72
have been successfully used for testing various dosimetry and national network
systems.

II-7. Conclusion

Technologies which utilize radiation have shown enormous potential

benefits for society. These benefits are best realized when proper knowledge of
radiation dosimetry is incorporated into the science and application of the
different technologies. While working modalities differ in the fields relevant to
radiation dosimetry, efforts are continually being made to improve their
accuracy. Strategies for measurements are applied worldwide to create
common international standards and comparison platforms, which play an
important role in QA programmes.
Radiotherapy is an example of an active field which relies heavily on
these QA programmes to ensure that patients are receiving the most effective
and safe treatments for their cancers. Advancements are being made in X ray
diagnostic radiology but dosimetry audits and comparison procedures have yet
to be implemented routinely. In nuclear medicine, pharmaceutical effects
determine distributions of radioisotopes, and thus dose, within a patient. Work
is currently being done to provide better patient specific, and organ specific
dosimetry, which in turn, will aid in drug development and in the provision of
better patient management. Non-medical and industrial exposures to radiation
are also of great interest, and require accurate measurement tools and method-
ologies to monitor work places and public environments. As technology
continues to grow, so do the efforts to assure safety, quality, and accuracy, in
radiation related fields. Progress is being made through development of
appropriate dosimetry, utilizing QA programmes, audits, new tools, and new
ideas.

REFERENCES TO ANNEX II

[II-1] BUREAU INTERNATIONAL DES POIDS ET MESURES, The International

System of Units (SI), BIPM, Sevres (1998).
[II-2] ROSS, C.K., et al., Final report of the SIM 60Co absorbed-dose-to-water
comparison SIM.RI(I)-K4, Metrologia 45 (2008) Tech. Suppl., 06011.
[II-3] INTERNATIONAL COMMISSION ON RADIATION UNITS AND MEAS-
UREMENTS, Dosimetry of High-Energy Photon Beams based on Standards of
Absorbed Dose to Water, Report 64, ICRU, Bethesda, MD (2000).

73
[II-4] INTERNATIONAL ATOMIC ENERGY AGENCY, Absorbed Dose Determi-
nation in External Beam Radiotherapy, Technical Reports Series No. 398,
IAEA, Vienna (2000).
[II-5] INTERNATIONAL ORGANIZATION FOR STANDARDIZATION,
General Requirements for the Competence of Testing and Calibration Labora-
tories, ISO/IEC 17025: 2005, ISO, Geneva (2005).
[II-6] INTERNATIONAL COMMISSION ON RADIATION UNITS AND MEAS-
UREMENTS, Measurement Quality Assurance for Ionizing Radiation Dosim-
etry, Report 76, J. ICRU 6 2 (2006).
[II-7] INTERNATIONAL COMMISSION ON RADIATION UNITS AND MEAS-
UREMENTS, Prescribing, Recording, and Reporting Proton-Beam Therapy,
Report 78, J. ICRU 7 2 (2007).
[II-8] IZEWSKA, J., ANDREO, P., The IAEA/WHO TLD postal programme for
radiotherapy hospitals. Radiother. Oncol. 54 (2000) 65–72.
[II-9] AGUIRRE, J.F., et al., “Thermoluminescence dosimetry as a tool for the remote
verification of output for radiotherapy beams: 25 years of experience”,
Standards and Codes of Practice in Medical Radiation Dosimetry (Proc. Int.
Symp. Vienna 2002), IAEA-CN-96/82, IAEA, Vienna (2003) 191–199.
[II-10] IZEWSKA, J., SVENSSON, H., IBBOTT, G., “Worldwide quality assurance
networks for radiotherapy dosimetry”, ibid., IAEA-CN-96/76, 139–156.
[II-11] GERSHKEVITSH, E., et al., Dosimetric verification of radiotherapy treatment
planning systems: Results of an IAEA pilot study, Radiother. Oncol. (in press).
[II-12] IBBOTT, G., et al., “An anthropomorphic head and neck phantom for the evalu-
ation of intensity modulated radiation therapy”, Standards and Codes of
Practice in Medical Radiotherapy Dosimetry (Proc. Int. Symp. Vienna, 2002),
IAEA-CN-96/85P, IAEA, Vienna (2003) 209–220.
[II-13] INTERNATIONAL COMMISSION ON RADIATION UNITS AND MEAS-
UREMENTS, Patient Dosimetry for X Rays used in Medical Imaging, Report
74, ICRU, Bethesda, MD (2007).
[II-14] INTERNATIONAL ATOMIC ENERGY AGENCY, Absorbed Dose Determi-
nation in External Beam Radiotherapy: An International Code of Practice for
Dosimetry based on Standards of Absorbed Dose to Water, Technical Reports
Series No. 457, IAEA, Vienna, (2007).
[II-15] OYEN, W.J., et al., Targeted therapy in nuclear medicine-current status and
future prospects, Ann. Oncol. 18 11 (2007) 1782–92.
[II-16] EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH, Complex
Workplace Radiation Fields at European High-Energy Accelerators and Ther-
monuclear Fusion Facilities (SILARI, M., Ed.), CERN 2006-007, CERN,
Geneva (2006).

74
 Annex III

ISOTOPES FOR MANAGEMENT OF TRANSBOUNDARY RIVERS

AND AQUIFERS

III.1. Introduction

Management of transboundary fresh water resources (also known as

trans-national, international, or internationally shared water resources) is of
increasing concern across the world. Transboundary water resources include
visible surface water bodies, such as lakes and rivers that cross borders, and
groundwater systems (or aquifers). Globally, over 260 transboundary river
basins have been identified. These basins cover 45% of the land surface of the
earth, affect ~40% of the world’s population, and account for ~60% of the
global fresh water supply [III-1]. Aquifers, including transboundary aquifers,
account for the rest of freshwater supply. Some of the large transboundary
aquifers include the Nubian and northwest Sahara aquifers in northern Africa
and the Guarani aquifer in Latin America. However, in many areas no
inventory of transboundary aquifers exists. The widespread occurrence of these
systems is exemplified by a recent United Nations survey that identified 89
transboundary aquifers in Europe [III-2].
Although management of transboundary rivers and lakes has been an
issue for many years, transboundary groundwater issues have largely been
overlooked. This is partly because surface water and groundwater historically
have been regulated as separate resources. However, the situation is starting to
change. For example, a recent Agency co-sponsored conference, ‘Groundwater
and Climate in Africa’ that was held in Kampala, Uganda, in June 2008, clearly
demonstrated that predicted climate change scenarios will lead to an increased
reliance on groundwater resources in Africa. Africa is already struggling with
over exploitation of groundwater in some locations and some of the largest
transboundary aquifers are essentially non-renewable [III-3] which increases
the potential severity of climate change effects.
Cooperation for the sustainable management of transboundary aquifers
is difficult to achieve in the absence of information regarding the links between
surface water and groundwater, as well as groundwater recharge, residence
times, and hydrological flow paths. Most conflicts over water between countries
have generally been addressed by non-violent means. However, the lack of
sufficient technical information regarding water resources increases the
chances of misunderstanding and confrontational situations, especially under
scenarios of decreased water availability and/or food scarcity (see the
discussion in Ref. [III-4] and references therein).

75
 Much can be gained through the application of traditional hydrological
characterization such as measurement of water levels, river discharge measure-
ments, etc. Despite the high value of such information, ambiguities about how
these systems function and/or unacceptably large uncertainties about a
particular water system all too often occur. This is why the application of
isotope techniques (i.e. isotope hydrology) as part of the characterization
process, can be an extremely important complement to traditional methods.
Isotope hydrology can provide key information to build and test conceptual
models of transboundary systems, and can also be extremely valuable for
testing or parameterizing numerical models of hydrological flow systems.

III-2. Mapping transboundary water bodies and their characteristics

The first step in addressing key transboundary problems is to identify and

map transboundary water bodies [III-2]. One important ongoing hydrological
mapping effort is the World Hydrogeological Mapping and Assessment
Programme known as WHYMAP (http://www.whymap.org/). An important
product of WHYMAP relative to this transboundary discussion is a global scale
map of major transboundary aquifers (Fig. III-1). This map shows the
frequency of transboundary groundwater across the world. This kind of global
scale mapping is typically too coarse for actual transboundary management
purposes, but it does have an important role in raising awareness and educating
policy makers and the general public about the fact that groundwater does not
follow national borders. Another effort to make aquifer characterization data
and maps (including transboundary related data) available to water resource
managers is through the UNESCO initiated International Groundwater
Resources Assessment Centre in the Netherlands (IGRAC, http://IGRAC).
IGRAC is compiling detailed groundwater information from studies across the
globe. The goal is to make key data and maps available to the public and at
scales meaningful to water managers and stakeholders.
With regard to maps of isotopes and isotope data in general, the Agency
has recently expanded its Water Isotope System for Data Analysis, Visuali-
zation, and Electronic Retrieval (WISER) worldwide web application
(accessible through http://www.iaea.org/water/). WISER is a GIS based
information system which makes a large amount of isotope hydrology data
available for addressing local and regional scale transboundary water issues (as
well as other water resource problems). The mapping application in WISER
includes high quality cartographic representation, processing of topographic
and thematic data, interactive manipulation and visualization of data. Various
query, exploration and analysis tools are included to lead the user towards

76
FIG. III-1. Transboundary aquifers of the world from the WHYMAP programme. While
the term ‘transboundary’ often refers to two or more countries, it may also refer to
internal boundaries within a country such as between states, provinces, or districts.

customised results. WISER contains unique isotope databases and spatial

products that will increasingly play an important role for addressing trans-
boundary water issues in the future (additional details are provided in
references [III-5, III-6]). During roundtable discussions at the 2007 Interna-
tional Isotope Hydrology Symposium in Vienna, participants clearly indicated
that the Agency’s efforts involving WISER are very relevant. For example, the
Global Network of Isotopes in Precipitation (GNIP) and the Global Network
of Isotopes in Rivers (GNIR) databases within WISER were cited as examples
of critical resources for isotope data at local, regional, and global scales.
Because new data are continually added to the WISER system, its usefulness in
understanding spatial relationships between isotopes and hydrological systems
and temporal impacts from such factors as land use and climate change make
WISER highly relevant to transboundary problems as well as other water
resources issues [III-6]. An example of an isotope map for the Guarani aquifer
in South America is shown below (Fig. III-2) and additional discussion of this
map is provided later in this annex.

III-3. Developing conceptual models of transboundary systems

The simple conceptual models of transboundary water systems shown in

Fig. III-3 below illustrate some of the basic characteristics that need to be
understood for a given transboundary location. It is clear from the figure that
simple questions such as where does the water come from, and where is it

77
FIG. III-2. Carbon-14 distribution (per cent modern carbon, pmC) in the Guarani aquifer
system in South America. Light coloured areas (low values of carbon-14) indicate parts of
the aquifer with old groundwater (> 10 000 years). The arrows indicated inferred direc-
tions of groundwater movement, with aquifer recharge in the north and discharge in the
south.

going, need to be answered if transboundary resources are to be used in a

sustainable and cooperative way. However, in many transboundary cases
around the world, it is currently not clear which of these simple models applies
to a given hydrological system. In addition, in cases where the basic conceptual
model is known, important details about the rates of movement, locations of
recharge, or sources of contaminants may not be known. As illustrated in the
examples below, future uses of isotope methods will contribute significantly to
the development of conceptual models of transboundary water systems and
help refine the quantitative aspects of such systems which are necessary for
sustainable management. Such approaches are now being used to address
transboundary water problems through various international collaborations.
Two prominent examples are the Agency and UNDP/Global Environmental
Facility collaborations on the Nubian and Nile systems in Africa (see Ref.

