In May the Office for Nuclear Regulation (ONR) issued a prohibition notice preventing staff from entering an area in the Plutonium Technology Centre at AWE Aldermaston which has reduced oxygen levels. The notice follows an enforcement letter in March and a series of events that ONR say demonstrate that current arrangements to control access to the area are “insufficient”.
Aldermaston is the larger of the two nuclear weapons manufacturing sites at the Atomic Weapons Establishement (AWE) in Berkshire. The UK’s nuclear weapons are designed at the site, and many of their components are manufactured there, including those made from plutonium, uranium and high explosives. In the area in question, the reduced oxygen levels are a consequence of the industrial processes used in the facility.
The plutonium facility, also known as A90, underwent a refurbishment and re-equipping project as part of the larger Nuclear Warhead Capability Sustainment Programme (NWCSP). A replacement facility had been planned to come into service between 2025 and 2030, but it does not appear to have ever gone through the formal MOD approvals process. Some of the projects planned under the NWCSP have been abandoned or postponed due to the massive cost overruns other projects, particularly the Mensa warhead assembly facility at AWE Burghfield.
The construction of A90 itself was fraught with delays and cost overruns, with two of the contractors, Balfour Kilpatrick and Balfour Beatty Power, being investigated by the Ministry of Defence Police amid allegations of fraud and malpractice. The investigation did not find evidence to substantiate these claims.
According to ONR, some of the events that gave rise to the prohibition notice occurred while it was engaging with AWE in regard to the issue. ONR said the shortfalls did not harm any staff or result in any radioactive release.
In April it was announced that Aldermaston was to remain under enhanced regulatory attention, despite Burghfield being deemed to have made sufficient progress on safety to be returned to the category of routine regulatory attention. The Chief Nuclear Inspector’s annual report, released in October, said Aldermaston still faced “significant challenge” in several areas, including managing its older facilities and upgrade projects. AWE’s plan to return the site to routine regulatory attention contains milestones throughout 2023, suggesting that it is likely to remain under enhanced attention until 2024 at the earliest.