Progress in Modelling Fission-Product Release: An Update with Respect to IRSN’s Release Codes

Abstract

IRSN presented in detail at this conference in 2003 the modelling of its release codes, ASTEC/ELSA and MFPR. Progress relating to key objectives is described here. ELSA aims to calculate reliably and rapidly release of fission products (FPs) and structural materials from a degrading core for all in-vessel configurations. Two areas were targeted for improvement: release of so-called semi-volatile FPs and release of structural materials. For the mechanistic code MFPR developed by IBRAE (Russian Academy of Sciences) and IRSN, with the new objective of analysis of design-basis loss-of-coolant accidents, modelling of fission-gas release has been improved mainly addressing processes occurring during normal operation. Further improvement depends in part on results of experiments and analyses that IRSN has launched with partners.