78
[III-3] for a review of these two transboundary systems). New collaborative
efforts similar to these will certainly be utilized as an effective way to deal with
transboundary problems in the years to come.
The effective use of isotope methods to understand a large transboundary
aquifer system is well demonstrated by recent work in the Guarani aquifer of
South America (Fig. III-2). The Guarani is one of the world’s largest aquifers
(over 1.2 M km2) covering parts of Argentina, Brazil, Paraguay and Uruguay
[III-7]. It is an important water source for industry, agriculture, and domestic
supplies, and a better understanding of the functioning of the aquifer is
required for sustainable management. A conceptual model of the aquifer based
largely on carbon-14 analyses is shown in Fig. III-2. The carbon-14 results

FIG. III-3. Conceptual models of groundwater and groundwater–surface water interac-

tions in transboundary water bodies (modified from [III-4] and references therein). The
dashed, red vertical line denotes the delineations between countries. Model A shows an
aquifer in one country that discharges into a river on the boundary between two countries.
Model B shows an aquifer in one country with a recharge zone in another country. Model
C shows a groundwater aquifer that extends across a political boundary. Model D shows
a shared border river that recharges an aquifer in only one of the countries.

79
revealed that much of the aquifer contains old groundwater, thus the system is
vulnerable to groundwater mining. The presence of old water was also noted in
Ref. [III-7] using chlorine-36 and uranium isotopes. Some present day recharge
also occurs, so the aquifer management strategy must account for both of these
situations. It is also important to note that some countries contain the present
day recharge areas, while others contain the discharge areas. Thus, the
information shown here can significantly aid the four Guarani aquifer countries
in their efforts to build a cooperative transboundary management strategy.
Radon-222 is another isotope technique that is expected to see increasing
use in the near future to address transboundary and other hydrological
problems. Radon-222 has been used for hydrological studies for many years
[III-8] and its particular usefulness lies with the fact that most groundwaters are
enriched with radon-222, while activities in surface waters are typically very
low. Thus, it can be used to map and quantify groundwater discharges into lakes
and streams, and also into marine coastal zones [III-8–III-10]. For example, a
groundwater discharge zone in a river typically has substantially higher radon-
222 activities than nearby river reaches above or below the groundwater
discharge zone. Knowing where groundwater discharge is occurring is an
important conceptual and quantitative factor when addressing transboundary
water problems as indicated by the conceptual models in Fig. III-3 (e.g. model
A). However, the short half life of radon-222 (3.83 days) has hampered its
broader use because of the need to conduct liquid scintillation analyses within
a few days after sampling to avoid excessive decay. On the other hand, the
availability of a relatively low cost, portable, yet high precision and accuracy
radon-222 detector capable of analysing a wide range of radon-222 activities in
water (Fig. III-4) should increase the use of radon-222 in hydrological studies.
The detector can be used to analyse collected water samples [III-10] or make in
situ measurements directly within a surface water body [III-9]. The instrument
and associated water analysis attachments (Fig. III-4) will make it far easier for
investigators to obtain radon-222 in groundwater and surface water with out
the need for rapid transport and analysis and if desired without collection of
samples at all. The in situ measurement capability makes it possible to obtain
high resolution distribution information on the spatial variability of radon-222
in a surface water body and also to collect temporal data at a 30 minute or less
time resolution.
As a transboundary application example, the Agency supported the
International Commission for the Protection of the Danube River (ICPDR) to
help improve understanding of the basin surface water and groundwater
system through the application of isotope techniques. In the summer of 2007,
the ICPDR launched the second Joint Danube Survey (JDS-2) to collect
information regarding water quality and ecological sustainability of the

80
FIG. III-4. Photo of the RAD-7 radon detector (small dark box with printer on top) and
RAD AQUA system (blue cylinder) in operation on board the Joint Danube Survey ship
Argus in 2007. River water is being pumped through the RAD AQUA where it releases
radon gas that is then pumped into the RAD-7 for detection of radon-222.

Danube. The survey entailed collection and analysis of samples for a wide
variety of water quality, hydrological, and other parameters. The survey began
in Regensburg, Germany, and finished 50 days later in the Black Sea. Samples
were collected by ship at over 90 points along 2375 km of the river covering ten
different countries. The radon-222 data were collected to identify potential
locations with significant groundwater inputs and also to examine mixing
between the Danube and its tributaries. The radon-222 profile along the
Danube has some interesting features as shown in Fig. III-5. Overall, the values
are low and the lowest values are effectively at the limit of detection as is
typical for surface water. However, there are significant differences between
some parts of the Danube and between the Danube and some of its tributaries.
The overall trend is for higher radon concentrations in the upper Danube
which suggests that this is the area where groundwater contributions to the
river are the largest. Some of the tributaries (e.g. the Sava, Velika Morava and
Siret) also have high radon-222, which suggests they have groundwater inputs

81
 180

Inn Danube Radon-222

160
Tributary Radon-222
Velika
140 Morava

120 Sio
Rn (Bq/m )
3

100 No Data
Siret
Sava Jantra
80
Moson
222

Danube
60
Arm
40 Prut
Drava

20
Tisa
0
2500 2000 1500 1000 500 0

Danube River km
FIG. III-5. Radon-222 in the Danube Basin. Uncertainties are better than 30 Bq/m3.

in the vicinity of the JDS2 sampling points. In terms of mixing, the Sava appears
to have the largest impact on the Danube radon-222 values although values
drop off quickly until the Velika Morava and then they decrease rapidly again.
Although the Siret has relatively high radon-222, its impact on the Danube
appears to be minor and is within the measurement error. This lack of impact is
probably related to the low discharge of the Siret relative to the Danube.

III-4. Final Discussion and Conclusions

There are other important areas and approaches where the use of
isotopes for solving transboundary water issues is expected to grow. One such
example involves nitrate, one of the most common transboundary contami-
nants. Isotope analyses of nitrate are now used to identify contaminant sources
and evaluate the extent of biodegradation which are key factors in the
prevention and mitigation of nitrate contamination. For example, nitrate
isotopes from a transboundary aquifer system in western part of Canada and

82
the USA showed that much of the contamination was originally derived from
manure with an increasing contribution from inorganic fertilizers [III-11].
The use of isotope hydrology will continue to grow because of the
increasing need to properly assess and manage water resources. This is
especially true for transboundary water systems where a sound, scientific
understanding of the hydrology and geochemistry is essential for sustainable
resource management, but also to further peace and cooperation between
countries using shared water resources.

REFERENCES TO ANNEX III

[III-1] WOLF, A.T., YOFFE, S.B., GIORDANO, M., International waters: identifying
basins at risk, Water Policy 5 1 (2003) 29–60.
[III-2] ARNOLD, G.E., BUZAS, Z., Economic commission for Europe inventory of
transboundary ground water in Europe, Groundwater 43 (2005) 764–770.
[III-3] WALLEN, B., et al., Isotope methods for management of shared aquifers in
northern Africa, Groundwater 43 (2005) 744–749.
[III-4] JARVIS, T., et al., International borders, ground water flow, and hydroscizo-
phrenia, Groundwater 43 (2005) 764–770.
[III-5] AGGARWAL, P.K., et al., New capabilities for studies using isotopes in the
water cycle, Eos 88 (2007) 437–438.
[III-6] AGGARWAL, P.K., et al., “Global hydrological isotope data and data
networks” J. West, J., Bowen, G., Dawson, T., Tu, K., Eds), Isoscapes: Under-
standing Movement, Pattern, and Process on Earth through Isotope Mapping,
2008 (in review).
[III-7] CRESSWELL, R.G., BONOTTO, D.M., Some possible evolutionary scenarios
suggested by 36Cl measurements in Guarani aquifer groundwaters, Appl. Radiat.
Isot. (in press).
[III-8] ELLENS, K.K., ROMAN-MAS, A., LEE, R., Using 222Rn to examine ground-
water/surface discharge interaction in the Rio Grande de Manati, Puerto Rico. J.
Hydrol. 115 (1990) 319–341.
[III-9] BURNETT, W.C., et al., Quantifying submarine groundwater discharge in the
coastal zone via multiple methods, Sci. Total Environ. 367 (2006) 498–543.
[III-10]SCHMIDT, A., SCHUBERT, M., Using radon-222 for tracing groundwater
discharge into an open-pit lignite mining lake – a case study, Isot. Environ.
Health Studies 43 (2007) 387–400.
[III-11]WASSENAR, L.I., et al., Decadal geochemical and isotopic trends for nitrate in
a transboundary aquifer and implications for agricultural beneficial management
practices, Environ. Sci. Technol. 40 (2006) 4626–4632.

83
 Annex IV

ADVANCED CONSTRUCTION METHODS FOR NEW NUCLEAR

POWER PLANTS

IV-1. Introduction

Relative to coal fired and natural gas fired power plants, nuclear power
plants are more expensive to build but less expensive to run. This annex
describes advanced construction methods to reduce nuclear power’s
construction costs, mainly by shortening the time needed to build a plant.
Each of the methods described below has been used in one or more of the
projects listed in Table IV-1. None is unique to the nuclear industry, nor to any
specific nuclear power plant design. Most are also used for other large
construction projects such as fossil fuel power plants, large civil construction
projects and shipbuilding.

IV-2. Open top installation

Constraints on installing major components inside the reactor and

containment building can have a major impact on the construction schedule. In
the past, the walls of the reactor and containment building were constructed
with temporary openings to allow the entry of large equipment. In open top
installation (Figs IV-1 and IV-2), the reactor and containment building is built
with a temporary roof with an opening through which major pieces of
equipment, such as the reactor vessel and steam generators, can be lowered
into position using very heavy lift (VHL) cranes. Today’s VHL cranes can lift
equipment weighing more than 1000 tonnes, with very long reach. Once the
equipment is placed inside, piping and electrical systems can be installed at the
same time that construction of the reactor and containment building is being
finished, including the replacement of the temporary roof by a permanent
containment dome.
Open top installation has been used successfully with modularization (see
next section) to shorten construction schedules. VHL cranes add additional
costs, but these are more than compensated for by the shortened construction
time. VHL cranes also add to planning requirements as it is vital to ensure that
they are strategically placed to conduct multiple lifting activities including the
installation of heavy equipment in other buildings of the plant or to provide
lifting capabilities for two units being built concurrently next to each other.

84
TABLE IV-1: REACTORS BUILT RECENTLY USING ADVANCED
CONSTRUCTION METHODS [IV-1–IV-5]

Construction Start of Type of reactor

Reactor Country period commercial (approx. MW(e))
(months)* operation **
Kasiwazaki Japan 48 Nov. 1996 ABWR (1350)
Kariwa-6
Kasiwazaki Japan 48 Jul. 1997 ABWR (1350)
Kariwa-7
Lingao-1 China 60 May 2002 PWR (1000)
Lingao-2 China 62 Jan. 2003 PWR (1000)
Qinshan 3-1 China 54 Dec. 2002 PHWR (720)
Qinshan 3-2 China 58 Jul. 2003 PHWR (720)
Tarapur-3 India 75 Aug. 2006 PHWR (540)
Tarapur-4 India 66 Sep. 2005 PHWR (540)
Shin Kori-1 Republic of 54 (planned) Dec. 2010 PWR (1000)
Korea (planned)
Olkiluoto-3 Finland 70 (planned) Jun. 2012 EPR (1600)
(planned)
Kudankulam-1 India 84 (planned) Mar. 2009 PWR (917)
(planned)
* The construction period is generally considered to be the time from the first major
pour of concrete for the main plant building to the commercial operation date.
** ABWR=advanced boiling water reactor; EPR=European pressurized water
reactor; PHWR= pressurized heavy water reactor; PWR= pressurized water reactor

During the construction of Qinshan 3-1 and 3-2 in China, a VHL crane
was used to position about 70 pieces of equipment (Fig. IV-1), including steam
generators which weighed 220 tonnes each (Fig. IV-2), the pressurizer
(103 tonnes), the reactivity mechanisms deck (43 tonnes), feeder frames
(40 tonnes each), fuelling machine bridges (16 tonnes each) and major heat
exchangers. It took just two days to install each steam generator instead of the
two weeks required for traditional horizontal access installation.
Figure IV-3 shows a VHL crane lifting the 200 tonne containment liner
double rings into place at Olkiluoto-3 in Finland, and Fig IV-4 shows the
containment dome at Kudankulam-1, in India, being lifted into position.
During the construction of Tarapur-3 and 4 in India, open top installation
was used to position about 50 pieces of equipment, including the steam
generators (Fig. IV-5), moderator heat exchangers, several other heat

85
 FIG. IV-1. Very heavy lift crane at Qinshan, China.

exchangers, pressurizer, calandria (Fig. IV-6), primary circuit headers and

fuelling machine. The lowering and positioning of each steam generator was
completed in less than a day, much less than the installation time of more than
one month required by other methods.

