Second Japanese BWR set to restart next month
Chugoku Electric Power Company has announced that it plans to resume operation of unit 2 at its Shimane nuclear power plant on 7 December. The 789 MWe boiling water reactor has been offline since January 2012.
In June 2021, Shimane 2 became the 17th Japanese reactor to pass the regulator's safety screenings and the fifth boiling water reactor (BWR) - the same type as those at the Fukushima Daiichi plant - 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 the restart of Shimane 2. His approval marked the completion of the process to gain the consent of local communities for the unit to resume operation.
In early October, Chugoku released a revised schedule for the restart of the unit. It said the reactor was expected to restart in early December, with power generation scheduled to begin in late December. The reactor will resume commercial operation in January 2025.
The utility has now specified that the unit will be restarted on 7 December.
Chugoku began loading fuel into the core of Shimane 2 on 28 October. The process of loading the 560 fuel assemblies was completed on 3 November.
Unit 2 at Tohoku Electric Power Company's Onagawa nuclear power plant was restarted on 29 October, becoming the first BWR in Japan to be restarted. However, the unit was taken offline on 3 November due to malfunctioning equipment. While a generator test was being conducted, an incident occurred in which a device for calibrating the detector that measures neutrons inside the reactor was stopped in the middle of the process.
Today, Tohoku said that it had identified the cause of the incident - "the connection between the expansion joint inside the reactor containment vessel and the guide pipe used to feed the detector cable into the reactor had become detached" due to a nut not being sufficiently tightened.
The utility has not yet said when it plans to restart the reactor again.
