#1THE EVENTS AT FUKUSHIMA NUCLEAR PLANT: WHAT IT MAY MEAN FOR THE UNITED STATES ELMO E. COLLINS, REGIONAL ADMINISTRATOR, REGION IV U.S. NUCLEAR REGULATORY COMMISSION Revision 0 U.S.NRC United States Nuclear Regulatory Commission Protecting People and the Environment#2FUKUSHIMA SEQUENCE OF EVENTS March 11, 2011 - magnitude 9.0 earthquake • Fukushima Dai-ichi Units 1, 2, and 3 automatically shut down EQ causes Loss of offsite power - emergency diesels start to supply site electrical loads Large Tsunami - about 45 minutes after EQ inundates Fukushima Dai-ichi site U.S.NRC United States Nuclear Regulatory Commission Protecting People and the Environment#3FUKUSHIMA SEQUENCE OF EVENTS • Onsite electrical systems lost - station black conditions • Eventual loss of reactor core cooling and containment cooling • Reactor core and containment damage in Units 1, 2, 3 • Hydrogen explosions Units 1, 3, and 4 reactor buildings U.S.NRC United States Nuclear Regulatory Commission Protecting People and the Environment#4PUS.NRC United over Maclear Regulatory Commission Protecting People and the Environment#5U.S.NRC United States Nuclear Regulatory Commission Protecting People and the Environment#6FUKUSHIMA SEQUENCE OF EVENTS Seawater, then freshwater injection restored to Units 1, 2, and 3 • Over the course of several weeks Units I, 2, and 3 cooled down, but remain in accident mitigation • Does not appear that fuel in spent fuel pool was damaged U.S.NRC United States Nuclear Regulatory Commission Protecting People and the Environment#7U.S.NRC United States Nuclear Regulatory Commiten Protecting People and the Bronz#8● NRC RESPONSE Monitoring Mode Japan Team Inspections Bulletin • Near Term Task Force U.S.NRC United States Nuclear Regulatory Commission Protecting People and the Environment#9Near Term Task Force - Conclusions • Similar sequence of events in the U.S. is unlikely • Mitigation measures could reduce the likelihood of core damage and radiological releases • No imminent risk from continued operation and continued licensing activities U.S.NRC United States Nuclear Regulatory Commission Protecting People and the Environment#10NTTF - Conclusions • NRC's regulatory framework would be enhanced by more balanced application of the defense-in-depth philosophy supported by risk insights Requirements for increased mitigation capability for design-basis and beyond design-basis events would significantly enhance safety U.S.NRC United States Nuclear Regulatory Commission Protecting People and the Environment#11NTTF - Recommendations • Twelve over-arching recommendations • Detailed recommendations support implementation Near-term and interim actions Rulemaking Longer-term evaluations topics U.S.NRC United States Nuclear Regulatory Commission Protecting People and the Environment#12• . • NEAR TERM TASK FORCE (NTTF) KEY AREAS Protection against natural phenomena Prolonged Station Blackout Emergency Preparedness capabilities ― multiple units - KEY RECOMMENDATIONS Require nuclear plant operators to re-analyze protection - especially seismic and flooding Enhance strategies to mitigate prolonged loss of a/c power Enhance emergency preparedness capabilities U.S.NRC United States Nuclear Regulatory Commission Protecting People and the Environment#13NRC LONGER TERM ACTIONS • Commission to consider the recommendations and decide agency actions • Public meeting July 28, 2011 • NRC to charter an executive steering committee guide the implementation actions U.S.NRC United States Nuclear Regulatory Commission Protecting People and the Environment#14QUESTIONS? U.S.NRC United States Nuclear Regulatory Commission Protecting People and the Environment