Design experience and improvement of 1100 MWe BWR power plant

14 years have elapsed since the construction of the Tsuruga Nuclear Power Station, Japan Atomic Power Co., with the first imported BWR had been started. Since then, Toshiba has taken part in the design and construction of 12 BWRs, initially as the subcontractor, and later, as the license of GE, USA. The improvement and standardization of LWRs by independent Japanese technologies have been promoted since 1975, and the draft design was decided. The aims of the design of BWRs in Toshiba are the improvements of safety, reliability and the rate of operation, that is, the prevention of unnecessary plant stopping, the shortening of regular inspection period and the extension of intervals of fuel exchange, moreover, the reduction of radiation exposure and the improvements of operational capability and economic efficiency. The main specifications of Japanese standard BWR plants with 1100 MWe capacity are shown. As the design method, the adoption of design models and the mechanization of design are carried out. The results of design to attain the above described aims are explained. As the new technologies for steam turbines, the standard types of turbines, the adoption of reheating cycle and feed water cycle, total capacity bypass system, all titanium condensers and the development of one-body LP rotors are described. (Kako, I.)