Energy Act 2023 Section 304 starts 2 Dec 2025
The UK has signed off the fourth set of commencement regulations under the Energy Act 2023. Made on 6 November 2025 and taking effect on 2 December 2025, they switch on section 304 - the rule that lets certain low‑risk nuclear waste disposal sites apply to be treated as “excluded disposal sites”. The statutory instrument is listed on legislation.gov.uk as S.I. 2025/1173.
If you’re new to this, commencement regulations are the legal “on” switch for parts of an Act. Parliament passes the law; ministers then bring sections into force in stages. This is the fourth such switch‑on for the Energy Act. Earlier commencement rules arrived in January and October 2024 - and an initial start for sections 303 and 304 in January 2024 was later revoked except for one technical provision, which is why a fresh start date matters.
So what does section 304 actually do? It amends the Nuclear Installations Act 1965 to create a legal route for “excluded disposal sites”. In plain English: if a disposal site only handles qualifying low‑activity nuclear matter and meets strict conditions, the site can sit outside the UK’s nuclear third‑party liability regime that normally applies to licensed nuclear installations. The government’s explanatory notes make clear this is aimed at lower‑risk facilities.
To qualify, the operator must hold an environmental permit that explicitly prevents the site from receiving “disqualifying matter”, and must show the site has never taken such material - or that any past disqualifying material has been removed. If satisfied, the Secretary of State issues written confirmation that the site is excluded.
What counts as “disqualifying matter”? UK law points to radioactivity concentration limits set out in a 2016 decision by the OECD Nuclear Energy Agency. If a site ever accepts waste above those limits, it must notify the Secretary of State within 21 days and remove it within 90 days. If it doesn’t, the site loses its excluded status.
Why would anyone step outside the nuclear third‑party liability regime? That regime is powerful but designed for higher‑risk nuclear installations. It imposes strict, no‑fault liability on operators and requires them to hold financial cover; the UK updated it in 2022 under the Paris and Brussels conventions, increasing the money available for compensation and widening what counts as damage.
The shift on 2 December also lines up with new, practical guidance for site managers. DESNZ has published instructions for low‑level radioactive waste sites explaining how to apply for exemption, what evidence is needed, and how the legal tests work. In parallel, the Nuclear Installations (Prescribed Conditions and Excepted Matter) Regulations 2025 are set to take effect the same day to spell out the technical criteria.
This is not a free pass. Excluded disposal sites still need environmental permits from regulators such as the Environment Agency, SEPA or Natural Resources Wales, and those permits must bar disqualifying material. If a site changes operator, the Secretary of State must be notified to keep the status active; Scottish Ministers are notified for sites in Scotland.
For communities near such facilities, the practical risk profile does not change - we’re talking about low‑activity materials like lightly contaminated equipment, already managed under environmental and health protections. What does change is the legal route for compensation if something goes wrong: for excluded sites, claims would fall under ordinary civil law rather than the special strict‑liability rules used for power stations and fuel plants.
If you’re studying this for A‑level law or a policy course, remember it this way: high‑risk nuclear sites stay within the Nuclear Installations Act liability regime; lower‑risk disposal sites can apply to be excluded if they meet section 304’s tests - and they remain tightly controlled through permits. For primary sources, read section 304 of the Energy Act 2023 and the new sections 7C–7D in the Nuclear Installations Act, then check DESNZ’s guidance for the step‑by‑step process.