South Korea’s Kepco Nuclear Fuel (KNF) and GS Engineering & Construction (GS E&C) are to collaborate with Denmark’s Seaborg Technologies to investigate the feasibility of developing a low enriched uranium (LEU) fuel salt production facility in South Korea. The companies see fluoride fuel salt supply as important for generation 4 advanced reactors.

In April, Korea Hydro & Nuclear Power (KHNP), Korean shipbuilding and offshore construction company Samsung Heavy Industries (SHI) and Seaborg set up a consortium to develop and commercialise floating NPPs (FNPPs) using compact molten salt reactors (CMSR). The power plants will be installed on barges to deliver from 200 MWe to 800 MWe, with the first project expected to be a 200MWe power barge. Previously, in January, South Korea’s Samsung Heavy Industries (SHI) received Approval In Principle from the American Bureau of Shipping (ABS) for a conceptual design of a CMSR power barge using technology being developed by Seaborg.

Seaborg's CMSR uses a low enriched fluoride fuel salt which is not yet commercially available. KNF offers nuclear fuel production and fluorides handling expertise, while GS E&C has broad experience in a variety of engineering and construction projects. Seaborg is engaged with a number of research partners covering different aspects of the fuel salt and its properties, and the partners believe they have a solid foundation to investigate the path to commercialisation of fuel salt production.

KNF President & CEO Choi Ik-Soo said KNF “wants to explore adding molten salt fuel for 4th generation reactors to our portfolio, enabling us to stay in the forefront of nuclear fuel development in order to serve our clients". Kim Young-Shin GS E&C Chief Technical Officer said development of molten salt reactors “looks promising”, and nuclear fuel for 4th generation reactors “is a very interesting business opportunity for GS E&C, which fits very well with our long-term strategic goals". Seaborg CEO Navid Samandari said the collaboration “brings us one step closer to securing LEU fuel salt for our CMSR” and “further strengthens Seaborg's engagement with Korean industrial partners”.

According to Seaborg, in the CMSR the fuel is mixed into a molten fluoride salt which also acts as the coolant with significant safety benefits. Should the fuel salt come into contact with the atmosphere, it will simply cool down and become “solid rock, containing all the radioactive material within itself”. The reactor “will operate at near-atmospheric pressures eliminating a wide range of accident scenarios”.

At the end of its 12-year fuel cycle, the fuel is returned to the supplier where short-lived fission products are separated and sent to storage. “Since the fuel is chemically stable and the fission products are short-lived, this waste is radiologically similar to radioactive hospital waste and can be handled using conventional methods,” says Seaborg. The remaining fuel salt will be mixed into new CMSR fuel at the fuel supplying facility.

There are a number of molten salt reactor projects under development worldwide. In the USA, companies such as Terrapower are receiving financial and other support from the US Department of Energy. In Canada, Terrestrial Energy is developing its Integral Molten Salt Reactor, and UK-based MoltexFLEX has launched its FLEX reactor design based on molten salt technology. US company Thorcon’s molten salt reactor has been under development for around nine years, with the aim of deploying it in Indonesia. However, as with Seaborg, all these projects remain in the design stage. Russia has also launched a programme to develop a molten salt reactor bringing together all its key institutes and nuclear enterprises to work on the project. It remains to be seen which of these projects is first to produce a demonstration plant.

Image: Signing ceremony between Kepco Nuclear Fuel, GS E&C and Seaborg (courtesy of Seaborg)