Production work has been halted in one of the main manufacturing facilities at the UK's nuclear weapons factory because of safety fears caused by corrosion of structural steelwork (1).

The government's nuclear safety watchdog, the Office for Nuclear Regulation, has issued a formal improvement notice at the Atomic Weapons Establishment at Aldermaston, Berkshire - where the warheads for the Trident nuclear weapons are manufactured - ordering managers to halt all non-essential operations in the building while the extent of the corrosion is investigated.

The problem came to light following a routine inspection at the facility – one of the older manufacturing facilities at the Aldermaston site.

Further inspections revealed that corrosion had spread over a wider area of steelwork, and routine operations in the building were immediately halted.

ONR is concerned that similar corrosion problems may exist in steelwork in other buildings at the sprawling 750 acre site, and has ordered a site-wide structural survey of buildings of a similar vintage.

The regulator is also conducting its own independent investigation to establish whether further enforcement action is warranted against the contractors responsible for operating the Establishment for failing to maintain building structures properly.

Brighton Pavilion MP Caroline Lucas has asked Philip Hammond, Secretary of State for Defence, a number of Parliamentary Questions to establish the extent of the corrosion problems and the costs of repair works.

Caroline said:

"I am glad that the Office for Nuclear Regulation has acted promptly to protect the public from any safety risks that could arise from the current problems at Aldermaston, but some serious questions remain over the adequacy of structural inspections conducted in the past.

"The Ministry of Defence's ancient and rickety nuclear infrastructure is obviously not up to the job of replacing the current Trident nuclear weapons system - and rebuilding it to modern safety standards will add even more to the massive costs of the programme.”

Although the corrosion was discovered in August 2012, details of the problems only emerged in a report on the AWE site which was published on the ONR website a few days ago.

The building which has been closed has not yet been identified by either AWE or ONR, Nuclear Information Service (2) understands that it is the A45 facility (3) – one of the largest nuclear production facilities carrying out higher risk operations with radioactive uranium metal at the Aldermaston site.

Peter Burt of the Nuclear Information Service said:

"We should be concerned that AWE apparently tried to hush these safety problems up and that the matter only became known to the public when ONR insisted on reporting details in one of its regular reports on the site."

AWE is currently facing prosecution from the Health and Safety Executive for breaches of safety law following a fire in an explosives handling facility at Aldermaston in August 2010.

ENDS

Notes for editors

1. The Office for Nuclear Regulation report which reveals details of the corrosion problems at AWE Aldermaston can be found online at http://www.hse.gov.uk/nuclear/llc/2012/awe-3.pdf (paragraph 2.2.2)

2. Nuclear Information Service is a not-for-profit, non-government information service which works to promote public awareness and foster debate on nuclear disarmament and related safety and environmental issues. More information is available at http://nuclearinfo.org.

3. A45 was built in the 1950s and is considered by ONR to fall short of modern nuclear safety standards. The building recently underwent a 're-kit' programme at a cost of £32 million to keep it in service until a new uranium handling facility, currently under construction at Aldermaston, enters service in 2019.

A45 played a major role in the production of Trident nuclear warheads in the 1990s but is currently working on the production of highly enriched uranium reactor fuel for the troubled Astute class submarine programme.

AWE is unable to process highly enriched uranium in other facilities at Aldermaston, and a prolonged closure of A45 may have the potential to cause further delays to the Astute construction programme.