Before the pomp of President Trump’s state visit to the UK, Washington and London announced a series of collaborations on nuclear research and regulation. A reminder to cynics that perhaps these events have some substance.

Britain is already undergoing a nuclear revival. Large power stations are under construction (albeit much delayed) at Sizewell in Suffolk and Hinkley Point in Somerset. Rolls Royce has been confirmed as the supplier for a fleet of small modular reactors (SMRs). These reactors use similar technology to the big power plants, but with all components designed to fit into a single container.

Now, as part of the US-UK deal, we can add proposals to build 12 advanced modular reactors (AMRs), using fundamentally different technology, in Hartlepool.

The UK’s nuclear regulator is therefore being asked to consider radically different designs on a scale and pace never before seen. That’s partly why, as part of the deal, the two countries have agreed to accept each other’s safety checks. The government claims this will “halve the time for a nuclear project to be licensed”. The question is whether this can be done as safely.

Two large cooling towers
With four reactors, Plant Vogtle in Georgia is the largest nuclear power plant in the US. PrasitRodphan / shutterstock

The US and UK take fundamentally different approaches to nuclear regulation.

The US’s Nuclear Regulation Commission (NRC) takes a “prescriptive” approach. It sets detailed rules based on its own research and enforces them directly.

Like police setting speed limits, the regulator decides the standards and then ensures nuclear operators meet them. If an accident happens, operators can point to meeting every requirement as evidence they followed the rules. They could even legitimately blame the regulator.

The UK’s Office for Nuclear Regulation (ONR) takes a “descriptive” approach. It sets broad standards but leaves operators to prove how they will meet them.

In road terms, the US sets the speed limit and checks drivers obey it. The UK simply says cars must stay on the road, leaving drivers to decide their own limits, prove they’re safe, and take full responsibility if they crash.

These two approaches are driven to a large extent by the two country’s history and make up of their nuclear industries.

The US has a few standard reactor designs, many operators, and vast federal research labs. The UK has fewer, often state-owned (or foreign state-owned) operators running bespoke reactors fleets, with in-house expertise.

The result is that the US’s regulator – the NRC – is large, well-funded, and deeply involved in design and research. The UK equivalent – the ONR – is smaller and focused on critically reviewing the judgement and processes of the operators.

Both systems have worked well. Nuclear regulation and the associated safety record in both countries is regarded as being among the best in the world.

Why collaboration now matters

A sudden surge of new nuclear in the UK would make closer alignment with US regulators more attractive. If the US has already assessed a proposed power plant design, the UK regulator could potentially rely on that evidence rather than duplicate the work. This would avoid bottlenecks and speed up approvals.

The aviation sector already does something similar. Aircraft are certified by either the US Federal Aviation Administration (FAA) or the European Union Aviation Safety Authority (EASA), with airlines around the world trusting those approvals.

There is a strong element of reciprocity, driven by the need for aircraft to fly from one nation to another. The approach makes sense, as it would be absurd for every airline or national regulator to retest the same Airbus wing. Nuclear power, some argue, should move in this direction.

The risk of imported risk

But there are dangers in relying too heavily on foreign regulators. The Boeing 737-Max scandal, in which software error caused two near-identical accidents and left 346 dead, exposed the need to get regulation right. Political pressure and weak oversight at the FAA contributed to design flaws being missed. If the UK simply rubber-stamped US approvals, it could import these risks too.

The nuclear industry has an extra history of mistrust. The US’s 1946 McMahon Act restricted the sharing of nuclear data between the US and UK, and a number of British spies were exposed in the US. Civilian and military technologies overlap, and there is a desire to prevent nuclear proliferation.

So while UK-US collaboration could boost Britain’s nuclear industry and accelerate the path to low-carbon energy, independence and transparency will be essential. Any perception of corner cutting or transatlantic political interference could undermine public trust and derail Britain’s nuclear ambitions.

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This article is republished from The Conversation, a nonprofit, independent news organization bringing you facts and trustworthy analysis to help you make sense of our complex world. It was written by: Thomas Haynes, University of East Anglia

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Thomas Haynes receives funding from Department for Energy Security & Net Zero and the UK Atomic Energy Authority. He is affiliated with the Nuclear Institute.