D. Warner North MS&E 290 Thursday, February 26, 2004

1. Nuclear Power as a Long-Term Energy Alternative: Nuclear Safety and Management of Radioactive Waste D. Warner North MS&E 290 Thursday, February 26, 2004

2. Outline for Today’s Lecture • Questions on Problem #3 • Nuclear Energy – Brief Review • Nuclear Safety: Perspectives on the • past • present, and • Future • Safe Management of Radioactive Waste

3. Nuclear Energy: A Brief Review • Nuclear fission: • how it works: • Explosion (multiplication of fast neutrons) vs. sustained chain reaction (slow neutrons with controls) • Water reactor: Release heat, make steam, spin turbine • Fuel: U-235, Pu-239, U-233 fissionable by slow neutrons • scarce (U-235 0.72% of natural uranium) or made by neutron capture • Potential fuel: “fertile” – U-238, Th-232. Plentiful in nature. “Breeder” reactors make more fuel from fertile material than they burn. • The residue: “spent fuel” – unused U-235, U-238, Pu-239 plus • “fission products” (split atomic nuclei, radioactive with a spectrum of half-lives, mainly less than 100 years. • Actinides (elements heavier than #92, uranium, formed by neutron capture: neptunium, plutonium, americium, etc.), radioactive half-lives often long, >10,000 years

4. History of Nuclear Energy • Prior to World War II, large energy possible from nuclear fission was known and discussed. Laboratory work with a few atoms. Comic strips and Sunday supplement articles on power for good and evil (Reference: Spencer Weart, Nuclear Fear: A History of Images, Harvard Univ. Press, 1988.) • Nuclear chain reaction first achieved at University of Chicago; Manhattan Project built nuclear reactors (graphite moderator), made plutonium at Hanford, WA; enriched uranium, Oak Ridge, TN. Bombs made in secrecy used on Japan in 1945. • “Atoms for Peace” – reactors could be used to generate electricity. Reactors used to power nuclear submarines adapted to power generation: Slightly enriched uranium (2-4% U-235), pressurized water (Westinghouse) or boiling water (General Electric) – Light Water. Most of World’s commercial reactors Light Water. Exceptions – reactors also used to provide plutonium in US weapons complex, Soviet RBMK (e.g., Chernobyl)

5. Regulation of Nuclear Safety (1) • Risks of nuclear energy/radioactivity were known by scientists. This knowledge motivated location of facilities for manufacture and testing in remote, unpopulated areas like Hanford, desert in Eastern Washington state • After World War II all nuclear energy was placed under the Atomic Energy Commission (AEC) by the Atomic Energy Act of 1946. Act revised in 1954 to promote nuclear energy for peaceful uses. AEC also regulated safety – for both the civilian and military applications. • Nuclear energy will be “too cheap to meter” • There will be “no chance” of a large release from a civilian power reactor.

6. Regulation of Nuclear Safety (2) • Probabilistic risk analysis (PRA) invented at General Electric’s Nuclear Division – and other places. Deterministic analysis used by government regulators. • By late 1960s, controversy about nuclear safety – many environmental organizations “anti-nuclear” • WASH-1400 study led by Prof Norman Rasmussen of MIT. • Nuclear Regulatory Commission (Ref: www.nrc.gov) and DOE created from AEC, 1974-5 • Three Mile Island accident, March 28, 1979. Loss of reactor, but radiation release small.

7. Regulation of Nuclear Safety (3) • Chernobyl Release, 1986: http://www.world-nuclear.org/info/chernobyl/inf07.htm • “the result of a flawed reactor design that was operated with inadequately trained personnel and without proper regard for safety … It was a direct consequence of Cold War isolation and the resulting lack of any safety culture. ” • “released about five percent of the radioactive reactor core into the atmosphere and downwind” • “30 people were killed, and there have since been up to ten deaths from thyroid cancer due to the accident” • “An authoritative UN report in 2000 confirmed that there is no scientific evidence of any significant radiation-related health effects to most people exposed.”

