SASPAM-SA WP2: Reports of the partners - Analyses of the employment of ATFs in iPWR scenario analyses

The HORIZON-EURATOM SASPAM-SA project, which was initiated in 2022 and is being coordinated by ENEA (Italy), is addressing a critical knowledge gap in the analysis of Severe Accidents (SAs) and Emergency Planning Zone (EPZs) for Integral Pressurised Water Reactors (iPWRs). The project aims to transfer the expertise developed for large light water reactors (LWRs) for use with iPWRs, thereby aligning with European licensing requirements. A key objective is to evaluate the predictive capabilities of state-of-the-art integral safety analysis codes — both European and non-European — in simulating postulated SA scenarios in two generic iPWR designs that are representative of leading concepts in the European market.
As part of the Work Package 2 (WP2-SCENARIO), the SASPAM-SA partners conducted an extensive study to assess the applicability and performance of the leading integral codes for modelling SA phenomena in two selected generic iPWR designs. This report presents the evaluation of Design-1 and Design-2 concepts with the codes ASTEC, MELCOR and AC², focusing on the behaviour of ATFs, specifically FeCrAl cladding, under SA conditions. Simulations were conducted by KIT, RUB-PSS, VTT, ENEA, LEI and UNIROMA1. Based on current knowledge and at the start of the accident, the main objective was to evaluate the influence of FeCrAl cladding on accident progression compared to conventional Zircaloy cladding, with focus on the hydrogen generation. This report provides the partners' reports relevant to the sudies perfromed in the WP2.3.