An analysis of ex-vessel steam explosions in a NPP has been performed for different scenarios with the standard version of the computer code MC3D, which will be upgraded with the developed melt droplets solidification model and the developed explosion model. A steam explosion may develop during a severe reactor accident if the reactor vessel fails and the molten core pours in the flooded reactor cavity. The influence of the pour location, the reactor coolant system pressure, the water subcooling and the explosion triggering time on the pressure loads during a steam explosion was established.
COBISS.SI-ID: 22923303
A steam explosion experiment, which was performed in the FARO facility (JRC-Ispra, Italy) was simulated and the influence of the melt solidification modelling on the steam explosion efficiency was analyzed. By the comparison of simulation results, obtained with the code MC3D, with experimental measurements we found out that the appropriate modelling of the melt droplets solidification during the premixing phase is crucial for the reliable estimation of the steam explosion strength.
COBISS.SI-ID: 23178535