Six workers at Japan's crippled Fukushima nuclear plant were exposed to a leak of highly radioactive water on Wednesday, the latest in a string of mishaps the country's nuclear watchdog has attributed to carelessness, saying they could have been avoided. Tokyo Electric Power Co, also known as TEPCO, has been battling to contain radioactive water at the plant, which suffered triple meltdowns and hydrogen explosions following a devastating earthquake in March 2011. In the latest incident, a worker mistakenly detached a pipe connected to a treatment system to remove salt from the hundreds of metric tons of water TEPCO pumps over the melted fuel in wrecked reactors at Fukushima to keep them cool. "It is serious in that it was another problem caused by carelessness, but I do not believe it is a seriously troubling dosage," Shunichi Tanaka, chairman of Japan's Nuclear Regulation Authority, said on Wednesday. "But the fact that there has been a string of incidents occurring on a daily basis that could have been avoided - I think that is a large problem." Tanaka urged TEPCO to improve its handling of contaminated water, but stopped short of saying whether it would face any penalties. The accidents at the Fukushima Daiichi plant, 220 km north of Tokyo, are adding to a crisis no one seems to know how to contain and stirring doubt over TEPCO's ability to carry out a complex cleanup widely expected to take decades. |