Qualitative Assessment of the Fission Product Release Capability of ELOCA.Mk5

Abstract

A qualitative assessment of the fission product release capability of the ELOCA.Mk5 computer code was performed by simulating two transients from the sweep-gas experiment, FIO-133.Improved agreement between calculated and experimental trends in release was obtained by applying an interface pressure stress component to the pellet center. As well, results show that the current system for defining the reference temperature distribution for the thermal stress component is not always realistic. These results are being used in the development of a new, mechanistic pellet stress model.