ATLAS MSLB Accident Analysis Using the SPACE Code

摘要

An integral effect test for a main stem line break (MSLB) was performed with the ATLAS (Advanced Thermal-Hydraulic Test Loop for Accident Simulation) by KAERI. A MSLB is defined as a pipe break in the main steam system. This data was used to validate the safety analysis code SPACE (Safety and Performance Analysis Code for Nuclear Power Plants). In the test, a double-ended guillotined break of the main steam line was simulated. After a steady-state was reached, the test was started by opening the break simulation valves. With the start of the test, the pressure of the secondary system was decreased rapidly, which is the set-point of the LSGP signal. With the occurrence of the LSGP signal, the secondary system was isolated. The SIP actuation signal was issued by the LPP signal. When the MSLB event was initiated by opening the break simulation valve, the SG was depressurized. The calculation results and experimental values differed due to the difference in the flow rate corresponding to the break point. In order to validate the SPACE code, a double-ended guillotine break of the main steam line at ATLAS was simulated. Most of the results were identical between the experiment data and the code values.