いまだに終わりが見えない福島原発危機
Sunday, June 5, 2011
Lethal four-sievert reading taken by robot; suppression chamber suspect
Radiation in No. 1 reactor building at highest level yet
Kyodo, AP
Tokyo Electric Power Co. said Saturday it has detected radiation of up to 4,000 millisieverts per hour in the building housing the No. 1 reactor at the Fukushima No. 1 nuclear plant.
Where there's smoke: A video image from the Fukushima No. 1 power plant shows steam rising from an opening in the floor of the No. 1 reactor building Friday. TEPCO / AP
The radiation reading, which was taken when Tepco sent a robot into the No. 1 reactor building on Friday, is believed to be the highest detected in the air at the plant so far.
On Friday, Tepco found steam spewing from the basement into the building's first floor. Nationally televised news Saturday showed blurry video of a steady stream of smoky gas curling up from an opening where a pipe rises through the floor.
The radiation is so high now that any worker exposed to it would absorb the maximum permissible dose of 250 millisieverts in only about four minutes. Tepco said there is no plan to place workers in that area of the plant and said it will carefully monitor any developments.
The utility said it took the reading near the floor at the southeast corner of the building. The steam appears to be entering from a leaking rubber gasket that is supposed to seal the area where the pipe comes up through the first floor. No damage to the pipe was found, Tepco said.
The reactor's suppression chamber is under the building, and highly radioactive water generated from cooling the reactor is believed to have accumulated there, Tepco said, adding that the steam is probably coming from there.
Meanwhile, tanks for storing radioactive water were on their way Saturday to the plant.
Tepco has said radioactive water could start overflowing from temporary storage areas on June 20, or possibly sooner if there is heavy rainfall.
Two of the 370 tanks were due to arrive Saturday from a manufacturer in nearby Tochigi Prefecture, Tepco said. Two hundred of them can store 100 tons, and 170 can store 120 tons.
The tanks will continue arriving through August and will store a total of 40,000 tons of radioactive water, according to Tepco.
Workers have been fighting to get the plant under control since the March 11 tsunami knocked out power, destroyed backup generators and halted the crucial cooling systems for the reactors, causing the world's worst nuclear disaster since Chernobyl in 1986. Several explosions have scattered radioactive debris around the plant, and reactors are spewing radiation into the air and leaking it into the sea.
On Friday, nine workers who entered the building to attach a pressure gauge to the pressure vessel of reactor No. 1 were exposed to around 4 millisieverts of radiation, according to Tepco.
The fuel rods are believed to have melted almost completely and sunk to the bottom of the containment vessels of reactors 1, 2 and 3.
A complete meltdown would have seen the fuel melt entirely through the containment vessels and into the reactor floor.
約１・７キロの福島県大熊町でプルトニウム
Monday, June 6, 2011
Plutonium found in soil at Okuma
Kyodo
Plutonium that is believed to have come from the crippled Fukushima No. 1 power plant has been detected in the town of Okuma about 1.7 km away from the plant's front gate, a Kanazawa University researcher said Sunday.
It is the first time plutonium ejected by the stricken facility has been found in soil beyond its premises since the March 11 megaquake and tsunami led to a core meltdown there.
Professor Masayoshi Yamamoto of Kanazawa University said the level of plutonium detected in soil in Okuma, Fukushima Prefecture, is lower than the average level observed in Japan after nuclear tests were conducted abroad.
The Education, Culture, Sports, Science and Technology Ministry has found plutonium in soil on the nuke plant's grounds, but it was believed to have been fallout from bomb tests abroad.
By analyzing the ratio of three types of isotopes in the plutonium, Yamamoto was able to determine that it was emitted by Fukushima No. 1 and not past bomb tests.
The soil samples were collected by a team of researchers from Hokkaido University before April 22.
AREVA is a French public multinational industrial conglomerate headquartered in the Tour Areva in Courbevoie, Paris. AREVA is mainly known for nuclear power.
Radioactive beef sold off in eight prefectures
Wednesday, July 13, 2011
By TAKAHIRO FUKADA Staff writer
Meat from six cows contaminated with radioactive materials from the Fukushima No. 1 nuclear power plant may have reached consumers in eight prefectures, including Tokyo, Kanagawa and Osaka, the Tokyo Metropolitan Government said Wednesday.
The other five prefectures are Aichi, Hokkaido, Tokushima, Kochi and Shizuoka.
Most of the prefectural governments, however, refused to disclose the names of retailers or even the cities where the meat was sold to shoppers.
"For the meat that was already sold and consumed, there is no particular necessity to worry about the health impact if (the amount individuals consume is limited)," Tatsuo Suzuki, a metropolitan government official, said at a news conference.
"There is no need for us to caution people" about the potential danger of consumption, he said, explaining that the metropolitan government has no intention of disclosing the name of any store that sold the meat.
Responding to inquiries by The Japan Times, four prefectural governments gave some more details about where the meat ended up.
Tokushima Prefecture said a Fuji GRAND supermarket in the city of Anan sold all 8.8 kg of the meat it procured from a wholesaler.
In Aichi, a barbecue restaurant in Ama whose name is being withheld sold 3.15 kg of the meat to consumers, according to the Tokyo Metropolitan and Aichi Prefectural governments.
In Hokkaido, an "izakaya" bar and barbeque restaurant in Chitose sold customers 3 kg, the Tokyo and Hokkaido governments said.
In Shizuoka, a retailer in Makinohara sold 14.5 kg to consumers.
