Sodium dynamic behavior simulation and analysis under whole large leakage sodium-water reaction accident process

Abstract

Under a large leakage sodium-water reaction accident in a sodium-cooled reactor, the whole accident process simulation, including pressure wave propagation (PWP) and long-term (LT) stages, needs to be carried out to understand the accident procedure and role of the protection system. To investigate the consequences of the accident, a whole large leakage sodium-water reaction (WLLSWR) model was derived to evaluate the sodium dynamic behavior. The WLLSWR accident simulation results demonstrated that the secondary loop integrity was ensured by the effective protection system action, regardless of the PWP or the LT stages. The water/steam leakage rate, gas chamber volume of the surge tank, SG rupture disks location, and the feedwater isolation valve time were found to influence the secondary peak pressure at the LT stage. Furthermore, the bursting action of rupture disk 3, the sodium level and the pressure of the surge tank, should be focused at the LT stage.