Intermediate level waste cementation at Dounreay

The United Kingdom Atomic Energy Authority (UKAEA) condition all Intermediate Level Waste (ILW) to ensure that it is suitable for either long-term storage or disposal. This paper concentrates on the cementation of raffinates arising from historic fuel reprocessing activities undertaken on the Dounreay site. There are 3 types of acidic reprocessing raffinate on the site - these have arisen from the reprocessing of irradiated fuel elements from the Dounreay Fast Reactor (DFR), the Prototype Fast Reactor (PFR) and various Materials Test Reactors (MTRs). The preferred immobilisation matrix for all of the United Kingdom's ILW is cement. For the MTR raffinate at Dounreay, the approved strategy for immobilisation is cementation. For the DFR raffinate, the reference strategy for immobilisation is also cementation. UKAEA have been undertaking significant development work to investigate the possibility of immobilising the PFR raffinate in a cement matrix. Obviously, different cement formulations will be required for both the DFR and PFR raffinates, and the processing of these may be carried out in different plants. This abstract concentrates on the cementation of MTR raffinate at Dounreay. (orig.)