Small reactors, less efficient, more waste

radioactive waste because they are naturally less efficient, researchers find. A
much-vaunted first wave of mini nuclear power stations may produce more
radioactive waste than traditional large-scale ones when generating the same
amount of power. Lindsay Krall at Stanford University in California and her
colleagues used data NuScale Power has shared publicly with US authorities to
assess the technology, and extrapolated to model the waste from three different
SMR technologies. They compared the SMR technology with a conventional 1.1
gigawatt nuclear reactor, roughly a third of the capacity of a new nuclear
plant being built in south-west England. They have found that SMRs could
increase the volume of short-lived low and intermediate level waste – the two
lowest of three categories – by up to 35 times compared to a large conventional
reactor, when looking at waste produced per unit of electricity generated. For the long-lived equivalent waste, SMRs
would produce up to 30 times more and for spent nuclear fuel, up to 5 times
more. The variation in these figures reflects expected variation in the SMR
designs now being developed. Diane Hughes at NuScale Power says the study
relies on outdated information and its waste per unit of energy compares
favourably with large reactors. “We don’t agree with the conclusion that the
NuScale design creates more used spent fuel per unit of energy compared to
currently operating light water reactors,” she says. The UK government has
provided funding for Rolls-Royce SMR to advance its own version of the
technology. This design was not considered in the new study, but a company
spokesperson said Rolls-Royce SMR would be submitting estimates on waste
volumes as part of its years-long journey through the UK’s nuclear regulatory
approval process, which started in April. The Rolls-Royce SMR design “includes
some technical innovations that reduce waste arisings”, said the spokesperson. Very
few countries have made progress on plans for long-term facilities to store
their nuclear waste underground, with Finland and Sweden two of the exceptions.
“We need to get more serious about practically managing their [SMRs’] nuclear
waste,” says Krall.

New Scientist 30th
May 2022

https://www.newscientist.com/article/2322252-mini-nuclear-power-stations-may-produce-more-waste-than-large-ones/