New approaches for sludge management in the nuclear industry

Globally the nuclear industry has a large number of legacy wastes that have been stored in ponds, silos and tanks nearing the end of their design lifetime that need processing. In the UK there are significant quantities of radioactive sludge that have arisen from the corrosion of early Magnox fuel cans stored underwater. As part of the aggressive clean-up programme these wastes will be retrieved, separated, processed and immobilised as dry products for long-term storage. The retrieval of these will require the design of new engineering systems that will locate, re-suspend the wastes such that the impact of shear and risk of pipe blockage are minimised. In order to optimise the retrieval design, BNFL are continuing to examine retrieval technologies, the key factors that influence the waste's re-suspension, transport behaviour and ultimately methodologies to model this. This paper discusses some of the retrieval technologies trialed, aspects of slurry management that are unique and important to the nuclear industry. The approach that was taken to model the waste, the experimental strategy to validate them and the results from preliminary models are presented. Globally the nuclear industry has a large number of legacy wastes that have been stored in ponds, silos and tanks that need processing. As part of the aggressive clean-up in the UK, these wastes will be retrieved, processed and immobilised as dry products for long-term storage. The retrieval of these will require the design of new engineering systems that will locate, re-suspend the wastes such that the impact of shear and risk of pipe blockage are minimised. Retrieval technologies trialed, aspects of slurry management that are unique and important to the nuclear industry and the modelling and experimental approaches employed to assess these are discussed. [Display omitted]