Moltex demonstrates its WATSS fuel recycling process

According to the company, WATSS is set to transform nuclear waste management by recycling nuclear waste to produce new fuel, providing a robust, commercially viable alternative to conventional direct disposal methods. Moltex intends to couple WATSS with the company’s stable salt reactor–wasteburner (SSR-W), transforming nuclear waste into clean energy while permanently eliminating long-lived transuranic elements like plutonium. WATSS can produce fuel for other reactor types as well, the company said.

The process: Moltex said it has demonstrated that, using a chemical process, it can extract 90 percent of transuranic material in 24 hours, with greater efficiency over longer periods of time. According to the company, the advancement not only reduces nuclear waste volumes but also unlocks fresh economic opportunities for waste owners and utilities—options previously deemed unfeasible because of financial constraints and the availability of waste management capabilities.

Under a 2020 collaboration agreement, CNL is supporting aspects of Moltex’s nuclear fuel development program for its SSR-W. Along with Moltex and the University of New Brunswick, CNL was tasked with designing, building, and optimizing a fuel testing apparatus at the university’s Centre for Nuclear Energy Research, with parallel complementary activities at the University of Manchester in England.

In October 2024, Moltex announced that research has demonstrated that the SSR-W, a 300-MW small modular reactor design developed by teams in New Brunswick and Ontario in Canada, the United Kingdom, and the United States, can consume as fuel the majority of transuranic elements present in used fuel bundles from Canada’s CANDU reactors.

Developments: In 2021, the Canadian government awarded C$50.5 million (about $40.2 million) to Moltex to support SMR research and technology development in New Brunswick. In addition to the SSR-W and WATSS, the company is developing GridReserve, thermal energy storage tanks that will enable the SSR-W to act as a peaking plant.

Moltex has the goal of deploying first-of-a-kind SSR-W, WATSS, and GridReserve units at the NB Power’s Point Lepreau site.

In addition, Moltex’s U.K.-based sister company, MoltexFLEX, has advanced the FLEX reactor—a modular molten salt reactor designed for low-cost, flexible operation across electricity generation, hydrogen production, and industrial heat.