Scientists in Massachusetts have made improvements to molten salt nuclear reactors which they hope will abet the widespread commercial deployment of the devices.
Scientists from Massachussetts-based Transatomic Power believe the improvements they’ve made to molten salt reactors have the potential to render the technology commercially viable by permitting the usage of uranium fuels with reduced enrichment levels.
Molten salt reactors have been around for over half a century, and were first developed by the Oak Ridge National Laboratory in the decades following the Second World War. The technology involves the usage of a liquid salt reactor as opposed to a conventional light water reactor to generate energy via the processing of radioactive materials.
Despite the benefits presented by the reactors in the form of heightened safety, increased efficiency and the ability to burn spent nuclear fuel, the technology has never been commercialised on a significant scale.
The reactors are finally poised to achieve commercial breakthrough in the second decade of the 21st century, however, as large developing economies scramble to find economical and environmentally friendly forms of power generation that don’t sully the atmosphere with greenhouse gases, or generate particulate matter which is harmful to human health.
China is working hard on a liquid fluoride thorium reactor of its own as part of efforts to wean its economy off the coal-fired power which has enshrouded its major cities in smog, while Bill Gates’ nuclear company TerraPower is also exploring the potential of the technology.
Leslie Dewan and Mark Massie, the co-founders of Transatomic and both holders of PhDs in nuclear engineering from the Massachusetts Institute of Technology, believe a set of improvements they’ve made to conventional molten salt reactors could seriously abet the widespread deployment of the technology by enabling the usage of uranium with lower enrichment levels, thereby forestalling the possibility of nuclear proliferation.
Their chief innovation is to introduce a zirconium hydride moderator and an LiF-based fuel salt to standard molten salt reactors. This makes the reactor capable of running on a fresh uranium fuel with an enrichment level as a low as 1.8 per cent U-235, or the entire actinide component of spent nuclear fuel.
The alteration effectively deals with the besetting drawback of molten salt reactors in the past – their reliance on highly enriched uranium with 33 per cent U-235, a level high enough to trigger concerns over proliferation of nuclear materials when deployed on a commercial scale.
The improved technology is also far more efficient and economical than conventional reactors, capable of taping the energy contained by nuclear fuel for decades as opposed to just the four or five years of power that can be extracted by means of standard technologies. A gigawatt of electricity generated by Transatomic’s reactor is expected to cost a mere half as much one produced using traditional technology.
According to Dewan, the reactor they’ve developed would also be “walk-away safe,” and in an extreme contingency the salt would simply freeze into a solid mass within several hours of operation coming to a stand-still.