The objectives of the research work are to establish the current state of selected nuclear facility structures with reference to durability and deterioration, extrapolate from the surveyed data to define long-term integrity of the structures systems and the development of a minimum cost care and maintenance strategy for delayed decommissioning options. Four different structures will be used to represent the types of structures normally used in nuclear facilities in Europe. Structures to be used will be agreed with the facility owners (Nuclear Electric, Scottish Nuclear, BNFL and AEA).
The care and maintenance strategy will be based on the minimal actions required to ensure that the buildings are structurally sound and weather-tight after a further 30 years or more from defuelling.
Four buildings will be surveyed: Reactor Building 1 Hunterston, Blower House 1 Berkeley, a building including a pond-retaining structure at Harwell (B466) and a steel-framed structure housing chemical plant at Sellafield (Building 204). These buildings have been selected to represent the broad cross section of the types of nuclear facility structures in use in Member States of the EC.
Principal components to be surveyed (Main structural elements; roof-cross-falls guttering and downpipes, waterproof membrane, moisture within insulation, metal decking; cladding fixings, glazing, glazing strips; brickwork joints, cracks in mortar, movement; penetrations for pipework, conduits; joints and detailing - expansion joints, change in sections or form).
Long-term integrity predictions will be carried out using information from the site surveys, the data base together with records of any work carried out, anticipated effects of changes to the internal environment and future demands on the structure.
Re-specification of the structure for its long-term containment function
Two different options will be considered: minimal initial work with planned maintenance at Hunterston, minimal maintenance at Berkeley after initial remediation works. The other structures will be considered along the lines of one of the options mentioned above.
The planned development will concentrate on when to initiate maintenance and what indications are deemed adequate to identify the need for action.
Each major building element will be reviewed and estimates provided on possible replacement options, timings, temporary works, options of planned vs. reactive maintenance, bound of likely cost.