RELAP5/MOD3 assessment using puma facility gdcs drain line break tests

摘要

The post-test Gravity Driven Cooling System (GDCS) drian line break analysis of the Purdue University Multi-dimensional Integral Test Assembly (PUMA) has been carried out using the reactor safety analysis code RELAP5/MDO3. A one-dimensional RELAP5 model was developed for PUMA and a full-duration integral test simulation has been achieved in a base case calculation. The primary safety concerns, such as the primary system inventory and containment integrity have been investigated. RELAP5 gives a reasonably accurate prediction of the system global thermal-hydraulic behavior. In particular, the various flows are well simulated which allows for an accurate prediction of the system mass inventory and energy balance. On the oher hand, the code prediction of the containment pressure deviates significantly from the experimental data. Sensitivity studies have been performed on the brak model mesh size and initial conditions variations. The results show that changes in both meash sinze and initial conditions will not result in significant phenomena variations in the GDCS Drain Line Break (GDLB) trnsient, as long as the mass and energy inventories are matched.