SDS No.2 Low Steam Generator Level and High/Low HTS Pressure Trip Instrumentation Improvement for Wolsong 1 NPP Refurbishment

In Wolsong Nuclear Power Plant Unit 1 (Wolsong-1), the Shutdown System (SDS) 2 low steam generator (SG) level trip provides protection against secondary side failures and the high/low Heat Transport System (HTS) pressure trip provides protection against loss of heat sink / small LOCA. While the SDS 1 monitors SG 1 and 4 levels, and reactor outlet header (ROH) 1, 3, 5 and 7 pressures, the SDS 2 monitors the parameters for SG 2 and 3 levels, and ROH 1 and 5 pressures. This refurbishment is to add the instrumentation for SG 1 and 4 level parameters and ROH 3 and 7 pressure parameters to enhance the effective trip coverage, redundancy and diversity for SDS 2