FIG. IV-2. Installing a steam generator at Qinshan 3-1 in China

86
 FIG. IV-3. Lifting the containment liner double rings at Olkiluoto-3 in Finland.

FIG. IV-4. Lifting the WWER-1000 containment dome into position at Kudankulam,
India (photo credit: NPCIL).

87
 FIG. IV-5. (a) and (b): Installing a steam generator at Tarapur-3, India.

IV-3. Modularization with pre-fabrication and pre-assembly

Prefabrication and pre-assembly of modules are construction techniques

used in many industries, including nuclear power plants. A module is an
assembly consisting of multiple components such as structural elements, piping,

FIG. IV-6. Lifting the calandria at Tarapur-3 in India.

88
valves, tubing, conduits, cable trays, reinforcing bar mats, instrument racks,
electrical panels, supports, ducting, access platforms, ladders and stairs.
Modules may be fabricated at a factory or at a workshop at the plant site, and
multiple modules can be fabricated while the civil engineering work is
progressing at the site in preparation for receiving the modules. This reduces
site congestion, improves accessibility for personnel and materials, and can
shorten the construction schedule. It can also significantly reduce on-site
workforce requirements.
Modularization also facilitates mass production of modules in the event
that several reactors are being built at the same time. Mass production reduces
production times and labour requirements. Modularization makes it easier to
ensure a controlled production environment, with associated improvements in
quality and efficiency. It makes it possible to manufacture modules before the
site itself is available, and, in the case of concrete, it facilitates the use of
accelerated curing techniques.
The decision to apply a modular approach should be made in the
conceptual design stage, and then it must be followed throughout the project,
for detailed design, engineering, procurement, fabrication, and installation,
through to the completion of commissioning. This allows equipment to be
designed to conveniently fit into a module, and for modules to be sized to
match the capacity of VHL cranes and transport routes to the site. A site
accessible by sea can accept larger modules. For less accessible sites, sub-
modules can be shipped to the site and then assembled into larger modules
before installation. Modularization also affects testing procedures as many
components can be initially tested at the fabrication facility to help eliminate
potential faults before formal post-installation tests at the construction site.
Other impacts of modularization are: the need to complete the total plant
design before fabricating modules; the need for factories or workshops to
fabricate modules; earlier expenditures on engineering, materials and
components for fabricating modules; the need for expensive heavy lift cranes;
and the costs of transporting modules.
Modularization with prefabrication and pre-assembly has been used in
combination with open top construction in recent construction projects for
evolutionary water cooled reactors [IV-1]. At Kashiwazaki Kariwa-7 in Japan,
the seven floors of the reactor building were divided into three modules and
fabricated in a pre-assembly yard before the pieces were successively lifted into
place by a VHL crane. The heaviest, most complicated module was the ‘upper
drywell super large scale module’ which consisted of a J shield wall, pipes,
valves, cable trays, air ducts and their support structures and weighed 650
tonnes (Fig. IV-7).

89
FIG. IV-7. Installing the upper drywell super large scale module at Kashiwazaki Kariwa-
7 in Japan.

At Lingao-4 in China, the containment dome was assembled on the

ground at the site and installed as a single module weighing 143 tonnes with a
diameter of 37 metres and height of 11 metres (Fig. IV-8). Previously, the dome
would have been assembled by moving sections into position  a process that
normally took about two months.
The Shin-Kori-1 and -2 projects in the Republic of Korea modularized the
fabrication and installation of the containment liner plate. This forms the inner
structure of the containment building for the Korean Optimized Power
Reactor. Normally, the installation process would have fifteen stages, each
involving the installation of one containment liner plate ring. At Shin-Kori-1
and -2, except for the first ring, all the other rings were modularized into two-
ring sections and installed with one lift for each section (Fig. IV-9). The number
of lifts is reduced, and the overall construction period is shortened. This
method also simplifies connections with auxiliary buildings since connecting
provisions, such as penetration sleeves for piping and electrical wire, are
attached to the ring modules before installation.
As a final example of modularization, at Tarapur-3 in India, the prefabri-
cation of piping was increased to 60–70%, compared with approximately 40%
for previous plants in India. This reduced field welding by 30–40%.

90
 FIG. IV-8. Lifting the dome module into place at Lingao-4 in China.

FIG. IV-9. Modularization of the containment liner plate assembly at Shin-Kori-1 in the
Republic of Korea.

91
IV-4. Advanced welding techniques

Nuclear power plant construction involves numerous welds to connect

both components of structures and components of pressurized systems. It also
involves weld cladding, which refers to one metal being deposited onto the
surface of another to improve its performance characteristics. Quality welding
is both crucial and time consuming, and techniques to increase the rate at which
weld metal can be deposited while maintaining high quality can reduce
construction times. Recent advanced welding technologies that meet this
objective include gas metal arc welding, gas tungsten arc welding and
submerged arc welding.
In addition, automatic welding equipment that makes it easier to weld in
narrow spaces can further decrease construction times. Automatic welding
equipment has been used to weld titanium tubes to condenser tube sheets at
Tarapur-3 in India and to weld piping at Kashiwazaki Kariwa-7 in Japan
(Fig. IV-10).

IV-5. Steel plate reinforced concrete and slip-forming

Reinforced concrete is used in the foundations of nuclear power plants

and in structures such as reactor containments, auxiliary buildings, turbine
buildings and spent fuel storage areas. Conventionally reinforced concrete is
fabricated in place using reinforcing bars (‘rebar’) with external forms to frame
the structure prior to pouring the concrete. The time required to place the
reinforcing bars and to construct and remove the forms into which the concrete
is poured is considerable. It is a major part of the construction schedule.

FIG. IV-10. Automatic piping welding at Kashiwazaki Kariwa-7 in Japan.

92
 Steel plate reinforced concrete is an alternative to conventionally
reinforced concrete [IV-6] and can be used for most floors and walls. The
concrete is placed between permanent steel plate forms with welds to tie the
steel plates, rebar and tie-bars together. The forms can include any necessary
penetrations and piping runs. Because of structural credit for the steel plate–
concrete combination, the amount of rebar may be reduced, and because the
steel plate structure can be self-supporting, reinforced concrete sections can be
modularized and prefabricated off-site, followed by placement and welding on
site.
Figure IV-11(a) shows standard reinforced concrete, and Fig. 11-IV(b)
shows steel plate reinforced concrete.
Steel plate reinforced concrete has been used to significantly shorten
construction schedules at plants recently constructed in Japan.
Construction schedules can also be shortened by slip-forming with
modular floor design technology. Slip-forming is the continuous pouring of
concrete at a very specific, calculated and monitored rate that is achieved by
continuous hydraulic lifting and moving of a short section (preferably less than
two metres) of formwork while inserting steelwork and pouring concrete
through the top. Using slip-forming, vertical walls can be constructed at a rate
of about 2 metres per day compared to a typical value of 1.2–1.5 metres per day
without slip-forming. Slip-forming requires a heavy lift crane to lift the heavy
steelwork that is inserted while the concrete is being poured.
Modular floor design and installation are used in conjunction with slip-
forming for the walls. After the outer vertical walls of a building are installed by
slip-forming, the modular floors can be installed through the open top of the
building by means of a heavy lift crane. Modular floors consist of steel modules,
which include rebar but no concrete, that are placed on supports embedded in
the concrete walls during the slip-forming process. The modular floors, which
are designed to be transported from the site assembly shop and installed by
cranes, are welded to the supports embedded in the walls and then filled with
concrete.

IV-6. Rebar placement for reinforced concrete

Rebar installation by individual placement of bars is quite time

consuming. Large amounts of rebar are needed in the base mat, containment
walls, containment dome, and structural walls of the reactor and turbine
buildings. The use of prefabricated modular rebar assemblies for these areas
can shorten construction schedules.

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 (a) Reinforced concrete.

(b) Steel plate reinforced concrete.

FIG. IV-11. Comparison of reinforced concrete structures.

Automation is another way to speed the installation of rebar. There are

several techniques. Figure IV-12 shows an automatic scaffold that moves
vertically while horizontally feeding rebar into place. It both speeds the process
and reduces labour requirements. Figure IV-13 shows a machine that automat-
ically assembles rebar according to instructions from a 3-dimensional computer
design model.

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FIG. IV-12. An automatic scaffold and horizontal rebar feeding machine at Kashiwazaki
Kariwa-6 in Japan.

IV-7. Advanced concrete composition

In addition to these advanced methods for pouring and installing

concrete, there have been recent advances in the composition of concrete to
improve strength, workability, and corrosion resistance. Examples are self-
compacting concrete, high performance concrete and reactive powder

FIG. IV-13. An automatic rebar assembly machine at Kashiwazaki Kariwa-7 in Japan.

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concrete. These are used not only in nuclear power plants but in other large
civil projects such as bridges, highway, large buildings and dams.

IV-8. All weather construction and working around the clock

To ensure that work can continue in all weather conditions, an all weather
cover dome can be put over the reactor building. This method was used, for
example, at Kashiwazaki-Kariwa-6 in Japan.
Working around the clock, both indoors and outdoors (see Fig. IV-14),
can save considerable time at critical stages of construction, for example during
excavation, concrete pouring, structural steel erection, calandria vault
construction and various welding activities.

IV-9. Bending small bore pipes to reduce welding requirements

For small bore pipes, elbow fittings and their associated welds can be
eliminated by forming bends within pipe lengths. Although the bending
operation introduces costs of its own, the benefits include time and labour

FIG. IV-14. Night view of site activities at Tarapur-4 in India.

96
savings through reduced welding requirements and, because there are fewer
welds to be inspected later, reduced inspection requirements.

IV-10. Advanced excavation methods

Advances in excavation that can be applied to nuclear power plants

include new equipment, such as large excavators designed for heavy workloads,
massive grading and material handling, and large equipment for vibratory soil
compacting. They also include precision blasting for excavating rock, which can
reduce costs relative to more conventional mechanical excavation methods, for
the reactor building, turbine building and other buildings. Several shafts are
drilled in a precise pattern in the required area to be excavated and filled with
explosives, which are then detonated. The possibility of using precision blasting
depends on a site’s geology and the plant’s design as well as applicable
regulations governing blasting.

IV-11. Cable installation

The installation of cables takes a significant amount of time and can be

part of the critical path. ‘Cable pulling’ is the term used for the process of
installing cables in cable trays (conduits) to connect plant equipment to power
sources. The conventional method involves applying a lubricant to a cable (or
group of cables) and pulling them into place with a rope. Improvements in this
method involve better lubricants and cable rollers. Another technique reduces
the need for cable pulling by splicing together the ends of cables that pass
through different modules. Such splicing techniques are well established in the
ship building industry.

