Research activities in the Czech Republic focusing on materials and technologies for advanced helium-cooled nuclear reactors

Organisations in the Czech Republic are involved in international research and development of advanced helium-cooled nuclear reactors, including both the very-high-temperature reactors (VHTRs) and the gas-cooled fast reactors (GFRs). To support this effort, a dedicated research infrastructure has been developed and constructed, incorporating large-scale facilities, such as the High-Temperature Helium Loop (HTHL), the S-Allegro helium loop, and other specialised equipment. Current studies are investigating the resistance of structural materials in high-temperature helium environments. Various metallic alloys and ceramic materials intended for high-temperature applications are tested at 750–900 °C. Additional activities focus on helium-coolant technologies – particularly purification, purity monitoring, recovery, and primary-circuit sealing – and on reactor safety and system behaviour under off-normal and emergency conditions.