New power lines were connected to the crippled Fukushima Dai-ichi nuclear plant early Saturday and electricity can be supplied, Tokyo Electric Power says, according to Reuters.
"Once we have an electric power supply, we will go slowly and carefully through the plant checking the various machines to see what is working and to also avoid short-circuiting them," aNuclear and Industrial Safety Agency official said at a briefing.
Agency spokesman Hidehiko Nishiyama said workers were trying to restore power to the plant's No. 1 and No. 2 reactors Saturday and at the No. 3 and No. 4 reactors by Sunday, Kyodo News says.
Some of the plant's power distribution boards are covered with water from the tsunami caused by last Friday's magnitude-9 earthquake, and TEPCO will use makeshift replacement equipment. Even with electricity restored, it is unlikely devices will be reactivated at least until Saturday as equipment needs to be checked.
The cores of the No. 1, No. 2 and No. 3 reactors may have partially melted, and radiation leaks continue from the reactors and spent fuel pools.
Nishiyama noted the difficulty in assessing radiation data to determine the effectiveness of airborne water drops and water cannons to douse exposed spent-fuel rods. ''We need to observe the situation a little more to determine whether the mission was a success or not,'' he said.
After days of news reporting one explosion after another at the Fukushima nuclear plant, there is finally a break in reports of new explosions.
Radiation levels remain high around the plant.
All efforts are being focused on restoring water levels at the sites spent nuclear fuel storage pools. There is an emerging experts consensus that there is only a day or two to raise water levels in spent nuclear fuel pools to avert a much larger catastrophe.
Cooling efforts
Two large Chinook helicopters were used to drop water on the spent fuel pools in reactors 3 and 4 at about 10am. Originally, 40-50 drops of 7.5 tons each were reported to be planned, but only four have been conducted so far: three drops on reactor three and one on reactor 4, after which the helicopters pulled back to limit crews' radiation exposure.Out of the total amount of 30 tons, 8 tons were believed to have made it to the pools.
More drops are being considered. The police have brought in 11 special vehicles equipped with water cannons and 4-ton water tanks. These are being used to spray water into the spent fuel pools. Operation has been reported for hours to be starting shortly. Damage to the road and debris have prevented access by heavy vehicles until this morning.
A new power line is being installed to provide grid power to pumps and other equipment; it is expected to be completed some time this afternoon.
The spent fuel pools have an area of roughly 150-200m2, so raising the water level by one meter requires about 200 tons of water.
At best, the spraying seems to be buying some time until more efficient cooling methods can be put in place.
Radiation levels
Levels above reactors reported as 4.13 “mSv” at 1000 feet and 87.7 “mSv” at 300 feet. The statements by the government and the Tepco spokespeople seem to contradict the reported values. The helicopters are equipped with lead panels and crews wearing protective gear, but were unable to hover above the reactors to improve accuracy and had to pull back after only 15 minutes, yet the government-authorised emergency dose limit of 250 mSv/h would allow the crews to stay at 1000 feet for 48 hours, even without shielding.
Ibaraki’s (130 km south of Dalichi) radiation readings on Tuesday just before the monitors went "under survey" are posted online. The readings measure at 3.4 micro-Sv/h = 30 milli-Sv per year. Current value is 0.92 micro-Sv/h = 8 mSv/y. In Saitama and Tochigi, close to Tokyo, readings of 1.2 and 1.3 microSv/h were measured yesterday.
Heightened fears and new evacuations
The US and French nuclear agencies warned yesterday of the possibility of a major catastrophe. The Japanese government has evacuated at least an additional 10,000 people from the 20-30km zone around the nuclear plant.
There are still tens of thousands of people within the zone, as the 71,000 strong city of Minamisoma falls within the zone. The evacuated people will be given radiation scans. The US Embassy in Japan issued a warning last night to US citizens within 80-kilometer to evacuate as a precautionary measure. The US has chartered aircraft to help Americans leave Japan and had authorised the voluntary departure of family members of diplomatic staff in Tokyo, Nagoya and Yokohama -- about 600 people. China moved to evacuate its citizens from northeastern Japan earlier in the week.
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