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OUTLINE Nuclear Energy
Part 1 - Nuclear Energy Review on Atoms
Lesson 1.1 : How Nuclear Energy is
Atoms are tiny particles in solid, liquid and gas,
generated
consisting of protons, neutrons, and electrons.
review on atoms
Protons and neutrons, which have a positive
History of Nuclear Power
electrical charge, that make up the nucleus.
Nuclear Reactions Neutrons are not negatively charged, but
Importance of Nuclear Energy electrons are. The bonds that keep the nucleus
Lesson 1.2 : Nuclear Energy Production together contain an enormous amount of
The Process of Nuclear Fission energy that may be released by nuclear fission
Uncontrolled Fission Reaction to create electricity.
Controlled Fission Reaction
Lesson 1.3 : Types of Nuclear Reactors
Pressurized Water Reactor
Boiling Water Reactors
Nuclear energy
is a powerful source of energy, generated
Part 2 : Nuclear Wastes
during a nuclear reaction, by change in the
Lesson 2.1 : Radioactive Wastes nucleus of an atom. The source of nuclear
Lesson 2.2 : Environmental Impact of energy is the mass of the nucleus and energy
Nuclear Energy generated during a nuclear reaction is due to
Lesson 2.3 : Radioactive Waste conversion of mass into energy. (Einstein's
Management Theory, 1905).
HISTORY
INSTRUCTOR: Uranium was discovered in 1789 by Martin
Klaproth, a German chemist, and named after
ENGR. NENITA R. VALENCIA
the planet Uranus.
PRESENTED BY:
ASIS, KOBE J.
German scientists, 1938, Otto Hahn and Fritz
ESGUERRA, CATALINO
Strassmann discovered that when uranium
MARIÑO, MARL CHRISTINE atoms were bombarded with neutrons, the
NOLASCO, LEONARD uranium split into smaller elements like barium,
SAMONTE. JAMES CARLO L. about half the mass of uranium. This splitting
SIAPNO, JEMOULE MIKHAIL S. process is known as atomic fission.
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Physicist Lise Meitner and her nephew Otto Types of Nuclear Reactions:
Frisch, building on this work, proposed that Nuclear Fission
when a neutron hits the uranium nucleus, it Nuclear Fusion
causes the nucleus to wobble and break into Nuclear Decay
two uneven parts. They calculated that this Transmutation
fission process released a huge amount of 200
million electron volts of energy. Additionally, the Nuclear Energy
process released extra neutrons, which could Nuclear Energy Production
hit other uranium atoms, potentially triggering a
self-sustaining chain reaction, releasing even unstable radioactive nuclei emit strong
more energy. radiations like the isotope uranium-238 or
uranium-235. The disintegration converts the
Niels Bohr suggested that fission was more uranium isotope into stable lead and in the
likely to happen in the uranium-235 isotope, process emits energy in the range of 1-5 mega
rather than the more common uranium-238. He electron volts(MeV), that’s 1-5 million electron
also pointed out that slow-moving neutrons volts and even higher amounts of energy can
were more effective at causing fission than fast be released by breaking unstable nuclei into
ones. even more parts.
Meanwhile, in Germany, physicist Werner Nuclear Fission
Heisenberg was overseeing a nuclear energy when nucleus of uranium-235 is
project, initially aimed at military applications. bombarded with neutrons it will absorb one
By the end of 1939, he had calculated that of the neutrons this will result in an unstable
nuclear fission chain reactions were possible. If compound nucleus and the nucleus breaks
these reactions could be controlled in a into two equal parts
"uranium machine" (now known as a nuclear a process in which heavy nuclei are
reactor), they could generate energy. If left bombarded with neutrons and split into two
uncontrolled, they could lead to an explosion equal masses releasing enormous amounts
far more powerful than any conventional bomb. of energy
Nuclear Reactions
The reaction that involves the change in the
identity or characteristics of an atomic nucleus,
induced by bombarding it with an energetic
particle. The bombarding particle may either be
an alpha particle, a gamma-ray photon, a
neutron, a proton, or a heavy ion.
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The Process of Nuclear Fission Uncontrolled Fission Reaction
uranium-235 initially absorbs a slow moving In the fission of 235U by slow neutrons, each
neutron, thus forming a highly unstable reaction releases three additional neutrons,
compound nucleus uranium-236. which can then trigger further fission events.
This leads to a second stage, where nine
uranium-236 splits into two product nuclei, neutrons are produced, followed by a third
which are barium-141 and krypton-92. notice stage generating 27 neutrons, and so on. This
that barium atom has 56 protons and krypton process, known as a chain reaction, releases a
has 36 protons which add up to uranium’s massive amount of energy with each fission. As
atoms 92 protons the reaction continues, the energy produced
becomes explosively intense.
the unstable uranium-236 nucleus releases
three neutrons in the process, this happens When a fission reaction is allowed to proceed
because barium-141 has 141 neutrons and without moderating the number of neutrons, it
krypton-92 has 92 neutrons adding to a total of becomes an uncontrolled fission reaction, the
233 neutrons, to balance the equation, principle behind nuclear bombs.
uranium-236 must emit 3 more neutrons.
since uranium-236 emits three neutrons in
the reaction, these neutrons can be absorbed
by other uranium-235 nuclei resulting in a chain
reaction
Controlled Fission Reaction
this leads to exponentially high amounts of A fission reaction where emitted neutrons are
energy being released by a single reaction removed from the fissionable material to
control the chain reaction rate. For instance, if
two out of three neutrons are removed, only
one neutron remains to sustain the reaction,
slowing its progress.
