Fission Gas Mobility in UO2 Simulating a Burnup of 30 MWd/kg U

Abstract

Fission gas mobility in UO₂ with a simulated burnup of 30 MWd/kgU (called SIMFUEL) was studied up to 1500°C using ion-implantation to introduce the rare gas Kr. Two widely separated gas implantation doses, corresponding to a low and a high gas concentration, were employed. No dramatic difference was seen between SIMFUEL and UO₂ Release from SIMFUEL was slightly enhanced at high temperatures. The presence of non-volatile fission products in UO₂ is therefore predicted to not cause a dramatic increase in release at high temperatures.