Characterisation of the activities associated with fast reactor cladding hulls

Abstract

Four batches of hulls from the reprocessing of fuel from the Prototype Fast Reactor at Dounreay have been examined visually and photographically. The appearance of the hulls (shiny or black) depended on the original location in the fuel pin. The total fissile activities measured corresponded to less than 0.1% of the original fuel. The α-emitter, fission product and activation product activities have been determined from dissolution studies. Profile diagrams have been constructed for the distribution of the principal activities along lengths of seventeen hulls. The evidence obtained suggested that much of the activity on the hulls arose through deposition from the dissolver liquors. The deposits included insoluble particulate material which was thought to be responsible for the wide variations in activity across short lengths of some of the hulls.