IV-12. Area completion schedule management

The area completion schedule management method has been applied in

the Republic of Korea at Shin-Kori-1 and -2. This approach replaces design and
procurement schedules that used to progress system by system or, for a given
building, floor by floor with an approach that divides each level of each
building into zones. This allows more detailed scheduling of material purchase
and the issuance of construction drawings to best integrate requirements in all
zones. The approach is also used to schedule integrated installation work and
set priorities among civil, mechanical, electrical and other needed work in each
zone.

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IV-13. Computer systems for information management and control

The use of computer systems for information management and control is

well established in the design, engineering and construction of large projects
including power plants. For nuclear power plants the design and construction
information must be maintained throughout the life of the plant including
decommissioning. Computerized databases centralize all design information
and allow quick access by all parties to design and construction drawings,
equipment specifications, and inspection and testing data. The benefits of
computerized information management and control systems are that they
improve productivity through concurrent engineering, procurement and
construction; allow drawings to be revised and accessed electronically; facilitate
accurate determination of material quantities; and facilitate efficient
procurement and construction management.
Such integrated systems can be used to develop 3-D models of:

• Engineered piping and in-line piping components such as valves and

strainers;
• Raceways;
• Structural steel;
• Concrete;
• Heating, air conditioning and ventilation components;
• Equipment (tanks, pumps, heat exchangers, etc.);
• Piping supports;
• Piping and instrumentation diagrams;
• Embedded parts and plates.

Such 3-D computer models can then be linked to the schedule to provide
‘4-D modelling’. Specific deliverables at any stage can be extracted from the
computer assisted design drawing model, including piping system isometric
drawings, general arrangement drawings, and materials quantities, and the
overall installation plan can be more easily visualized. During operation such
models can be used to train operators and system engineers and to help nuclear
safety engineers to visualize systems when evaluating performance and safety
issues. For nuclear power plants, the system can also be expanded to track the
inspections, tests, analyses and acceptance criteria that must be applied during
construction to meet regulatory requirements.

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IV-14. Summary

The construction methods available for new nuclear power plants are
generally the same as those used for other large construction projects. There
have been numerous improvements in construction methods in the past few
years, and recent experience in nuclear power plant construction has shown
that those advanced methods are fully applicable and can help shorten
construction schedules. Recent nuclear construction projects have been
completed in as little as four years. The decision to apply some of these
methods must be made in the conceptual design stage and then followed
through consistently. Some advanced construction methods require earlier
investments for factories and workshops and earlier outlays of funds to
purchase materials, although they later save time and labour. Thus a shorter
schedule does not necessarily mean lower total costs, and the relative costs and
benefits for each of the methods summarized here must be weighed for each
project independently.

REFERENCES TO ANNEX IV

[IV-1] INTERNATIONAL ATOMIC ENERGY AGENCY, Construction and

Commissioning Experience of Evolutionary Water Cooled Nuclear Power
Plants, IAEA-TECDOC-1390, IAEA, Vienna (2004).
[IV-2] Application of Advanced Construction Technologies to New Nuclear Power
Plants, MPR-2610 (2004), prepared for the US Department of Energy.
[IV-3] INTERNATIONAL ATOMIC ENERGY AGENCY, Improving Economics
and Safety of Water Cooled Reactors: Proven Means and New Approaches,
IAEA-TECDOC-1290, IAEA, Vienna (2002).
[IV-4] OECD NUCLEAR ENERGY AGENCY, Reduction of the Capital Costs of
Nuclear Power Plants, OECD, Paris (2000).
[IV-5] CHEN, S., et al., “Qinshan CANDU Project open top construction method”
(Proc. 24th Annu. Conf. Canadian Nuclear Society Toronto, June, 2003).
[IV-6] OMOTO, A., “Improved construction and project management”, Proc. Int.
Conf. on Advances in Nuclear Power Plants (ICAPP) (2002).

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 Annex V

INTERFACING NUCLEAR POWER PLANTS WITH THE ELECTRIC

GRID:
THE NEED FOR RELIABILITY AMID COMPLEXIty

V-1. Introduction

For a country that does not yet use nuclear power, the introduction and
development of nuclear power is a major undertaking. It requires the country
to build the necessary infrastructure so it can construct and operate a nuclear
power plant (NPP) profitably in a safe, secure and technically sound manner. A
major part of the necessary infrastructure is the electric grid to which the NPP
will connect. While most countries already have an electric grid system, it may
require significant development to be suitable for the connection of an NPP.
The efficient, safe, secure and reliable operation of the NPP requires that the
grid to which it connects is also efficient, safe, secure and reliable. This annex
explains the characteristics of the electric grid, its relationship with the NPP,
and the reasons why a reliable grid is so important to the NPP.
The grid is the electrical highway through which all electricity traffic
passes as it moves energy from the supplier (‘generation’) to the customer
(‘load’). Interconnected electric grids can encompass several countries and are
probably the largest machines in the world. They consist of hundreds of power
suppliers, thousands of kilometres of transmission and distribution lines and
millions of different electrical loads. Rapid economic development in the 20th
century made the electric grid system a critical part of the economic infra-
structure in industrialized countries and a permanent feature of the landscape.
NPPs are unique and powerful generators compared to other electricity
generating plants. Moreover, they are both electricity generators and
customers. They thus maintain a symbiotic relationship with the electric grid at
all times. NPPs supply large amounts of energy to the grid as well as relying on
it to receive power for crucial safety operations, especially during emergency
conditions. The safe startup, operation and shutdown of NPPs require a reliable
and stable power supply from the electric grid, referred to generally as ‘off-site
power’.
The grid’s principal function is to transport electricity from the power
plant to customers. But it does much more than that. A reliable, balanced and
well maintained electric grid is crucial for bringing new nuclear power plants
online and operating them cost effectively and safely. In particular, the grid
plays an important safety role by providing a reliable source of electricity to

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power the plant’s cooling system to keep nuclear fuel cool after a reactor has
been shut down (although NPPs also have on-site back-up power available for
emergency situations). The fewer instabilities and interruptions there are in
NPP–grid interactions, the more productively and consistently the NPP can
supply full power to consumers. Siting decisions must therefore take into
account the local grid conditions and usage, and, because of the grid’s role in
plant safety as well as plant economics, integration of NPPs into an electric grid
poses a complex set of regulatory as well as engineering challenges.
Countries expanding or introducing nuclear power programmes are
advised to consider their electric grids as part of their planning process, partic-
ularly as the grid impacts the size and type of reactor that can be deployed.
Specific issues that should be considered in the early phases of a nuclear power
programme include grid capacity and future growth, historical stability and
reliability, and the potential for local and regional interconnections.
Assessment of the current grid and plans for improving the grid should
therefore be developed to be consistent with plans for nuclear power.

V-2. Vulnerability of the electric grid

The grid must maintain a precise frequency of alternating current; a

relatively small imprecision can cause disproportionate damage. The electric
power received at a house or a factory is the result of hundreds of distant,
widely dispersed generators sending electricity through a maze of circuits, wires
and transformers, and under varying weather conditions, at a single synchro-
nized precise frequency without missing a beat.
Section G.1 describes how such synchronization is normally maintained,
but this section outlines what can happen when things go wrong. Even a well
balanced grid is subject to events that can potentially lead to large scale distur-
bances or even to a collapse of the grid if the grid operates near its capacity
with no margin for faults. A small shift of power flows caused by a sudden
increase or decrease of electricity generation or the load can trip protective
circuit breakers which send larger power flows to neighbouring power lines,
possibly triggering a chain reaction of failures.
The grid systems in developed countries are normally designed and
operated with a contingency margin. They are operated so that no single fault
on the system can lead to unacceptable problems such as abnormal voltage,
abnormal frequency or disconnection of demand. However, if this margin is
not maintained, or multiple faults happen close together in time, a major failure
can still occur.
Much of the north-eastern United States of America and part of Canada
were plunged into darkness in August 2003 when a disruption in the electric

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grid’s intricate balance caused a massive blackout (Fig. V-1) with substantial
economic consequences. This was an example of cascading events resulting in
the complete shutdown of the grid. The blackout affected an estimated 10
million people in Ontario and 40 million people in eight US States.
The collapse of the grid was caused in this case by a combination of
human errors and technical challenges: power plant outages, overextended
controllers, transmission line failures, the overheating of alternate transmission
lines causing lines to sag into trees, an insufficient ability to repair or replace
sensors and relays quickly, poor maintenance of control room alarms, poor
communications between load dispatchers and power plant operators, insuffi-
cient understanding of transmission system interdependencies, and the grid
operating very near its transmission capacity. As a consequence, nine NPPs in
the USA and eleven NPPs in Canada were disconnected from the grid because
of electrical instabilities.
The North American blackout was in fact only one of seven blackouts in
a six week period in 2003 that affected more than 120 million people in eight
countries: Canada, Denmark, Finland, Italy, Malaysia, Sweden, the United
Kingdom and the USA. In Sweden, in September, a nuclear power plant
tripped (i.e. rapidly shut down), resulting in the loss of 1200 MW(e) to the grid.
Five minutes later a grid failure caused the shutdown of two units at another

FIG. V-1. Blackout in the north-eastern USA and Ontario, Canada, August 2003.

102
nuclear power plant with the loss of a further 1800 MW(e). To respond to this
loss of 3000 MW(e) (about 20% of Sweden’s electricity consumption) the grid
operators isolated the southern Sweden–eastern Denmark section of the grid,
but the voltage eventually collapsed due to the insufficient power supply. At
the time of the original reactor trip two high-voltage transmission lines and
three links to neighbouring countries were out of service for normal
maintenance work and four nuclear units were off-line for annual overhauls.
Their unavailability severely limited the options of the grid operators.
Electric grids are also vulnerable to natural disasters such as tornadoes,
hurricanes, earthquakes and ice storms. One well known example is the North
American ice storm of 1998. In January 1998, a massive ice storm struck a
relatively narrow area from eastern Ontario via southern Quebec to Nova
Scotia in Canada as well as bordering areas from northern New York to south-
eastern Maine in the USA. Freezing rain coated the area with 7–11 cm of ice. It
caused massive damage to trees and power lines throughout the area, leading
to widespread long term power outages (Fig. V-2). Trees and electrical wires
fell, and utility poles and transmission towers came down causing massive
power outages, some for as long as one month. It was the most expensive
natural disaster in Canada. Over four million people in Ontario, Quebec and
New Brunswick lost power. Some 130 power transmission towers were
destroyed, and more than 30 000 utility poles fell.

FIG. V-2. Freezing rain caused extensive damage to transmission lines in Quebec,
Canada, in January 1998.

