Japan’s Chugoku Electric Power Company has restarted unit 2 at its Shimane NPP in Matsue in Shimane Prefecture, which has been closed since shortly after the 2011 Fukushima Daiichi disaster, the company said. The reactor is scheduled to begin commercial operation in early January 2025.
The 820 MWe Shimane 2 is the second boiling water reactor (BWR) in Japan to restart, after unit 2 at Tohoku Electric Power’s 789 MWe Onagawa NPP in Miyagi Prefecture resumed operation in October. This brings the number of Japan’s operational reactors to 14, with a combined capacity of 13,253 MWe.
Both Onagawa 2 and Shimane 2 are the same type as the reactors at Tokyo Electric Power Company Holdings’ Fukushima Daiichi NPP, which suffered a triple meltdown following the Great East Japan Earthquake.
Shimane 2 began commercial operations in 1989 and was closed in January 2012 for regular inspections. In June 2021, it became the 17th Japanese reactor (and the fifth BWR) to pass Nuclear Regulation Authority’s safety screenings to receive regulatory approval to restart.
Following approvals by the cities of Matsue, Izumo, Yasugi and Unnan, in June 2022 the governor of Shimane prefecture approved restart of the unit. Shimane 2 was set to resume in August, but this was postponed because of required safety upgrade work.
Ahead of the restart, it was pointed out that there was no effective way for about 450,000 people living within a 30-kilometre radius of the plant to evacuate safely in the event of an accident. Some residents filed for a provisional injunction in May to ban the restart of the unit but the court refused to accept it.
Shimane unit 1 – a 460 MWe BWR that started commercial operation in March 1974 – is now being decommissioned. However, Chugoku has initiated the regulatory process for starting up Shimane 3, a new 1,373 MWe advanced boiling water reactor, which is nearing completion.
Chugoku President and CEO Kengo Nakagawa said: “We believe that we have reached an important milestone in the restart process. We will continue to put safety first and work with even greater intensity as we steadily proceed with inspections and checks of equipment in preparation for paralleling (restarting) generators and resuming commercial operations one by one.”
To date, following the closure of all of Japan’s reactors in the wake of the Fukushima disaster, 24 have already been decommissioned. Of the 27 that have undergone safety screenings, the restart of 17 has been approved, 13 of which have already resumed operations (12 pressurised water reactors and one BWR). The remaining four are preparing to resume operations after improving safety measures. The screenings of 10 reactors are still ongoing.
