Shimane Nuclear Power Station Unit 2 scheduled inspection completion date moved up to September 16

Chugoku Electric Power Co., Inc. announced on August 5 that the schedule for the 18th periodic utility inspection of Shimane Nuclear Power Station Unit 2 has been revised, with the inspection completion date moved up from September 17, 2026 to September 16, and the power generation resumption date moved up from August 19 to August 18.

Shimane Nuclear Power Station Unit 2 is a boiling water reactor unit with a rated electrical output of 820 MW. The unit was shut down on February 9, 2026 and entered its 18th periodic utility inspection. The reason for this adjustment is that, during the reactor start-up preparation work, the procurement of the nitrogen gas source used to fill the reactor containment vessel was completed earlier than planned, allowing the related work to be advanced accordingly.

Under the revised schedule, the unit will resume power generation on August 18 after completing fuel reloading, reactor pressure vessel head installation, and start-up preparation work, followed by power ascension and rated thermal power operation. A comprehensive load performance inspection is planned for September 16 to conclude this round of periodic utility inspection.

The periodic utility inspection is a regular inspection of power reactor facilities conducted in Japan pursuant to the Act on the Regulation of Nuclear Source Material, Nuclear Fuel Material and Reactors, primarily to confirm whether the equipment conforms to technical standards and whether it can continue to maintain such conformity until the next inspection.

The nitrogen gas filling work involved in this start-up preparation is intended to reduce oxygen concentration by filling the reactor containment vessel with nitrogen, maintaining an inert environment in which hydrogen is less likely to combust. According to the inspection work schedule, this periodic inspection also includes reactor pressure vessel head removal, full core fuel discharge, inspection of equipment such as the reactor pressure vessel, and engineering work related to specific severe accident mitigation facilities. In addition, to meet the special inspection requirements for units operating beyond 40 years, the operator will also conduct non-destructive testing and other data collection work on equipment such as the reactor pressure vessel.