EPJ Nuclear Sci. Technol. 11, 28 (2025)
https://doi.org/10.1051/epjn/2025025

Regular Article

Looking ahead to severe accident research

¹ Centre for research on Energy, Environment and Technology (CIEMAT) Avda. Complutense, 40 28040 Madrid Spain
² Autorité de Sûreté Nucléaire et de Radioprotection (ASNR), PSN-RES F-92262 Fontenay-aux-Roses France
³ Autorité de Sûreté Nucléaire et de Radioprotection (ASNR), PSN-RES/SAM F-13115 Saint-Paul-lez-Durance France
⁴ Agenzia nazionale per le nuove tecnologie, l’energia e lo sviluppo economico sostenibile (ENEA) Via dei Mille n. 21 Bologna (BO) Italy

^* e-mail: luisen.herranz@ciemat.es

Received: 21 November 2024
Received in final form: 29 March 2025
Accepted: 5 May 2025
Published online: 20 June 2025

Abstract

Severe Accident (SA) research is currently facing new challenges coming from changes in the energy and computer science sectors. Therefore, it is imperative to reassess the current status in the area to optimize where the research resources should go to reach even higher safety standards both in the running Nuclear Power Plants (NPP) and the upcoming new designs, particularly Water-Cooled Small Modular Reactors (WC-SMR). Three Horizon Euratom projects stand out in such context. SEAKNOT (SEvere Accident research and KNOwledge managemenT) is progressing in setting a SA research roadmap by ranking the major phenomena involved in terms of knowledge and safety significance in LWRs (large water-cooled reactors) and SMRs, at the same time that it is strengthening paths for Education & Training (E&T) on SA for forthcoming generations of researchers and engineers. SASPAM-SA (Safety Analysis of SMR with PAssive Mitigation strategies-Severe Accident) is supplying valuable information on phenomena, boundary and accident conditions that might prevail in WC-SMRs, specifically integral PWR (iPWR). The project allows the assessment of the applicability of the current state-of-the-art simulation codes and the relevance of large reactor experiments to iPWRs. Different SA mitigation strategies, like In-Vessel Melt Retention (IVMR), are being explored. Finally, ASSAS (Artificial intelligence for Simulation of Severe AccidentS) is working to prove the possibility to develop fast-running SA simulators thanks to Artificial Intelligence, to support training, engineering and emergency response. This paper discusses the major progress made in the three projects and their complementarity contributes to a safer nuclear energy production.