CNL to help develop IMSR fuel monitoring technology

16 September 2020

Terrestrial Energy and Canadian Nuclear Laboratories (CNL) are to collaborate on a programme of work evaluating safeguards related to the operation of Terrestrial's Integral Molten Salt Reactor (IMSR). The work will involve developing and testing techniques to track the behaviour of the proposed liquid fuel that would be used in Terrestrial's IMSR design.

A cutaway of the IMSR (Image: Terrestrial Energy)

Safeguards is an international regulatory framework that ensures the security of nuclear material. Under international regulations, nuclear operators are required to account for their entire inventory of fissile material at any given time. This system is administered in Canada by the Canadian Nuclear Safety Commission (CNSC) and verified internationally by the International Atomic Energy Agency (IAEA) under national treaty arrangements. Terrestrial has already developed a safeguards programme for the IMSR power plant operation. These safeguards follow CNSC regulatory requirements on safeguards and nuclear material accountancy.

The IMSR fuel is dissolved in molten salt and moves around the reactor core as a liquid. As the reactor uses a moving fuel, different accounting methods are required. Under this project, CNL will work to identify and experimentally verify a number of techniques to monitor IMSR fuel, including an innovative new use of neutron detectors recently developed by CNL researchers. This technique has the potential to serve as a new tool for the independent verification of nuclear reactor activities. CNL recently filed a patent to protect the technology.

The project - expected to be completed by June 2021 - will be carried out under CNL's Canadian Nuclear Research Initiative (CNRI). This was launched in July last year to accelerate small modular reactor deployment by enabling research and development and connecting global vendors of SMR technology with the facilities and expertise within Canada's national nuclear laboratories. Recipients are expected to match the value contributed by CNL either in monetary or in-kind contributions. Kairos Power, Moltex Canada, Terrestrial Energy Inc and UltraSafe Nuclear Corporation were selected in November as the first recipients of support under the initiative.

"The CNRI programme was established to make our facilities and researchers easily accessible to SMR developers, such as Terrestrial Energy, so that we can help support deployment of these technologies," said CNL President and CEO Joe McBrearty. "This CNRI-supported project will help to enable Terrestrial Energy's IMSR safeguard programme and methods, which are essential for regulatory approval. We look forward to working with Terrestrial Energy on this important project."

"The tracking and monitoring of liquid fuel in a proposed SMR reactor design is a new area of R&D for CNL, and will expand our capabilities and expertise in advanced fuel research," said Jeffrey Griffin, CNL's vice-president of science and technology. "In this instance, we also have the opportunity to apply a new technology that we developed and patented here at CNL, which is very exciting. We continue to believe that SMRs represent the future of clean energy here in Canada, and the CNRI programme is moving us closer towards this vision."

The collaboration agreement between CNL and Terrestrial further strengthens the relationship between the two companies that started in June 2016 with a Master Task Agreement for consulting, technical and scientific services.

Molten salt reactors (MSRs) use fuel dissolved in a molten fluoride or chloride salt, which functions as both the fuel (producing the heat) and the coolant (transporting the heat away and ultimately to the electricity generating equipment). Terrestrial's IMSR builds on 50 years of MSR experience at the USA's Oak Ridge National Laboratory, and integrates the primary reactor components, including the graphite moderator, into a sealed and replaceable reactor core unit with an operating lifetime of seven years.

Researched and written by World Nuclear News