When the heaviest material in nature, uranium, induces a "nuclear fission" reaction, several particles are released with heat.

One of the emitted particles, a neutron, acts as a trigger for another nuclear fission reaction, then, a chain reaction of nuclear fission occurs in the reactor core. If the number of nuclear fission reactions is kept constant in the reactor (critical state), the reactor can be operated stably. The number of released neutron and heat are also kept same values. Nuclear power plants use the heat released by nuclear fission reactions to generate electricity.

The neutrons have an ability to penetrate materials. Therefore, it is possible to see through the structure of various objects and the phenomena occurring inside the objects without destroying the object. By observing inside of various objects, it may be possible to improve the products or create completely new products.

To advance the safety and performance of nuclear reactors, it is desirable to perform the experiments in the similar conditions inside the nuclear power reactors. By using test samples placed in a nuclear reactor where various types of radiation are exposed, safety can be verified by observing the changes occurred in the samples. During the reactor operation, development of human resources for the safe operation of nuclear reactors can also be done, simultaneously.

Expected roles of the reactor

The new research reactor aims to be a core base for R&D and human resource development in the nuclear energy field in west Japan area. The reactor can be expected to use not only for R&Ds such as basic science, innovative research, medical radioisotope research, and nuclear safety, but also for the contribution to human resource development and to harmonious coexistence with the local community.

Contribution of new research reactor to SDGs

Background

At the 2016, Meeting of cabinet ministers charged with nuclear energy decided to decommission the prototype fast breeder reactor "Monju". The installation of a research reactor in the "Monju" site are also decided.
The Ministry of Education, Culture, Sports, Science and Technology (MEXT) conducted research on the reactor candidates from FY2017 to FY2019.

As a result of the research, medium power reactor (thermal output less than 10MW) was chosen to utilize neutron beams as a core base for nuclear research and human resource development in western Japan.

Along to this decision, MEXT solicited proposals for a "conceptual design of a new test and research reactor to be installed at the Monju site and a review of its operation". JAEA, Kyoto University and University of Fukui were adopted as the core institutions of the entrusted business to carry out conceptual design (FY2020-2022). JAEA is the representative organization of the core institutions.