UK NIREX geological investigations at Sellafield

SUMMARY Geological investigations of the Sellafield area, west Cumbria by UK NIREX Ltd are part of a site characterization process to assess its suitability for the construction of an underground radioactive waste repository. The geological characterization is an input to the NIREX post-Closure Safety Assessment. This will address all aspects of post-closure radiological safety of the repository, particularly the potential for radionuclide migration in groundwater back to the surface (the biosphere) through the various geological units (the geosphere). This characterization forms the largest geotechnical investigation in Britain and encompasses scales of study from ‘large scale, regional’, covering north-west England and the East Irish Sea Basin to ‘microscopic’, requiring detailed examination of drill cores and individual rock fractures.