In a news conference early Friday local time, plant operator Tokyo Electric Power Company said radiation levels just outside the power plant were down by nearly 20 points on Thursday at 8:40 pm and by 11 pm had dropped again.
Chief cabinet Secretary Yukio Edano said at a press conference, "Through combined missions by the Self-Defense Forces to supply water from the air and by the police to supply water from the ground level with high-pressure pumps, we are doing our very best to achieve cooling as soon as possible."
TEPCO released this image of damage to its Fukushima Daiichi nuclear plant with steam rising after water was dropped to cool the nuclear fuel. (Image courtesy TEPCO)
The Japan nuclear safety agency said Self-Defence Forces dropped seawater four times on Unit 3. The company says steam billowed from the Unit 3 building after the water injection, indicating the water reached its target.
At Units 1, 2 and 3, seawater now is being injected to cool the nuclear fuel rods. At Unit 4, water injection was suspended as of 17:30 Thursday.
Four of the six reactors at the Daiichi plant were damaged by the magnitude 9.0 earthquake and tsunami wave that hit northeastern Japan on March 11. Outside power to the plant was cut off and emergency generators were damaged, disrupting the flow of cooling water to the nuclear fuel in the reactors.
Three explosions since the quake have damaged two of the reactors and caused the release of radioactive steam. Fires at the fuel pool of Unit 4 on Tuesday and Wednesday added to the damage and released more radiation. The company has declared nuclear emergencies at four of the six reactors at the power plant.
"In order to cool spent fuel pool of Unit 3 we conducted water spray by helicopters of Self-Defense Force at approximately 9:48 am," TEPCO said in a statement Thursday. "We are continuously monitoring the spent fuel pool and plan to conduct water spray to other units. We have been injecting sea water into the reactor pressure vessel."
The company worked Thursday to reinstall electric cables to the power plant to power the water injection cooling systems. The cable for receiving electricity from the Tohoku Electric transmission line was installed and is scheduled to be connected to Unit 2 later today.
Webcam image of TEPCO's Fukushima Daiichi nuclear power plant, March 18, 2011 local time (Image courtesy TEPCO)
The nuclear safety agency said in its latest report that one emergency diesel generator is now operable and is supplying electricity to Units 5 and 6. These units were shut down for periodic maintenance when the quake occrred and have not been as troublesome as the other four in the post-earthquake period.
The safety agency said "water injection to spent fuel pool through the make up water condensate system is progressing" at Units 5 and 6 and the plant will inject water to the reactor pressure vessels after the external power source is recovered.
But radiation from the damaged power plant has traveled far to the northwest. On Thursday, Japan's science ministry tested radiation levels in 28 places from 20 to 60 kilometers from the power plant and found elevated radiation levels as far as 30 kilometers (20 miles) to the northwest.
Experts say exposure to those levels for just six hours would result in absorption of the maximum level considered safe for a year.
The government has evacuated residents closer than 20 kilometers to the damaged power plant and instructed residents living within a 20 to 30 kilometer radius of the plant to stay indoors. Still many are voluntarily leaving the 20-30 km area.
Professor Toshiso Kosako, a professor in the graduate school at the University of Tokyo, has been appointed as Special Advisor to the Cabinet in the field of radiation safety, and will provide information and advice to Prime Minister Natao Kan on the ongoing incidents at the nuclear power stations.
Today officials reported 4,255 deaths resulting from the earthquake and tsunami, while 8,194 people are still missing. The death toll is expected to climb past 10,000 after water levels recede and search teams can access the devastated areas.
Narumi Kawahima, 12, and sister Kotomi, 10, in a evacuee shelter after their home in Sendai, Japan was destroyed. (Photo by Jensen Walker courtesy Save the Children Canada)
At least 305,000 people displaced by the earthquake and tsunami are housed in shelters, many of which have little food or water. Aid supplies coming into Japan from countries around the world are being handled by prefecture governments, Edano said.
The UN's World Food Programme is deploying experts in logistics and supply chain management to Japan to help facilitate swift movement of relief items to communities in need of clean water, food and shelter.
"Today WFP stands with Japan - one of the most generous humanitarian nations on Earth that has always been there when others have needed help," said WFP Executive Director Josette Sheeran. "WFP's emergency operation responds to their request for help in meeting the epic logistical challenges they face in their heroic rescue efforts."
The Tokyo area barely avoided blackouts Thursday after the government warned of power demand that exceeded supply amid cold temperatures and urged businesses and residents to save power.
Tokyo Electric has been implementing rolling blackouts for the past four days, mainly in the Kanto region surrounding Tokyo, to adjust for power shortages due to the crippled nuclear reactors. Some 18 million households were affected by TEPCO's electricity rationing Thursday.
To save power, railway operators reduced the number of local trains running in the Tokyo metropolitan area during the Thursday afternoon rush hour.
The power saving rolling blackouts are expected to continue until the end of April in areas surrounding Tokyo.
There is an increased risk of submergence and flooding during the spring tides because the earthquake caused the ground to sink off Japan's Pacific coast, the Japan Meteorological Agency warned today.
"It is necessary to pay special attention to the tide level and to prepare for the submergence and flood in these regions, especially during the spring tide, when the flood tide level becomes higher than usual," the agency said, especially from March 18-26, April 1-11, and April 16-24.
Copyright Environment News Service (ENS) 2011. All rights reserved.