Abstract
For core design codes used to calculate thermal margin in BWR core, the validation of their pin power distribution models can be performed based on pin gamma scan measurement of fuels burned in reactor cores. However, since the number of pin gamma scan measurements is very limited, it is difficult to confirm the validity of the pin power distribution evaluation over the entire application range of core design code from such validation results alone. In this paper, in order to supplement the validation based on the pin gamma scan measurements of fuels burned in reactor core, we demonstrated an additional verification and/or validation process for the pin power distribution model of the core design code system CASMO5/SIMULATE5. First, we describe the validation on the pin power distribution model of CASMO5 from the results of pin gamma scan measurements in a criticality test facility. Next, as verification, the comparison results between the pin power distributions calculated by CASMO5 and SIMULATE5 are shown, which describes that the difference between the codes are in a range to satisfy a predetermined acceptance uncertainty for the verification process considering the various ranges of parameters. The verification and/or validation process with CASMO5 and SIMULATE5 combined provides a more strengthened basis as to the application range of SIMULATE5 by supplementing the limited number of the pin gamma scan measurements of fuels burned in reactor core.
