A report by Weinberg Next Nuclear, part of the Alvin Weinberg Foundation, urges the UK government to use its nuclear R&D funding to ensure that at least three advanced reactors complete regulatory assessment by the early 2020s. The report, ‘Next Steps for Nuclear Innovation in the UK’ was sponsored by Terrestrial Energy, Urenco and Moltex Energy, with Weinberg Next Nuclear retaining sole editorial control. It says the reactors should include at least one small modular reactor (SMR) and a Generation IV design.
"The UK’s energy mix must be based on diversity," said Stephen Tindale,who wrote the report. "So the policy argument should not be whether to support solar, wind, [carbon capture and storage] or nuclear. ‘All of the above’ will be needed. Existing nuclear technology is very good, but future nuclear technology can be even better. If the £250 million is sensibly spent, it could contribute to the UK becoming a world leader in both small and Generation IV reactors."

The report emphasises the value of clean, low-carbon nuclear energy in improving energy security and mitigating climate change, but notes that existing reactor designs have high upfront capital costs and are not sufficiently flexible to provide back-up to more intermittent generating options such as wind and solar. Advanced designs could address these problems.

The criteria that should be considered in selecting reactor designs include safety and non-proliferation which are of "critical importance". Others are cost, waste management, past experience with related designs, the ability to use alternative nuclear fuels, the ability to re-use used nuclear fuel and plutonium, flexibility to provide back-up for intermittent renewables and the potential to provide low-carbon heat and hydrogen. At least one of the reactors supported should be a Generation IV design that could use fuel made from previously used reactor fuel and from the UK’s plutonium stocks. The study says that SMRs and "micro-reactors" (less than 20MWe capacity) will be cheaper to build.

It supports a proposed increase in the resources of the UK’s Office for Nuclear Regulation (ONR), noting that the lack of regulatory capacity is a "significant barrier" to nuclear innovation in the UK. The generic design assessment (GDA) process for a reactor design can take up to five years, but ONR can only undertake two assessments the same time. The report says UK regulators should cooperate with their peers in other countries, noting that in the USA and Canada proposed reactor designs are discussed with developers before the formal regulatory process begins. It calls for a three-way collaboration with the aim of establishing international standards for the safety of advanced reactors.