FGD Program; SCANAIR preparatory calculations

Trgours, N.*; Sugiyama, Tomoyuki 

The JAEA and IRSN are planning an experimental program to clarify the dynamics in fission gas release from fuel pellets under reactivity-initiated accident (RIA) conditions. In the Fission Gas Dynamics (FGD) test, high burnup fuel pellets in a rigid chamber is pulse-irradiated in the NSRR and the history of fission gas release is evaluated by transient measurements of the pressure and temperature in the chamber. In order to validate the chamber design and test conditions, preparatory calculations were performed on the high burnup UO and MOX fuels, which had been tested in the NSRR, using the transient fuel behavior analysis code SCANAIR. The calculations provided informative results for the chamber design; the newly developed pressure sensor, which uses a linear variable differential transformer (LVDT), has an enough quick response, the thermal insulation around the chamber can be omitted because of the large heat capacity of the chamber wall, and so on.