7.0 Nuclear Energy
Frank R. Leslie,
B. S. E. E., M. S. Space Technology, LS IEEE
2/2/2010, Rev. 2.0.2
fleslie @fit.edu; (321) 674-7377
www.fit.edu/~fleslie
FPL’s St. Lucie Nuclear Plant
In Other News . . .
~1/25/2010
 Crude oil at $73 due to “demand destruction”, that is
demand has dropped due to layoffs, plant closings,
consumer lack of confidence
When the economy improves, more demand will
drive prices up
 Energy Act of 2009 or 2010 may be revisited “soon”
 Nuclear fission/fusion hybrid reactor investigation of
“spent fuel” reduction (transuranic wastes)
 Florida Public Service Commission denies rate increases
leading to FPL and Progress Energy stopping plans for
nuclear power plant additions
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7.0 Overview of Nuclear Energy
 Nuclear energy was once gushingly said to be “too cheap to
meter” in the future (the meter and reading it would cost
more than the electricity would sell for)
 That isn’t close to happening 50 years later and is not likely now
 Think of the economics of having a flat rate for electricity!
 US commercial nuclear power began at Shippingport PA in
1957; Soviets began in 1954
 Nuclear power supplied ~20% of US energy in 2005
 Nuclear energy is cheap to the consumer; but heavily
subsidized by the Federal Government (only taxpayers pay for
that!)
 Great controversy (among some) about dangers and eventual
doom from spent fuel
 Plants will likely be built again after none since 1978(?)
 Developing countries considering/building nuclear power
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7.0 About This Presentation
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7.1 Nuclear Reactions
7.2 Sources
7.3 Reactor Types
7.4 Fuel Cycle and Spent Fuel
7.5 Reprocessing of Spent Fuel
7.6 Safety Record
7.7 Risk Assessment
7.8 Conflicts and Controversy
7.9 Advantages and Disadvantages
7.10 Degree of Nuclear Use
7.11 Shutdown Scenario
7.12 Future Trends
7 Conclusion
7.1 The Nuclear Fission Reaction
 Fission occurs when uranium atom is “split” into atoms
of lesser atomic weight plus emitted energy Gamma
Ray
85 to 104 a.w.
Clumping
89Kr
236U
Fission
235U
Neutron
130 to 149 a.w.
Neutron
Neutron
Mass no., nucleons=
protons + neutrons
235U
92 143
Protons
At. No., Z
Neutrons
n = 1.00867
89Kr = 88.91660
144Ba = 143.92000
235U= 235.04394
236U = 236.05261
Gamma
Ray
Gamma
Ray
144Ba
[After Ristinen, p. 174]
144Ba
89Kr
n + 235
U  236
U

+
144
88
53 + 3n + 176.9 MeV
92 143
92
56
36
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7.1 The Nuclides and Radiation Decay
Nuclide Table Example
235
U92
Rows are Atomic Number, Z
236
U92
236
Pa91
236
Th90
236
Ac89
238
U92
238
Th90
Columns are Mass Number, A
 A beta particle emission moves up to the next element;
an alpha emission moves down and left
 These tables also have another format, Z vs. N
 238U is common; 235U is required for fission
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7.2 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 238U, 99.28%; 235U, 0.71%; and 234U,
0.006%
 Uranium extraction
 Convert raw ore to uranium oxide (U3O8) or “yellowcake”
 ~$15.50/lb to $43.00 (2010) http://www.uxc.com/review/uxc_Prices.aspx
 Convert that yellowcake to uranium hexafluoride gas
 Enrich the 235U 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 diam 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
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7.3 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 (recyclable?)
 Ft. Vrain CO HTG reactor shut down and converted to a
natural gas plant
 Fusion Reactors (based upon hydrogen) 2H2 into helium, 1He4
 Cold Fusion (Univ. of Utah mistake or worse?) could not be
replicated by anyone!
