Assessment of RELAP5-3D multi-dimensional component model using data from LOFT Test L2-5

The capability of the RELAP5-3D computer code to perform multi-dimensional analysis of a pressurized water reactor (PWR) was assessed using data from the Loss-of-Fluid Test (LOFT) L2-5 experiment. The LOFT facility was a 50 MW PWR that was designed to simulate the response of a commercial PWR during a loss-of-coolant accident (LOCA). Test L2-5 simulated a 200% double-ended cold leg break with an immediate primary coolant pump trip. A three-dimensional model of the LOFT reactor vessel was developed. Calculations of the LOFT L21-5 experiment were performed using the RELAP5-3D computer code. The calculations simulated the blowdown, refill, and reflood portions of the transient. The calculated thermal-hydraulic response of the primary coolant system was generally in reasonable agreement with the test. The calculated results were also generally as good as or better than those obtained previously with RELAP5/MOD3