15 Oct 2020

Thermal transfer modelling for Stable Salt Reactor

Jacobs, the global technology-forward solutions company, is supporting the development of a new type of nuclear power plant.

Based on breakthrough science, Moltex Energy’s Stable Salt Reactor (SSR) is designed to generate low cost electricity by burning processed spent fuel pellets which would otherwise have to be stored as radioactive waste.

In the SSR reactor, heat is generated when nuclear fission takes place in tubes filled with molten salt fuel. This heat is then transferred to a primary salt coolant, where it circulates through heat exchangers and passes to a secondary salt coolant which sends the heat to storage tanks. The heat can be used to produce electricity, hydrogen, or in other industrial processes.

Moltex Energy’s impression of a Stable Salt Reactor  (© Moltex Energy)
Moltex Energy’s impression of a Stable Salt Reactor  (© Moltex Energy)

Jacobs is assisting with validation of thermal transfer modelling by building a bespoke experimental facility for thermal transfer testing at its Birchwood Park research and development facility in the UK.

The company’s chemistry, materials, engineering, instrumentation and modelling teams are collaborating with Moltex to create a technically complex simulation to replicate the heat output of a fuel channel and to validate computational fluid dynamics modelling of the thermal transfer across the fuel assemblies into the coolant. 

Moltex already uses Jacobs’ ANSWERS® software for radiation transport modelling and simulation of reactor performance.

“We’re looking forward to continuing our support for Moltex into this new phase of development, as part of our strategy to be at the cutting edge of research into advanced reactors,” said Jacobs Critical Mission Solutions International Senior Vice President Clive White. ”The Stable Salt Reactor design is significant because of its potential to recycle waste in a clean, safe and economical way, generating electricity which will power communities while reducing carbon emissions.” 

Moltex has been awarded more than $6 million in funding from Advanced Research Projects Agency-Energy, a United States Department of Energy agency, to help develop the reactor.

Moltex Chief Executive Officer, North America, Rory O’Sullivan said: “The Stable Salt Reactor is an inherently safe design. Because the fuel is in a liquid state, there is no risk of a large release of radioactive gas into the atmosphere.

“There is no contained pressure in the reactor because everything happens at atmospheric pressure; and the fission reaction slows down as the temperature rises, so the system is self-damping.”


Ryan Morris