OPTROP: A Computer Code for Optimized Design of ROP Detector Systems

Abstract

In large CANDU power reactors, the Regional Overpower Protection (ROP) system protects against local fuel and channel overpower s which could arise from various perturbations in the reactor power shape or during a Loss-of-Regulation power transient. The computer code OPTROP has been developed to find an optimum set of ROP flux detectors and detector trip setpoints. The optimization seeks to maximize operational trip margins, while providing the required protection against fuel and channel overpowers over an input set of perturbation cases. The code uses a substitution-improvement method with an easily calculated figure of merit that approximately reflects the average trip margin. Experience with use of the code, and possible future modifications to the optimization algorithm are also outlined.