Studies of Ceramic Fuels with the Use of Fission Gas Release Loop, (I)Fission Gas Release from UO2-Graphite Mixture during Irradiation

摘要

Fission gas release from a UO2-graphite mixture was studied during irradiation with the use of the Fission Gas Release Loop in the JRR-3 reactor. The release rates of fission krypton and xenon increased proportionally with neutron flux (6×1010-6×1012n/cm2?sec) and exponentially with temperature (400°-1, 000°C). A burst of fission gas was observed when the specimen was abruptly heated to a higher temperature. These results can be explained by a mechanism whereby fission gas is trapped in defects created in graphite by fission fragments and released through annealing of the defects.