South Korea’s Samsung Heavy Industries (SHI) has said it has received Approval In Principle from the American Bureau of Shipping (ABS) for a conceptual design of a Compact Molten Salt Reactor (CMSR) Power Barge – floating offshore NPP – using technology being developed by Denmark’s Seaborg. SHI signed a business agreement with Seaborg in January 2022 to develop a floating NPP and plans to commercialise it by 2028 after completing detailed design of all power generation facilities.

In April, SHI and Seaborg signed a partnership agreement to develop floating nuclear power plants based on Seaborg’s CMSR. The agreement included development of hydrogen production plants and ammonia plants, as the CMSR is an ideal power source for supply of stable, clean, and safe electricity.

The Power Barge, designed by SHI, can be equipped with 2-8 100MW CMSRs as required. SHI says it is not only an alternative to existing fossil fuel power generation facilities, but also can produce electricity and heat for industrial systems, hydrogen production, and seawater desalination facilities.

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.

In June, Seaborg was awarded an innovation grant by the European Innovation Council (EIC). The EIC Accelerator, with a budget of €10.1bn, provides financial support and business acceleration services to companies. Selected companies each receive grants and/or equity investments, depending on their needs, up to €17.5m.

Seaborg is also developing its own power barge “as a turn-key product, ready to be moored at an industrial harbour”, where a transmission cable will be connected from the barge to the electric grid on shore. An optional solution is to place a hydrogen or ammonia production plant next to the barge which will supply power to that plant. According to Seaborg’s timeline, the first barge will be delivered in 2028, with serial production to begin in 2030.

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: Artist's impression of a compact molten salt reactor power barge (courtesy of Seaborg)