Long-term storage of radioactive solid waste within disposal facilities

A study of the feasibility and implications of operating potential disposal facilities for low and intermediate level solid radioactive waste in a retrievable storage mode for extended periods of up to 200 years has been carried out. The arisings of conditioned UK radioactive waste up to the year 2030 have been examined. Assignments of these wastes to different types of underground disposal facilities have been made on the basis of their present activity and that which they will have in 200 years time. Five illustrative disposal concepts proposed both in the UK and overseas have been examined with a view to their suitability for adaption for storage/disposal duty. Two concepts have been judged unsuitable because either the waste form or the repository structure were considered unlikely to last the storage phase. Three of the concepts would be feasible from a construction and operational viewpoint. This suggests that with appropriate allowance for geological aspects and good repository and waste form design that storage/disposal within the same facility is achievable. The overall cost of the storage/disposal concepts is in general less than that for separate surface storage followed by land disposal, but more than that for direct disposal. (author)