Radiation Inside Fukushima Reactor So High That New Machines Must Be Designed to Monitor It
TOKYO — One of Japan’s crippled nuclear reactors still has fatally high radiation levels and hardly any water to cool it, according to an internal examination Tuesday that renews doubts about the plant’s stability.
A tool equipped with a tiny video camera, a thermometer, a dosimeter and a water gauge was used to assess damage inside the No. 2 reactor’s containment chamber for the second time since the tsunami swept into the Fukushima Dai-ichi plant a year ago. The probe done in January failed to find the water surface and provided only images showing steam, unidentified parts and rusty metal surfaces scarred by exposure to radiation, heat and humidity.
The data collected from the probes showed the damage from the disaster was so severe, the plant operator will have to develop special equipment and technology to tolerate the harsh environment and decommission the plant, a process expected to last decades.
Tuesday’s examination with an industrial endoscope detected radiation levels up to 10 times the fatal dose inside the chamber. Plant officials previously said more than half of melted fuel has breached the core and dropped to the floor of the primary containment vessel, some of it splashing against the wall or the floor.
Particles from melted fuel have probably sent radiation levels up to dangerously high 70 sieverts per hour inside the container, said Junichi Matsumoto, spokesman for Tokyo Electric Power Co.
“It’s extremely high,” he said, adding that an endoscope would last only 14 hours in that condition. “We have to develop equipment that can tolerate high radiation” when locating and removing melted fuel during the decommissioning.