Talks advance on Japanese role in Wyoming fast reactor project

Yomiuri Shimbun file photo
The Monju fast reactor is seen in Tsuruga, Fukui Prefecture, in May 2021.

The Japan Atomic Energy Agency and Mitsubishi Heavy Industries, Ltd. signed Wednesday a memorandum of understanding with U.S. nuclear start-up TerraPower, LLC on technical cooperation over a next-generation fast reactor development project.

The move paves the way for Japan to maintain and develop its fast reactor-related technology, following the scrapping of a plan involving Monju, a prototype fast reactor in Fukui Prefecture, after a series of accidents and problems were found at the facility.

The JAEA plans to call for the participation of Japanese companies that had been engaged in fast reactor development, eyeing construction of a domestic facility in the future.

With the support of the U.S. Energy Department, TerraPower plans to start the construction of a next-generation fast reactor in 2024 in Kemmerer, Wyoming, with operation scheduled to begin in 2028. The reactor will have an output of 345,000 kilowatts.

Yomiuri Shimbun file photo
The Joyo fast reactor is seen in Tokai, Ibaraki Prefecture, in August 2020.

The Japanese side also included Mitsubishi FBR Systems, Ltd., which will be in charge of designing the fast reactor.

According to the agency and other organizations, the Japanese side will provide technologies accumulated through the development of Monju, which is currently undergoing decommissioning work, and Joyo, another research fast reactor in Ibaraki Prefecture that is presently undergoing a periodic inspection.

The two sides agreed to discuss the development of core equipment, such as fuel-handling devices and a system to identify damaged fuel. Mitsubishi Heavy Industries possesses such technologies.

According to sources, other crucial technologies such as ones involving in-core structures may be included as well. The JAEA and TerraPower also signed a confidentiality agreement.

The details of cooperation will be discussed based on the design presented by the U.S. side, and the official contract is expected to be concluded by summer.

The JAEA will urge domestic companies connected to the development of Monju and Joyo — such as Hitachi-GE Nuclear Energy, Ltd., Toshiba Energy Systems & Solutions Corp., and Fuji Electric Co. — to take part in the project. The agency hopes to promote the nuclear industry by creating business opportunities for such companies to supply products that will be necessary for the U.S. fast reactor.

The U.S. side has said it would like to make use of AtheNa, the agency’s world-leading sodium experimental facility in Ibaraki Prefecture.

“We’d like to consider such ways as receiving orders to conduct experiments on behalf of the U.S. side and earn income,” a JAEA official said.

By utilizing the characteristics of high-speed neutrons, fast reactors can burn plutonium and other fuels more effectively than conventional light-water reactors, producing lower amounts of radioactive waste that emits intense radiation for a long time.

Although fast reactors are indispensable to Japan’s nuclear fuel cycle policy, which aims to make more effective use of nuclear fuel, the development of related technologies has been stalled since the 2016 government decision to scrap Monju.

Aiming to reduce greenhouse gas emissions to net zero and achieve a carbon-neutral society by 2050, the government plans to promote research and development of next-generation nuclear reactors, including fast reactors.

“Nuclear power is a decarbonizing energy source, and we hope to maintain Japan’s own technologies through our contributions in nuclear power development,” said Hideki Kamide, vice chief of the JAEA’s Sector of Fast Reactor and Advanced Reactor Research and Development.