Workers were unable to enter four reactors of the nuclear plant of Fukushima Daiichi since the days immediately after the earthquake and the tsunami that struck on March 11. Vital plant cooling systems have been eliminated, and the explosion of hydrogen which ensued in four of the six reactors blew off the coast of their roofs and jonchaient site with radioactive debris.
Sunday, two robots were moving to two units reactor, doors opening and navigating the radioactive debris and puddles to return with readings of temperature, pressure and radioactivity. Readings, published Monday, showed high continuous radiation levels.
Unit 1, robots detected up to 49 millisieverts per hour; Unit 3, the reading was 57 millisieverts per hour. In recent weeks were much higher readings have come from areas where contaminated water has accumulated as the unit 2 turbine, where experts say the reactor under pressure can be cracked and leaks of nuclear material.
Again, the exposure of the Japan emergency workers is currently capped at 250 radiation millisieverts per year. If current levels of effectively limit a worker to a few hours of work.
"It is a harsh environment for human beings humans to work," said Hidehiko Nishiyama, Assistant Director-General to the nuclear and industrial safety agency.
He said the levels would require the operator of the plant, the Tokyo Electric Power Company, to be "creative" by bringing the plant to a stable known state that a case of cold within six to nine months, the company set forth in a schedule Sunday.
The Japanese Government continues to severe, technical and political challenges following a multifaceted disaster which left 13 800 dead and 14 000 missing. At least 137 000 people are still in evacuation centres, of some pipes in their homes by leaks of radiation of the Fukushima plant.
Ministry of Finance of the Japan said that the damage caused by the earthquake and tsunami alone could reach $ 300 billion, which makes higher global disaster. The number of victims of the nuclear disaster - which has disrupted agriculture and fishing, reduced power supply through the East of the Japan and inflicted other injuries on the economy - not a not yet be accounted for.
Prime Minister Naoto Kan were under fire Monday from opposition lawmakers who accused him of bungling the initial response to the nuclear crisis.
"Many Japanese feel that Prime Minister Kan has no leadership," Masashi Waki, a member of the main opposition, the Liberal Democratic Party, said in an unusually heated parliamentary session. Sadakazu Tanigaki, the leader of the Liberal Democratic Party, last week called Mr. Kan to resign.
"I do not think that my response was insufficient, as many say," a Kan excited-to research Mr. said, in the heckling. "Nonsense!"
A survey published Monday by the Nikkei business on the largest of the Japan daily, appeared in support of the claims of the opposition. 69% Of respondents say that Mr. Kan should be replaced, while 70% said that the response of the Government in the nuclear crisis was unacceptable. The Nikkei said as he surveyed 983 people across the country from April 15 to 17, excluding some areas where telephone lines is remained down.
Tokyo Electric plan ambitious to bring reactors to a cold case has also been criticized. The plan, the order of the Government, aims to give residents evacuated from the area around the plant an idea of when they might be able to return home.
But experts question the viability of the plan, which calls for building new cooling systems quickly critical. Faces of Tokyo Electric "significant obstacles" following calendar, said Haruki Madarame, President of the Commission on nuclear safety, an independent group of experts appointed by the Government to oversee the nuclear industry.
Mr. Madarame, a former Professor of nuclear engineering at the University of Tokyo, told journalists Monday that the presence of highly radioactive water in unit 2 poses a particular challenge. He and other units, workers were cooling nuclear fuel at the core of the reactor and in pools of storage by pumping in hundreds of tons of water a dangerous amounts of day, producing runoff water.
"We must ensure that the schedule tight does not lead to a neglect of safety," said Mr. Madarame.
Robots could help to resolve some of the challenges. The remote PackBots used Sunday, built by iRobot of Bedford, Massachusetts, are 60 books with weapons steel gear and tractor treads. They can lift approximately 30 pounds, up and down steps, send images to an operator and transport hazardous materials kit that detects the radiation.
IRobot, which is also the popular Roomba vacuum, has delivered more than 3 800 PackBots, mainly for the Government and the army, according to Tim Trainer, a Vice-President of iRobot.
After arriving in mid-March, the robots have been programmed to open the doors of the reactor and navigate through narrow passages, said Mr. Nishiyama of the nuclear safety agency.
Robots, with stationary drone aircraft dominated by Honeywell called T-Hawks, have left engineers lifted and measures at the plant, while minimizing the exposure of workers to harmful radiation. A PackBot in a reactor of third building later Sunday.
Ken Belson and Keith Bradsher contributed reporting.
没有评论:
发表评论