Instrumentation and control system for the prototype fast breeder reactor 'MONJU' power station

The fast breeder reactor 'Monju' power station is constructed as the nuclear power station of next generation in Tsuruga City, Fukui Prefecture. In order to realize high safety and operational reliability as the newest nuclear power station, the measurement and control system of Monju (electric power output 280 MW) has been designed and manufactured by reflecting the experiences of construction and operation of the experimental FBR 'Joyo' and the results of various research and development of sodium instrumentation and others, and by using the latest digital control technology and multiplexing system technology. In this paper, the results of development of the characteristic measurement and control technology as fast breeder reactors and the state of application to the measurement and control system which was designed and manufactured for Monju are described. Central monitoring panel, plant control system, sodium instrumentation, preheating control system and so on are reported. In the case of Monju, the heat capacity and thermal inertia of the primary and secondary cooling systems are large, and the system comprises three loops. (K.I.)