Aftershock Batters Nuclear Plants

Friday, April 08, 2011 14:14 +0900 (JST)

Aftershock batters nuclear plants

Nuclear power plants and related facilities in the coastal areas of northeastern Japan were forced to rely on emergency power after their electricity was cut off in Thursday night's quake. Operations have been suspended at all nuclear power plants from Aomori to Ibaraki prefectures since the March 11th earthquake and tsunami. But electricity is still crucial to keep their cooling systems operating. Japan's nuclear agency says all external power lines at Higashidori nuclear power plant in Aomori Prefecture were knocked out in Thursday's quake. The plant switched to emergency diesel power generators for some hours, but power was later restored. The quake shut down 3 of the 4 external power lines at Onagawa nuclear power plant in Miyagi Prefecture. It is still operating on the one remaining power line. The Onagawa plant also suffered water leaks at 8 locations, including water that spilled from spent fuel storage pools at each of its 3 reactors. A device to control pressure inside a turbine building was also damaged. In addition, the quake disabled all external power lines at a nuclear fuel reprocessing plant in Aomori Prefecture. The cooling systems here are still running on emergency diesel power.

Thursday's quake damages Onagawa nuclear plant

Tohoku Electric Power Company says Thursday night's strong earthquake caused water to overflow from spent fuel storage pools at one of its nuclear power plants. The power company reported on Friday that water had spilled onto the floor at all 3 reactors at the Onagawa nuclear power plant in Miyagi Prefecture. The amount of water spilled was 3.8 liters at the most. The utility firm also found water leaks at 5 locations in the plant, including inside buildings housing the reactors. The company added that blowout panels--devices designed to control pressure inside the buildings--were damaged at the turbine building of the Number 3 reactor. The newly reported problems add to the downing of 3 of 4 external power lines at the Onagawa plant. The plant is maintaining its cooling capabilities with the remaining power line. Tohoku Electric Power Company is continuing its efforts to determine the extent of the damage caused by the latest quake. But it says no change has yet been seen in radiation levels around the plant.

Aftershock puts nuclear plants on emergency power

Japan's nuclear agency says the quake that struck northeastern Japan on Thursday, disabled all but one outside power supply line at the Onagawa nuclear power plant in Miyagi Prefecture. The Nuclear and Industrial Safety Agency says 2 of the 3 power lines became unavailable and the plant is using the only remaining line to cool its nuclear reactors. It says the cooling systems of 3 spent fuel pools were disabled at one point, but had all been restored. The agency reports no abnormal radiation readings at the plant. At the Fukushima Daiichi and Daini nuclear power plants, instrument readings and radiation monitors showed no changes following the quake. At the Higashidori nuclear power plant in Aomori Prefecture, the quake shut down all outside power lines, prompting the plant to switch on emergency diesel power generators.

The plant had shut down its reactors and was undergoing an inspection at the time of the quake. No serious effects were reported with the cooling systems of storage pools for spent fuel rods. A nuclear fuel reprocessing plant in Rokkasho, Aomori Prefecture, also lost all outside power and is operating on emergency diesel generators at the moment. No irregularities have also been reported at the Tokai Daini nuclear power plant in Ibaraki Prefecture. All these nuclear power plants had suspended power generating operations at their reactors after the March 11th earthquake and tsunami.

http://www.jaif.or.jp/english/news_images/pdf/ENGNEWS01_1302261533P.pdf