A team of international nuclear safety experts today completed a review of Japan's two-stage process for assessing nuclear safety at the nation's nuclear power plants. The team began its work on 23 January and delivered a Preliminary Summary Report to Japanese officials today and plans to finish the final report by the end of February.
National safety assessments and their peer review by the IAEA are a key component of the IAEA's Action Plan on Nuclear Safety, which was approved by the Agency's 152 Member States following last year's nuclear accident at Fukushima Daiichi Nuclear Power Station. At the request of the Government of Japan, the International Atomic Energy Agency (IAEA) organized a 10-person team to review the Japanese Nuclear and Industrial Safety Agency's (NISA) approach to the Comprehensive Assessments for the Safety of Existing Power Reactor Facilities and how NISA examines the results submitted by nuclear operators.
The IAEA safety review mission consisted of five IAEA and three international nuclear safety experts. To help its review, the team held meetings in Tokyo with officials from NISA, the Japanese Nuclear Energy Safety (JNES) Organization, and the Kansai Electric Power Company (KEPCO), and the team visited the Ohi Nuclear Power Station to see an example of how Japan's Comprehensive Safety Assessment is being implemented by nuclear operators. "We concluded that NISA's instructions to power plants and its review process for the Comprehensive Safety Assessments are generally consistent with IAEA Safety Standards," said team leader James Lyons, director of the IAEA's Nuclear Installation Safety Division.
In its Preliminary Summary Report delivered today, the team highlighted a number of good practices and identified some improvements that would enhance the overall effectiveness of the Comprehensive Safety Assessment process.
Good practices identified by the mission team include:
- Based on NISA instructions and commitments of the utilities, emergency safety measures were promptly addressed in Japanese NPPs following the accident on 11 March 2011;
- NISA's practice of conducting an independent walkdown of emergency measures implemented at nuclear power plants enhances confidence that plants and operators can respond effectively during an emergency; and
- By observing European stress tests, NISA is demonstrating its commitment to improving Japanese nuclear safety by gaining experience from other countries.
Improvements that would enhance the overall effectiveness of the Comprehensive Safety Assessment process include:
- Although NISA has demonstrated a notable level of transparency and interested party consultation related to the Comprehensive Safety Assessment and its review process, NISA should conduct additional meetings with interested parties near nuclear facilities that are subject to Comprehensive Safety Assessment;
- NISA should use the experience it gains from the first few reviews to clarify its guidance for how nuclear power plants should conduct their Comprehensive Safety Assessments and for how NISA should review those assessments;
- In the Secondary Assessment, there are areas that NISA could address more thoroughly, such as seismic safety margins and severe accident management; and
- NISA should ensure that the Secondary Assessments are completed, evaluated and confirmed by regulatory review within an appropriate timeframe.
"We enjoyed excellent cooperation from our Japanese counterparts during this mission," Lyons said. "I encourage all nations to implement the IAEA Action Plan to improve global nuclear safety."