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Japan is advancing the nuclear fuel cycle in which spent fuel from nuclear reactors is reprocessed for efficient utilization. This article, while summarizing the basics of the nuclear fuel cycle, presents the current status of the project, including the reprocessing facilities under construction.

Nuclear fuel cycle to efficiently utilize resources and reduce radioactive waste

The nuclear fuel cycle is a process in which spent fuel from nuclear reactors is reprocessed to recover uranium and plutonium and produce MOX fuel for power generation.

The nuclear fuel cycle has the following benefits:

Spent fuel from nuclear reactors consists of 95 to 97% uranium and plutonium, which can be recovered and reprocessed to be reused as fuel.

The Strategic Energy Plan, which shows the direction of Japan’s energy policy, has stated that promoting the nuclear fuel cycle is a basic policy. The latest 6th Strategic Energy Plan, on which a Cabinet decision was made in October 2021, reiterates the importance of continuing efforts toward realizing the nuclear fuel cycle.

Nuclear power generation, which emits no CO2 during operation, is an important source of energy toward achieving carbon neutrality by 2050. The Basic Policy for the Realization of GX, on which a Cabinet decision was made in February 2023, depicts a roadmap for energy and environmental policies toward simultaneously achieving a stable supply of energy, economic growth and decarbonization. It also advocates a policy for promoting the nuclear fuel cycle.

The present status of the reprocessing plant under construction

There are several challenges lying ahead toward establishing the nuclear fuel cycle.

First, it is essential to commission the Rokkasho Reprocessing Plant, which is under construction in Aomori Prefecture.

The Rokkasho Reprocessing Plant (RRP) is required to comply with new regulatory standards formulated in 2013 to be applied to all nuclear facilities. To do so, Japan Nuclear Fuel Limited (JNFL), the operator of the plant, advanced the necessary construction work and applied for an examination based on the new regulatory standards in 2014. In July 2020 JNFL was granted permission for an operational change, which allowed it to implement various measures based on the new regulatory standards.

JNFL obtained approval for the first part of the design and construction plans on December 21, 2022, with major safety work being almost completed by the end of 2022. The RRP is in the final stage of completion with efforts being made toward commissioning it as early as possible within the first half of FY2024.

The Government of Japan is giving guidance and instruction to JNFL and power utilities with a view to commissioning the RRP, which will have a capacity to process approximately 800 tons of spent fuel per year when in full operation.

Spent fuel now occupies 80% of the storage capacity

The second critical challenge is increasing spent fuel in storage. Japan has been utilizing nuclear power generation for more than half a century and has 19,000 tons of spent fuel in storage. Spent fuel stocks are managed by respective nuclear power stations (NPSs) within the maximum controlled capacities determined for each NPS. The controlled capacities in all facilities across Japan total 24,000 tons, 80% (19,000 tons) of which is occupied as of 2023.

Under such circumstances, the government and the Federation of Electric Power Companies of Japan (FEPC) jointly established a Council for Promoting Measures for Spent Fuel Management (tentative translation) to step up efforts toward increasing storage capacities through collaboration and cooperation among utilities as well as with the government.

Power utilities as a group have plans to increase the storage capacity by approximately 6,000 tons in total, specifically 4,000 tons by around the mid-2020s plus 2,000 tons by around 2030. Efforts are currently being made toward securing approximately 4,600 tons of incremental storage capacity. This involves the construction of dry storage facilities at Ikata NPS of Shikoku EPC and Genkai NPS of Kyushu EPC, as well as the interim storage facilities in Mutsu City of Tokyo EPC and Japan Atomic Power, which passed a safety examination by the Nuclear Regulation Authority.

Those projects need to be advanced on the major premise of obtaining the understanding of local people, and the Government of Japan will make all-out efforts to achieve this through careful dialogues and similar measures.

As explained above, promoting the nuclear fuel cycle will also contribute to a reduction in stored spent fuel.

Collaboration among power utilities toward expanding the use of MOX fuel

The third challenge is regarding the use of MOX fuel, which is currently used in light-water reactors for power generation.

In the plutonium-thermal program, MOX fuel (recycled fuel), which is produced from a mix of uranium and plutonium recovered at the Rokkasho Reprocessing Plant, is used in light-water reactors at nuclear power stations. Plutonium-thermal power generation is currently in operation at four reactors, including two at Kansai EPC’s Takahama NPS. In order to advance the nuclear fuel cycle, it is essential to increase the number of power stations using MOX fuel.

In December 2020, nine utilities (excluding Okinawa EPC), Japan Atomic Power Company, and J-Power published the New Pluthermal Program, aiming to have at least 12 reactors utilizing plutonium-thermal power generation by 2030. To this end, it is essential to obtain the understanding of local stakeholders. The Federation of Electric Power Companies of Japan (FEPC) formulated the Action Plan for the Promotion of the Plutonium-Thermal Program, calling for efforts toward obtaining the understanding of local people and strengthening collaboration among electric power businesses.

We will promote the nuclear fuel cycle through a concerted effort involving the public and private sectors.

Division in charge

About this article

Nuclear Facilities Development and Nuclear Fuel Cycle Industry Division, ANRE

About Special Contents

Research and Public Relations Office, Commissioner’s Secretariat, ANRE