EXPERIMENTAL STUDY ON THE STEAM LINE BREAK (SLB) ACCIDENT WITH THE STEAM GENERATOR TUBE RUPTURE (SGTR)

The integral effect test to simulate a steam line break (SLB) accident accompanied by a steam generator tube rupture (SGTR), named SLB-SGTR-02 test, was performed to investigate the thermal hydraulic phenomena during a multiple failure accident. In this study, a thermal-hydraulic integral effect facility, ATLAS (Advanced Thermal-hydraulic test Loop for Accident Simulation) was utilized to simulate thermal hydraulic phenomena which can occur in the nuclear power plant, especially for the pressurized water reactor, as realistically as possible. The SLB is simulated as a guillotine break on the main steam line and, in the SGTR, five steam generator tubes on the steam generator hot-side are modeled. Due to the initiation of SLB, a reactor was tripped by low steam generator pressure (LSGP) signal and the SGTR was initiated when the water inventory in the secondary system of the affected steam generator was dried-out. During the transient simulation for SLB-SGTR-02 test, major thermal-hydraulic parameters such as the system pressures, the collapsed water levels, the flows in the primary loops and the fluid temperatures, were measured and analyzed. Through this experimental result, insights about the accident management procedure can be provided in the case of the multiple failure accident, such as an SLB with a SGTR.