Software safety analysis application of safety-related I&C systems in installation phase

This work performed a software safety analysis (SSA) in the installation phase of the Lungmen nuclear power plant (LMNPP) in Taiwan, under the cooperation of INER and TPC. The US Nuclear Regulatory Commission (USNRC) requests licensee to perform software safety analysis (SSA) and software verification and validation (SV&V) in each phase of software development life cycle with Branch Technical Position (BTP) 14. In this work, 37 safety grade digital instrumentation and control (I&C) systems were analyzed by Failure Mode and Effects Analysis (FMEA), which is suggested by IEEE Standard 7-4.3.2 (2003). During the installation phase, skew tests for safety grade network and point to point tests were performed. The FMEA showed all the single failure modes can be resolved by the redundant architecture. The common mode failures can be resolved by operator manual actions via the diverse displays.