Radioactive Sodium Waste Treatment and Conditioning

Radioactive sodium waste in the nuclear industry arises from the operation of liquid metal fast reactors (LMFR). In this type of reactor, sodium (Na) or sodium-potassium alloys (NaK) are used as a low-effect neutron moderating coolant medium for extracting and transferring thermal energy from the core. Sodium radioactive waste is not one of the common waste streams during plant operation, although it is one of the more important waste streams for plant decommissioning. More importantly, it represents a significant technical and safety challenge during operation and decommissioning. In addition to the challenges related to the management and disposition of sodium waste, the extremely high chemical reactivity of sodium and sodium eutectics must be taken into account during every evolution involving the primary circuit and the sodium waste, including treatment and conditioning for safe storage or disposal.This publication provides the reader with technologically oriented information on the present status of sodium waste management approaches and recent achievements related to treatment and conditioning, with the objective of facilitating planning and preparatory work for the decommissioning of LMFRs.