Comparison of LWR and SFR in-containment source term: Similarities and differences

•Identification of similarities/differences between in-containment source terms.•Discussion of the applicability of LWR safety codes to the SFR domain.•Highlight key missing models in LWR codes for SFR applications.

The fundamental differences between Light-Water Reactors (LWRs) and Sodium Fast Reactors (SFRs) (i.e., breeding ratio, neutron energy spectrum, power densities, coolant nature, reactor architecture and so on) entail major differences in safety aspects. In particular, the in-containment source terms in the event of a severe accident differ in major ways. Nevertheless, an in-depth analysis of similarities and differences based on the present available knowledge should allow assessment of the applicability of LWR safety-analysis tools to the SFR domain. This is the final goal of this paper. A thorough literature review indicates that the capabilities of present LWR safety-analysis codes to address in-containment SFR accident scenarios are uneven for different areas: while they appear acceptable for predicting aerosol evolution, they require significant expansion in other areas like aerosol generation and fission-product partitioning. Additionally, some areas in need of further experimental research are highlighted in this paper.