US federal funding granted for SSR technology development

Friday, 5 July 2019

The funding, from the US Department of Energy's Advanced Research Project Agency-Energy (ARPA-E), will be used to develop composite structural technologies (COST) for the reactor. Moltex says this will bring the Stable Salt Reactor-Wasteburner (SSR-W) - the first variant of the SSR being developed by the company - even closer to market and global roll-out.

"If we are to displace fossil-fuelled generation fast, the entire plant - from reactor to final construction and operation - needs to consider the real-world financing, economic issues, operating practicalities and lead times of nuclear new build," said Adam Owens, principal investigator of Moltex's COST programme. "This project demonstrates SSR-W as an economically practical solution to climate change in the urgent timeframes required, in the highest impact areas for global decarbonisation in the 2030s, rather than the 2040s or 2050s."

Moltex will work in collaboration with Argonne National Laboratory, Oak Ridge National Laboratory, the Electric Power Research Institute, Purdue University and Vanderbilt University on the SSR, exploiting innovative technologies such as advanced structural composites and coatings to enable rapid construction.

The SSR is a molten salt reactor. This type of reactor uses fuel dissolved in a molten fluoride or chloride salt, which also functions as the reactor's coolant and operate at atmospheric pressure. In Moltex's SSR design, molten salt fuel is held in vented tubes bundled into fuel assemblies which make up the reactor's core modules. Each 150 MW module is factory built and contains a support structure for the fuel assemblies, heat exchangers and all other pumps and controls. The rectangular core modules are held in a larger tank, which is filled with a molten salt coolant. A second similar coolant salt system takes heat from the primary coolant salt.

Moltex’s technical advisory committee for the project is comprised of leading international experts and utility customers, including its technology demonstration partner New Brunswick Power (NB Power).

The SSR-W is the first variant of SSR being developed by the company and will use fuel produced from used nuclear fuel from conventional reactors. Moltex last year signed an agreement with the New Brunswick Energy Solutions Corporation and NB Power to build a demonstration SSR-W at the Point Lepreau nuclear power plant site in Canada. The second-generation SSR envisaged by the company, which will use uranium fuel, is aimed at those countries which do not have existing nuclear reactors and therefore have no waste to burn. The company also envisages a thorium breeder version of the reactor.

Moltex CEO for North America Rory O’Sullivan said the project will allow the company to access US expertise in construction technology, design codes and design safety analysis to support Moltex Energy Canada, which is leading the licensing, plant design and deployment of the demonstration reactor.

"At the same time, the [company's] UK laboratory will drive the fundamental scientific research and experiments related to the Moltex SSR technology portfolio," he said.

ARPA-E says it advances "high-potential, high-impact energy technologies that are too early for private-sector investment".

The award to Moltex is part of ARPA-E's MEITNER (Modeling-Enhanced Innovations Trailblazing Nuclear Energy Reinvigoration) programme, which, ARPA-E says, "seeks to identify and develop innovative technologies that can enable designs for lower cost [and] safer advanced nuclear reactors".