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7.3.1 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)
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7.3.1.1 St. Lucie Plant on Hutchinson Island FL
• 1680 MW
• Services
much of
Eastern
Florida
• Ocean
water
cooling exits
to lagoon
• On barrier
island
subject to
hurricane
wave
overwash
http://www.fmpa.com/html/power_supply/st_lucie.html
Uprating will take it to 2400 MW
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7.3.2 Boiling Water Reactors (BWR)
www.nrc.gov
 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
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7.3.3 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
www.nrc.gov
http://www.nrc.gov/reactors/operating/ops-experience/vessel-head-degradation/vessel-head-degradation-files/pwr-rx-vessel.html
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7.3.4 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
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7.3.5 Mixed Oxide Reactor
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http://www.fepc.or.jp/english/nuclear_power/cycle/thermal.html
7.3.6 Pebble-bed; Breeder reactor
 Pebble-bed reactors use fuel/carbon/ceramic pellets
sized like a billiard ball
The balls can be pushed through pipes into the
reactor on top and removed at the bottom, thus no
shutdowns are required; refueling is continuous
 Breeder reactors produce more fissile fuel than they
consume
The US (under Pres. Carter’s administration)
presently prohibits breeder reactors because of
potential weapons that could be made
President Bush was considering using breeder
reactors; President Obama decided against them
Without breeder reactors, uranium ore may be
depleted in ~50 - 80 years
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7.3.7 Fusion Reactors
 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
http://en.wikipedia.org/wiki/Shiva_laser
www.llnl.gov
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7.3.7.1 New Fission/Fusion Reactor Studied
Compact Fusion Neutron Source
“A new fusion-fission hybrid pairs
nuclear fission reactors with a
fusion reactor neutron source to
eliminate virtually all of their
waste and produce clean power,
even with older fission reactor
designs. (Source: Angela
Wong/University of Texas at
Austin)“
www.dailytech.com/New+FusionF
ission+System+Invented+Promis
es+Clean+Nuclear+Power/article
14081.htm
7.4 The Fuel Cycle and the Spent Fuel Problem
 Conventional reactors require 18-month refueling to remove 1/3
“spent” fuel and replace it with active fuel
 Spent fuel must be reprocessed to make more active fuel or be
stored in isolation
 Newly removed fuel is lowered into water tanks to allow
radioactivity to diminish safely with time ~2 years
 Intense radiation causes the blue luminescence of the
Cherenkov Effect; thus I claim nuclear-generated hydrogen
is “blue” (fossil=black, wind or sun=green)
 After several years, the fuel assemblies can be removed and
placed in “casks” for dry storage on site or elsewhere
 A National Repository at Yucca Mountain, Nevada intended to
receive fuel transported by train and truck
 Not many voters in the lowest population state, but one is
Sen. Reid, the Democrat majority leader, who is blocking
storage there
 This project is now dead (wasted effort and materials)
www.bnl.gov
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7.4.1 Spent Fuel Diversion & Nuclear Weapons
 In the FSU, there is concern that nuclear material may be diverted to
criminal or terrorist purposes
“Now I am become death, the destroyer of
worlds.“ Vishnu in Bhagavad Gita
 Nuclear weapons
- Robert Oppenheimer at the Trinity Site
 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
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7.5 Reprocessing (Dilution)
 The US buys excess nuclear weapon warhead materials from
Russia to reduce danger of “leakage” to terrorists
Reprocesses (mixes) the plutonium with uranium spent
fuel to form reusable fuel that would be hard to separate
for future weapons use (remember the centrifuges?)
Reduces diversion or sale to terrorists or “evil-doers”
They’ll buy from North Korea or Iran instead
 Now, the problem is not traditional weapons but the
cheap “Dirty Bomb”; processing is stirring and mixing
High explosive mixed with radioactive waste explodes
to cast radioactive particles over a wide area
The degree of radioactivity isn’t important (old
radioactive gloves and such would do), since terrorists
seek terror, not necessarily death and injury
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7.6 Safety Record
www.grida.no & AMAP
 US plants have a good safety record
The Three-Mile Island gas venting event caused
disruption and evacuation, but no deaths or injuries
Core breaching or meltdown would have made this a
far worse event! Very close to that happening
 Chernobyl had a poor design that is not used in the US
31 died, and 35,000 (?) were predicted to have long
term radiation poisoning; cities relocated
Radioactivity released into the air was detected in
Norway
 Safety inspectors must report to the highest level of
organization; resident Federal inspectors must be
present to check the commercial inspectors
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7.6.1 Radioactive Plume Blown to NW
www.grida.no & AMAP
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7.6.1.1 Three Mile Island, PA
 Unit 2 still closed and defueled
 Cemented in to seal it
http://www.solcomhouse.com/tmi.htm
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7.6.2 Boric Acid Problem near Lake Erie, OH
 Boric acid (moderator) leaks were found under insulation; now fixed
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7.7 Risk Assessment (from Failure Analysis)
 Risk assessment estimates the probable loss from various
sources and is based upon failure analysis
 Risk = Probability of damage x dollar consequence of damage
 Dropped Light Bulb Scenario:
Prob(event) = 1 in 1000 (guess based upon experience)
C = $0.37/bulb (in four-packs)
Risk = P x C = 0.001 x $0.37 = $0.00037 (skip insurance)
 “Armageddon” (Bruce Willis) meteor strikes Pacific Ocean:
P = 10-12/year (wipes out Earth; my guess)
C = $10+24 (my wild guess; what’s yours?)
Risk = $10+12/year (should we spend this $1 trillion
annually to attempt to prevent disaster? How?)
