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Spent Fuel Revisited

Spent Fuel Revisited. Tad Cleaves thollandc@hotmail.com Energy Law April 26, 2006. Overview. World Demand for Electricity is Growing Nuclear Energy & Fuel Cycle Safety Environment Conclusions. Demand for Electricity is Growing Rapidly.

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Spent Fuel Revisited

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  1. Spent Fuel Revisited Tad Cleaves thollandc@hotmail.com Energy Law April 26, 2006

  2. Overview • World Demand for Electricity is Growing • Nuclear Energy & Fuel Cycle • Safety • Environment • Conclusions

  3. Demand for Electricity is Growing Rapidly • Electricity Consumption will almost double in next two decades. • Industrialization • Population Expansion

  4. Demand For “Energy” Growing • Oil – Up 50% • Coal – Up 57% • Natural Gas – Up 140%

  5. Fossil Fuels are Kings of Electricity • Fossil Fuel: ~66% • Nuclear: ~17% • Hydro: ~17% • Other: ~2%

  6. Fuel Supplies are Dwindling • Inexpensive Petroleum Supply measured in terms of decades… • Natural Gas measured in decades to maybe a century… • Coal measured in centuries… • Inexpensive Uranium deposits measured in decades to maybe a century…

  7. More Efficient Nuclear Fuel Cycle • Extend Present Reserves • Lower Carbon Emissions

  8. General Information • ~20 % of U.S. electrical generation • 50 % of Illinois electrical generation • Same principles as coal or natural gas plants • 103 U.S. nuclear power plants • 440 global power plants • All but 2 are Thermal Light Water Reactors

  9. Nuclear Fuel • Thermal Pressurized Water Reactors are most common type of reactor • Start with enriched uranium • In nature: • 99.3% U238 “Fissionable” and “Fertile” • .7% U235 “Fissile” • Enriched Uranium: • ~5% U235 • Pu239 by-product of neutron absorption. “Fissile”

  10. Source of Heat: A Possible Reaction in a Reactor • n + 235U 141Ba + 92Kr + 3n • Masses: U = 235.043 924u Ba = 140.909 241 Kr = 91.905 038 n = 1.008 665 236.053u  235.84u

  11. Mass Difference = E 236.053u  235.84u is a mass difference of 0.2123u E = mc2 E = 0.2123 x c2 Yields ~ 197.757 MeV energy Per atom, this is about 5,000,000 times!! the energy released in combustion of oxygen.

  12. The Goal: Controlled Chain Reaction

  13. Two Chain Reactions... Controlled Chain Reaction: Electricity Uncontrolled Chain Reaction: Bad News…

  14. Spent Fuel: Radioactive “Waste” 3 Classes of “Waste” Material • Fission Products (5%) • Mostly Cesium 137 and Strontium 90 • Dangerous ~300 years • Uranium 238 (~94%) • Transuranics (1%) • Everything “heavier” than Uranium • Dangerous, long-lived isotopes. • 10,000+ year half-lives

  15. Transuranics…

  16. Once-Through Fuel Cycle • All of this material is considered “waste” • Inefficient: • Only 5% of potentially fissionable atoms have been used!! • Only 10% of mined uranium is converted into fuel in enrichment process. • Bottom Line: Less that 1% of the ore’s total energy is used to generate energy in once-through regime!

  17. This “Waste” Can Still Power Reactors • Needs to be “Reprocessed” First • France, Japan, Russia, and UK reprocess • Jimmy Carter banned civilian reprocessing in US in 1977 • Fear of weapons-grade Pu239 proliferation • Two types of reprocessing: • PUREX and Pyro

  18. PUREX • Plutonium URanium Extraction • Devised for weapons manufacture • Synonymous with “reprocessing” when reprocessing was banned in 1970s • Extracts pure Pu239 from spent fuel • Pu239 is the isotope of Pu used for atomic weapons

  19. PUREX for Electricity • Pu239 is used to power reactors in the form of metal oxides (MOX). • Can be burned in thermal reactors • Total Energy Usage: • 6% of original reactor fuel energy is used • 94% still unharnessed • Massive amounts of waste left over.

