At the Vogtle power plant near Augusta, Georgia, the first new large nuclear reactors to start construction in the US for more than 30 years are taking shape. Units 3 and 4 are scheduled to start up in November 2021 and November 2022, respectively, and are intended to keep the lights on in Georgia and Florida, with no carbon emissions, into the 2080s and possibly beyond.  The project has been so fraught with difficulties, delays and cost overruns, however, that it seems likely to be another 30 years at least before anyone tries building another such plant in the US again.

Nuclear power appeals as being a source of reliable electricity without causing greenhouse gas emissions. But new reactors are so expensive that in many countries they are unable to compete with cheap gas and coal or renewable energy sources. If new nuclear plants are to play any significant role in curbing future emissions in developed economies, their costs are going to have to come down a long way.

That is the argument underlying the recent upsurge in interest in new nuclear technologies, including small modular reactors (SMRs). When Fatih Birol, executive-director of the International Energy Agency, gave evidence to the US Senate Committee on Energy and Natural Resources in February, he suggested there were two priorities facing the US nuclear industry. In the short term, it needs to find ways to keep open plants that are running well but faced economic challenges, he said. In the longer term, developing new reactor technologies “will be of crucial importance to have US leadership continuing in the nuclear domain”.

In the broadest terms, new nuclear technologies divide into two varieties: first, there are those that use water for temperature regulation and enriched uranium fuel, like the standard reactors in use today; second, there are advanced reactors that can have a wider range of coolants including molten sodium or salt and use a wider range of fuels including depleted uranium.

A recent report on breakthrough technologies from the Energy Futures Initiative, a think-tank, and IHS Markit, a research company, suggests that the light water SMRs could start coming into service in 2020-35 while the advanced reactors might be in operation from 2025-30. Backers of both technologies advocate building new reactors in factories rather than entirely on location to improve productivity and reduce costs.

“The reactors they are building at Vogtle are enormous construction projects, with many thousands of workers on site,” says Ernest Moniz, who was energy secretary in President Barack Obama’s administration and founded the EFI think-tank. “If you have to build a workforce of many thousands, that is not a very easy labour pool to assemble.”