The U.S. Congress asked the National Academy of Sciences to conduct a technical study on lessons learned from the Fukushima Daiichi nuclear accident for improving safety and security of commercial nuclear power plants in the United States. This study was carried out in two phases: Phase 1, issued in 2014, focused on the causes of the Fukushima Daiichi accident and safety-related lessons learned for improving nuclear plant systems, operations, and regulations exclusive of spent fuel storage. This Phase 2 report focuses on three issues: (1) lessons learned from the accident for nuclear plant security, (2) lessons learned for spent fuel storage, and (3) reevaluation of conclusions from previous Academies studies on spent fuel storage.

Contents

• The National Academies of SCIENCES • ENGINEERING • MEDICINE
• COMMITTEE ON LESSONS LEARNED FROM THE FUKUSHIMA NUCLEAR ACCIDENT FOR IMPROVING SAFETY AND SECURITY OF U.S. NUCLEAR PLANTS
• NUCLEAR AND RADIATION STUDIES BOARD
• Acknowledgments
• Reviewer Acknowledgments
• Synopsis
• Summary
  • TASK 1: SECURITY-RELATED LESSONS LEARNED FOR PLANT SYSTEMS, OPERATIONS, AND REGULATIONS
  • TASK 2: LESSONS LEARNED FOR SPENT FUEL STORAGE
  • TASK 3: REEVALUATION OF THE FINDINGS AND RECOMMENDATIONS FROM PREVIOUS NAS REPORTS
• 1. Introduction
  • 1.1. STUDY PROCESS
  • 1.2. STRATEGY FOR ADDRESSING THE STUDY CHARGE
  • 1.3. REPORT ORGANIZATION
• 2. Fukushima Daiichi Nuclear Accident: Lessons Learned for Spent Fuel Storage
  • 2.1. SPENT FUEL STORAGE AT THE FUKUSHIMA DAIICHI PLANT
  • 2.2. IMPACTS OF EARTHQUAKE AND TSUNAMI ON THE UNIT 1-4 SPENT FUEL POOLS
  • 2.3. COMMITTEE ANALYSIS OF UNIT 4 POOL WATER LEVELS
  • 2.4. FINDING AND RECOMMENDATION
  • APPENDIX 2A. Spent Fuel Storage in Units 5 and 6, the Common Pool, and Dry Cask Storage at the Fukushima Daiichi Plant
  • APPENDIX 2B. Analysis of Spent Fuel Pool Heat-up
  • APPENDIX 2C. Orifice Flow-Rate Correlation
• 3. Fukushima Daiichi Nuclear Accident: Lessons Learned for Nuclear Plant Security
  • 3.1. LESSONS LEARNED FOR SECURITY AT U.S. NUCLEAR PLANTS
  • 3.2. LESSONS LEARNED FOR IDENTIFYING AND APPLYING DESIGN-BASIS EVENTS FOR ACCIDENTS AND TERRORIST ATTACKS TO EXISTING NUCLEAR PLANTS
  • APPENDIX 3A. Security Systems at Nuclear Plants
• 4. Reevaluation of Findings and Recommendations from Previous NAS Reports
  • 4.1. TERRORIST ATTACKS ON SPENT FUEL STORAGE OR THEFT OF SPENT FUEL
  • 4.2. SAFETY AND SECURITY OF POOL STORAGE
  • 4.3. SAFETY AND SECURITY OF DRY CASK STORAGE AND COMPARISON WITH POOL STORAGE
  • 4.4. IMPLEMENTATION ISSUES
  • APPENDIX 4A. Dry Cask Storage Regulations
• 5. Security Risk Assessment
  • 5.1. BACKGROUND ON RISK ASSESSMENT
  • 5.2. APPLICATION OF RISK ASSESSMENT TO SECURITY
  • 5.3. SECURITY RISK ASSESSMENT METHODOLOGIES
  • 5.4. CHALLENGES FOR APPLYING RISK ASSESSMENT TO SECURITY
  • 5.5. DISCUSSION
  • APPENDIX 5A. Expert Elicitation
  • APPENDIX 5B. CARVER Analysis
• 6. Loss-of-Coolant Events in Spent Fuel Pools
  • 6.1. RESPONSE OF SPENT FUEL POOLS TO LOSS-OF-COOLANT EVENTS
  • 6.2. MITIGATING LOSS-OF-COOLANT EVENTS IN SPENT FUEL POOLS
  • APPENDIX 6A. USNRC and Sandia Studies on Loss-of-Cooling Accidents in Spent Fuel Pools
• 7. Expedited Transfer of Spent Fuel from Pools to Dry Casks
  • 7.1. BACKGROUND ON USNRC SPENT FUEL STORAGE ANALYSES
  • 7.2. SPENT FUEL POOL STUDY
  • 7.3. EXPEDITED TRANSFER REGULATORY ANALYSIS
  • 7.4. DISCUSSION
  • APPENDIX 7A. Spent Fuel Pool Racking
• References
• Appendixes
  • Appendix A. Committee and Staff Biographies
  • Appendix B. Presentations
  • Appendix C. Conversions and Units
  • Appendix D. Acronyms

Suggested citation:

National Academies of Sciences, Engineering, and Medicine. 2016. Lessons Learned from the Fukushima Nuclear Accident for Improving Safety and Security of U.S. Nuclear Plants: Phase 2. Washington, DC: The National Academies Press. doi: 10.17226/21874.