Computerized radiation monitoring system for nuclear power plant

In nuclear power plants, strict radiation monitoring and control are being performed based on the concept of ALARA (as low as reasonably achievable), to protect the general public around and the workers inside power plants from exposure to radiation. Recently Hitachi Ltd. and Japan Atomic Power Co. have cooperated to systemize the radiation control works and applied it to Tokai No. 1 and No. 2 nuclear power plants. This system is composed of a number of monitoring equipments located inside and outside the plant sites, exposure dose measuring instruments to conduct the measurements and checks on the exposure dose of each worker on every entrance at each check point prepared at the entrance of control area or working area on the sites, and various computer peripherals, centering around the control computer. The computer system consists of dual systems; a system mainly to acquire data and the monitor on real time and the other system to file that data and statistically analyze them. The functions of the system are described by dividing them into personal exposure control, radiation level control inside the plants and environmental radiation control. (Wakatsuki, Y.)