An overview and update of the site characterization studies at Sellafield

SUMMARY Nirex is responsible for providing and managing facilities for the safe disposal of intermediate-level and certain low-level radioactive waste. In 1991 Nirex chose an area near Sellafield, west Cumbria as the focus for further investigations, following preliminary geological investigations undertaken there and at Dounreay in Scotland from 1989. The Nirex Science Programme aimed to assess the suitability, or otherwise, of the Sellafield site as the host for a repository. Such an assessment included the requirement to develop an understanding of the geological and hydrogeological characteristics of the area. The background to the selection of the Sellafield area for site characterization for a potential radioactive waste repository and the early results from Nirex’s site investigations at Sellafield were reported to the Yorkshire Geological Society in October 1994. We present an update of the site characterization activities undertaken at Sellafield since then together with an overview of the advances in geological and hydrogeological understanding of the site resulting from those investigations.