United States Spent Fuel Management Issues and Actions Following the 2011 Great East Japan Earthquake J.S. Armijo
Forum on Spent Fuel Management and the Future of Nuclear Energy, Taipei, Taiwan, December 5, 2014
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Outline Spent Fuel Management Issues
U.S. Regulatory Structure and Process Status of U.S. Nuclear Power
Great East Japan Earthquake and Tsunami Regulatory Actions Resolution of Spent Fuel Issues
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U.S. Spent Fuel Management Issues • Pre-Fukushima – Obstruction Of The Nuclear Waste Policy Act of 1987 (NWPA) – Legal Challenges To The NRC Waste Confidence Rule • Post-Fukushima – Spent Fuel Pool Cooling And Instrumentation – Expedited Transfer Of Spent Fuel From Spent Fuel Pools To Dry Cask Storage. 3
Evolution of U.S. Regulatory Structure • 1946 – Atomic Energy Act established the Atomic Energy Commission (AEC)
• 1954 – Atomic Energy Act of 1954 gave the AEC broad powers to license nuclear facilities and to issue and enforce regulations, and formed the Advisory Committee on Reactor Safeguards (ACRS) • 1957 – Price Anderson legislation established the ACRS as a statutory committee. • 1974 – Energy Reorganization Act established the Nuclear Regulatory Commission , including the ACRS, and the Department of Energy (DOE) 4
Nuclear Regulatory Commission Structure Commissioners ASLB
ACRS
Staff
Executive Director for Operations
• 15 Members • 25 Full Time Staff • 20 Subcommittees
• • • • • •
New Reactors Nuclear Material Safety and Safeguards Nuclear Reactor Regulation Nuclear Regulatory Research Regions I-IV Enforcement: Investigations: Incident Response: Others 5
ACRS Scope • Advises the Commission on: – the hazards of civilian nuclear facilities – the adequacy of proposed safety standards; • Reviews and report on: – safety studies – reactor licenses and license renewal applications; • Provides advice in the areas of health physics and radiation protection • Initiates reviews of specific generic matters or nuclear facility safety-related issues
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Current Status – U.S. Operating Plants • Operating: • 65 PWRs & 35 BWRs -- generating 20% of U.S. electrical power • Power uprates • 156 applications approved ( + 7326 MWe) ,
• 7 under review ( + 1666 MWe) • License Renewals • 75 applications approved (60 year licenses).
• 17 under review, 6 additional applications expected • Additional 20 year extensions under study. 7
Site Permits, Design Certifications and New Plants • Early Site Permits: Four Issued, One Under Review • Design Certifications:
– AP-1000 And ESBWR Issued – US-EPR, US-APWR and ABWR Renewals Under Review
• Five New Reactors Under Construction. – Watts Bar 2 – One 1100 MWe PWR – Vogtle – Two 1117 MWe AP-1000s – Summer – Two 1117 MWe AP-1000s 8
Construction at Vogtle Units 3 and 4
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Independent Spent Fuel Storage Installations (ISFSIs) • 56 General Licensed ISFSIs At Reactor Sites • 15 Specific Licensed ISFSIs At/Or Away From Reactor Sites • Tens of thousand of spent fuel assemblies are stored in 34 States.
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The Nuclear Waste Policy Act of 1987 The Act: • Designated the Yucca Mountain in Nevada as the site for the nation’s high level waste and spent fuel repository. • Was passed by large majorities in both houses of congress and signed into law by the President. • Has not been amended or repealed, and is the law of the land.
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Yucca Mountain Chronology, 2008 to 2011 • June 2008 - DOE submitted a license application to the NRC to construct the repository at Yucca Mountain. • March 2010 - DOE filed a motion with the NRC’s Atomic Safety and Licensing Board seeking permission to withdraw its application. • June 2010 -The ASLB denied the DOE motion and DOE appealed decision to the Commission.
• September 2011 - The Commission was evenly divided and took no action. Further NRC review suspended by the Chairman. 12
Great East Japan Earthquake* • On March 11, 2011- a M9 undersea earthquake lasting 170 seconds occurred off the east coast of Japan. This was followed by 6 aftershocks >M7 and 93 > M6. • A block of sea floor 450 km long and 150 km wide was displaced by approximately 30 m, producing a tsunami 15 meters above mean sea level at the Fukushima Daiichi nuclear site.
