Design and Qualification of an Improved Flux Monitoring Safety System

This paper describes a new type of ex-core flux monitoring startup and safety system suitable for the typical pressurized water reactor (PWR). By utilizing more of the information contained in the detector signals in the signal processing, the need for both intermediate range channels and the conventional boron proportional counters and preamplifiers required for source range has been eliminated. This results in a higher reliability system and one that is easier to qualify to meet the latest IEEE standards and the typical design-base events (DBE) postulated for nuclear plants. Qualification of the system to IEEE 323 (1974) will be discussed.