Analysis of LOFT experiment L6-8C-3 using the RELAP5 code

The Loss-of-Fluid Test (LOFT) facility, operated by EG and G Idaho, Inc., is a 55-MW(t) experimental reactor designed to simulate the major components and system response of a commercial pressurized water reactor (PWR) during hypothetical loss-of-coolant accidents. LOFT experiment L6-8C-3, conducted on August 31, 1982, simulated a small break in the primary coolant system, a transient that has a high probability of occurrence during the lifetime of a commercial PWR. The experiment was designed to investigate a small-break transient with extended operation of the reactor coolant pumps and to demonstrate the use of pump current (or power) monitoring as a diagnostic technique for accident management. Post-experiment calculations were performed with the RELAP5/MOD1 computer code using the specified initial conditions and the measured initial and boundary conditions. The objectives of the calculations were to evaluate the capability of the RELAP5/MOD1 code to calculate the thermal-hydraulic phenomena that occurred during the experiment.