Japan’s first interim facility to temporarily store used nuclear fuel in began official operations in Mutsu, Aomori Prefecture, after the Nuclear Regulation Authority (NRA) certified completion of pre-operation inspections.
NRA received a report from its secretariat that safety management measures at the Mutsu facility are being implemented appropriately. Five NRA members unanimously decided to issue a certificate that confirms the completion of inspections at the Recyclable-Fuel Storage Company (RFS) – the facility’s operating company in which Tokyo Electric Power Company Holdings (Tepco) and the Japan Atomic Power Company (JAPC) each have a stake.
In September, the facility had received its first shipment of 12 tonnes of fuel in a cask from Tepco’s Kashiwazaki-Kariwa NPP. It is scheduled to receive a total of 96 tonnes of used nuclear fuel by fiscal 2026. The facility’s two buildings will store a maximum of 5,000 tonnes of fuel for up to 50 years.
Government policy is to reprocess nuclear fuel to create uranium-plutonium mixed oxide (MOX) fuel, which is then reused in nuclear power plants. However, neither the reprocessing plant nor the MOX plant in the village of Rokkasho, Aomori Prefecture, are yet complete, and Japan’s NPPs have to store used fuel on-site.
According to the Federation of Electric Power Companies on-site storage in Japan has reached nearly 80% of storage capacity of about 20,000 tonnes. The Mutsu facility is intended to relieve that pressure. RFS issued a statement pledging to make safety its top priority and to operate the facility with transparency and in line with local demands. Tepco said in a statement. “We believe that the interim storage business for spent fuel is important and effective from the perspective of expanding the storage capacity of spent fuel, providing flexibility to the operation of the entire nuclear fuel cycle, and contributing to medium- to long-term energy security.”
Tepco and JAPC formed RFS in November 2005 and in March 2007 it applied to the government for a licence to construct the facility. In 2010, the joint venture received approval from the Ministry of Economy, Trade & Industry for the design and construction of the facility. Construction was completed in 2013 but new post-Fukushima safety standards required further assessments to ensure the facility’s ability to withstand earthquakes, tsunami, volcanoes and tornadoes. The company submitted its initial design and construction programme in 2016 to NRA, which approved its safety plans in 2020.
