A PPT On Nuclear Energy

1. NINAD KHARE
ME-32
PPE PRESENTATION
SVCE,INDORE
Nuclear Energy

2. 92
n + 235
U143 → 236
U144 → 144
Ba88 + 89
Kr53 + 3n + 176.9 MeV
n = 1.00867
89
Kr = 88.91660
144
Ba = 143.92000
235
U= 235.04394
236
U = 236.05261
365692
Neutron
89
Kr
144
Ba
Fission occurs when uranium atom is “split” into atoms
of lesser atomic weight plus emitted energy
The Nuclear Fission Reaction
Gamma
Ray
235
U
85 to 104 a.w.
130 to 149 a.w.
Fission
Clumping
Gamma
Ray
Gamma
Ray
Neutron
Neutron
92
236
U
235
U143
Protons
At. No., Z
Mass no., nucleons=
protons + neutrons
Neutrons

3. Sources, extraction, and preparation
 Found in Congo, Canada, US (CO, WY, UT, NM, etc.), Africa,
Ukraine, and everywhere to some extent
 Uranium mining of ore
US Carnotite contains 238
U, 99.28%; 235
U, 0.71%; and 234
U,
(0.006%)
 Uranium extraction
Convert raw ore to uranium oxide (U3O8) or “yellowcake”
~Rs. 2370.2/lb to RS. 7000 (2016)
Convert that yellowcake to uranium hexafluoride gas
Enrich the 235
U from 0.7% up to 2% to 5% for power plants; 93%
for weapons (lots of centrifuges [Iran has 6000] in series)
 Uranium fuel preparation
Make uranium dioxide pellets (~0.4 inch dia. x 0.4 inch long)
Load the pellets end-to-end in a zirconium alloy tube
Place tubes in assemblies for ease of handling and loading

4. NUCLEAR POWER PLANTS (WORLD)

5. Types of Reactors
 Major Reactor Categories:
Light Water Reactors (LWR) use H2O
Heavy Water Reactors (HWR) use D2O or deuterium oxide
Canadian CANDU (Canadian deuterium oxide) reactor
Boiling water reactors produce steam at top of the core area
Pressurized water reactors keep water from boiling
Mixed oxide (MOX) reactors contain both plutonium and
uranium oxides (make from old warheads)
Breeder reactors produce additional radioactive fuel that may
be used in conventional reactors.
Fusion Reactors (based upon hydrogen) 2H2 into Helium.

6. Light Water Reactors
Ordinary, but pure, deionized (noncorrosive) water is
used as a fuel core coolant
Some reactors have used liquid sodium metal as a
“coolant” with a heat exchanger
The coolant flows around the fuel elements and carries
off the heat
Heat exchangers prevent leakage of the radioactive
water into the steam turbines
The primary side water remains in liquid state due to
high pressure
If the water area vents and goes dry, the core can
melt if the reaction isn’t stopped in time (the “China
Syndrome)

7. Boiling Water Reactors (BWR)
 Boiling water reactors have part of the water as steam around the fuel
 The water acts as a moderator to slow the neutrons to fission the uranium, while the
steam is less dense and doesn’t moderate well
 If overheating occurs, the steam pushes the water level lower, slows the reaction and is
protects the reactor

8. Pressurized Water Reactor (PWR)
 Water is under high pressure
so it can’t flash into steam
 The reaction is modified
entirely by the control rods

9. CANDU Reactor
The Canadian heavy water (deuterium oxide,
DO2) reactor can use unrefined uranium U238
as
fuel
Canada, Argentina, and Pakistan use this
reactor type
This avoids the expense of uranium
enhancement, but deuterium oxide must be
separated from ordinary water
Deuterium occurs about once in 6500
molecules of water

10. Mixed Oxide Reactor
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11. Hydrogen can be fused into helium yielding more energy
than was required to create the fusion
The Shiva machine (named after the multiple-armed Indian
Goddess) has 20 lasers that simultaneously strike a small
plastic shell containing deuterium oxide to create fusion
Immense amounts of energy fire the 20 lasers
simultaneously to cause a negligible amount of fusion
energy
Remember EROEI, where a high
amount of energy must come out
compared to what went in for the
conversion to be useful, but this
is the reverse so far
Fusion Reactors

12. Spent Fuel Diversion & Nuclear Weapons
 In the FSU, there is concern that nuclear material may be diverted to
criminal or terrorist purposes
 Nuclear weapons
 Fission
 Two subcritical masses are pushed together to critical mass
 A surround of explosive detonates to compress the core to dense
critical mass
 Fusion
 Atomic explosion initiates hydrogen fusion bomb
 Electromagnetic Pulse Weapon
 High altitude burst radiates EMP and damages electrical and
electronic equipment by induced voltage overload
 Neutron Bomb
 Neutron pulse kills without building destruction [Jack Welch, GE]
 Contamination by “Dirty Bomb”
 Radioactive materials are spread by conventional explosive to
cause terror and decontamination delays; more psychological effect
090124
“Now I am become death, the destroyer of
worlds.“ Vishnu in Bhagavad Gita
- Robert Oppenheimer at the Trinity Site

