Laboratory experiments carried out using simulated fuel have substantially derisked the Waste To Stable Salt - or WATSS - process, and experiments using real used fuel are currently ongoing.

(Image: ElasticComputeFarm from Pixabay)

WATSS is part of a suite of reactor technologies that are being developed by Moltex Energy Canada that can be deployed individually or jointly: the Stable Salt Reactor - Wasteburner (SSR-W), a fast reactor that uses recycled nuclear waste as fuel; the WATSS recycling process; and GridReserve thermal energy storage tanks. Together, these allow the generation of inexpensive electricity that can be dispatched as needed, complementing intermitent renewable sources such as wind and solar, the company says.

The experiments in Moltex's own uranium-licensed laboratory were carried out using simulated fuel made of uranium dioxide and cerium oxide proportional to levels found in used nuclear fuel: the use of cerium oxide as an analogue to transuranic oxides is supported by literature and thermodynamic modelling. Building from these studies, experiments in secure hot cells at Canadian Nuclear Laboratories facilities are now under way, using "real" used fuel from Candu reactors.

"These important experiments not only demonstrate the viability of our waste recycling technology but also reaffirm our unwavering commitment to developing clean energy solutions that combat climate change," Moltex CEO Rory O'Sullivan said.

The company is also currently in discussions with the Canadian Nuclear Safety Commission (CNSC) to formalise a service agreement to help facilitate a bilateral dialogue on its used fuel recycling design.

CNSC completed the first phase of the pre-licensing vendor design review of the SSR-W in 2021, and the design has now reached a technology readiness level that "inspires confidence in its feasibility and economic viability", allowing the technical team to reallocate resources towards optimising the WATSS process, Moltex said. This strategic refocus is supported by Moltex partners AtkinsRéalis and IDOM, it added.

The company said it is planning to deploy the first WATSS unit at the Point Lepreau site in New Brunswick, where it has also plans to deploy the first SSR-W by the early 2030s. NB Power's existing Candu reactor at Point Lepreau is expected to retire around 2040.

"Waste recycling is poised to be a game-changer in the nuclear industry, offering a cost-effective and socially acceptable solution to reducing global waste stockpiles prior to final disposal," it said.