The bridge to decarbonization: Small modular reactors show potential, with some reservations
- February 1, 2022: Vol. 9, Number 2

The bridge to decarbonization: Small modular reactors show potential, with some reservations

by Mike Consol

Can small nuclear power go big?

That question is raised anew by New Scientist magazine reporter Adam Vaughan in his weekly Fix the Planet newsletter. Having recently returned from the COP26 summit in Glasgow, where 196 countries agreed to ramp up action on climate change, he reports the subject of small modular reactors (SMRs) cropped up several times.

SMRs, mini nuclear plants that would be built in a factory and transported to a site for assembly, are being pursued by a U.K. consortium led by Rolls-Royce, which wants to build a fleet in the country to export around the world as a low carbon complement to renewables. During COP26 the consortium received $284 million from the U.K. government, and private investment was expected to follow.

Among the questions swirling around this effort: Why should SMR technology succeed where large nuclear plants have failed to take off in recent years? If these plants are small, will they make a sizeable enough dent in emissions? And will they arrive in time to make a difference to a rapidly warming world?

SMR exponents argue the technology solves those problems because building components in a factory and assembling them onsite will be faster and less expensive. They are also more flexible, an important quality in energy systems increasingly dominated by the variable nature of renewables.

The reactors Rolls-Royce SMR is looking to manufacture have been in development for six years and have their roots in ones the company previously built for nuclear submarines. Despite being billed as “small,” the new reactor design is fairly large, according to New Scientist. Each would have 470 megawatts of capacity, a good deal bigger than the 300 megawatts usually seen as the max for an SMR. The consortium hopes to initially build four plants on existing nuclear sites around the United Kingdom, and ultimately wants a fleet of 16, enough to replace the amount of nuclear capacity expected to be lost over the next decade as aging U.K. atomic plants are decommissioned. The eventual hope, again, is to export them around the world.

Alastair Evans, a Rolls-Royce SMR executive, told the magazine the first SMR would cost about $3.1 billion and could be operational by 2031. Later versions may fall to $2.4 billion.

By way of comparison, an offshore wind farm with twice the capacity costs about $1.4 billion, and that figure is expected to be lower in a decade’s time.

Still, Richard Howard, an analyst at Aurora Energy Research, told New Scientist he still thinks there is much potential. For one, he says, the expected subsidy cost for Rolls-Royce SMR is significantly lower than obvious alternative ways of providing a continuous supply of low-carbon power — large-scale nuclear and gas plants fitted with carbon capture and storage. Secondly, SMRs should be more flexible — as in capable of dialing up and down their output as needed — compared with large nuclear plants, which are usually always on.

“What SMRs are providing is complementing renewables really well,” said Howard.

Whether SMRs play an important role in helping renewables decarbonize power grids remains to be seen, but observers think they will have a part to play.

Howard added: “My summary is we can’t get to net zero based on renewables alone. SMRs, on paper, seem to offer an attractive proposition.”


Mike Consol ( is editor of Real Assets Adviser. Follow him on Twitter (@mikeconsol) and LinkedIn ( to read his latest postings. Read the original version of the story by Adam Vaughan on the New Scientist website at this link:


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