  20. The Pyrometallurgical Process • “Pyro” collects virtually all of the transuranics and much of the uranium • Few transuranics in the final waste stream • Pure Pu239 is never isolated • Based on electroplating

  21. Problems with Pyro… • Basic principles have been demonstrated, but the technology is not ready for immediate commercial use. • The fuel extracted can be burned in Fast Reactors only. • NOT usable in Thermal Light Water Reactors • Only 2 Fast Reactors operating in the world…

  22. “Fast” Refers to Neutron “Speed” • Light Water Reactors take advantage of “Slow,” thermal neutrons • These neutrons can easily split unstable, fissile atoms: Pu239, U235 • Sometimes split other atoms: U238 • High “capture cross section” • Fast Neutrons • Have higher “fission cross section” • Can split all actinides

  23. Fission vs. Capture in PWR and Fast Reactor

  24. Fast Reactor Designs

  25. Energy Efficiency of Fast Reactors • Can recover 99% of energy in spent thermal reactor fuel • After thermal reactor fuel runs out, Fast reactors can burn depleted uranium. • Depleted = Non-enriched U238 • 99% energy recovery • MUCH GREATER YIELD

  26. Fast Reactors In Operation • Not a new technology… • Los Alamos, NM, 1946 • Naval Applications • Especially Soviet • US, France, Russia, and Japan have built FRs • India is pursuing FRs • Only 2 in civilian operation • France & Russia

  27. Why are FRs not in use? • “Reprocessing” is a bad word. • Out-dated bias • “Pyro” process also untested commercially • No infrastructure at this point • Uranium is inexpensive • Fuel is not significant portion of cost • ~5% of total cost of nuclear generation is fuel • Compared to ~75%-80% of cost of natural gas generation. • Easier keep loading the proven thermal reactors with cheap uranium…

  28. Greater Safety Issues? • No • Safer than light water reactors • Operate at atmospheric pressure • Use liquid metal coolant instead of water • Have more passive safety features • Strong track record • The problems encountered (e.g. Monju, Japan) have resulted in little more than big messes… • No radiation released.

  29. No Plutonium Proliferation • Fast Reactors efficiently consume plutonium. • Light Water reactors are plutonium breeders • The only waste products are the “fission products” • Nuclear Ash • No “Plutonium Mines”

  30. Bad Presentation Timing…Chernobyl Disaster – 20 Years Ago, TODAY! • Cause • Unauthorized testing that caused the reactor to lose control • Reactor lost control • Effect • Steam explosion blew the top containment off the reactor core • Large contamination release across a 20 square mile area • LIFE: 48deaths directly • Shady records… • Thousand exposed to elevated radiation

  31. Other Energy Related Accidents • China Coal Mining Industry • (11/05) Qitahe, China: 171 workers were killed • 5,491 coal workers deaths in 2005 • Unofficial statistics closer to 20,000 deaths… • 2,900 reported accidents

  32. Environmentally Superior • Emission free • The only waste produced by FRs with this fuel cycle is nuclear ash. • 1,000 MWe FR would produce 1 ton of fission products. (1% the “waste” of light water reactor) • Only very small amounts of long-lived transuranics • FRs can burn the 30+ years-worth of stored spent fuel. • No need for long-term storage (Yucca Mountain)

  33. Environmental Cost of Hydro Before & After: Grand Coulee Dam Everything has a price...

  34. Conclusions • Need more research • Pyro and FRs in large-scale production • Several Decades Required • Huge upside • Produce electricity indefinitely • Transmutate nuclear waste • Price Stability • Environmentally sound

  35. For more information: • Decide the Nuclear Issues for Yourself Nuclear need not be Unclear by J.A.L Robertson http://www.magma.ca/~jalrober/Decide.htm • The New Economics of Nuclear Power, World Nuclear Association, http://www.uic.com.au/neweconomics.pdf • The Path to Sustainable Nuclear Energy Basic and Applied Research Opportunities for Advanced Fuel Cycles, 2005, http://www.sc.doe.gov/bes/reports/files/PSNE_rpt.pdf • http://www.energy.gov/engine/content.do?BT_CODE=NUCLEAR • Smarter Use of Nuclear Waste by WilliamHannum

  36. Questions??

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