REGDOC-2.4.1 Compliant Loss of Reactivity Control Trip Coverage Analysis

Abstract

As part of New Brunswick Power's REGDOC-2.4.1 implementation plan, the loss of reactivity control (LORC) trip coverage analysis has been performed. Fast LORC was identified and classified as anticipated operational occurrence (AOO) based on initiating event frequencies from PSA. Based on technical and PSA rationalizations, sub-division of the LORC events to update their classification into AOO, design basis accident (DBA) and beyond design basis accident (BDBA) was further examined. This paper presents the trip coverage analysis of LORC at power encompassing AOO, DBA and BDBA for Point Lepreau Nuclear Generating Station based on regulatory requirements for safety analysis and industry guidance for limit of the operating envelope and realistic operating envelope analysis approaches. The robustness of level 2 defence-in-depth has been demonstrated explicitly through LORC AOO analysis in addition to traditional DBA analysis focusing on demonstrating level 3 defence-in-depth. An example of LORC BDBA analysis in support of level 4 defence-in-depth is also presented.