Moltex's WATSS process for converting used uranium oxide fuel into molten salt reactor fuel has been validated on used fuel from a commercial nuclear reactor.

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...