Probabilistic Evaluation of the Post Disassembly Energetics of a Hypothetical Core Disruptive Accident in a Sodium-Cooled SMR by using a Phenomenological Relationship Diagram

An innovative probabilistic approach based on the Phenomenological Relations Diagram is developed to perform risk analyses of Hypothetical Core Disruptive Accidents in Sodium Fast Reactors (SFRs). The novel method is applied to evaluate the probability distribution of the thermal-to-mechanical energy conversion ratio in an ULOF/Post-Disassembly Expansion Phase scenario in a small- to medium- size SFR. The results provide a comprehensive picture of the fuel energy distribution in the system.