Robot Detects High Radiation in Japanese Nuclear Plant
TOKYO –  Readings  Monday from a robot that entered two crippled buildings at Japan's  tsunami-flooded nuclear plant for the first time in more than a month  displayed a harsh environment still too radioactive for workers to  enter.
Nuclear officials said the radiation  readings for Unit 1 and Unit 3 at the tsunami-flooded Fukushima Dai-ichi  plant do not alter plans for stabilizing the complex by year's end  under a "road map" released by the plant operator Sunday.
Workers have not gone inside the two reactor  buildings since the first days after the plant's cooling systems were  wrecked by a catastrophic earthquake and tsunami on March 11. Hydrogen  explosions in both buildings in the first few days destroyed their roofs  and littered them with radioactive debris.
A U.S.-made robot that looks like a drafting  lamp on treads haltingly entered the two buildings Sunday and took  readings for temperature, pressure and radioactivity. More data must be  collected and radioactivity must be further reduced before workers are  allowed inside, said Hidehiko Nishiyama of Japan's Nuclear and  Industrial Safety Agency.
"It's a harsh environment for humans to work  inside," Nishiyama said.
It is still possible, he said, to achieve  plant operator Tokyo Electric Power Co.'s goal of achieving a cold  shutdown of the plant within six to nine months as laid out in a  timetable the company announced Sunday.
"I do believe we must be creative to come up  with ways to achieve our goals," Nishiyama said. "I still think the  plan ... is as appropriate as we can get at the moment."
TEPCO official Takeshi Makigami said the  robots must pave the way for workers to be able to re-enter the  building.
"What robots can do is limited, so  eventually, people must enter the buildings," Makigami said.
The robot was set to investigate Unit 2  later Monday.
As work continues inside the plant to reduce  radiation levels and stem leaks into the sea, the Defense Ministry said  it would send about 2,500 soldiers to join the hundreds of police,  outfitted with protective suits, who are searching for bodies in tsunami  debris around the plant.
Around 1,000 bodies are thought to be buried  in the muddy piles of broken houses, cars and fishing boats. As of  Sunday, searchers had located 66 bodies and recovered 63, police said.
The combined earthquake and tsunami have  left more than 27,000 people dead or missing.
The robots being used inside the plant,  called Packbots, are made by Bedford, Massachussetts company iRobot.  Traveling on miniature tank-like treads, the devices opened closed doors  and explored the insides of the reactor buildings, coming back with  radioactivity readings of up to 49 millisieverts per hour inside Unit 1  and up to 57 millisieverts per hour inside Unit 3.
The legal limit for nuclear workers was more  than doubled since the crisis began to 250 millisieverts. The U.S.  Environmental Protection Agency recommends an evacuation after an  incident releases 10 millisieverts of radiation, and workers in the U.S.  nuclear industry are allowed an upper limit of 50 millisieverts per  year. Doctors say radiation sickness sets in at 1,000 millisieverts and  includes nausea and vomiting.
The robots, along with remote controlled  miniature helicopters, have enabled TEPCO to photograph and take  measurements of conditions in and around the plant while minimizing the  workers' exposure to radiation and other hazards.
TEPCO's plan for ending the crisis, drawn up  at the government's order, is meant to be a first step toward letting  some of the tens of thousands of residents evacuated from the area  around the company's Fukushima Dai-ichi nuclear power plant return to  their homes.
It drew a lackluster response Monday,  though, as polls showed diminishing public support for the government's  handling of the country's recent disasters.
Those forced to flee due to radiation leaks  from the plant are frustrated that their exile will not end soon. And  officials acknowledge that unforeseen complications, or even another  natural disaster, could set that timetable back even further.
"Well, this year is lost," said Kenji  Matsueda, 49, who is living in an evacuation center in Fukushima after  being forced from his home 12 miles (20 kilometers) from the plant. "I  have no idea what I will do. Nine months is a long time. And it could be  longer. I don't think they really know."
Pressure has been building on the government  and TEPCO to resolve Japan's worst-ever nuclear power accident, and  Prime Minister Naoto Kan is facing calls for his resignation.
"You should be bowing your head in apology.  You clearly have no leadership at all," Masashi Waki, a lawmaker from  the opposition Liberal Democratic Party, shouted during an intense  grilling of Kan and members of his Cabinet in parliament Monday.
"I am sincerely apologizing for what has  happened," Kan said, stressing that the government was doing all it  could to handle unprecedented disasters.
TEPCO's president, Masataka Shimizu, looked  visibly ill at ease as lawmakers heckled and taunted him.



0 comments:
Post a Comment