Integrating History and Measurement Into a Case for Site Release

The United Kingdom nuclear research programme started in the 1940s. Research Sites Restoration Limited (RSRL) is responsible for the restoration of two sites which were at the forefront of this research, under a programme funded by the UK Nuclear Decommissioning Authority (NDA). These are the 100 hectare Harwell site in Oxfordshire and the 84 hectare Winfrith site on the south coast of England. The work performed on these sites covered a huge range of nuclides, combinations of nuclides, chemical and physical processes, far more complicated than a power station, for example. The sites have a complex history with records of hundreds of buildings, many kilometres of drainage systems, groundwater contamination issues and land areas which require remediation. Formal work towards site release began in the 1990s, but demolition and clearance for re-use started many years earlier. An efficient restoration programme requires appropriate quality data. It is vital to decide what you need to know and how well you need to know it. As part of this, a challenging number of factors need to be considered in its design. This paper discusses these factors using the examples of the approach used at the Harwell and Winfrith sites including: • historical knowledge and associated uncertainties; • relevant clearance criteria; • availability and limitations of surveying equipment; • effective targeted and validation sampling with appropriate analytical methods; • data capture and analysis techniques; • effective communication between RSRL and the relevant technical teams; • mapping technologies (Global Positioning Systems, Geographical Information Systems); • use of Babcock’s IMAGES land quality software tool; • integration of the above over long time scales. The RSRL programme of works at the Harwell and Winfrith Sites is producing large volumes of different types of information from decommissioning, site investigation and remediation projects. This will be required to be accessible and understandable to support the process of site release which will continue over many years. The paper illustrates the methods by which RSRL is using effective knowledge management to compile a verifiable record to support site release as the site restoration works progress.