Post-implementation review of inadequate core cooling instrumentation

Instrumentation needs for the detection of inadequate core cooling are discussed, and a review of reactor coolant inventory tracking systems (RCITS) is presented. RCITS installation experience is considered, and attention is given to operating experience, accuracy, and procedures. It is noted that the addition of inadequate core cooling accident monitoring instrumentation to all PWRs (pressurized water reactors) is nearing completion after more than eight years. The response of and acceptance by the utilities have been largely positive, with only a few holdouts. It is concluded that the systems developed, while not providing the precision that might be desired, are sufficient to provide vital information for accident avoidance and recovery. In addition, unexpected benefits for normal operation have resulted, and operator acceptance and confidence have been good