During the interpretation of the geological structure of the Sellafield site, a series of 3-D models were created using EarthVision and Vulcan software. These models have been imported into the computer systems operated by British Geological Survey. Geological investigations of the Sellafield and Dounreay areas were undertaken between 1989 and 1997 as part of its programme to determine whether one of the areas might be a suitable location of a deep repository for the disposal of radioactive waste. The Nirex (Nuclear Industry Radioactive Waste Executive) Geological Archive was deposited with BGS in 2000 and BGS have undertaken to retain the records for a minimum of 50 years as part of its national geological archive. The archive has been moved to permanent storage locations and normal BGS arrangements will apply for non-commercial (academic) access to the material. The ownership of NIREX (Nuclear Industry Radioactive Waste Executive) was transferred from the nuclear industry to the UK Government departments DEFRA and DTI in April 2005, and then to the UK's Nuclear Decommissioning Authority (NDA) in November 2006.