Data logger system of Tokai (I) Nuclear Power Station, the Japan Atomic Power Company

The Tokai(I) nuclear power station, the Japan Atomic Power Company, was commissioned in July, 1966. In this station, temperatures of about 700 points are monitored and recorded with a data logger. However, the logger was manufactured some 15 years ago, therefore it is now old-fashioned, and has caused frequent failures these 2 or 3 years. So it was decided to replace it with a new one, and the process control computer, U-300 system including CRT display, has been adopted considering the latest trend in U.K. The control and monitoring system in this station is not a centralized control system, but a distributed control system divided into three control rooms, namely main control room, turbine generator control room and fuel exchanger (cask machine) control room. Therefore for grasping the complete plant conditions at the main control room, the system has not been convenient, and the centralization of data processing has been desired from the viewpoint of operation. The new logger system is composed so as to facilitate the centralized monitoring in the main control room, considering the above requirement. It has been improved so as to have seven important functions in addition to the existing functions. Hardware and software of this system are briefly explained. The new system was started up in February 1977, and is now operating well, though some early failures were experienced. (Wakatsuki, Y.)