Authors: A. Samantara, J. Abraham, K. Natesan
Year: 2025
Industry: Nuclear & SMR
Keywords: Use FSE, Transient, Dynamic, SFR, Validation, Comparison, Parametric
ABSTRACT
Secondary sodium main circuit (SSMC) in a fast reactor transports heat from reactor core in primary circuit to steam generator. Pressure transient in SSMC for design basis events are studied using an in-house developed 'Swept code'. Method of characteristics (MOC) formulation is used in the code to solve the governing continuity and momentum equations. Two events are studied, viz., isolation valve closure in steam generator and sodium pump seizure in the secondary sodium system. Maximum pressures during the events are estimated, which is used for design of safety systems. Parametric studies are carried out by varying valve closure and pump seizure timings and the results are discussed. Swept code predictions are compared against results obtained from commercial system dynamics code Flownex, which uses implicit method to solve the governing equations. It is seen that Swept code predictions are in reasonably good agreement with Flownex. This will help in increasing confidence level in the code predictions and thus, safety of the sodium systems.