The Office for Nuclear Regulation (ONR) has closed an improvement notice issued to AWE Plc after the company addressed a safety concern at its Aldermaston site in West Berkshire.
The enforcement was served in October 2024 after an explosive component was unintentionally damaged during assembly for testing, when workers failed to follow the correct manual handling procedures.
The notice required AWE to strengthen planning, oversight and control of activities in the site’s Explosive Technology Centre. According to ONR, the incident did not present any radiological risk and posed no danger to the public or the environment. Throughout the compliance period, inspectors conducted regular visits, held structured discussions, reviewed safety arrangements and observed the application of new procedures.
The Aldermaston site is a core facility within the Atomic Weapons Establishment, responsible for the design, manufacture, and maintenance of the UK’s nuclear warheads in support of the nation’s continuous at-sea deterrent. The site carries out advanced hydrodynamic trials, high-performance computing simulations and non-nuclear experiments to ensure the safety, performance and reliability of the stockpile without conducting live nuclear tests.
In addition to warhead maintenance, Aldermaston undertakes research in materials science, explosive engineering and nuclear forensics, providing technical expertise for defence and national security operations. The site works closely with the Ministry of Defence and operates under strict regulatory oversight to maintain compliance with UK nuclear safety and security standards.
“AWE Plc has constructively and proactively engaged with us throughout the compliance process for this notice,” said Tim Allmark, ONR’s Head of Regulation for Weapons Sub-Directorate. “The licensee has taken clear and coordinated action to address the identified shortfalls and we are satisfied that it has demonstrated compliance with the notice.”
ONR said it will continue its routine regulatory oversight of Aldermaston to ensure safety procedures remain robust.