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V-3. Structure of the electric grid

The electric grid consists of two separate infrastructures. The electric

power lines that are most visible are the high voltage transmission system
carrying electricity for large distances with relatively low current. Electricity is
generated by power plants at a relatively low voltage (ranging from 2 kV to 50
kV, depending on the size of the power station) and must be transformed into
high voltage electricity by step-up transformers at the stations’ switchyards.
The high voltage (from 100 kV to 800 kV) allows the transmission lines to carry
electric power at low current, therefore minimizing electrical losses over long
distances. Losses in electricity are generally due to the electrical resistance and
consequent heating of the cables. Typical losses for the United Kingdom and
the USA are around 7% of the energy passed through the transmission and
distribution networks.
The second system is the low voltage distribution system that draws
electricity from the high voltage transmission lines and distributes it to
individual customers. At the interface between the high voltage transmission
lines and the distribution systems, an electrical substation uses transformers to
‘step down’ the transmission line voltage to the lower voltage of the distri-
bution system. Substations also include electrical switches and circuit breakers
to protect the transformers and the transmission system from electrical failures
on the distribution lines. Transformers are located along the distribution lines
to further step down the line voltage for household use (120–380 V) and are
protected by circuit breakers that locally isolate electrical problems, such as
short circuits caused by downed power lines.
The transmission grid, with multiple generating stations and distribution
system connections, functions as one entity potentially stretching for thousands
of kilometres. Physically and administratively divided smaller networks are
often connected together forming a large electric grid. For example, in North
America there are three loosely coupled networks covering the USA and
Canada (Fig. V-3). Within each network, power flows through alternating
current (AC) lines, and all power generators are tightly synchronized to the
same cycle in terms of frequency. The three networks are joined by trans-
mission lines carrying direct current (DC), so the coupling and the need for
frequency and phase synchronization are more relaxed than within the
individual networks. The capacity of the DC transmission lines connecting the
networks is also much less than that of the AC transmission lines within them.
In North America, prior to electricity deregulation, regional and local
electric utilities were regulated vertical monopolies. A single company

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 FIG. V-3. Electric grids covering the USA and Canada.

controlled electricity generation, transmission, and distribution in a given

geographical area. Each utility generally maintained sufficient generation
capacity to meet its customers’ needs in its service area, and long distance
energy shipments were usually reserved for emergencies, such as unexpected
generation outages and transmission line failures. In essence, the long range
connections served as insurance against a sudden loss of power. This limited the
use of long distance connections to aid system reliability because the physical
complexities of power transmission rise rapidly as distance and the complexity
of interconnections grow.

V-4. Grid operation

Stability in the grid system is maintained by matching the electricity

generation with the ever changing demand. The electricity from many power
generating stations is ‘pooled’ in the transmission system, and each customer
draws from this pool. Power entering the system flows along all available paths
to the distribution systems. This pooling of electricity also means that power is
provided from a variety of generating stations of different sizes, including
nuclear, coal, oil, natural gas and renewable energy sources such as wind, solar,
biomass and hydropower, which must all be synchronized to the same ‘rhythm’

105
with millisecond accuracy. For a power grid to remain stable, the frequency and
phase of all power generation units must remain synchronous within narrow
limits. A generator that loses synchronism with other generators but stays
connected to the grid will experience large electrical currents, which will lead to
overheating and large mechanical forces that will rapidly destroy the
generator. So protective circuit breakers disconnect (trip) a generator from the
grid when the generator loses synchronism.
Electric power takes the path of least impedance from its source to the
load, which generally means the shortest route but may also include parallel
flow paths through other parts of the system. When a utility agrees to send
electricity to a customer, the utility increases the amount of power generated
while the customer increases its load. The power then flows from the utility to
the customer along as many of the paths that connect them as it needs to make
the trip with the least impedance possible. This means that changes in
generation and transmission at any point in the system will change loads on
generators and transmission at every other point, which is not easily controlled.
To avoid system failures, the amount of power flowing through each trans-
mission line must remain below the line’s capacity. Exceeding capacity can
cause overheating. Overhead lines which overheat will sag, and may cause
electrical flashover to trees or the ground. Underground cables which overheat
can damage their insulation. Exceeding capacity can also create power supply
instability such as phase and voltage fluctuations.
The transmission grid, with multiple generating stations and distribution
system connections, functions as one entity potentially stretching for thousands
of kilometres. The grid must accommodate changing electricity supply and
demand conditions, planned or unexpected outages of generating stations,
transmission lines, and customers, as well as extreme weather conditions. The
balance between electricity supply and demand must be maintained at any time
by increasing or decreasing the output of the operating power plants or turning
power plants on or off. Nuclear power plants are rarely operated in this ‘load
following’ mode. Rather they provide a constant ‘baseload’ supply of electricity
to the grid. Thus having a baseload nuclear plant on a grid means that other
plants must be ‘load following’, i.e. able to increase or decrease their output to
balance changes in electricity demand.

V-5. Interfacing nuclear power plants with electric grids

Both nuclear power plants and electric transmission grids (Fig. V-4) are
fascinating engineering achievements on their own. When they are connected
together in a highly controlled, dynamic and distributed network, further
complexity is created. This complexity of engineered systems is a consequence

106
of several factors: the sheer size and interconnectivity of the electric grid, the
nuclear safety requirements imposed on NPPs, the need to balance electricity
supply and consumption throughout the grid at all times, and the nature of
electricity — that it is generated as it is used. Unlike other commodities, it is
difficult to store electricity. This means the electric grid system requires
continual surveillance and adjustment to ensure supply always matches
demand. Unlike nuclear power plants, the inherent, natural and passive safety
feedback systems based on physical laws are rather weak. Hence electric grids
require continuous control and balancing actions based on engineered systems.
Nuclear power plants are operated usually in baseload mode (i.e. steady
state operation at full power) and less frequently in load following mode. The
integration of large NPPs into an electric grid brings nuclear safety require-
ments that impose additional requirements on the grid design, operation and
stability. Specifically, when NPPs are not generating electricity, they, like other
power plants, still need electricity from the grid to support maintenance work,
operate other equipment, keep the plant ready to restart, and, very impor-
tantly, operate critical safety systems. In NPPs the source of energy (the nuclear
chain reaction) can be turned off in a few seconds. However, significant heat is
still generated from the long term decay of highly radioactive fission products.
This residual heat has to be removed from the reactor core indefinitely in order
to prevent overheating of the reactor fuel and its consequent damage. The
reactor cooling systems must be therefore powered by a long term stable
source of electricity. In addition, to prevent fuel rod damage, sufficient and
reliable power is needed to maintain conditions in the coolant system and
containment and to run vital safety related instrumentation, control,
monitoring and surveillance systems. Electric power is also needed for heating,
ventilation and air conditioning (HVAC) systems used for assuring operable
environments for equipment and personnel. This stable source of power comes
either from the grid (off-site power), or from on-site emergency back-up
power, such as batteries, diesel generators or gas turbines.
The reliability of off-site power is usually assured by two or more
physically independent transmission circuits to the NPP to minimize the
likelihood of their simultaneous failure. Similarly, the reliability of on-site
power is enhanced by sufficient independence, redundancy and testability of
batteries, diesel generators, gas turbines and the on-site electric distribution
systems to perform safety and other functions even if a single failure occurs.
Because of the importance of reliable off-site power as well as considerations
of cost effectiveness and efficiency, the electric grid is an important factor in
NPP site selection, which must take into account the plant’s position within the

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 FIG. V-4. Power lines coming into the Callaway NPP.

grid as well as its proximity to centres of electricity demand, population density

and other factors.
In addition to assuring that the electric grid will provide reliable off-site
power to NPPs, there are other important factors to consider when an NPP will
be the first nuclear unit on the grid and, most likely, the largest unit. If an NPP
is too large for a given grid, the operators of the NPP and the grid may face
several problems.

• Off-peak electricity demand might be too low for a large NPP to be

operated in baseload mode, i.e. at constant full power.
• There must be enough reserve generating capacity in the grid to ensure
grid stability during the NPP’s planned outages for refuelling and mainte-
nance.
• Any unexpected sudden disconnect of the NPP from an otherwise stable
electric grid could trigger a severe imbalance between power generation
and consumption causing a sudden reduction in grid frequency and
voltage. This could even cascade into the collapse of the grid if additional
power sources are not connected to the grid in time.

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V-6. Operational modes of nuclear power plants

Most NPPs are baseload plants operating normally at 100% power.

Startup, shutdown and load changes are very infrequent, usually dictated by
NPP requirements such as refuelling, inspections and internal restrictions.
Baseload operation of NPPs is more economic for the system as a whole
because fuel costs are lower for NPPs than for fossil fuel plants and because
turning NPPs off and on is more complex and expensive than it is for fossil fuel
plants. However, there may be other reasons to consider some operational
flexibility and load following for an NPP. For example, in a developing country
with a small grid, off-peak electricity demand may be too low for baseload
operation, or NPPs may need to do some load following as the share of nuclear
power is increased by additional NPPs coming on line.
NPPs operating in a load following mode can be further divided into two
categories. Firstly, scheduled load following plants that normally operate at
100% power but may, at certain predetermined times, operate at partial power
according to grid requirements. These plants can follow a predetermined daily
pattern, e.g. operating at 100% power for 12 hours, then, over the next three
hours, reducing to 50% power, operating at 50% power for six hours, and then
increasing back up to 100% over the next three hours. Secondly, arbitrary load
following plants that operate in their upper power range and are expected to
meet the daily grid load requirements, including rapid power changes of up to
10% per minute. Some disadvantages of operating NPPs in a load following
mode are that plant components will be exposed to many thermal stress cycles
and that more sophisticated instrumentation and control systems will be
needed. Both add costs.

V-7. Disturbances affecting the interaction between nuclear power plants

and electric grids

Grid interconnectivity and redundancies in transmission paths and

generating sources are key elements in maintaining reliability and stability in
high performance grids. However, operational disturbances can still occur even
in well maintained grids. Similarly, even an NPP running in baseload steady
state conditions can encounter unexpected operating conditions that may cause
transients or a complete shutdown in the plant’s electrical generation. When
relatively large NPPs are connected to the electric grid, abnormalities
occurring in either can lead to the shutdown or collapse of the other.
The technical issues associated with the interface between NPPs and the
electric grid include:

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 • The magnitude and frequency of load rejections and the loss of load to
NPPs.
• Grid transients causing degraded voltage and frequency in the power
supply of key safety and operational systems of NPPs.
• A complete loss of off-site power to an NPP due to grid disturbances.
• An NPP unit trip causing a grid disturbance resulting in severe
degradation of the grid voltage and frequency, or even to the collapse of
the power grid.

V-8. Influence of grid disturbances on nuclear power plants

V-8.1. Load rejection and complete loss of load

A load rejection is a sudden reduction in the electric power demanded by

the grid. Such a reduction might be caused by the sudden opening of an inter-
connection with another part of the grid that has carried a large load. An NPP
is designed to withstand load rejections up to a certain limit without tripping
the reactor. An NPP’s ability to cope with a load rejection depends on how fast
the reactor power can be reduced without tripping and then how fast the
reactor power output can be increased back to the original level when the fault
is cleared. Load rejections of up to 50% are accommodated by a combination
of several actions: rapidly running back the steam turbine to the new lower
demand level, diverting the excess steam from the turbine to the main steam
condenser unit or to the atmosphere if this is permitted by licensing regulations,
and reducing reactor power via insertion of control rods without tripping the
reactor.
A loss of load is a 100% load rejection, that is, the entire external load
connected to the power station is suddenly lost, or the breaker at the station’s
generator output is opened. Under this severe condition, it may still be possible
to ‘island’ the NPP so that it powers only its own auxiliary systems. During this
‘house-load’ operating mode, the reactor operates at a reduced power level
that is still sufficient to assure enough electricity for its own needs, typically 5%
of full power. Once the grid disturbance has been eliminated, the NPP can be
re-synchronized to the grid and its production quickly raised again to full
power. This operational characteristic of the NPP is important when the loss of
load is expected to last for just a short time.

V-9. Degraded grid voltage or frequency

Electric grids are controlled to assure that a particular frequency, either

50 or 60 Hz, is maintained within a small tolerance, typically within ±1%. When

110
the grid develops an imbalance between generation and load, the grid
frequency tends to ‘droop’ if the load exceeds generation and increase if
generation exceeds the load. A reduction in frequency can be caused by several
events, such as insufficient available generation, a major electrical disturbance
such as a circuit fault, or the trip of a major generator unit. A small droop in the
grid frequency caused by the loss of generation can be controlled by:

• Quickly activating the grid’s available ‘spinning reserve’30, either

automatically or manually,
• Starting up additional generation capacity, such as gas turbines or hydro-
electric power, and
• Disconnecting selected loads (i.e. customers) from the grid (load
shedding).

