Press Information

MHI Selected as Core Company for New Research Reactor for JAEA
Basic Contract Signed and Design Process Set to Commence


Illustration of current reactor core
(from 5th Consortium Committee Meeting)

Illustration of current reactor core (from 5th Consortium Committee Meeting)

Illustration of new research reactor facility
(from JAEA website)

Illustration of new research reactor facility (from JAEA website)

Tokyo, November 29, 2023 - Mitsubishi Heavy Industries, Ltd. (MHI) has been selected as a core company for the design, production and installation of an atomic reactor for research purposes (new research reactor) in a project led by the Japan Atomic Energy Agency (JAEA). A basic contract has been signed between MHI and JAEA. MHI is contracted by JAEA to handle all work related to the development of the new research reactor, and will commence construction.

It was decided at Japan's Cabinet meeting on atomic energy in December 2016 that government policy on the Monju fast breeder prototype reactor in Tsuruga City, Fukui Prefecture would shift to measures to close the reactor, and a new research reactor would be set up at Monju's site in future. The conceptual design and operation of the new research reactor were then discussed by three core institutions selected by the Ministry of Education, Culture, Sports, Science and Technology-JAEA, Kyoto University and the University of Fukui-and it was decided that the new research reactor would be used as a core base for research and development and personnel training in the atomic energy field, led by JAEA, including fundamental research using neutrons, research and development on the safety of RI and atomic energy for innovative technologies and medical treatments, and education on atomic energy. For JAEA, this is the first opportunity to build a plant since the high temperature engineering test reactor (HTTR) opened in Oarai Town in the Higashiibaraki District of Ibaraki Prefecture in 1998, and the building of this new research reactor is a crucial project for the agency.

MHI has already completed many construction projects for atomic energy plants, including construction projects and renovations to meet new regulations for a total of 24 pressurized water reactors (PWRs) around Japan. MHI played a leading role in the construction of the HTTR for JAEA's previous test reactor, and has extensive knowledge and a strong track record in areas from power reactors to research reactors. MHI also oversaw the closing of Monju, and is able to coordinate the development of the new research reactor with the schedule and area of Monju's closure to ensure that the construction process is carried out smoothly. MHI's track record and knowledge, along with its ability to ensure a smooth construction process, impressed JAEA.

MHI will utilize the technical capabilities it has accumulated thus far as it works on the development of the new research reactor as a core company.

■Japan Atomic Energy Agency (JAEA) New Research Reactor Promotion Office

About MHI Group

Mitsubishi Heavy Industries (MHI) Group is one of the world’s leading industrial groups, spanning energy, smart infrastructure, industrial machinery, aerospace and defense. MHI Group combines cutting-edge technology with deep experience to deliver innovative, integrated solutions that help to realize a carbon neutral world, improve the quality of life and ensure a safer world. For more information, please visit or follow our insights and stories on