NUCLEAR-POWER-PLANT TRANSIENT DIAGNOSTICS USING TRANSFER-FUNCTIONS ASESTIMATORS

Diagnostic methodologies for nuclear power plants (NPPs) are usually b ased on mathematical models and generation of residuals. To avoid comp licated, time-consuming, and costly diagnostic simulations of the phys ical phenomena in NPPs, an algorithm that determines a significant pat tern for major transients is investigated. Coefficients of the transfe r function between the observed parameters are used as the pattern fea tures. The algorithm uses a recurring least-squares method known from the literature to determine the transfer functions. The case study inc ludes 30 different scenarios in the primary and secondary systems. Eac h scenario produces its own significant recognized pattern. The RELAP5 /MOD3.2 code is used to simulate the input data for the Krsko pressuri zed water reactor NPP. The algorithm recognizes the prepared scenarios , and it classifies them into groups.