News

Terrestrial Energy, an American developer of small modular nuclear power plants, and NRG PALLAS are starting the final phase of their graphite irradiation program for Terrestrial Energy’s Integral Molten Salt Reactor (IMSR). The irradiation tests will enable Terrestrial Energy to finalize the qualification of graphite for licensing and future operation of its IMSR plant. The tests are conducted at the High Flux Reactor (HFR) Research Center of NRG PALLAS in Petten (the Netherlands). 

Material tests enable the selection of graphite type and licensing for the Generation IV Integral Molten Salt Reactor (IMSR) core technology. This technology is designed to deliver high-temperature heat and electrical energy, for industrial purposes among other things. Terrestrial Energy’s IMSR is a thermal spectrum reactor that uses around 125 tonnes of graphite as the neutron moderator. The completion of tests at the High Flux Reactor will confirm the predicted performance of selected graphite grades. 

Terrestrial Energy’s goal is to build, license and commission the first IMSR plants in the early 2030s. Since 2020 Terrestrial Energy works with several suppliers of nuclear graphite in western markets on a test program for the selection and qualification of the most suitable graphite grade.

"Comprehensive irradiation tests are essential for advanced reactor development and reactor licensing, as they validate the performance of critical materials under actual operating conditions. The tests are providing the data needed to make our final graphite grade selection for the IMSR," said Simon Irish, CEO of Terrestrial Energy. “This work will be a major step toward Terrestrial Energy’s goal of achieving early fleet deployment. NRG PALLAS’ technical expertise and research capabilities are unparalleled in the world of advanced reactor development”. 

NRG PALLAS has more than 50 years of experience in nuclear technology research and considerable experience with irradiation tests of materials for the development of nuclear reactors. Using the High Flux Reactor (HFR), NRG PALLAS simulates ageing processes of reactor materials in an accelerated manner. This allows the effects of irradiation on materials to be measured in order to support reactor design and licensing.

"NRG PALLAS is committed to supporting the development of advanced reactors, " said Arjan Vreeling, manager R&D Nuclear Fuels & Materials of NRG PALLAS. " We have been collaborating with Terrestrial Energy now for 5 years and are delighted to be moving to the final stage of irradiation testing of IMSR graphites. Terrestrial Energy is the first developer to begin such tests for this type of molten salt reactors."