Regulatory justification, broadly, is the approval required to show that the benefits of a nuclear technology outweigh the potential impacts on human health. Regulatory Justification is a requirement in the UK under the Justification of Practices Involving Ionising Radiation Regulations 2004, which requires regulatory justification on 'a new class or type of practice'. This post-dates all the UK’s current reactors, the most recent of which, Sizewell B, was completed in 1995. All currently operating and historic reactors were ‘grandfathered-in’ as existing classes or types of practice of the use of ionising radiation.

We, and others (see here), have written about how this approval is being used on a technology-by-technology basis, rather than more general purpose as intended. This would mean that each SMR design would need to seek it’s own regulatory justification. We have been given permission to share this legal opinion which makes clear that an approach which determined all light-water fuelled reactors were justified is lawful and possible. Please do read the whole legal opinion, it’s a great read. In the meantime, a parliamentary question has been asked about effectively taking this approach.