[en] In the Onagawa Nuclear Power Plants in the Tohoku Electric Power Co., Inc., two plants of No. 1 Plant (524 MWe; operation starting on June, 1984) and No. 2 Plant (825 MWe; operation starting on July, 1995) are in operation, and No. 3 Plant (825 MWe; planned operation starting on January, 2002) is now under construction, together with No. 1 Plant of the Higashidori Nuclear Power Plants (1100 MWe; planned operation starting on July, 2005). Here were introduced on outline of sites and overall displacement plan, outline and characteristics of instruments, construction process and engineering characteristics, progressing states of construction, and so forth on these two under-construction plants. (G.K.)