Counterpart Experiment and Analysis of ATLAS DVI-line Break Accident utilizing SNUF

The thermal-hydraulic phenomena of Direct Vessel Injection (DVI) line break accident in pressurized water reactor, APR1400, were investigated by ATLAS (Advanced Thermal-hydraulic Test Loop for Accident Simulation) test facility. In this study, the experiment and analysis, as the counterpart of the ATLAS DVI-line break accident, were performed with the reduced-height and reduced-pressure integral test loop, SNUF (Seoul National University Facility), The SNUF was constructed with scaling down the ARP1400. For the appropriate test conditions in the experiment of the SNUF, the energy scaling methodology was adopted to determine the test conditions in the low pressure and low temperature conditions. And, the design changes, such as secondary heat removal system, discharge flow rate measurement system, broken DVI line nozzle and so on, were carried out to perform the counterpart experiment. To investigate the capability of the changed systems, the pre-test were performed. Also, the MARS code analysis was carried out about the pre-test. The experimental and analytical results of the pre-test can be utilized to increase the reliability of the 100%, 50%, 25% DVI line break accident experiments which will be performed afterward