A secret plant that enriches uranium for Britain’s nuclear warheads on submarines has been shut due to “corrosion” in vital structural steelwork.
The AWE Aldermaston facility was closed following inspections by the Office for Nuclear Regulation (ONR), the nuclear division of the Health and Safety Executive.
Regulators feared one of the “older manufacturing facilities” at the complex in Berkshire, which builds components for the Trident ballistic nuclear missiles on Royal Navy Vanguard-class submarines, did not conform to standards that demand buildings are capable of withstanding “extreme” weather and seismic events.
The ONR issued an “improvement” notice that prompted the closure by the AWE, the private consortium that operates the plant for the Ministry of Defence. AWE has been given until the end of this year to rectify the problems by the ONR.
The group’s role is to manufacture and sustain the Trident warheads and “maintain a capability” to produce a successor to the ageing nuclear deterrent in the future.
AWE said it covers the entire “life cycle” of warheads in Britain from initial concept and design through manufacturing and assembly to decommissioning and disposal.
The firm is run by a group of three private companies: US firms Lockheed Martin and Jacobs Engineering Group, and the Serco in Britain.
Critics last night said the corrosion in an older building highlighted the Britain’s “ancient and rickety” nuclear infrastructure.
The ONR notice was served on November 8 after a scheduled inspection in August that found an “unexpected” area of steel corrosion in structural steelwork.
The issue emerged through information published in the ONR’s regional community newsletters which are published quarterly. Inspections at the plant were said to have “discovered an unexpected area of corrosion on structural steelwork in one of their manufacturing facilities at Aldermaston”.
Subsequent inspections by AWE found “further degradation” and all non-essential operations were stopped at the facility.
It is understood the building in question is used for the manufacture of nuclear components and was found not be able to withstand “exceptional challenges”.
“ONR investigated, and found that AWE had not fully complied with Licence Condition 28(1) in so far as its arrangements to examine, maintain and inspect the structure were not adequate to prevent the degradation of the structure, and the resulting challenge to its nuclear safety functions,” said an ONR spokesman last night.
He added: “The Improvement Notice required AWE to ensure that the structure is repaired such that its safety function is fully restored.”
The Ministry of Defence last night said the ONR demands had not had any immediate impact on Britain’s nuclear submarine programmes. A spokesman said AWE was accessing the “extent of the problem” and considering “how best to rectify it”.
“The MoD’s ancient ancient and rickety infrastructure is clearly not up to the job of replacing the current Trident nuclear weapons programme,” said the Green MP Caroline Lucas. She added: “Rebuilding it to modern safety standards will add even more to the vast costs of the programme.”
An AWE spokeswoman said operations had been suspended as a “precaution”. She add that the improvement notice “formalises a lot of the inspection and review work” that had already been carried out by the company.