Pivotal moment for Moltex recycling process

Monday, 3 March 2025

The innovative process - short for Waste to Stable Salt - extracts valuable materials and radioactive byproducts from used nuclear fuels in oxide form, including Candu, light water reactor and certain fast reactor fuels, such as mixed oxide (MOX) fuels. It does this in a single, streamlined 24-hour chemical process, with a versatile pretreatment step that the company says can accommodate exotic, experimental, or advanced reactor fuels.

The extracted transuranic elements are concentrated to produce molten salt fuel, while fission products are removed. This reduces waste volumes dramatically but also transforms nuclear waste into clean, dispatchable energy, permanently eliminating long-lived transuranic elements like plutonium, the company says. Coupled with Moltex's Stable Salt Reactor-Wasteburner - or SSR-W - reactor technology, the process enables the creation of a closed fuel cycle. 

The WATSS process has now been validated on used fuel bundles from a "commercial reactor in Canada" through hot cell experiments carried out by Canadian Nuclear Laboratories, which has the only facilities in Canada equipped to handle used nuclear fuel. The experiments demonstrated that the process can extract 90% of the transuranic material from used fuel in 24 hours, with greater efficiency over longer periods of time, the company said.

"It's crucial that increased demand for nuclear energy is matched by increased back-end fuel cycle capabilities," Moltex CEO Rory O’Sullivan said. "WATSS is a transformative solution that not only reduces liabilities but also adds value, turning waste into a valuable energy asset."

The company plans to deploy the first WATSS unit at NB Power's Point Lepreau site in New Brunswick, where it also plans to deploy the first SSR-W by the early to mid-2030s. In a newly released report on its work, Moltex said the commercial-scale demonstration facility will recycle an anticipated 260,000 used fuel bundles from existing Candu pressurised heavy water reactors and create recycled fuel for the entire 60-year operating life of one 300 MW demonstration SSR-W.

The development of WATSS has received support from the Government of Canada, the Province of New Brunswick, and NB Power. Indigenous communities in New Brunswick are also supportive of the technology and have invested in its development.

The North Shore Mi'kmaq Tribal Council and its seven First Nation member communities announced in 2023 that it would be taking a stake in both Moltex Energy Canada Inc and ARC Clean Technology Canada Inc, and has recently signed a memorandum of understanding to promote the selection and deployment of Westinghouse technology for nuclear new build projects in New Brunswick.

Jim Ward, General Manager of the North Shore Mi’kmaq Tribal Council, said the Council's investment in Moltex was driven by the potential to make nuclear more sustainable and reduce nuclear waste liability. "Moltex also engaged with us at the earliest stages of the project. We are pleased to see this important milestone being met and look forward to more to come," he said.