RECOVERY & SIZE REDUCTION OF ILW FLOOR STORAGE LINERS

A major task entrusted to NUKEM Nuclear Ltd (NUKEM) at UKAEA’s Winfrith Technology Centre concerned the recovery, size reduction and disposal as LLW of nine contaminated steel floor storage hole liners. These had been used to hold a variety of irradiated fuel elements and other items associated with post-irradiation-examination programmes on the site. Following a survey and monitoring of the general activity levels of these liners, it was established that two contained a quantity of water and corrosion sludge and seven were dry. NUKEM devised a safe means of recovery of these items from the floor storage holes in a cost-effective manner. A full assessment was made of the hazards involved in emptying the contaminated water and sludge from the wet liners and their subsequent staged recovery. In the case of the other seven liners that only contained dry sludge residues at lower radiation levels, a simpler recovery procedure was developed prior to decontamination, size reduction and disposal. This report describes the techniques developed for recovery of all the liners, including the means of removal of the contaminated water and sludges and the basis of the safety arguments used to support recovery operations. The whole process was completed ahead of schedule over a period of 6.5 months with lower than expected man absorbed doses. Examples of good practice were captured at the end of the operations for incorporation in future projects of this nature.