Technical achievement of advanced 1,100 MW BWR turbine and generator system

No.3 plant in Fukushima No.2 Nuclear Power Station, Tokyo Electric Power Co., Inc., started the commercial operation on June 21, 1985, without trouble in the trial operation. In order to meet the needs of improving the economical efficiency of nuclear power generation, many new techniques have been adopted in this plant. In this report, the features of the main new techniques in the turbine-generator system and the results of operation are described. The plant is composed of an improved standard BWR-5 of 3293 MWt and a turbine-generator of rated output 1100 MWe. For improving the operation properties, a 100 % turbine bypass system, a super-rapid response exciting system, new condensate and feed water system, the electro-hydraulic control of feed pump driving turbines, and a low flow rate feed regulating valve were adopted. For improving the reliability, a low pressure rotor of one-body construction and tripled electro-hydraulic control system were adopted. For rationalization, four stages of neck LP feed heaters, a small size turbine building, a flexible turbine-generator foundation, the backwashing for condensers by changing six valves and so on were adopted. Also many improvements of construction method were carried out. (Kako, I.)