Simulation Of Thermal Hydraulic Performance In Advanced Containment

Containment is the last barrier of safety in a reactor that used for keeping the radioactivematerial from external environment. Therefore, the integrity of containment is of vitalimportance to the safety of nuclear power plants. While the loss of coolant accident, such as alarge break LOCA, might destroy the integrity of the containment. For this reason, theresearch of how the design basis accidents affect the medium in containment and calculationof temperature and pressure in containment which are vary with time due to the quality andenergy released from the break are essential.In this paper, a code (called the advanced containment thermal-hydraulic performancesimulation code) is developed with lumped parameter method to simulate the phenomena incontainment which is under design basis accident. the code developing progress includesestablishment of physical models, confirmation of numerical methods, debugging andverification of the code by comparing with the result calculated by MELCOR, which provesthe code reliable. After that, influence of hydrogen to calculation result has been analyzed andphenomena in the containment while the double ended cold-leg break/double-ended mainsteam line break occurs have also been simulated.Besides, phenomena in the containment have also been simulated by the advancedcontainment thermal-hydraulic performance simulation code, which is coupled the openPCCS (passive containment cooling system) code. The results of advanced containmentthermal-hydraulic performance simulation code coupling PCCS code simulating containmentthermal-hydraulic performance under the design basis accident conditions show thatcontainment has been cooled and pressure been reduced effectively. The influence ofchanging original conditions to the heat transfer between containment and PCCS has beencalculated and analyzed..