Molten salt reactor moves one step closer to realisation
Last week, research into materials for the molten salt reactor commenced at the High Flux Reactor (HFR). This irradiation research examines the interaction between the salt and the construction materials of a future molten salt reactor. This type of reactor offers strong safety prospectsand produces less long-living radioactive waste than existing nuclear power plants. A molten salt reactor is therefore an attractive concept as a “small modular reactor” (SMR). This research is being conducted as part of the NRG PALLAS research programme on behalf of the Ministry of Economic Affairs and Climate Policy (KGG).
‘The molten salt programme at NRG PALLAS includes research into suitable construction materials, the processing and purification of molten salts, and the stabilisation of radioactive waste. Several projects have already been completed within the programme. This irradiation is groundbreaking because the influence of irradiation on the corrosion of construction materials has not been tested before. Within a few years, we will be able to see how the material behaves,' says Arjan Vreeling, manager of nuclear irradiation at NRG PALLAS. 'In addition, we are identifying which fission products are released from the fuel during irradiation. The fuel must remain as pure as possible during use, so it is important to know whether the fission products formed remain dissolved, precipitate or are gaseous. Within this molten salt programme, we are collaborating with the Joint Research Centre. The salt is supplied from Karlsruhe and the design of the irradiation facility is being carried out in collaboration with Petten. This is unique research that is bringing the realisation of molten salt reactors even closer."
NRG PALLAS has a unique, end-to-end infrastructure for irradiating nuclear fuels and construction materials in Petten. Since 2015, we have been developing capabilities to qualify molten salt fuel and MSR construction materials (alloys, graphite) for use in a high-temperature neutron field. In combination with special facilities for characterisation prior to irradiation and advanced facilities for post-irradiation examination at the Petten site, this forms a comprehensive qualification platform for molten salt reactors.
The HFR is one of the few material testing reactors in the world that can investigate nuclear fuels and achieve a significant neutron damage in construction materials. The reactor is used for both the production of medical isotopes and for research into nuclear energy, and operates at full power for approximately 260 days per year, with intermittent stops for maintenance and fuel loading. A high neutron flux in combination with instrumentation enables accelerated testing of materials and fuels under controlled conditions. The HFR will be replaced by the new PALLAS reactor, currently under construction in Petten, ensuring the continuity of these unique irradiation services for nuclear fuels and materials.
About Molten Salt Reactors (MSR)
The molten salt reactor was invented by American nuclear physicist Alvin Weinberg. In the 1960s, an experimental reactor operated for five years at the American government laboratory in Oak Ridge. NRG PALLAS is collaborating on molten salt reactor research with, among others, the European Commission's Joint Research Centre in Karlsruhe and Petten. Several companies around the world are working on designing and obtaining licences for MSRs, including Thorizon (Netherlands/France) and Terrestrial Energy (US/Canada). In order to demonstrate the compatibility of the salts and construction materials under reactor conditions, they will be able to use the irradiation facilities in Petten in the future, which will significantly accelerate the realisation of these innovative reactors.
