For four years at Onagawa-2, since February 2020, after a safety examination for a change in the reactor installation involving compatibility with new regulatory standards, safety measures work has been proceeding toward restarting operations, currently planned for September 2024. Expecting that the spent fuel pool at Unit 2 will reach the limit of its capacity four years after that, the power company has decided to install two dry storage facilities to temporarily store the spent fuel within the premises, until it can be moved out of the nuclear power plant (NPP).

Dry storage involves storing spent fuel that has first been allowed to cool sufficiently in fuel pools―called “fuel pits” in the case of pressurized water reactors (PWRs)―in sealed containers known as storage and shipping casks, those to be cooled by natural air convection. Such a facility is now being utilized within the premises of the Tokai-2 NPP, owned and operated by the Japan Atomic Power Company (JAPC).

At the Hamaoka NPPs (Chubu Electric Power Co.), the Ikata NPPs (Shikoku Electric Power Co.) and the Genkai NPPs (Kyushu Electric Power Co.), power companies are preparing for installation of similar facilities, including examinations by the NRA.

Recently, on February 8, the Kansai Electric Power Co. (Kansai EP) announced its plan for dry storage facilities at its Mihama, Takahama and Ohi NPPs, and requested preliminary talks with Fukui Prefecture and the relevant municipalities.

Dry storage containers are designed to maintain safety functions in case storage buildings are damaged as a result of natural phenomena, such as earthquakes or tornados. For example, during the massive earthquake in eastern Japan in 2011, the dry storage facility at Fukushima Daiichi remained robust.

Tohoku Electric Power plans to launch construction of two dry storage facilities in May 2026, aiming at completion in March 2028 and June 2032. The power company will respond appropriately to examinations by the NRA, and endeavor to provide thorough, easy-to-understand explanations to obtain understanding throughout the local area.