Isolating the section of the grid with the NPP from the rest of the grid
(‘system islanding’) can also help maintain the proper frequency in the islanded
system. System islanding may reduce the load on the NPP, requiring that its
generation be reduced accordingly by a quick set-back to an intermediate
power level. Proper islanding prevents the NPP from tripping because of the
lower frequency, but may further aggravate the power imbalance in the rest of
the grid. A plant trip including reactor shutdown should be regarded as a last
resort. During a trip the plant is subject to rapid changes in power, pressure and
temperature, which shorten the lifetime of the plant. Moreover, if the NPP is
immediately disconnected from the grid, the lost generation will exacerbate the
already degraded conditions on the grid.
Any change in the grid frequency affects an NPP’s operation by changing
the speed of the NPP’s turbogenerator and the speed of pumps circulating
coolants through the reactor and the secondary coolant circuits. The main
reactor circulating pumps, steam generator feedwater pumps and long term
decay heat removal systems rely on stable electric power to function properly.
The speed of the reactor’s main coolant pumps is directly proportional to the
frequency of the electric power supply. Therefore, if the frequency of the power
from the grid drops far enough, the pumps will slow, which will lead to
inadequate core cooling, and the reactor will trip.
Other AC motors in the NPP may also trip due to rising currents and
consequent overheating caused by reduced frequency. The performance of AC

30
Spinning reserve is any unused capacity that is already connected and synchro-
nized to the grid (‘spinning’) and can be activated immediately on the decision of the
grid operator, reaching its full capacity within ten minutes.

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motors is directly affected by the voltage and frequency of their power supplies.
If electric grid voltages are not sufficient, motors cannot develop sufficient
motor torque to start, and if the frequency drops below a certain value, the start
and operation of AC motors would require higher operating voltages. If the
voltage is insufficient, it results in excessive current being drawn by the motor
that in return would lead to overheating and the opening of protective
breakers.
The frequency and voltage ranges in which large AC motors can operate
are relatively narrow. Thus, in severely abnormal conditions, safety systems in
nuclear power plants are required to take protective actions such as tripping
the reactor and turbine, separating the plant electrical systems from the
degraded conditions present on the grid, and switching to on-site emergency
power sources until the grid voltage and frequency are restored to acceptable
values. These actions protect the NPP by safely shutting it down and keeping it
cooled. However, any sudden automatic shutdown of a large baseload nuclear
unit during periods where there is already a mismatch between generation and
load on the grid can only further degrade the grid’s condition, potentially
leading to a partial or full collapse.

V-10. Loss of off-site power

Any loss of off-site power would be caused by external events beyond the
NPP’s switchyard, such as transmission line faults and weather effects like
lightning strikes, ice storms and hurricanes. A loss of off-site power interrupts
power to all in-plant loads such as pumps and motors, and to the NPP’s safety
systems. As a protective action, safety systems will trigger multiple commands
for reactor protective trips (e.g. turbine and generator trip, low coolant flow
trip, and loss of feedwater flow trip). The reactor protection system will also
attempt to switch to an alternate off-site power source to remove residual heat
from the reactor core. If this fails, in-plant electrical loads must be temporarily
powered by batteries and stand-by diesel generators until off-site power is
restored. However, diesel generators may not be as reliable as off-site power
from the grid in normal conditions. Diesel generators may fail to start or run
1% of the time. However, the probability of failure can be significantly reduced
by installing independent trains of diesel generators. Batteries can provide
power only for a limited time.

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V-11. Influence of NPP disturbances on the grid

V-11.1. Trip of an NPP causing degraded grid frequency and voltage

Even at steady state conditions, when the generation and loads on a grid
are in balance, if a large NPP (e.g. 10% of the grid’s total generating capacity)
trips unexpectedly, the result can be a significant mismatch between generation
and load on the grid. Unless additional power sources are quickly connected to
the grid, this can degrade the grid’s voltage and frequency and thus the off-site
power supply to the NPP. As discussed in Section G.1, degraded voltage and
frequency on the grid can potentially result in the NPP protection system
disconnecting the degraded off-site power to the NPP. This will force the NPP
to switch to on-site emergency power to run safety and core cooling systems
until off-site power is restored. This should be done as soon as possible for
safety reasons: the possible concurrent failure of the NPP’s on-site power
system and delayed recovery of off-site electric power would make it nearly
impossible in most NPPs to cool the core, a situation that must be avoided
under all conditions. The introduction of new reactor designs that use passive
cooling would alleviate this problem. Therefore, in unreliable grid systems, it is
recommended to consider NPP designs with passive safety systems.
The grid’s response over time to the sudden loss of the NPP can be
modelled by computer simulations, conditioned by the capacity and intercon-
nectivity of the grid and the size of the lost NPP generation, as well as the
timing of switching additional power sources to the grid. Large interconnected
electric grids can usually meet the requirement of providing reliable off-site
power to NPPs connected to the grid. However, in some scenarios involving
poorly interconnected or controlled electric grids, the sudden shutdown of a
large NPP, or any other large generating station elsewhere on the grid, might
result in severe degradation of the grid’s voltage and frequency, or even to the
collapse of the overall power grid. Similarly, when an NPP is sited on a well
maintained but small and isolated grid of limited generating capacity (e.g. on an
island), the sudden loss of its generation may lead to the same outcome.
Complex computer models are used to decide whether the loss of the
largest operating unit on the grid could result in the loss of grid stability and of
off-site power. In simulation studies, the consequences of various single faults
(e.g. the sudden loss of key transmission lines or a power generating unit) are
explored. The output of the simulations provides the time dependent response
of the grid (in terms of voltage and frequency) to the event, including
protective actions, such as automatic load shedding, emergency disconnects
and starting up additional power sources that can start quickly.

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 Results show that isolated grids are inherently less stable than equivalent
grids of the same size with supporting grid interconnections. Therefore the
design and licensing basis for ‘poorly sited’ NPPs should include provisions for
more reliable on-site power, i.e. additional capacity for the on-site power
system beyond the normal requirements (e.g. more diesel generators and fast-
starting gas turbine engines). This would compensate for less reliable off-site
power by providing more reliable on-site power, and it would assure that the
degradation or collapse of the grid would not make an NPP’s decay heat
removal systems inoperable.

V-12. Conclusions

As noted at the outset, countries expanding or introducing nuclear power

programmes are advised to consider their electric grids as part of their planning
process:

• The electric grid should provide reliable off-site power to NPPs with a
stable frequency and voltage.
• Any potential lack of reliability in off-site power from the grid must be
compensated for by increased reliability of on-site power sources.
• Enough reserve generating capacity should be available to ensure grid
stability to replace NPP generation during planned NPP outages.
• The grid should also have a sufficient ‘spinning reserve’ and standby
generation capacity that can be quickly brought online in case the NPP
were to be disconnected unexpectedly from the grid.
• The off-peak electricity demand should preferably be large enough for
the NPP to be operated in a baseload mode at constant full power.
• If there is any possibility of the NPP being operated in a load following
mode, any additional design requirements to ensure safe load following
operation should be discussed in advance with the NPP designer or
vendor company.
• If baseload operation will not be possible, the NPP should have additional
design margins to compensate for the increased exposure to thermal
stress cycles, and more sophisticated instrumentation and control systems.
• The national grid should have enough interconnections with neigh-
bouring grids to enable the transfer of large amounts of electricity in case
it is needed to offset unexpected imbalances of generation and demand.
• In preparation for the introduction of an NPP, if grid reliability and the
frequency and voltage stability of the existing grid are insufficient, they
should be made sufficient before the NPP is brought online. Any

114
 improvements will not only allow the grid to incorporate the new NPP
but will have additional benefits for all customers and other generators.
• Communication is critical, in this case between the NPP operators and
grid dispatchers. Effective communication protocols will need to be
developed.

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 Annex VI

SEEKING SUSTAINABLE CLIMATE, LAND, ENERGY

AND WATER (CLEW) STRATEGIES

VI-1. Introduction

Given growing global demands, the world’s resources of water, land and
energy are relatively scarce; the use of each affects demand for the others; and
the use of all affects the climate. There are 1.1 billion people without safe water
and 1.6 billion without electricity [VI-1]. The need for more cultivated land
drives deforestation. Energy prices are high, and anthropogenic greenhouse
gas emissions (GHGs) continue to rise. High oil prices in turn mean high
transport costs. Those, together with biofuel crops competing with food crops
for land, recently caused food prices to spike beyond the reach of many of the
world’s poor — a trend some analysts do not see abating [VI-2].
These interdependencies mean that energy policies based on energy
analyses alone, for example, might have adverse unanticipated effects on water
resources, land resources and the climate. The same is true for water policies
based only on analyses of water issues, and for land policies based only on land-
use analyses. Better methods and models are therefore needed that consider all
the linkages among climate, land, energy and water (CLEW). This annex
analyses that need by reviewing the models available today, by summarizing
examples where they fall short, by reviewing the history and remaining
challenges of ‘systems approaches’, and by outlining a way forward.
The specific focus is on the expansion of a systems approach to underpin
the analysis of sustainable development with an emphasis on CLEW resources.
Analyses of individual systems such as energy and water systems are
undertaken routinely. The IAEA provides and supports detailed analyses of a
country’s or region’s energy system with the MESSAGE model31. A commonly
used model for water planning is the Water Evaluation and Planning system

31
MESSAGE (Model of Energy Supply Systems and their General Environ-
mental Impacts) is a systems engineering optimization model which can be used for
medium to long term energy system planning, energy policy analysis and scenario devel-
opment. The model provides a framework for representing an energy system with its
internal interdependencies [VI-3].

116
(WEAP32), and for water scarcity and food security planning, the Global Policy
Dialogue Model (PODIUM) is well established33. However, these and other
models are, in one way or another, all lacking, especially if one wants to use
them for policy analysis for developing countries. Generally, they either focus
on one resource and ignore interconnections with other resources, have overly
simplified spatial representations or analyse scenarios which are impractically
long term.
What is needed is an integrated analysis tool that includes all CLEW
aspects in a manner that is accessible and useful to analysts and planners in
developing countries. Key improvements over existing approaches should
include: finer geographical coverage, simplified data requirements, a medium
term temporal scope, multi-resource representation (including their inter-
linkages) and software accessible to developing country analysts. Such a tool
would help decision makers assess different technological options with diverse
benefits and disadvantages; estimate the impacts of different development
scenarios; and analyse and evaluate policies.
The IAEA is ideally suited to develop such an integrated tool by virtue of
its expertise in a number of key areas, such as energy systems planning34, water
resources and isotope hydrology35, nuclear desalination36, and food and
agriculture in cooperation with the FAO37. The Agency also has a strong
mandate as part of the UN system to support Member States, through its
technical cooperation programme38, in their development and implementation
of strategies for sustainable development. In particular, Member States have
clearly and frequently articulated their concerns about sufficient water
supplies, food security and energy security39. However, the IAEA’s current
assistance is necessarily limited and compartmentalized. An effort such as this
will help better meet the needs of Member States, drawing on significant
existing in-house capacity. Further, it is envisaged that after initial incubation of

32
The WEAP energy model is maintained and supported by the Stockholm Envi-
ronmental Institute: http://www.weap21.org/
33
PODIUM is maintained and supported by the International Water Manage-
ment Institute http://podium.iwmi.org/podium/
34
http://www.iaea.org/OurWork/ST/NE/Pess/
35
http://www.iaea.org/programmes/ripc/ih/
36
http://www.iaea.org/OurWork/ST/NE/NENP/Desalination/
37
http://www-naweb.iaea.org/nafa/index.html
38
http://wwwtc.iaea.org/tcgc/gc/gcstart.html
39
See for example the recently completed Country Program Framework (CPF)
of Cameroon, 2009–2013, and others.

