Post-accident heat removal from particulated fuel debris

As part of the safety studies of nuclear fission reactors, consideration is given to hypothetical low-probability accident sequences in which the reactor core may become degraded from an ordered array of sheathed fuel to a random bed of particulate material. Any threat to the environment or population which may be associated with such unlikely accidents is much reduced if decay heat can always be adequately removed from the particulate material. For this reason, a major international effort has been mounted to research cooling of self-heated particle beds. Work being done in the USA and Europe is outlined and the contribution being made at AEE Winfrith is described. (author)