This reaction can be dangerous if it is not
controlled, as seen in atomic bombs Materials called moderators, like cadmium (Cd),
(Uncontrolled Fission Reaction). However, when absorb these extra neutrons. The reaction rate
controlled(Controlled Fission Reaction), it can is regulated by limiting neutron availability to
be harnessed for electricity production. maintain a stable rate
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NO
Nuclear Energy Nuclear Wastes
Types of Nuclear Reactors Radioactive Wastes
- Radioactive wastes are materials that contain
Pressurized Water Reactor (PWR) radioactive elements and are no longer useful,
1. The core inside the reactor vessel creates requiring careful disposal due to their potential
heat. health and environmental risks.
2. Pressurized water in the primary coolant
loop carries the heat to the steam there are 4 general categories of radioactive waste:
generator. High-level waste - High-level waste includes
3. Inside the steam generator, heat from the used nuclear fuel from nuclear reactors and
primary coolant loop vaporizes the water in waste generated from the reprocessing of spent
a secondary loop, producing steam. nuclear fuel.
4. The steamline directs the steam to the main
turbine, causing it to turn the turbine Transuranic waste - Transuranic wastes refer to
generator, which produces electricity man-made radioactive elements that have an
atomic number of 92 (uranium) or higher. This
waste includes common items such as rags,
tools, and laboratory equipment contaminated
during the early age of nuclear weapons research
and development.
Boiling Water Reactor (BWR) Uranium or thorium mill tailings - Mill tailings are
1. The core inside the reactor vessel creates radioactive wastes that remain after the mining
heat. and milling of uranium or thorium ore.
2. A steam-water mixture is produced when
very pure water (reactor coolant) moves Low-level waste - Low-level waste is
upward through the core, absorbing heat. radioactively contaminated industrial or research
3. The steam-water mixture leaves the top of waste that is not high-level waste, transuranic
the core and enters the two stages of waste, or uranium or thorium mill tailings.
moisture separation where water droplets
are removed before the steam is allowed to Radioactive waste can have many negative impacts
enter the steamline. on the environment and human health, including:
4. The steamline directs the steam to the main
turbine, causing it to turn the turbine Soil and water contamination - Radioactive
generator, which produces electricity. waste can contaminate soil and groundwater,
making it toxic and infertile. Plants grown in
contaminated soil can absorb the radiation and
pass it on to animals that eat them, which can
lead to radiation in the food chain.
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Marine life - Radioactive substances can enter !. SHORT TERM STORAGE
the food chain of marine life through water and
marine plants. Used Fuel Pools
Deep pools of water at nuclear power plants
Human health - Exposure to radiation can store radioactive spent fuel, providing cooling
cause immediate damage to the body, and radiation shielding. These pools typically
including radiation sickness and death at high remain for several years until it cools enough
doses. At lower doses, radiation can cause for further management.
health effects such as cardiovascular disease, Dry Cask Storage
cataracts, and cancer. Fuel pools store spent nuclear fuel for years,
then it is transferred to dry cask storage, a safe
Agricultural land - Radioactive waste can and long-term management method,
threaten agricultural land. containing radioactive materials in reinforced
containers for decades.
Nuclear Wastes 2. LONG TERM STORAGE
Radioactive Waste Management
Deep Geological Disposal
the processes and methods used to safely The waste is buried underground in stable
handle, store, and dispose of radioactive waste geological formations like granite, salt, or clay,
generated by nuclear power plants, medical ensuring isolation from groundwater and human
facilities, and other sources. This involves activity, ensuring long-term stability and
containment, isolation, and treatment preventing radioactivity migration.
techniques designed to prevent harmful Near Surface Disposal
radiation exposure to people and the Low-level waste (LLW) is primarily disposed of
environment. Key strategies include interim in engineered trenches, a method with a shorter
storage, deep geological disposal, and half-life, ensuring safe and environmentally
continuous monitoring to ensure long-term friendly disposal, minimizing environmental
safety. impacts and minimizing leakage.
Transmutation and Recycling
there are various ways of disposal methods and Nuclear reactions convert radioactive isotopes
they are divided to 2 categories; short term and into shorter-lived isotopes, reducing nuclear
long term disposal methods: waste volume and toxicity. Recycling
techniques separate usable materials from
1. SHORT TERM STORAGE
spent fuel, aiming to improve efficiency and
Used Fuel Pools
safety. However, challenges remain due to
Dry Cask Storage
technological, economic, and regulatory
2. LONG TERM STORAGE
barriers, hindering widespread implementation
Deep Geological Disposal
of these methods.
Near Surface Disposal
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Transmutation and Recycling
