Disposability of the UK's intermediate level wastes

The UK's intermediate level waste (ILW) comprises a range of waste types, which vary widely in terms of physical and chemical properties, radionuclide content (including fissile) and half-life. ILW needs to be conditioned in such a way as to provide confidence that a future disposal facility for such wastes will be able to meet or exceed the basic long-term safety and environmental protection standards. The reactive properties and heterogeneous nature of certain ILW can present waste immobilisation challenges and, depending on the waste conditioning process that is adopted, may ultimately preclude the production of truly passive waste-forms. Of considerable interest is the extent of long-term containment likely to be afforded by the waste container, the wasteform and any engineered barriers within the disposal system. A regulatory view of the current uncertainties is provided and areas where further understanding would be beneficial are identified. (authors)