DisastersRobot reports high radiation inside crippled reactors
A U.S.-made robot traveled inside Unit 1 and Unit 3 of the crippled Fukushima plant, and came 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
A robot that entered two crippled buildings housing nuclear reactors which were damaged during the 11 March earthquake and tsunami, sent back readings which showed a harsh, radioactive environment too dangerous for workers to operate in.
The operator of the reactors said, however, that the harsh readings from Unit 1 and Unit 3 at the Fukishima plant do not change the timetable fro bringing the complex under control by the end of the year.
The robot was set to investigate Unit 2 on Monday.
Fox News reports that 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. Hydrogen explosions in both buildings in the first few days destroyed their roofs and littered them with radioactive debris.
The U.S.-made robot 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.
The robots being used inside the plant, called Packbots, are made by Bedford, Massachussetts-based 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.
