Japan’s Kansai Electric Power Co said on 12 May that it will restart the ageing unit 3 reactor at its Mihama NPP in Fukui Prefecture, in late June for commercial operation in July. Fuel loading is planned to begin on 20 May. However, as Kansai Electric will be unable to complete the construction of required anti-terrorism facilities at the unit by the deadline of 25 October, its operation will be suspended again at that time.

Mihama 3 unit will be the first nuclear reactor over 40 years old in Japan to be reactivated since the March 2011 Fukushima disaster. Following the accident, the maximum operating period for nuclear power reactors was set at 40 years in principle through a revision of the reactor regulation law. However, the Nuclear Regulation Authority (NRA) granted approval in 2016 for the reactor to operate beyond the 40-year limit for an additional period of up to 20 years, after screening the company's safety measures for the unit. The mayor of Mihama also gave his consent for the resumption in February this year, followed by Fukui Governor. Tatsuji Sugimoto in April.

Two other Kansai Electric reactors in Fukui Prefecture, Takahama 1&2, have also secured NRA approval and local consent to operate beyond the 40-year limit. However, the units will not resume operation for the time being as the utility is unlikely to meet a 9 June deadline to complete necessary counterterrorism measures.

Mihama 3 unit began commercial operation in 1976; Takahama 1 in 1974 and Takahama 2 in 1975.

Photo: Mihama nuclear plant (Alpsdake – Own work, used under CC BY-SA 4.0)