The U.S. Congress asked the National Academy of Sciences (NAS) to examine the causes of the March 11, 2011, accident at the Fukushima Daiichi nuclear plant and identify lessons learned for the United States. Brief descriptions of key selected findings and recommendations are provided below.
Causes of the Fukushima Daiichi Accident: The Fukushima Daiichi nuclear accident was initiated by the March 11, 2011, Great East Japan Earthquake and tsunami. Personnel at the plant responded to the accident with courage and resilience; their actions likely reduced its severity and the magnitude of offsite radioactive material releases. However, several factors relating to the management, design, and operation of the plant prevented plant personnel from achieving greater success and contributed to the overall severity of the accident.
Lessons Learned from the Fukushima Daiichi Accident for the United States: NAS recommends that several actions be taken to improve the resilience of U.S. nuclear plants and enhance U.S. emergency response. These actions are summarized below.
• Nuclear plant licensees and their regulators must actively seek out and act on new information about hazards that have the potential to affect nuclear plant safety.
• The U.S. nuclear industry and its regulator (the U.S. Nuclear Regulatory Commission) should improve specific nuclear plant systems, resources, and training to enable effective responses to severe accidents.
• The U.S. nuclear industry and the U.S. Nuclear Regulatory Commission should strengthen their capabilities for assessing risks from events that could challenge the design of nuclear plant structures and components and lead to a loss of critical safety functions. The U.S. Nuclear Regulatory Commission should support industry’s efforts to strengthen its capabilities by providing guidance on approaches and by overseeing rigorous peer review.
• The U.S. Nuclear Regulatory Commission should further incorporate modern risk concepts into its nuclear safety regulations using these strengthened capabilities.
• The U.S. nuclear industry and U.S. emergency response organizations should examine and, as needed, revise their emergency response plans, including the balance among protective actions, to enable effective responses to severe nuclear accidents.
• The U.S. Nuclear Regulatory Commission and the U.S. nuclear power industry must maintain and continuously monitor a strong nuclear safety culture in their safety-related activities and should examine opportunities to increase the transparency of and communication about their efforts to assess and improve nuclear safety.