PLANNING THE ACCELERATED RESTORATION OF CONTAMINATED LAND AT THE DOUNREAY EXPERIMENTAL NUCLEAR ESTABLISHMENT, UK

UKAEA Dounreay started construction in 1955 and operated as a fast reactor experimental facility with associated fuel reprocessing until 1998. The site is now in the early stages of decommissioning. The original decommissioning plan extended to a 100-year period followed by a long period of institutional control; this is now being reduced to a 30-year period to reach an end-point to be agreed with key stakeholders. Investigations have suggested that the volume of radioactively contaminated material at shallow depth is up to 50,000 m 3 . Contamination is known to be present to more than 50 m below ground surface in competent rock, as a result of historic waste disposal. By using a risk-management based remediation target, rather than an absolute concentration- based target, the amount of contaminated material to be disposed, and therefore the time and costs, could be reduced considerably. This will, however, leave substantial volumes of slightly contaminated material in situ. There are two critical steps in implementing a risk-management based strategy: demonstrating to a sufficient degree of confidence that the risks remaining from this strategy are tolerable in the broad sense, and achieving regulator acceptance that statutory requirements have been met. The amount of remediation on the site will depend on forthcoming government policy and on consultation with key local stakeholders.