The Sellafield site has had its own on-site licensed landfills for disposal of waste throughout the operation of the plant, initially in trenches within the Separation Area in the 1950s (before development of the LLWR) and then in mounds built up on the coastal fringe and on the northern perimeter of the site. Two sites remain in operation, the south landfill site and the Calder Plain landfill extension. These primarily receive low level radioactive soil (BNFL, 1976-2004).

On-site waste disposal has been undertaken at other sites in the UK (notably Hunterston and Dounreay in Scotland), but this practice has not been widespread within UK nuclear licensed power generation sites.