Onagawa-cho, Osika-gun and Ishinomaki City, Miyagi Prefecture
A Profile of the Nuclear Power Station
The onagawa nuclear power station is located in both Onagawa-cho and Ishinomaki
City, along the coast of the Pacific Ocean, 70 km to the north of the Sendai
City. The site area is about 1,730,000 sq. meters. The site was excavated to
place the buildings of the station on deep rigid bed-rocks and artificial rocks.
From the beginning, the main buildings of the Onagawa Station, such as the reactor
buildings, the turbine buildings and the control building, have been arranged
in consideration of nature. In January of 2001, the facilities obtained ISO14001
certification, an international standard related to the environment.
-Thermal Effluent Countermeasures-
|Cooling seawater, after passing through the main condenser, is discharged into the sea as thermal effluents about
7°C warmer than ambient water at the outlet. An underwater outlet, about 10 meters below the surface,
is used for discharging thermal effluents to reduce their influence on the ecosystem of the neighboring sea area.
Predicted Diffusion Range Diagram Thermal Effluents
Cross Section of the Predicted Diffusion Range Diagram
The power station is located on the Oshika Peninsula near Matsushima, one of the three best scenic places in Japan.
The peninsula, jutting out into the Pacific, contains Minami Sanriku Kinkazan Quasi-National Park where visitors can enjoy a
magnificent view of the Cobalt Line road, a 30-km-long Rias coast. Off the tip of the peninsula is Kinkazan Islet which is
known as the site of the first gold mine in Japan. The islet is covered with virgin forests, so visitors can enjoy watching
herds of wild deer and monkeys and a scenic view of white rocks and the blue sea.