Conditioning (radioactive waste)
Conditioning refers to the process in which radioactive waste is converted into a chemically stable state that is insoluble or only slightly soluble in water and then packed in appropriate containers (e.g. Castor casks). Depending on the radioactive waste, different processes are used for this purpose. After conditioning, the waste can be prepared for storage, transport or disposal.
Radioactive raw waste is conditioned in different ways depending on the type of waste and, if applicable, the waste acceptance requirements of a repository. Common conditioning methods are e.g. drying, incineration, compaction, mixing (e.g. with concrete), grouting and vitrification. High-level radioactive waste from reprocessing, for example, is vitrified, poured into a metal sleeve and then welded gas-tight. This type of waste container is called a vitrification waste canister.
The products of individual conditioning processes are generally suitable for storage but must be further packaged in repository casks for disposal according to the specific waste acceptance requirements for disposal. Waste acceptance requirements for disposal are derived from safety analyses based on the properties of the waste and the location of the repository.