[en] Tohoku Electric Power Company promotes development of various power sources to provide a stable supply of electricity in the future, and nuclear power takes a leading part. In August 1989, construction of Onagawa nuclear power plant Unit No. 2 (825MW) was started, following Unit No. 1 (524MW) which went on line in 1984 as Tohoku Electric's first nuclear power plant unit. Unit No. 2 began commercial operation in July 1995 through satisfactory construction work such as RPV hydraulic test in March 1994, fuel loading in October 1994, and various startup tests in each power stage. The design and construction of Unit No. 2 reflect construction and operation experience gained from Unit No. 1, and the latest technology, including that of the LWR Improvement and Standardization Program, was adopted to enhance facility reliability, improve operation and maintenance performance, and reduce worker dosage. Features of the facility, construction techniques, and a description of preoperation of Onagawa nuclear power plant Unit No. 2 are described in this paper. (author)