Preliminary Analysis of LOFT LP-FW-1 Test using SPACE code

The LOFT LP-FW-1 test simulated a total loss of feed water (TLOFW) events, which is one of the initiating events categorized in the DEC. Thus, this result can be a basis of methodology for TLOFW analysis using SPACE code. In this study, the LOFT LP-FW-1 is analyzed using SPACE code in order to evaluate the analysis capability and to give a basis of analysis methodology for the DEC events. In the pre-analysis, the prediction of a short-term transient is reasonable except a little delay. The most sensitive parameter is the discharge coefficient in the PORV and the off-take model in pressurizer surge-line. When the PORV is opened, the vapor phase is initially discharged. When the liquid level in the pressurizer reaches the top and two-phase mixture begins to be discharged, which results in a re-pressurization of the primary system. When vapor discharge coefficient is increased to 1.2, the reduction rate of primary system pressure during the short-term is well predicted. When the off-take model is applied to the pressurizer surge-line, the primary system re-pressurization is reduced due to lower density in the pressurizer relief-line. In addition, the heat loss can be effective parameter to reduce the system pressure and temperature.