117
the concept within the IAEA, consultation with other experts and agencies in
the UN system will take place.
The next section briefly summarizes key past examples of related
modelling efforts, presents some motivating examples of uncoordinated devel-
opment, and introduces the challenges faced by policy makers. The subsequent
sections discuss aspects of the CLEW system and suggest a simple integrated
framework and goals for a systems tool.

VI-2. Modelling the CLEW systems

While the proposed tool will be unique and designed specifically to better
meet the needs of IAEA Member States, it will build on previous work and an
established methodological approach.
The most famous systems analysis to address some of the CLEW issues
was the study The Limits to Growth40 in the early 1970s [VI-4]. While providing
important insights, the analysis was of little use to national policy makers
because it had a very coarse geographical resolution in that it modelled the
world as a whole, rather than a country or local area; it did not account for
changes in technology, knowledge or behaviour; and it did not account
adequately for the effects of price changes. A second approach, developed
around the same time to analyse the provision of energy services, focused on
five connected resources: water, energy, land, materials and manpower
(WELMM) [VI-5]. However, this approach was never developed into a
manageable software package that could be used by national analysts.
Since then a large range of planning models, which, to lesser or greater
extents, overcome those limits, have been developed and applied regularly.
However, these are generally focused only on a single resource, such as water,
land or energy41. Integrated assessment models attempt to include more
aspects of the CLEW system, but these are aggregate, focused at the global or
regional level, and often designed for long term analysis. They are not useful
for medium term national analysis42. Further they can be limited by requiring
data and computational support beyond the reach of local analysts in some
developing countries.

40
In 1981, another global study, focused specifically on energy issues, was
published by the International Institute for Applied Systems Analysis (IIASA) under
the title Energy in a Finite World [VI-6].
41
A notable exception is the (albeit limited) combined energy and water
planning being undertaken within certain US districts [VI-7].
42
Examples include MINICAM [VI-8], IMAGE [VI-9] and TIAM [VI-10].

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 The ‘systems approach’ referred to in this annex is extensively used
(although its application to CLEW is still missing). It refers to a physical
accounting of resource, technology and other requirements to meet certain
needs and services, with the accounting extended far upstream. For example,
water, crop, fertilizer and land requirements can be calculated for a given food
production level. Each of these inputs in turn requires its own inputs, which are
also accounted for. Fertilizer, for example, requires transport and production,
both of which require energy, water and technologies and emit greenhouse
gases. In turn, those energy and water inputs are associated with their own
inputs, technologies and emissions, etc. The accounting continues until satis-
factory estimates of resource and other needs, as well as impacts, are calculated.
In some instances, the proposed development path may prove to be limited by
resource constraints, in which case an alternative can be investigated.
At each step in the systems approach, costs can be calculated, and a
systems model can be programmed to identify which development path, given
various constraints, is the most economic.

VI-3. Notable examples of CLEW challenges

The following examples of interconnected CLEW relationships highlight

the need for integrated planning to meet energy, water and land related service
requirements.

• Punjab has only 1.5% of India’s land, but its output of rice and wheat
accounts for 50% of the grain the Government purchases and distributes
to feed more than 400 million Indians. The problem is that farmers are
pumping (‘mining’) aquifers faster than they can be replenished, and, as
water levels drop, increased pumping is sapping an already fragile and
overtaxed electricity grid. Moreover, because farmers in Punjab pay
nothing for electricity, they run their pumps without stopping. This both
further depletes the water table and, as water is pumped from ever
increasing depths, requires ever more electricity to maintain a constant
level of irrigation water [VI-11]. Overall, irrigation accounts for about 15–
20% of India’s total electricity use [VI-12]. The Government recognizes
that all these issues are interconnected, but the planning does not.
• The United Nations Environment Programme (UNEP) expects the
frequency of weather and climate extremes in Colombia to increase by
2050 [VI-13]. Regional impacts will include: changes in the composition
of ecosystems and biome distribution; reduced water availability and
hydropower generation; increasing desertification; aridity; crop pests and
diseases. Colombia will face hydropower shortages caused partly by

119
 increased El Niño events, which will force a further reduction in agricul-
tural activity and, possibly, the future import of fuels for electricity
generation. Such fuels are expensive, and, particularly in a volatile
market, increased imports reduce the country’s energy security.
• Uncoordinated development efforts in Uganda have slowed development
and increased environmental stresses. Limited access to electricity (only
9% of Ugandans have electricity access) is a major drag on development,
and major environmental problems include overgrazing, deforestation,
and (often) low productivity agricultural methods, all of which lead to soil
erosion. 93% of the country’s energy needs are supplied by wood. The
resulting deforestation is a severe problem, although its pace has slowed
significantly, from a 67% loss of forests and woodlands between 1962 and
1977 to a 7.7% loss between 1983 and 1993. Wetlands have been drained
for agricultural use, and the nation’s water supply is threatened by toxic
industrial pollutants. Mercury, for example, from mining has been found
in the water supply. Roughly 20% of the urban population and 53% of the
rural population do not have access to pure drinking water [VI-14].
Development is essential; coordinated development, urgent.
• South Africa is a semi-arid country. Ninety per cent of the country lies
within arid, semi-arid or dry sub-humid zones. Yet the country is of key
importance to Africa and its development. South Africa is the continent’s
largest exporter of agricultural products [VI-15] and requires large
quantities of electricity to pump irrigation water. In addition, South
Africa is a major electricity exporter, supplying over 40% of Africa’s
electricity. It is also an important exporter of international commodities,
such as coal and gold, both of which consume substantial electricity in
their production. But development is being retarded by inadequate
investments in new electricity generating capacity. This supply shortage is
estimated to cost the region billions of dollars as power shortages affect
the international supply of commodities. Shortages in 2007, for example,
forced gold prices to increase globally by 5% [VI-16]. As this was a result
of a cost increase (rather than a demand increase), higher prices are likely
to reduce sales and profit. Further, any increases in power supplies will
require more water. Thus, if such increases are not coordinated with
policies concerning other water uses, they may decrease water availability
for such uses, including agriculture. On the other hand, expanding the
cultivation of marginal lands for maize, together with overharvesting of
fuel wood by the poor, are important causes of accelerated desertifi-
cation. To address all of these issues, an integrated approach is clearly
required.

120
 • Global grain prices are volatile. Recent spikes were caused by many
factors, including increased prices for fuel and thus transport, increased
demand for biofuels driven by energy security and climate change
concerns43, as well as changing diets in populous fast growing developing
countries. Diets that include more meat and more calories require
substantially more land, both for livestock and for feed production.
Increased feed production requires additional fertilizer and irrigation.
Both fertilizer and irrigation (pumping) require energy, and if that energy
is fossil fuel based, GHG emissions will increase. Moreover, as the
demand for food, feed and biofuel grows, and as food requirements grow,
so does the competition between the two for land. Similarly, there is
competition between biofuels and food for fresh water and for fertilizers,
especially as more marginal land is cultivated. Important positive impacts
of increased biofuel production might include much needed economic
opportunities for farmers and countries trapped by economic barriers. On
the negative side it may cause short term opportunism, such as unsus-
tainable clearing of forests for extra farmland, which may have long term
consequences. Sorting out all the interconnections to provide useful
insights for policy and decision makers requires better integrative
analytical methods than are available today.

VI-4. Decision making and analysis

The intricate links among energy, water, land use, climate and other
features of the environment, have been well documented for a long time, but
governmental administrative structures tend to keep the management and
development of these sectors separate from one another. Different ministries
are usually responsible for energy, water and land, and any one of these is
sometimes sub-divided among different administrative entities. For example,
the responsibility for land use planning may be distributed among separate
departments handling agriculture, forestry and urban development. As a result,
there can be a lack of broad coherence, and, at times, decisions by one ministry
or department can conflict with the objectives of others. Public policies can,
therefore, be inadequately connected or researched. Energy supply options
might be discussed with little reference to their water demands; water

43
The actual impact of biofuels on climate change can be negative as well as
positive, depending on the resulting land-use changes, and production, harvest and
conversion methods. The need to analyse all these factors together reinforces the need
for better methods and models that consider all the linkages among CLEW factors.

121
management options can be proposed without assessing their impacts on energy
needs; land use development might be planned without thoroughly considering
implications for energy and water; and the consequences for all these areas
could be insufficiently considered in the light of longer-term climate policies.
A method for integrating local and national assessments would signifi-
cantly improve information flows, and harmonize different departmental data
collection, decision and policy making activities. Some assert that such a
method is essential and that without such an integrated systems analysis tool,
development, planning, policies and therefore development will not be sound
and sustainable [VI-17 and VI-18].

VI-5. Goals

Given the desirability of a CLEW analysis and planning tool, it is

important to clarify what the output of the tool should be. First, it should
simulate, or account for, the CLEW system interactions both now and in the
future. The primary target for its application should be developing Member
States, and thus the tool should calculate the resource and service requirements
to meet socio-economic goals — such as the Millennium Development Goals —
in a growing economy. Thus, the tool should simulate important interactions
within the CLEW system to meet energy, water and food related service
demands, within constraints imposed by the physical and economic environ-
ments. In order to do this, a clear mapping should be made of relations within
the CLEW system, and between it, other important resources and the economy.
In addition to incorporating such a mapping and quantification of key
relationships, the tool should be designed for use in the following applications.

• Decision making: A well formulated integrated CLEW tool would help

decision and policy makers assess options in terms of their likely effects
on the broad CLEW system. The tool should be able to transparently
evaluate the trade-offs reflected in different options.
• Policy assessments: Given limited resources, it is important for policy
makers to ensure that policies are as cost-effective as possible. If multiple
objectives can be achieved by a single policy, it may advance development
more than policies focused separately on single objectives44. A CLEW

44
See, for example Ref. [VI-19], which shows how different industrial energy effi-
ciency options could affect water use, employment, GHG emissions and energy invest-
ment requirements. Analyses that consider the multiple benefits of each option will
yield better estimates of the overall development potential of each.

122
 tool should therefore provide a more complete, multi-system policy
assessment.
• Facilitating policy harmonization and integration: In the examples in
Section B.1 there are instances of very contradictory policies, e.g.
electricity subsidies that accelerate aquifer depletion, which in turns lead
to greater electricity use and subsidy requirements. A CLEW tool would
help harmonize potentially conflicting policies.
• Technology assessments: Some technology options can affect multiple
resources, e.g. nuclear power could reduce GHG emissions and reduce
the exposure to volatile fossil fuel markets. Although it would use water
for cooling, nuclear power can generate electricity for seawater desali-
nation. As with policies, a CLEW tool should allow a more inclusive
assessment of technological options.
• Scenario development: Another goal is to elaborate consistent scenarios
of possible socio-economic development trajectories with the purpose of
identifying future development opportunities as well as understanding
the implications of different policies. This is important for understanding
whether current development is sustainable, and for exploring possible
alternative development scenarios and the kinds of technology improve-
ments that might significantly change development trajectories.

VI-6. Developing a CLEW system analysis framework

This section provides an initial outline of a CLEW system. It provides

only an indication of substantive interactions in the CLEW system, which are
represented in simplified aggregate reference system diagrams (RSDs). This
initial attempt is meant to provoke future quantitative investigations, and many
aspects are therefore deliberately aggregated.

