Question to the Ministry of Defence:

To ask the Secretary of State for Defence, pursuant to the Answer of 20 October 2025 to Question 79413 on Nuclear Installations: Safety, what criteria define each classification of nuclear site event.

Categorisation is based on an independent assessment of the incident against the Nuclear Regulatory guidance of both the Office for Nuclear Regulation and the Defence Nuclear Safety Regulator; the relevant regulations including the Ionising Radiations Regulations 2017 and any appropriate Relevant Good Practise. Events are reported to Nuclear regulators as required in accordance with standing arrangements.