Modelling of core protection and monitoring system for PWR nuclear power plant simulator

A nuclear power plant simulator was developed for Y ounggwang units 3 and 4 nuclear power plant (YGN Nos 3 and 4) in Korea; it has been in operation on training center since November 1996, The core protection calculator (CPC) and the core operating limit supervisory system (COLSS) for the simulator were also developed, The CPC is a digital computer-based core protection system, which performs on-line calculation of departure from nucleate boiling ratio (DNBR) and local power density (LPD). It initiates reactor trip when the core conditions exceed designated DNBR or LPD limitations. The COLSS is designed to assist operators by implementing the limiting conditions for operations in the technical specifications. With these systems, it is possible to increase capacity factor and safety of nuclear power plants, because the COLSS data can show accurate operation margin to plant operators and the CPC can protect reactor core. In this study, the function of CPCjCOLSS is analyzed in detail, and then simulation model for CPCjCOLSS is presented based on the function, Compared with the YGN Nos 3 and 4 plant operation data and CEDIPS/COLSS FORTRAN code test results, the predictions with the model show reasonable results,