Targets for LMFBR sub-assembly fault detection systems

The choice of the detection systems, the design of the equipment, and the systems availability is discussed for LMFBR sub-assembly fault detection systems. The development of instrumentation for fault detection must be closely integrated with work on the ways in which faults develop. The choice of detection systems depends upon the adequacy of response time and the ability to distinguish between 'benign' and potentially dangerous fuel failures. For rapidly developing fault situations, systems for detecting sodium boiling such as boiling noise detection and measurements of fluctuations in flow or temperature should be capable of development to provide adequately rapid detection. In the leading large fast reactors, as the mode of failure will not be fully known, maximum instrumentation is desirable. The complexity, the signal processing and the amount of cable involved may require complexing or computer systems to be used. High reliability of the instrumentation must be demonstrated under realistic conditions and the safety requirements of sub-assembly instrumentation reconciled with the need for high availability. (U.K.)