• Approximately 520 km 2 of four prefectures were flooded, resulting in 19,000 dead and missing, 6000 injured, massive property damage and displacement of thousands. • All of these deaths, missing persons and injuries were caused by natural causes and none by radiation released from the Fukushima Daiichi reactors. * Examination of Accident at Tokyo Electric Power Co., Inc.’s Fukushima Daiichi Nuclear Power Station and Proposal of Countermeasures, Japan Nuclear Technology Institute Examination Committee on Accident at Fukushima Daiichi Nuclear Power Station, October 2011 13
Fukushima Daiichi Before the Earthquake
1
2
3
4
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Tsunami Impact - 3/11/2011
46 meters
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After the Tsunami and Hydrogen Explosions
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Nuclear Plant Consequences • Great economic damage resulted from the destruction of four reactors, forced evacuations, ongoing costs of cleanup, and the prolonged shutdown of all nuclear plants in Japan. • Despite these severe consequences, no members of the public or workers were killed or harmed by radiation released from the destroyed reactors. • In 2013, the World Health Organization reported that the residents of the area who were evacuated were exposed to so little radiation that long term radiation induced health impacts are likely to be below detectable levels. 17
Dry Cask Storage Consequences • Nine dry storage casks had been stored near the sea. • Large amounts of seawater, sand and debris entered the building . • Inspections in 2011 confirmed that cask integrity was maintained and met safety functions. • Detailed inspections in 2013 confirmed that casks and fuel were undamaged.
Worker removing debris at the dry cask storage building 3/17/2011
Report of Investigation and Maintenance Results of the Dry Casks at Fukushima Daiichi Nuclear Power Station, July, 2013 Tokyo Electric Power Company
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Spent Fuel Pool Consequences * • Loss of AC power to Units 1- 4 resulted in loss of forced cooling of the pools and required emergency actions (helicopters, water cannon trucks, concrete pump trucks, and other means) to add water to the pools. • Spent fuel pool water level and temperature instrumentation was either inoperable or unreliable, leading to uncertainty in the conditions in the SFPs. • The most severe consequence attributed to the spent fuel pools was the hydrogen explosion in Fukushima Unit 4.
* Report of the Japanese Government to the IAEA Ministerial Conference on Nuclear Safety The Accident at TEPCO’s Fukushima Nuclear Power Stations June 2011, Nuclear Emergency Response Headquarters Government of Japan
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Damage to Fukushima Unit 4
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Spent Fuel Pool Error • On March 16 (one day after the hydrogen explosion in Unit 4) American citizens in Japan were advised by the U.S. Government that they should move at least 50 miles (80.5 km) away from the Fukushima site. • The Chairman of the U.S. Nuclear Regulatory Commission stated that the decision was based in part on concerns that all the water in the spent fuel pool at Fukushima reactor No. 4 had boiled dry . • Based on available information at the time, Japanese authorities disagreed and maintained their 20 km evacuation radius.
• The Japanese analyses and decisions were correct.
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Unit 4 Fuel Pool Floor, March 16, 2011
Water Level
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Aftermath of Spent Fuel Pool Error • April 2011 ACRS Briefing – Members critical of technical basis for 50 mile Japan evacuation order.
• June 2011 -- NRC staff announced that the Unit 4 pool “probably was not dry”. • Misinformation persisted and exploited by nuclear power opponents.
• Political demands made for NRC action to require expedited transfer of spent fuel from pools to dry cask storage. 23
NRC Conclusions Regarding Fukushima Events • July 2011, Near Term Task Force Report Issued. • Similar sequence of events in the U.S. unlikely.
• No imminent risk from continued operation of U.S. reactors and continued licensing activities. • Mitigation activities could reduce the likelihood of core damage and radiological release. 24
Resolution of Spent Fuel Management Issues • Spent Fuel Pool Cooling and Instrumentation • Spent Fuel Pool Structural Integrity / Expedited Transfer to Dry Cask Storage • The NRC Waste Confidence Rule • The NRC Safety Evaluation of the DOE Yucca Mountain Application. 25
Spent Fuel Pool Cooling and Instrumentation March 2012, NRC Orders Issued to Licensees: – EA-12-049 requires development and implementation of mitigating strategies to maintain or restore core cooling, containment, and spent fuel pool cooling capabilities in the event of a beyond-design basis external event. – EA-12-053 requires installation of enhanced spent fuel pool instrumentation capable of reliably monitoring pool water level from a remote location.
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Spent Fuel Pool Makeup Capability Rulemaking in progress requiring licensees to: • Provide safety-related AC electrical power for SFP makeup. • Require one train of onsite emergency electrical power be operable for makeup and instrumentation whenever irradiated fuel is in the pool. • Have an installed means to spray water into the SFP, including an easily accessible connection to supply the water. 27
Expedited Transfer to Dry Cask Storage Resolved by two major NRC studies: • The Spent Fuel Pool Study Detailed deterministic evaluation of the safety consequences of severe accidents on a specific U.S. BWR, and the safety benefits of expedited transfer. • The Generic Regulatory Analysis Extension of the Spent Fuel Pool Study to various classes of U.S. reactors and plant sites using conservative safetygoal screening analyses and cost/benefit analyses. 28
Spent Fuel Pool Study * • Detailed deterministic evaluation of the consequences of a beyond design basis earthquake affecting the fuel pool of a U.S. Mark 1 Boiling Water Reactor. • Concluded that: – Spent fuel pool is very likely to withstand low probability beyond design basis earthquakes without leaking. – If leaking occurs, health and safety consequences would be very small and independent of pool loading. – Expedited transfer from pool to dry cask storage provides no substantial safety benefit.
