WM 2009 Conference , March 1 - 5 , 2009 , Phoenix , AZ Remediation of Irradiated Fuel

The Dounreay nuclear site, located on the north coast of Scotland, was responsible for the accidental release of an unknown quantity of approximately sand-sized fragments of irradiated nuclear fuel during the 1960’s and 1970’s. In the last decade, major research programmes were carried out by UKAEA and contractors to detect and remove the particles from both local beaches and from the offshore zone, to characterize the particles and their environmental behaviour and to carry out a Best Practicable Environmental Option (BPEO) for the management of the contamination. Following 9 years of recovery of offshore particles by divers and four years of offshore mapping using an innovative tracked remotely operated vehicle (ROV), the project has now moved into a remediation phase. Independent assessments by an external advisory group show that of the order of 5000 particles, covering a range of Cs activities and burial depths, currently remain in the offshore plume. Preliminary proving trials of a modified ROV were carried out in December 2007 and four particles were successfully detected and retrieved remotely for laboratory analysis and eventual disposal. An initial phase of offshore cleanup, to assess the performance of the modified retrieval system, was completed during August and September 2008 and 55 buried particles were retrieved to the Dounreay site for waste disposal. The Site is presently reviewing the performance of remote retrieval technology and the experience gained from these offshore remediation operations and will discuss future remediation efforts with its key stakeholders. This paper will describe the various offshore surveys carried out, from the early diving programmes in the late 1990s through the stages of development of remote particle detection technology and up to the present status of remote particle recovery trials offshore at Dounreay.