Sensitivity Analysis of a Two-Out-of-Four Coincidence Logic Reactor Protective System

The mathematical models for a reactor protective system were developed for sensitivity analysis. The models are for the two-out-of-four coincidence logic configuration and reflect the "spurious trip" and "no trip" system failure modes. The models, developed from conditional probabilities and series chain configuration techniques, are adaptable to other coincidence logic schemes as well. An example is included to demonstrate the sensitivity analysis technique.