Decommissioning & Demolition of a Redundant UK Research Facility at AWE Aldermaston

Abstract

The redundant two-storey, brick built research facility on the AWE Site at Aldermaston, UK is in the latter stages of decommissioning by Nuvia Limited. The facility was used for a variety of purposes up to 1995 involving the use predominately of alpha-emitting isotopes. After a period of site establishment and preparation of supporting safety case documentation, the two main areas of alpha-based contamination have largely been decommissioned with the removal of hot -boxes and fume cupboards on the ground floor and HEPA filter units and ventilation equipment on the first floor. Many of these activities have been undertaken using both airline fed suits and respirators, the former supplied from a free standing, mobile unit newly located outside the building to allow reuse on future projects. The late detection of exposed asbestos on the first floor associated with an electrostatic particulate filter caused some delay to the programme but these materials have now been removed by a specialist contractor to allow the programme to continue. At an early stage of the programme all sections of active drains running from the building to the site-based active effluent disposal system have been removed from the external drain ducts without incident using well-established techniques.

Specialist monitoring equipment is being used in order to provide confidence in the data required for disposal of the decommissioning debris. In particular a dedicated high resolution gamma scanning unit for waste drums and wrapped packages has been utilised. The final stages of the building decommissioning are in sight and the monitoring and sampling of the structure will become important milestones ahead of the development of the demolition plan. A number of useful lessons have been learnt during the operations and are set out in the main text of this paper.