Development and practical use of improved pressurized water type reactors (APWR)

As for improved pressurized water type reactors, the development was carried out as a part of the third improvement and standardization activities as the light water reactors of the next generation which conform to the circumstances in Japan, with the background of the history of introducing and improving light water reactors in Japan and under the perspective that the dependence on light water reactors as a stable energy source continues over long period. The development was carried out by five electric power companies of Hokkaido, Kansai, Shikoku, Kyushu and Japan Atomic Power, Mitsubishi Heavy Industries and Westinghouse, aiming at the improvement of the rate of operation, economical efficiency, operability, safety and maintainability. Many confirmation and verification tests were carried out on the developed design. The development and upgrading research was begun in 1982, and completed in 1987. The technical features of the APWR plant are 1350 MW class large capacity, high efficiency plant, the improved core with spectral shift control and improved neutron economy, high performance, high reliability steam generators, four subsystem safety and protection facilities, high efficiency turbine and so on. (K.I.)