A fault tolerant process control system for PHWRs

Many computer control application have stringent requirements for continued correct operation of the control system in the presence of internal faults. There is undoubtedly a great need in the power industry, particularly in the nuclear segment, for reliable control and monitoring systems. One must guarantee safe control and avoid false alarm that can spuriously cause plant shutdown when it is not necessary. This paper discusses the issues involved in the design of fault tolerant systems and describes the features of a fault-tolerant process control system being developed for use in future PHWRs. The processes selected for this computer control application include primary coolant and steam generator pressures. (author). 8 refs., 1 fig