A review of irradiation-induced densification in uranium dioxide fuel. Special report

This review traces the evolution of the understanding of fuel densification from 1972 to 1975. Progress includes (1) identification of microstructural features of the fuel having the greatest impact on densification; (2) establishment of in-reactor operating conditions dominating densification kinetics; (3) confirmation by theoretical models that parameters identified by experimental evident play a major role in fuel densification; and (4) assurance that stable fuels can be routinely provided by control of pellet fabrication process variables. Also, resintering tests can provide ready ex-reactor confirmation of differences between fuel types that are likely to be stable or unstable under in-reactor conditions; and the irridation of stable fuel types should have a minimum impact on core performance. Advances in understanding the fuel densification phenomenon and success in routinely fabricating stable fuels support the view that fuel densification will no longer be a problem in light water reactor operation