Mr. Hancock: To ask the Secretary of State for Defence what evidence his Department holds on the safety of airborne particulate debris arising from the functioning of the Main Process Facility at AWE Burghfield. 
Mr. Quentin Davies: The release of radioactive material to the environment is regulated by the Environment Agency (EA) under the Radioactive Substances Act 1993 (RSA93). Under this regulatory regime, the Atomic Weapons Establishment (AWE) has an authorisation, issued by the EA, which places various requirements and limits on AWE operations, including those associated with the main process facility for the assembly/disassembly of nuclear warheads at AWE Burghfield.
The methodology used by AWE and accepted by the EA is based on air sampling and modelling and shows that actual discharges are well within safe levels i.e. those required by legislation. Sampling results are reported regularly by AWE plc to the EA and to the Ministry of Defence.
Mr. Hancock: To ask the Secretary of State for Defence whether the risk from activity in the gravel gerties to (a) building workers, (b) other on-site workers and (c) the general public is below the basic safety objectives in the Burghfield assembly facility. 
Mr. Quentin Davies: The basis for demonstrating the safe operation of nuclear facilities is that the requirements of good practice in engineering, operation and safety management are met. Risks from activities in the gravel gerties have to meet the legal requirement to be As Low As Reasonably Practicable (ALARP). There are also in place numerical risk targets defined by the independent nuclear safety regulator, the Health and Safety Executive's Nuclear Installations Inspectorate (NII).
When compared to these numerical targets, risks for building workers lie between the Basic Safety Objective and the Basic Safety Level and have been assessed to be ALARP. The risks for other on-site workers and the public are below the Basic Safety Objective. An ongoing programme of work in the gravel gerties, agreed with the NII, continues to drive risks down further. The NII is satisfied with this strategy and that operations continue to be completed safely.