13. Chernobyl is a small
city in Ukraine near
the border with
Belarus, north of
Kiev. At 1 A.M. on
April 25, 1986, at
Chernobyl Nuclear
Power Station-4, a
test was begun to
measure the amount
of electricity that a still
spinning turbine
would produce if the
steam were shut off.
Imp.information because the emergency core cooling system required
energy for its operation and the coasting turbine could provide some of
that energy until another source became available. But the test was
delayed because of a demand for electricity, and a new shift of workers
came on duty.

14. The operators failed to program the computer to maintain power at
700 megawatts, and output dropped to 30 megawatts. This
presented an immediate need to rapidly increase the power, and
many of the control rods were withdrawn. Meanwhile, an inert gas
(xenon) had accumulated on the fuel rods. The gas absorbed the
neutrons and slowed the rate of power increase. In an attempt to
obtain more power, operators withdrew all the control rods. This
was a second safety violation.
At 1 AM on April 26, the operators shut off most emergency
warning signals and turned on all eight pumps to provide adequate
cooling for the reactor following the completion of the test. Just as
final stages of the test were beginning, a signal indicated an
excessive reaction in the reactor. In spite of the warning, the
operators blocked the automatic reactor shut down and began the
test.
As the test continued, the power output of the reactor rose beyond
its normal level and continued to rise. The operators activated the
emergency system designed to put the control rods back into the

15. The core had already
deformed, and the rods
would not fit properly: the
reaction could not be
stopped. In 4.5 seconds the
energy level of the reactor
increased 2000 times. The
fuel rods ruptured, the
cooling water turned into
steam, and a steam
explosion occurred. The
lack of cooling water
allowed the reactor to
explode. The explosion
blew the 1102 ton concrete
roof off the reactor and the
reactor caught on fire.
In less than 10 seconds, Chernobyl
became the scene of the world’s worst
nuclear accident. It took 10 days to
bring the runaway reaction under control.
By November, the damaged reactor was
entombed in a hastily built concrete
covering that may have critical flaws. A 2nd
containment is planned.

16. The immediate consequences were 31 fatalities, 500 persons
hospitalized, including 237 with acute radiation sickness; and
116,000 people were evacuated. More than a year after the
disaster at Chernobyl, the decontamination of 27 cities and
villages was considered finished. That does not mean they were
safe just that all practical measures had been completed. Some
areas were simply abandoned. The largest city to be affected
was Pripyat which had a population of 50,000 and was only 4
kilometers from the reactor. A new town was built to
accommodate those displaced by the accident and Pripyat
remains a ghost town. Seventeen years after the accident some
scientists believe the worst is yet to come. Compared to the
general public (control) the rates of some noncancerous
diseases, endocrine disorders, and stroke for instance appears
to be rising disproportionately among the roughly 600,000
“liquidators” who cleaned up the heaviest contamination in the
plant’s vicinity. Whether people who live in the shadow of
Chernobyl remain at risk is an intensely debated question now.

17. Degree of Nuclear Use
Nuclear plants provide so much energy (~20%) that
they cannot be discontinued quickly; replacement
power would be required first at high cost
Nuclear power primarily has a political problem and is
opposed by strident antinuclear activists/protesters
Condo owner organizations next to St. Lucie Plant
spoke in favor of relicensing citing “Good Neighbor”!
Miami area anti-nuke activist drew attention to
potential fire in spent fuel pool if cooling water level
fell and pellet zirconium cladding fire resulted, thus
spreading radiation
US nuclear plant construction likely to start again
since population growth demands more energy, and
natural gas prices will be higher in the future
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18. Advantages and Disadvantages
Advantages
Low-cost electricity
due to Govt.
subsidies, services, &
insurance
Provides “Baseload”
constant power to
carry most of the load
Clean power without
air pollution (no CO2?)
Requires highly paid
work force (job votes)
Source of local
taxation revenue
Disadvantages
Potential for radiation
leakage and health
effects
Possible terrorist
target
Useful just as
threat
Apparent cheap power
retards renewable
energy development
What to do with the
spent fuel?

19. Conclusion
Nuclear plants provide a significant 10% of INDIAN
energy
Some antinuclear organizations want all plants closed
right now and vocally oppose them
Nuclear energy provides too much energy to readily
close them without a substitute (~1600 MW/plant)
Nuclear energy may be a transitional approach from
fission plants to fusion plants some far away day
Nuclear plants likely will be built again since population
growth demands more energy, natural gas prices will be
higher in the future, and fossil fuel plants pollute
Wind energy is the closest renewable, since major
hydro is difficult (see China’s Three Gorges Dam)
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