Preliminary Probabilistic Safety Assessment for SMART

The SMART(System-integrated Modular Advanced ReacTor) Pre-project Engineering joint project is performing with Korea and Kingdom of Saudi Arabia. As a part of this project, the preliminary PSA was performed. The SMART is the integral type of a pressurized water reactor with a nominal thermal power is 365 megawatt thermal power, which contains core, reactor coolant pumps, steam generators and pressurizer within a single reactor pressure vessel. The inner diameter of all pipes of the primary system less than 2 inches because of SMART design features, so the large break LOCA(Loss of Coolant Accident) could be eliminated. The active support system are designed as the RTNSS(Regulatory Treatment of Non Safety Systems) requirements to ensure their reliability. The PSA is performing to confirm the safety level and to find the vulnerability for SMART plant which is performing. In this paper, the results of preliminary level-1 internal events PSA at power operation are presented. The preliminary PSA for SMART was performed to confirm the safety and to find the vulnerability for SMART plant. Ten event trees were developed and quantification was performed for 10 initiating events category. The quantification results shows that no vulnerable point in SMART design but some detailed analysis is needed to reduce uncertainty and conservatism such as ATWS(Anticipated Transient Without SCRAM) and passive safety system reliability analysis.