 Total all risks and rank them high $ to low $ for examination
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7.8 Conflicts and Controversy
 Basic “Anti-Nuc”, “Anti-war” ideology drives protesters who have a
separate progressive/liberal/leftist agenda [in my humble opinion]
 Hiroshima and Nagasaki bombings ended World War II with less
loss of life than continuing the war
 Anti-war activists attack nuclear energy and food preservation
radiation for civilian use (Mulberry, Florida)
 Cassini launch to Saturn was vociferously protested because of
the 72.3 lb 238Pu radioisotope power source (invaded CCAFB and
were arrested); New Horizons launch was protested as well
 Yucca Mt., NV attacked for seismic activity, heat, not good enough
for 250,000 years storage of isotopes
 Possibly future generations might recover the waste and change
the storage in 1000 years?
 Safe or not? By what scoring? Who decides? Obama did, and
stopped the project by executive order
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7.9 Advantages and Disadvantages
 Advantages
Low-cost electricity
due to Gov’t 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?
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7.10 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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7.10 US nuclear reactors are near user load centers
Note reactors in Pres. Obama’s home state of Illinois
http://www.nrc.gov/info-finder/reactor/
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7.11 Shutdown Scenario for “Anti-Nucs”
 Why not close down reactors right now? ! ?
 Likely scenario that would follow:
 Utilities warn public to cut energy use 20% immediately!
 Public ignores warning; consumes as usual
 Nuclear generators are taken off the Grid by law on stop date
 Immediate Grid overload occurs (~20% of energy missing)
 Electricity outages occur simultaneously across the entire
country, not just as in the past Northeast states disruptions
 Electric lighting, communication, refrigeration, trains, elevators,
traffic lights, gas pumps, oxygen generators, etc. fail to operate
 Back-up diesel generators use up reserve fuel in days
 Civilization as we know it drops back to the 1700s, but without
the appropriate conveniences they were using back then
 As widespread hunger spreads, pillaging mobs kill for food (and
TVs), while soldiers shoot looters by thousands
 So should we shut off nuclear reactors immediately?
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7.12 Future Trends in Nuclear Energy
Older plants (>40 years) must seek relicensing from
the NRC to continue operation
The St. Lucie Nuclear Plant at Ft. Pierce FL was
recently granted a 20-year license extension
Standardized plant designs speed construction and
increase safety; use additional reactor units as
needed
Nuclear energy will increase in the less-developed
countries in order to have long-term energy
Some countries may desire to create nuclear
weapons at the same time; e.g., North Korea,
Iran?
Fusion reactors may become useful in the future but
years of research have only yielded less energy than
was put in to the process --- I like our fusion sun!
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7.12.1 Future Trends in Nuclear Energy (Con’t)
ITER (Latin for “The Way”, I T E Reactor)
Produce 0.5 GW for 400 seconds!
Fuse deuterium and tritium to make H2 and emit a
neutron
Seven countries researching fusion energy
Tokamak accelerator
Goal is >10 units of energy out for each unit in
Perhaps demo ready between 2030 to 2035
 http://www.iter.org/default.aspx
 http://www.pppl.gov/polImage.cfm?doc_Id=48&size_code=Doc
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7.C Conclusion
 Nuclear plants provide a significant 20% of US 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)
060127
Olin Engineering Complex 4.7 kW Solar PV Roof Array
Questions?
080116
7.B References: Books
 Glasstone, Samuel. The Effects of Nuclear Weapons. 1950 out of print, ~$315.
 Brower, Michael. Cool Energy. Cambridge MA: The MIT Press, 1992. 0-262-02349-0,
TJ807.9.U6B76, 333.79’4’0973.
 Duffie, John and William A. Beckman. Solar Engineering of Thermal Processes. NY:
John Wiley & Sons, Inc., 920 pp., 1991
 Gipe, Paul. Wind Energy for Home & Business. White River Junction, VT: Chelsea
Green Pub. Co., 1993. 0-930031-64-4, TJ820.G57, 621.4’5
 Patel, Mukund R. Wind and Solar Power Systems. Boca Raton: CRC Press, 1999, 351
pp. ISBN 0-8493-1605-7, TK1541.P38 1999, 621.31’2136
 Sørensen, Bent. Renewable Energy, Second Edition. San Diego: Academic Press,
2000, 911 pp. ISBN 0-12-656152-4.
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7.R References: Websites, etc.
www.energyquest.ca.gov/story/chapter13.html
http://fsv.homestead.com/FSVHistory.html
http://eia.doe.gov/cneaf/nuclear/page/nuc_reactors/superla.html
http://www.fpl.com/environment/nuclear/nuclear_power_serves_you.shtml
______________________________________________________________
__
mailto:energyresources@egroups.com
www.dieoff.org. Site devoted to the decline of energy and effects upon
population
www.ferc.gov/ Federal Energy Regulatory Commission
www.google.com/search?q=%22renewable+energy+course%22
solstice.crest.org/
dataweb.usbr.gov/html/powerplant_selection.html
en.wikipedia.org/wiki/Fusion_power
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