Initial government response
Preparation for the post-Brexit position began with the passing of the Nuclear Safeguards Act 2018. The Act makes provisions for the government to pass regulations on, and implement agreements relating to, nuclear safeguarding. In addition, the Act extends the role of the Office for Nuclear Regulation (ONR) to oversee application of the new UK regime.
The legislation filled some of the gaps created by leaving Euratom, but did not address other functions, like access to expertise and capital to develop and operate nuclear technology.
In addition, the government:
- established Nuclear Cooperation Agreements (NCAs) with the US, Australia, Canada, Japan and the International Atomic Energy Agency (IAEA);
- allocated increased funding to the UK regulator;
- procured a new IT system and trained new inspectors for the ONR’s increased role.
UK–EU Nuclear Cooperation Agreement
The core of the post-Brexit position is set up by a nuclear agreement, alongside the TCA. Within the TCA package, the UK and the EU negotiated an NCA for civil purposes. This is a bilateral international treaty whose full title is Agreement for Cooperation on the Safe and Peaceful Uses of Nuclear Energy.
Under the UK-EU NCA:
- the UK has no voting rights, institutional role, or policy influence over Euratom;
- there is no EU supranational authority over the UK in relation to the agreement;
- UK law governs UK nuclear activity, but Euratom law governs EU activity;
- disputes are handled through treaty mechanisms, under the International Court of Justice, not the Court of Justice of the European Union.
The NCA has a Joint Committee to facilitate participation in the agreement and resolve technical issues and disputes. It also has the power to make mutually-agreed amendments to the NCA.
Previously, Euratom inspected UK facilities. Now, the UK and the EU have separate, but mutually recognised safety and inspection regimes. Under the NCA, the UK:
- is responsible for its own safety regime, implemented through the Office for Nuclear Regulation (ONR);
- must meet IAEA standards and demonstrate equivalence to Euratom safeguards.
The NCA permits trade only under the terms of the agreement, which means transfers now require compliance checks, and must meet conditions on use, reprocessing, and retransfers. However, the new approach is designed to keep civil nuclear supply, safety and research as seamless as possible.
Medical isotopes used to diagnose and treat cancer are now subject to customs processes, transport arrangements and regulatory compliance checks (as opposed to the pre-Brexit minimal friction in procurement and transport).
UK participation in EU programmes, for example for research (including fusion programmes) and training, is no longer automatic and requires separate association agreements and financial contributions.
The TCA allows the UK to participate as an associated country in the Euratom Research and Training Programme (2021–25), maintaining links to Euratom‑funded nuclear R&D despite leaving the Community. However…..