The Boiling water reactor (BWR) concept was originally developed based on an early collaborative research between the General Electric Company (GE) and the ANL, and a series of the nuclear reactor experiments called the BORAX experi­ments. The first prototype BWR for electric power generation was Dresden Unit 1 (180 MWe) constructed near Chicago in 1960. The reactor was characterized by a dual cycle design of both direct and indirect cycles. After that, a forced circulation type of a single direct cycle has been used as a standard BWR design. The full-scale commercial BWR power plants began with Oyster Creek (650 MWe) which started operation in 1963. The GE also built an test reactor, Vallectios BWR (VBWR), in 1957 and used it in various improvements of BWR.

The first electricity from nuclear energy in Japan was generated by a 12.5 MWe — BWR, Japan Power Demonstration Reactor (JPDR), at the Japan Atomic Energy Institute (JAERI) in 1963. Later, the commercial BWRs started operation with Tsuruga Unit 1 (357 MWe) of the Japan Atomic Power Company in 1969 and Fukushima Daiichi Unit 1 (460 MWe) of the Tokyo Electric Power Company in 1970.

The history of BWR technology is summarized in Fig. 3.2 and Table 3.2. The main research and development of the BORAX series is shown in Table 3.3. In addition to USA and Japan, commercial BWRs are operated in Sweden, Germany, Mexico, India, etc.