Radiation Leak Found at Plant Vent

The plant at the center of Japan’s worst nuclear accident kept pumping small amounts of radiation into the air for more than a week before officials discovered it, the facility’s operator said. Radioactive iodine-131 at double the legal limit was detected Friday at a ventilator opening in the building, but officials waited until three days later to turn off the exhaust fan and seal the opening. The ventilator had been left running after the Sept. 30 nuclear leak that exposed at least 49 people to radiation, according to JCO Co., which runs the nuclear fuel processing plant in Tokaimura, about 80 miles northeast of Tokyo. A JCO official said that although the iodine-131 in the vent exceeded safety levels, a monitor 50 yards from the plant detected it at only a hundredth the safety level.