* Consequence Study of a Beyond-Design-Basis Earthquake Affecting the Spent Fuel Pool for a U.S. Mark I Boiling Water Reactor June 2013
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SFP Study Damage and Release Probabilities Seismic Event – 0.7g peak ground acceleration, six times design basis SSE, frequency 1 in 60,000 years, (1.75 e -5 /year) Loss of Cooling – station blackout probability, (0.84)
Pool Damage – concrete cracks, liner leak probability , (0.10) Post Refueling – period of operating cycle during which fuel is not air-coolable and can ignite, (0.08) Mitigation – existing equipment not credited, (1.00) Radionuclide Release – 1.1 e -7 /year 30
Alternate Loading Arrangement
1x8
1x4
1x8 Arrangement prevents ignition and release Comparable to low density loading 31
Generic Regulatory Analysis * •
Safety Goal Screening Analysis – NRC staff evaluated safety benefits of expedited transfer on compliance with NRC Quantitative Health Objectives (QHOs). – Found no significant benefits in prompt fatality risk or latent cancer risk. – Both high density and low density pool loadings met QHOs with several orders of magnitude margin.
• Cost/Benefit Analysis – NRC staff evaluated economic costs and benefits of expedited transfer. – Found that costs of implementation far exceeded benefits for all classes of plants and sites. • NRC staff recommended no further study of expedited transfer.
* Staff Evaluation and Recommendation for Japan Lessons-Learned Tier 3 Issue on Expedited Transfer of Spent Fuel
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Individual Latent Cancer Fatality Risk Within 10 miles
Insignificant Safety Benefits of Expedited Transfer
NRC Safety Goal = 2 x 10 -6 per year
No Mitigation
High Density SFP Loading
Low Density SFP Loading
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ACRS Conclusions - Generic Regulatory Analysis • The staff’s safety goal screening analysis adequately evaluated the safety benefits of expedited transfer.
• The analysis demonstrated that the NRC Safety Goal Policy and Quantitative Health Objectives are met with orders of magnitude margin for both current high-density SFP loadings and proposed low-density fuel loadings. • There is insufficient safety benefit to justify the expedited transfer of spent fuel from pools to dry casks. • The economic benefits of expedited transfer were far less than the costs of implementation. • The analyses are adequately conservative and support the staff’s recommendation that more detailed evaluations of the benefits of expedited transfer of spent fuel need not be pursued. 34
Waste Confidence Issue National Environmental Policy Act (NEPA) NRC Compliance Challenged In Court Court Vacates Waste Confidence Rulemaking - Failure to secure permanent disposal for spent nuclear fuel - Potential spent fuel pool leaks and spent fuel pool fires
NRC Suspends Licensing Actions
NRC issues “Continued Storage Rule� - Resumes licensing -
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Continued Storage Environmental Impact Statement Provides generic analyses of: • environmental impacts of spent fuel pool fires and leaks, • environmental impacts in the event that a repository is delayed or never built. Evaluates impacts of: • Short Term (60 year) , • Long Term (160 year), and • Indefinite storage. Provides assumptions applicable to all time periods. Finds that: • Impacts of spent fuel pool leaks and fires are small. • Impacts of indefinite storage are generally small to moderate. 36
Yucca Mountain Chronology 2013 to 2014 • August 2013 - U.S. Court of Appeals ordered the NRC to complete it’s review and decide whether to approve or reject the DOE application. The Court stated: "At this point, the Commission is simply defying a law enacted by Congress, and the Commission is doing so without any legal basis.“
• October 2014 - the NRC issued the final volume of it’s Safety Evaluation Report on the DOE application. • NRC staff found, with reasonable expectation that DOE has demonstrated compliance with NRC regulatory requirements for postclosure safety, including but not limited to: – – – –
Performance objectives for the geologic repository after permanent closure Requirements for performance assessment Requirements for multiple barriers Postclosure Public Health and Environmental Standards 37
Summary • U.S. civilian nuclear plants continue to provide safe, reliable, and non-polluting electrical power. • Substantial nuclear capacity has been added by systematic power uprates and plant life extensions, and five new plants are under construction. • The U.S. nuclear regulatory structure, processes, and staff have been effective in resolving complex spent fuel management issues. – Improvements in fuel pool cooling and water level Instrumentation ordered. – Rulemaking in progress to require safety grade power for SFP makeup, and spray cooling. – Expedited transfer of spent fuel to dry casks determined to provide no significant safety benefit. Adequate safety is provided by pools and by dry casks. – The Continued Storage Rule has been issued, and licensing activities resumed. – Safety Evaluation Reports of DOE Yucca Mountain License Application have been issued with positive findings. 38