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

7.0 Nuclear Energy

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 confidenceWhen the economy improves, more demand

will drive prices upEnergy 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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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

nowThink 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

7.0 Overview of Nuclear Energy

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7.0 About This Presentation

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

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92

n + 235U143 236U144 144Ba88 + 89Kr53 + 3n + 176.9 MeV

n = 1.0086789Kr = 88.91660144Ba = 143.92000235U= 235.04394236U = 236.05261

365692

Neutron

89Kr

144Ba

Fission occurs when uranium atom is “split” into atoms of lesser atomic weight plus emitted energy

7.1 The Nuclear Fission Reaction

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GammaRay

235U

85 to 104 a.w.

130 to 149 a.w.

Fission

Clumping

GammaRay

GammaRay

Neutron

Neutron

92

[After Ristinen, p. 174]

236U

235U143

ProtonsAt. No., Z

Mass no., nucleons=protons + neutrons

Neutrons

Nuclide Table Example

235U92236U92

238U92236Pa91236Th90

238Th90236Ac89

Rows are Atomic Number, Z Columns are Mass Number, A

7.1 The Nuclides and Radiation Decay

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 oreUS 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 gasEnrich 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 preparationMake uranium dioxide pellets (~0.4 inch diam x 0.4 inch

long)Load the pellets end-to-end in a zirconium alloy tubePlace 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 oxideCanadian CANDU (Canadian deuterium oxide) reactor

Boiling water reactors produce steam at top of the core areaPressurized water reactors keep water from boilingMixed 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 plantFusion 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 coolantSome reactors have used liquid sodium metal

as a “coolant” with a heat exchangerThe coolant flows around the fuel elements and

carries off the heat Heat exchangers prevent leakage of the

radioactive water into the steam turbinesThe primary side water remains in liquid state

due to high pressureIf 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

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http://www.fmpa.com/html/power_supply/st_lucie.html

Uprating will take it to 2400 MW

7.3.2 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 090124

www.nrc.gov

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

040202http://www.nrc.gov/reactors/operating/ops-experience/vessel-head-degradation/vessel-head-degradation-files/pwr-rx-vessel.html

www.nrc.gov

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 waterDeuterium occurs about once in 6500

molecules of water

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7.3.5 Mixed Oxide Reactor

                                                                               

http://www.fepc.or.jp/english/nuclear_power/cycle/thermal.html090124

7.3.6 Pebble-bed; Breeder reactor

Pebble-bed reactors use fuel/carbon/ceramic pellets sized like a billiard ballThe 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 consumeThe 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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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 fusionImmense 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

7.3.7 Fusion Reactors

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www.llnl.govhttp://en.wikipedia.org/wiki/Shiva_laser

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+FusionFission+System+Invented+Promises+Clean+Nuclear+Power/article14081.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 isolationNewly 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 truckNot 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)

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www.bnl.gov

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

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

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“Now I am become death, the destroyer of worlds.“ Vishnu in Bhagavad Gita

- Robert Oppenheimer at the Trinity Site

7.5 Reprocessing (Dilution)

The US buys excess nuclear weapon warhead materials from Russia to reduce danger of “leakage” to terroristsReprocesses (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 mixingHigh 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

US plants have a good safety recordThe Three-Mile Island gas venting event caused

disruption and evacuation, but no deaths or injuriesCore breaching or meltdown would have made this

a far worse event! Very close to that happeningChernobyl 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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www.grida.no & AMAP

7.6.1 Radioactive Plume Blown to NW

www.grida.no & AMAP 090124

7.6.1.1 Three Mile Island, PA

Unit 2 still closed and defueledCemented in to seal it

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http://www.solcomhouse.com/tmi.htm

7.6.2 Boric Acid Problem near Lake Erie, OH

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Boric acid (moderator) leaks were found under insulation; now fixed

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 warAnti-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 isotopesPossibly 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

AdvantagesLow-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

DisadvantagesPotential for

radiation leakage and health effects

Possible terrorist targetUseful just as

threatApparent 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

090124http://www.nrc.gov/info-finder/reactor/

Note reactors in Pres. Obama’s home state of Illinois

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 disruptionsElectric lighting, communication, refrigeration, trains,

elevators, traffic lights, gas pumps, oxygen generators, etc. fail to operate

Back-up diesel generators use up reserve fuel in daysCivilization 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 energySome 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 neutronSeven countries researching fusion energyTokamak acceleratorGoal is >10 units of energy out for each unit inPerhaps 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 energySome antinuclear organizations want all plants closed

right now and vocally oppose themNuclear 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 dayNuclear 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 polluteWind energy is the closest renewable, since major

hydro is difficult (see China’s Three Gorges Dam)

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Olin Engineering Complex 4.7 kW Solar PV Roof Array

080116

Questions?

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.htmlhttp://eia.doe.gov/cneaf/nuclear/page/nuc_reactors/superla.htmlhttp://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

populationwww.ferc.gov/ Federal Energy Regulatory Commissionwww.google.com/search?q=%22renewable+energy+course%22solstice.crest.org/dataweb.usbr.gov/html/powerplant_selection.htmlen.wikipedia.org/wiki/Fusion_power

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Slide stockpile follows!

Older slides follow this one. Look at these if you have interest or time. It’s difficult to decide what to leave out of the lecture to save time!