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What are the Lessons Learned from Fukushima?

Lessons Learned Logo After the Fukushima accident, a task force of senior NRC staff reviewed the circumstances of the event to determine what lessons could be learned. In July 2011, the task force provided recommendations to enhance U.S. reactor safety, and these became the foundation of the NRC's post-Fukushima activities. The Commission then approved a three-tiered prioritization of the recommendations as summarized below (note that Recommendation 1 is being addressed outside of the three tiers).

Post Fukushima Safety

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Tier 1 Activities

Activity Brief Description NRC Addressing by…
Mitigation Strategies
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To enhance the capability to maintain plant safety during a prolonged loss of electrical power. Order
Containment Venting System
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To provide a reliable hardened containment vent system for boiling water reactors (BWRs) with Mark I or Mark II containment designs. Order
Spent Fuel Pool Instrumentation
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To provide a reliable wide-range indication of water level in spent fuel storage pools. Order
Seismic Reevaluations
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To reanalyze potential seismic effects using present-day information to determine if safety upgrades are needed. Request for Information
Flooding Hazard Reevaluations
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To reanalyze potential flooding effects using present-day information to determine if safety upgrades are needed. Request for Information
Seismic and Flooding Walkdowns
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To inspect existing plant protection features against seismic and flooding events, and correct any degraded conditions Request for Information
Emergency Preparedness – Staffing and Communications
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To assess staffing needs and communications capabilities to effectively respond to an event affecting multiple reactors at a site. Request for Information
Station Blackout Mitigation Strategies
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To enhance the capability to maintain plant safety during a prolonged loss of electrical power. Rulemaking
Onsite Emergency Response Capabilities
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To strengthen and integrate different types of emergency procedures and capabilities at plants. Rulemaking
Filtration and Confinement Strategies
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To evaluate potential strategies that may further confine or filter radioactive material if core damage occurs Rulemaking

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Post Fukushima Tier 2, Tier 3 and Non-Tiered Activities

In October 2015, the NRC staff developed an overall approach and specific project plans to resolve the remaining non-Tier 1 Near Term Task Force (NTTF) recommendations, as well as other activities with a direct nexus to Fukushima, by the end of 2016. The staff's evaluation considered existing requirements and voluntary measures, the overall risk posed by the issue, and insights gained during work on the Tier 1 activities, to determine if a recommendation would provide a substantial safety improvement if implemented. For the majority of the remaining recommendations, the staff's evaluation determined that the NRC's existing regulatory framework and requirements are adequate and that no further regulatory action or analysis is needed. Through this effort, all non-Tier 1 recommendations have been resolved. See Resolution of Post Fukushima Tier 2, Tier 3, and Non Tiered Activities for a discussion on how each non-Tier 1 recommendations have been addressed.

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Page Last Reviewed/Updated Tuesday, May 08, 2018