Among the emergent companies exploring the potential for small modular reactors and nuclear plants that use different fuel technology than conventional light water reactors, two PhD candidates from the Massachusetts Institute of Technology are making the case for a liquid salt reactor that derives its energy from the unburned uranium in spent LWR fuel.
Incorporated last year, Transatomic Power has attracted attention to its founders’ goal to license a design that uses liquid salt fuel. Military and federal labs successfully built similar reactor designs in the 1950s and 1960s, with early research stemming from an ill-fated nuclear jet engine project at the Idaho National Laboratory. What founders Leslie Dewan and Mark Massie hope will rekindle interest in the technology is their concept to use a molten salt reactor as a way to substantially reduce the volume and radiation of spent fuel while generating power.
Their design, as described in a recent interview with BostInno.com and a TEDx Talk last fall, uses a salt and uranium mixture as both fuel and coolant. (The uranium is derived from reprocessed LWR fuel.) It reaches a critical configuration in the core and moves at low pressure through a heat exchanger.
"What we have here is environmentally sound nuclear power that we can use to meet the world's energy needs," Dewan said during the talk.
Transatomic’s descriptions of its 200 megawatt design are vague, and they do not describe its moderator or treatment systems to remove actinides from the fuel. Previous molten salt reactors used a graphite moderator.
The Transatomic WAMSR’s (Waste-Annihilating Molten Salt Reactor) primary passive safety feature is a freeze valve that, if the plant loses electrical power, will melt and release fuel into emergency storage tanks in a non-critical configuration.
Transatomic’s concept will compete with similar molten-salt technologies advanced by proponents of thorium-powered reactors, as well as other SMR designs that use light water technology.