Counterpart Tests on the SMART SBLOCA Scenario using Integral Effect Test Facilities and Their Code Analyses

A series of integral effect tests for the SMART integral reactor were conducted for a small-break loss-of-coolant accident (SBLOCA) scenario involving a pressurizer safety valve line break. Counterpart tests for the same SBLOCA scenarios were performed using two integral effect test facilities, FESTA and VISTA-ITL, and by comparing the test results, we were able to better understand the phenomena expected to occur in the SMART design. Appropriate initial and boundary conditions were provided for each test, and the overall trends of the major thermal-hydraulic variables showed consistency between the test results of the two facilities. Although small differences arose between the test results due to the difference in facility scales, the tests provided generally reasonable thermal-hydraulic behavior during the SBLOCA scenarios of the SMART reactor. Therefore, it is concluded that the test results from FESTA and VISTA-ITL properly simulate the thermal-hydraulic behavior expected during the design and licensing process of the SMART reactor. Also the code simulations for the pressurizer safety valve line break SBLOC A tests using FESTA and VISTA-ITL were performed using the MARS-KS code. The simulation results generally well-predicted the trends of the major variables obtained from the experiments. However, further improvements in modeling of break flow rate and steam generator heat transfer rate are deemed necessary.