Simulation of VVER-1000 Guillotine Large Break Loss of Coolant Accident Using RELAP5/SCDAPSIM/MOD3.5

The safety performance of nuclear power plants (NPPs) is a very important factor in evaluating energy sustainability. Safety analysis passive and active systems have positive influence on reactor transient mitigation. One the common transients primary coolant leg rupture. This study focused guillotine large break loss (LB-LOCA) one vessels, which cold rupture occurred, after establishment steady-state condition for VVER-1000. responses emergence core cooling (ECCSs) were investigated. main margin considered during this simulation was to check maximum value clad surface temperature, it then compared with design licensing limit 1474 K. calculations event progression used engineering-level RELAP5/SCDAPSIM/MOD3.5 thermal-hydraulic program, also provide more detailed treatment system thermal hydraulics behavior. obtained results show that actuation ECCSs at their set points provided by injecting water into pressure vessel, as expected. peak cladding temperature did not overpass LB-LOCA transient. above decreased rapidly from 15.7 MPa 1 less than 10 s, stabilizes up end fuel 847 K 378 first 30 s time. leakage reduced 9945 kg/s approximately 461 190 Overall, shows that, within VVER-1000, inherent robustness containing LB-LOCA.