Rokkasho Reprocessing Plant Delays Impact Spent Nuclear Fuel Management
TEPCO Outlines Medium-Term Transfer Plans in Aomori
On July 7, TEPCO President Tomoaki Kobayakawa met with Aomori Governor Soichiro Miyashita at the prefectural office to outline medium-to-long-term transfer plans, according to JAIF. Kobayakawa explained that post-accident inspections and technical evaluations confirm interim storage and reprocessing are technically feasible. The facility in Mutsu employs dry storage, where spent fuel is cooled by air, and began receiving spent fuel from the Kashiwazaki Kariwa Nuclear Power Plant in September last year. Specific transfer timelines have not yet been finalized, but TEPCO anticipates moving roughly 200 to 300 tons annually in the 2030s to meet storage deadlines. Spent fuel will be stored for a maximum of 50 years before transport to the Japan Nuclear Fuel Limited Rokkasho Reprocessing Plant.
Regional Utility Interest and Local Governance Hurdles
Kansai Electric Power Co. and Tohoku Electric Power Co. have expressed an intention to use the Mutsu interim storage facility, people familiar with the matter stated in September 2026, according to Jiji Press. TEPCO and Japan Atomic indicated last December that they wanted to consider having the Mutsu facility accept spent fuel from other operators after determining their own plants would fall short of expected storage amounts. Mutsu Mayor Tomoya Yamamoto gave approval for the move, prompting TEPCO and Japan Atomic to survey eight other Japanese power firms.
Despite utility interest, Aomori Governor Soichiro Miyashita has stated that adding outside companies to the list of nuclear plant operators using the interim storage facility was not envisaged under the original agreement with local host governments. It remains uncertain whether Kansai Electric and Tohoku Electric will receive permission to use the facility.
Capacity Pressures at Regional Nuclear Plants
Both Kansai Electric and Tohoku Electric face imminent storage constraints at their existing reactor sites. Kansai Electric stores spent fuel in pools at its Mihama, Oi, and Takahama nuclear power plants in Fukui Prefecture, where 80 to 90 percent of storage capacity is already filled. Those pools are expected to reach maximum capacity between fiscal 2028 and fiscal 2030, leading the company to plan a dry storage facility and transport fuel out of Fukui by the end of 2035. Tohoku Electric faces similar pressure, with spent fuel pools at its Onagawa nuclear plant in Miyagi Prefecture projected to max out around November 2028. Tohoku Electric plans to start building a dry storage facility to begin operating in March 2028.
Meanwhile, the ultimate destination for the spent fuel, the Japan Nuclear Fuel Limited Rokkasho Reprocessing Plant in Aomori, remains under construction after experiencing repeated completion postponements.