8. Regulation of Nuclear Safety (4) • Operating experience of other plants generally favorable; no major accidents, availability high, major contribution to US (20%) and world electric energy supply. (US about 30% of world nuclear total; Lithuania, France highest shares, 80, 78% - 2002 figures) • Defense-in-depth philosophy, redundant safety systems, extensive safety research by worldwide nuclear community • PRAs used to investigate safety of individual nuclear plants BUT • No new reactors licensed in US since 1970s, most new reactors going into Asia • Special concern over Soviet-design reactors that are still operating

9. Radioactive Waste • What is it? Review of Nuclear Fundamentals – fission products, actinides, neutron activation of adjacent materials. Sources: weapons complex, civilian nuclear power, minor sources involving radioactive materials such as in medicine • Low and intermediate level waste – problem for universities, hospitals, power plants at state level. A few sites open, high prices. • TRU waste – plutonium residues from weapons complex. TRU waste going into Waste Isolation Pilot Plant in Carlsbad, NM • High-level waste (HLW) and spent nuclear fuel (SNF): this is most of the radioactivity. The proposed US repository at Yucca Mountain, NV

10. Yucca Mountain, Nevada Source: EPRI Journal, November 2002

11. Geology Setting and Engineered Barriers

12. Yucca Mountain: Diagram Source: EPRI Journal,

13. Tunnel Boring at Yucca Mountain Source: EPRI Journal,

14. History on HLW and SNF • Early efforts – AEC era, the 1957 NAS report, intention to reprocess and recyle the uranium and plutonium • The Ford and Carter Administrations: the US changes to a once-through nuclear fuel cycle • The 1982 Nuclear Waste Policy Act – staged competition for two sites, eastern and western US • The 1987 Nuclear Waste Policy Amendments Act: • Characterize one site – Yucca Mountain, NV • Oversight by US Nuclear Waste Technical Review Board (www.nwtrb.gov)

15. Risk and Performance Assessment

16. The Many Processes to Consider …

17. Fuel Pool and Dry Cask Storage

18. Recent History • DOE’s push for Presidential and Congressional Approval, over Nevada’s opposition • Details: See websites: DOE www.ocrwm.doe.gov, Nuclear Regulatory Commisssion www.nrc.gov, EPRI Journal November 2002 (http://www.epri.com/journal/details.asp?doctype=features&id=497), Nevada opposition: www.nvantinuclear.com • The debate – terrorism, do we know enough, did DOE follow the rules, is the EPA standard of 10,000 years reasonable? • In 2002 Congress overturned Nevada’s veto. Now what will the courts, NRC do?

19. The Biggest Challenges Are Societal The 2001 National Academy Report, Disposition of High-Level Waste and Spent Nuclear Fuel Report discusses all HLW and SNF, not just for USA. Full text available at http://www.nap.edu/books/0309073170/html/index.html • “Today the biggest challenges to waste disposal are societal. Difficulties in achieving public support have been seriously underestimated in the past, and opportunities to increase public involvement and to gain public trust have been have been missed. Most countries have made major changes in their approach to waste disposition to address the recognized societal challenges. Such challenges include initiating decision processes that maintain choice and are open, transparent, and collaborative with independent scientists, critics, and members of the public.”

20. Relation to Global Climate Issues • Martin I. Hoffert et al. (17 co-authors), “Advanced Technology Paths to Global Climate Stability: Energy for a Greenhouse Planet” Science, Vol. 298, pp. 981-987 (1 November 2002): • “We conclude that a broad range of intensive research and development is urgently needed to produce technological options that can allow both climate stabilization and economic development.” (p. 981, abstr.) • “… both fission and fusion are unlikely to play significant roles in climate stabilization without aggressive research and, in the case of fission, without the resolution of outstanding issues of high-level waste disposal and weapons proliferation.” (p. 986)

21. Near Future • Upcoming soon: outcome of current litigation • How to transport SNF to Yucca Mountain – dedicated rail line or truck? DOE plan has been proposed. • License application in 2005 for construction by DOE, then evaluation by NRC. This may be the next big US decision. • Other countries are moving ahead – slowly. Finns and Swedes furthest ahead for SNF.