AWE Burghfield, a former munitions factory, occupies a 225 acre site between Aldermaston and Reading. It is responsible for the complex final assembly and maintenance of the warheads while in service, as well as their decommissioning.

Unlike AWE Aldermaston with multiple entrances and exits, AWE Burghfield only has two gates. The main entrance gate is in The Mearings, off Reading Road, Burghfield. The second gate is on Burnthouse Lane.

Nuclear Warhead and nuclear materials convoys often depart from Burghfield when moving nuclear warheads between AWE and Coulport in Scotland for storage and servicing.

At present AWE’s high precision manufacturing capability is spread across a number of individual facilities at Burghfield and Aldermaston. It had originally been intended that future requirements in relation to this aspect of AWE’s existing operation would be met by refurbishing existing buildings at both sites. However, following further consideration of the matter it was concluded that a new build approach would  likely be a more cost effective solution.

The plan itself is described as:“Construction of main process facility (MPF) and support building with 16 lightning protector towers, associated plant building, gate houses, vehicles inspection bays, sub-station buildings, security fence, access roads, hardstanding and sustainable drainage system (SuDS) infrastructure.”

The proposed development, known as MENSA, will replace the existing assembly and
disassembly facilities – including the ‘gravel gerties’ built 50 years ago – with a facility
which will incorporate modern environmental and safety standards.

MENSA will comprise a main process building, approximately 130 metres long by 112 metres
wide, a support building and a plant building. The proposed new development will carry out
the same work currently undertaken in the existing assembly and disassembly facilities.
This includes the final assembly of warheads required for the UK nuclear deterrent,
maintenance and the disassembling of warheads when they are taken out of service.

The location for the new building, is in the northeastern corner of the Burghfield site. The cost of the Mensa project  (new warhead assembly / disassembly facility) is £734m.

The new development plan for Burghfield is expected to continue until at least 2015. The overall cost of currently approved site developments at AWE  stands at £2 billion.