Repair work on corroded structural columns in the A45 facility at the Atomic Weapons Establishment (AWE) Aldermaston has begun after the facility was closed last year for failing to meet nuclear safety standards.
The Office for Nuclear Regulation (ONR) has granted permission to AWE to commence remediation work to modify and restore structural steelwork within the facility, which manufactures uranium components for the UK's nuclear warhead programme and reactor fuel for the Royal Navy's nuclear powered submarines.
Corrosion was discovered at the base of a steel structural column during a scheduled inspection of the building in August 2012, and further inspections revealed the presence of corrosion on a significant number of columns. AWE was unable to demonstrate that the building could withstand the impacts of extreme weather or a seismic event, and normal operations in the building were halted until repairs had been effected. Following an investigation ONR served AWE with a formal improvement notice requiring improvements to arrangements for maintaining the structure.
Since the discovery of the corrosion AWE has undertaken a programme of inspection, measurement, sampling, and testing to establish the extent of the problems. A three dimensional structural model of the building has been prepared and used to design repair work and demonstrate that the building will meet safety requirements.
After assessing AWE's proposals, the regulator concluded that the repair work which was planned would reduce risk from facility and should therefore be permitted to go ahead.
The A45 building was built in 1956 and over its lifetime the building's structural steelwork has corroded as a result of the accumulation of rain water.