Jules Horowitz Reactor

A CEA nuclear research reactor project built at the Cadarache centre.


Unlike a production reactor, the HJR is not designed to produce electricity, but to provide scientific data on the behaviour of nuclear materials and fuels when subjected to very high loads.

The HJR will bombard samples of components that researchers or industry wish to test with an intense neutron beam. In the RJH's experimental facilities, these samples can also be subjected to extreme pressures and temperatures if required. These components will be subjected to accelerated ageing and will be taken out of their nominal use, under accidental conditions, if necessary, to qualify them for industrial use. 

The RJH project is intended to replace the Osiris reactor, which was shut down at the end of 2015. Its objective is to study the behaviour of materials and fuel of all power reactors: 2nd, 3rd and 4th generation, by bombarding them with neutrons to simulate the ageing of the equipment. At the same time, the reactor will become a major radioelement producer, capable of producing up to 50% of the technetium used in nuclear medicine operations in Europe.

With increasing energy demands and limited fossil fuel resources, it is reasonable to expect that nuclear energy could play an important role in meeting the needs of industry and the electricity grid. Nuclear energy is generated from fission reactions before the industrial use of fusion reactions. The introduction of nuclear fission energy is accompanied by continuous research and development to improve plant safety and productivity. 

In the context of more than 40 years of nuclear power plant operation, research is needed to improve the performance and safety of power reactors. Therefore, these experimental reactors allow to test the behaviour of materials and fuels, which is very important for the qualification of prototypes or industrial products to be used in existing or future reactors.

The RJH concept, with a thermal power of 100 MW, will allow up to 20 different irradiation experiments to be performed in parallel. The reactor will be cooled by water, liquid lead, liquid sodium or gas. The working temperature can reach 1000°C.  As such, the HJR will be particularly well suited to testing the concepts, components and fuels of the innovative prototype reactors developed under the Generation IV International Project (a US Department of Energy initiative to establish international cooperation in the development of so-called Generation IV nuclear systems).