– Reactors in Japan were left idle after the Fukushima disaster in 2011
– Japanese regulators introduced regulations in 2013 allowing for 20-year extensions to reactor operating periods
– Kansai Electric Power Company received a license extension in 2016 for its Mihama unit 3, which became the first reactor to operate beyond 40 years.
The International Atomic Agency (IAEA) found that Kansai Electric Power Company in Japan is implementing measures for the safe long-term operation of unit 3 at its Mihama NPP. Japanese reactors are regulated to have a nominal operating period of 40 years, with the possibility of a 20-year extension under strict safety requirements. Unit 3 at Mihama received a license extension in 2016, allowing it to operate until 2036, making it the third Japanese unit to operate beyond 40 years. After the Fukushima disaster in 2011, Mihama shut down but restarted in 2021 to become the first Japanese reactor to operate beyond 40 years.
The IAEA carried out a safety review at Mihama 3 to assess its long-term operation aspects. The review addressed strategy and key elements for the safe operation of nuclear power plants and was completed by the IAEA team. The team commended Kansai Electric for implementing measures for safe long-term operation and found that some activities already meet IAEA safety standards. The plant was encouraged to address the review findings and implement all remaining activities for safe long-term operation as planned.