VI-6.1. Energy

An aggregate simplified RSD featuring the energy segment of a CLEW

tool is shown in Fig. VI-1. Figures VI-2–VI-4 will focus on the water, climate
and land use segments.
Primary energy (on the left of Fig. VI-1) is needed to provide energy
services (on the right of the figure), such as lighting, cooking, heating and

123
 FIG. VI-1. Aggregate reference system diagram: energy.

motive power. Primary energy is extracted from renewable or depletable

resources45. Extraction, whether from wind farms or mines, scars and requires
land46. Biofuel production requires water47 and cultivable land48, thereby
reducing their availability for other activities. Often biomass collected for fuel
wood in poor regions with growing populations contributes to deforestation
and land degradation.
After energy is extracted, it is processed into forms which are easier to
use or transport. For hydropower, electricity is generated from run of river
turbines or water stored in reservoirs. This can require the use of large land
areas and the significant alteration of water flows. Where vegetation is flooded,
it will decompose and release GHGs such as methane. For other energy sources
electricity and heat are the most common forms in which energy is transported
or used. Crude oil, biofuel feedstocks, coal and natural gas can also be
transformed into petroleum products and other liquid fuels.

45
Note that where a renewable resource such as fuel wood is consumed faster
than it is regrown, it is also in a sense depletable, especially where land is damaged due
to overuse.
46
A 60 MW(e) solar thermal power plant, for example, requires about 1 square
kilometre of land [VI-20], and more land might be required to provide back-up power to
augment the intermittent nature of solar energy.
47
The biofuel feedstock maize, for example, needs about 860 litres of water to
produce one litre of ethanol.
48
For example, over 3000 square kilometres of land can be required to produce
18 million tonnes of the biofuel, palm oil, annually [VI-21].

124
 Generally, primary fuel extraction, fuel processing49 and electricity
generation require large amounts of cooling water50. The combustion of fossil
fuels commonly releases GHGs such as CO2.
Fuels are then transported, distributed and converted into the energy
services mentioned earlier. Conversion devices range from the simple to the
complex, for example from appliances (like a kettle) to equipment (like a
compressor) to more complex technologies (like an automobile). Energy
services are important in all socio-economic sectors. For integrated CLEW
analyses, noteworthy energy services include the transportation of biofuels and
crops, pumping of water for irrigation, and energy consuming chemical
processes for manufacturing fertilizer. In most cases, GHGs and various
pollutants are emitted either directly if non-renewable fuels are burned, or
indirectly if they are burned to produce the fuel that is used to produce the
energy service.

VI-7. Water

An aggregate simplified RSD featuring the water segment of a CLEW

tool is shown in Fig. VI-2.

FIG. VI-2. Aggregate reference system diagram: water.

49
According to the United States Bureau of Land Management, surface mining
and retort operations produce 8–38 litres of wastewater per tonne of processed oil shale
[VI-22]. Similarly, an estimated three barrels of water are required per barrel of oil
equivalent of tar sands.
50
In the face of water shortages in dry areas, special technologies have been
developed to reduce water use by about 60% in steam cycle thermal power plants [VI-23].

125
 Water, like energy, provides a number of essential services. Broadly
speaking, there are three water sources: the sea, local precipitation and aquifers
(or ‘fossil water’). Seawater can be desalinated using energy for evaporation or
reverse osmosis. Local precipitation fills river basins and lakes with fresh water,
and fossil water can be mined. Where water supplies are far from demand,
water is pumped or fed to users via canals or pipes and can be stored in
reservoirs. When aquifers are depleted faster than they are replenished, their
levels will drop, and more pumping (and therefore fuel) may be required to
supply the same amount of water. Such pumping can be an extensive user of
energy51.
In the power sector, thermal power plants52 use large amounts of water
for cooling — much of which is lost to evaporation. Hydropower plants use
significant quantities of land53 and interfere with existing water flows, changing
silting patterns in river basins54. Significant quantities of water are also required
for other energy processing activities, such as refining oil products or manufac-
turing synthetic fuels55. However, new ‘dry cooling’ technologies offer reduced
water consumption in many activities which use water for cooling.
Water has a particularly important role to play in agriculture. In arid
developing countries, irrigation can account for as much as 90% of total water
use [24], and irrigation together with sufficient nutrients can transform
marginal land to cultivable land (although overfertilization and irrigation can
also damage land). Irrigation can be gravity driven but increasingly requires
energy for pumping.

51
In California, for example, up to 3.5 kW·h per 1000 litres can be consumed
supplying water. More energy can be required for local irrigation and treatment [VI-25].
52
 The US Geological Survey [VI-26] estimates that over 50% of freshwater with-
drawals are for cooling thermal power plants, with the majority of that water returned to rivers,
lakes or the ocean after use.
53
The large land requirements of hydropower can require the relocation of activ-
ities and people. Over a million people, for example, had to be relocated because of the
Three Gorges Dam Project [VI-27].
54
Damming the Nile River, for example, caused the silt which was deposited in
the yearly floods and made the Nile floodplain fertile to be deposited behind the dam.
This lowered the water storage capacity of Lake Nasser. Poor irrigation practices further
waterlog soils and bring the silt to the surface.
55
In New Mexico, for example, refineries currently use 50–180 litres of water per
barrel of crude oil and generate 30–120 litres of wastewater [VI-28].

126
 After use, water has a high potential for purification and recycling, which,
however, require energy56.
As available water can be scarce, its management to reduce evaporation
can be important. Thus low evaporation storage, drip irrigation, recycling,
‘grey’ water use, and other techniques and technologies are important in
improving the efficiency of the water system.
Finally, water is returned to the atmosphere via evaporation and transpi-
ration, with the greatest quantities released by evaporation from the ocean.

VI-8. Climate and weather

An aggregate simplified RSD featuring the climate segment of a CLEW

tool is shown in Figure VI-3.
The climate is affected by releases of GHGs from anthropogenic
activities57 such as fossil fuel power production, fertilizer production and use,
crude oil and biomass refining, transport and land cultivation [VI-29]. Fossil
fuel combustion accounts for the bulk of emissions58.
There is a significant drive to adopt energy technologies which mitigate or
reduce the quantities of CO2 emitted. Examples include nuclear energy and
renewable energy such as hydropower, wind power and biofuels (such as diesel
or ethanol produced from crops). Other methods of reducing CO2 emissions
include sequestering CO2 in forests and the future use of CO2 capture and
storage technologies.
With changes in the climate come changes in weather patterns. When
droughts occur, water for electricity generation is limited, irrigation demands
increase and desertification can take place. Conversely flooding can damage
crop land, infrastructure and human settlements.

56
For example, the energy required in California to treat wastewater for reuse
ranges between 0.1 and 4.0 kW·h per 1000 litres [VI-25].
57
Important contributors to anthropogenic releases include burning fossil fuels,
land use, land use change, forestry, cement production, waste water processing, natural
gas flaring and chemical processes and products [VI-30].
58
The IPCC estimates that CO2 from energy use accounted for 56% of global
GHG emissions in 2004. Power generation accounted for 30.5% of total CO2 emissions
and transport for 17% [VI-31].

127
 FIG. VI-3. Aggregate reference system diagram: climate.

VI-9. Land

An aggregate simplified RSD featuring the land segment of a CLEW tool

is shown in Fig. VI-4.
Land that has the potential for cultivation can be classified into four
categories: deserts, marginal land, cultivable land and forests or other natural
vegetation such as savannahs. The quantity of cultivable land increases as
either forests are cleared or marginal lands and deserts are made cultivatable
by irrigation and fertilization.
The quantity of available land is limited. Thus, depending on the value of
what it can produce, competition among alternative uses can be high. Typical
land uses include habitation (such as in towns and cities), grazing of livestock,
crops for food, biofuel and other products, fuel wood and infrastructure such as
roads, cities, canals and dams. Where practices are poor, land can be damaged

FIG. VI-4. Aggregate reference system diagram: land.

128
by overgrazing, overcropping and fuel wood harvesting. As vegetation changes,
e.g. as dense forests, which contain substantial carbon in wood, are cleared for
crops, significant amounts of carbon can be released to the atmosphere. Land
can also be damaged through excessive silting and erosion related to
agriculture and weather patterns. Depending on the crop, annual rainfall and
quality and type of soil, different amounts of irrigation, fertilizer and land are
required, with the production of each of these inputs having important impacts
in turn, for example increased energy use and associated emissions.

VI-10. Towards a CLEW system representation

Figure VI-5 combines Figs VI-1–VI-4. The result is an initial simplified

single CLEW reference system diagram (RSD).
The RSD is a useful tool for visualizing relations which need to be
represented by simplified mathematical expressions. Each line represents a
‘flow’ and each box an activity, or group of activities, that change various flows.
This approach is common, particularly in energy modelling where the RSD is
known as a reference energy system (RES).
Once the flows, activities and their linkages are defined, the levels of each
flow need to be calibrated in terms of physical quantities, and the activities

FIG. VI-5. Aggregate CLEW reference system diagram.

129
need to be calibrated in terms of their historical capacities (where systems of
equipment are used), operational costs, investment costs, and technical charac-
teristics (such as their efficiencies). Each system should meet a range of
demands for services as an economy, or population, grows. However, flows and
activities may be limited by physical or financial limits, and there may be
restricted interactions between the demands for services and the manner in
which they are provided. For example, a computer can be run only on
electricity, not coal. Taken together and further developed, the set of relation-
ships in a CLEW reference system can be implemented in a software tool and
used to determine scenarios of how future needs can be met within the
constraints inherent in the system.
This discussion provides only an outline of selected features of a CLEW
tool. The final section addresses possible next steps and the unique role that the
IAEA could play, within the family of UN organizations, in the development
and application of such a tool.

VI-11. IAEA services

The UN has a broad mandate to help its Member States develop

sustainably. It has adopted the Millennium Development Goals (MDGs) in the
short term with the objective of meeting these goals by 2015. The commitment
to sustainable development, however, reaches far beyond the MDGs. As an
organization within the framework of the UN, the IAEA has a unique capacity
to further contribute to these aims and support Member States and other
agencies once a CLEW tool is available. The MDGs, and sustained longer term
development, require services which all draw on the CLEW system either
directly or indirectly. Without efficient policy design informed by a CLEW tool,
development may be retarded.
The IAEA has a specific mandate to efficiently meet the needs of its
Member Sates. The concerns of developing Member States include the
provision of clean water, energy security and food security. Through its own
mandate to promote the peaceful use of nuclear technologies and techniques,
the IAEA currently supports many projects on energy planning, nuclear desal-
ination modelling, isotope hydrology and, through a joint Division with FAO,
crop improvement. These services are provided to Member States through the
IAEA’s technical cooperation programme. The initial incubation of, eventual
application of and training on a CLEW tool would form a very natural
extension of these services.
Further, it is envisaged that after initial incubation of the concept within
the IAEA, consultation with other experts and agencies in the UN system will
take place.

130
VI-12. Conclusion

A tool to assess the interrelated aspects of climate, land, energy and water
(CLEW) is definitely needed. This is essential in the context of sustainable
development, the key challenge for the coming decades. Moreover, in order to
meet growing demands for energy, water and food services, the CLEW system
needs to be managed. Although the components of the CLEW system are
closely interrelated, decision and policy making for each component usually
take place separately. This can result in suboptimal resource allocations,
counter-productive policies and, at worst, accelerating long term unsustainable
development. Particular attention needs to be given to apparently short term
gains which undermine longer term development opportunities.
A CLEW system would be a valuable addition to the IAEA suite of
energy analysis and planning tools, especially for comparative technology and
policy assessments, policy harmonization and designing and testing future
scenarios of development. The IAEA provides an ideal setting to incubate a
pre-prototype of a CLEW modelling tool. This tool could contribute to
stimulating integrated CLEW analysis and planning in Member States and to
supporting the achievement of broad UN development goals, and it could
provide a natural and useful extension of current IAEA technical cooperation
activities.

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