Terrestrial Energy USA and US Department of Energy’s (DOE’s) Argonne National Laboratory (ANL) have begun detailed testing of the Integral Molten Salt Reactor (IMSR®) Generation IV advanced nuclear power plant fuel salt.

The testing programme is part of a broader ongoing confirmatory testing programme for fuel, components, and systems used in the IMSR power plant. The results will support licensing applications as first commercial deployment of the IMSR power plants advance, a press release said.

The 400MWt (190MWe) IMSR power plant operates at high temperatures (600°C) and is 50% more efficient than traditional reactors. It uses a graphite moderator, and standard assay low-enriched uranium fuel with the same level of enrichment (less than 5% U-235) as in conventional nuclear plants.

Terrestrial Energy USA began working with ANL in 2016 after receiving an award from the DOE's Gateway for Accelerated Innovation in Nuclear (GAIN) programme. GAIN directs support to the nuclear community commercialising innovative nuclear technologies.

“We are delighted to expand our relationship with ANL, which began in 2016 as the result of DOE’s GAIN programme. Our first GAIN award catalysed what is now a full-scope commercial engagement with the lab,” said Simon Irish, CEO of Terrestrial Energy USA. “Our strategy is to continue working with world-class laboratories offering expertise in relevant areas, rather than building that testing capability in-house,” he added.

ANL will use an "extensive array of characterisation techniques and advanced laboratory equipment to determine thermo-physical properties of the IMSR fuel salt to regulatory standards." It will also prepare and test fuel salt mixtures that replicate the fuel salt composition over the full reactor operating cycle. The laboratory investigations will include melting point determinations, density, viscosity, heat capacity, and thermal diffusivity measurements, Terrestrial Energy said.

Photo: Rendering of the IMSR® Core-unit (Credit: Terrestrial Energy):