Monday, April 18, 2011

Spike in iodine levels may signal new leak at Japan reactor: Samples 6,500 times over limit; Zeolite dumped in sea

The government on Saturday said that levels of radioactivity in seawater near the Fukushima No. 1 nuclear plant had risen significantly in recent days, according to samples taken Friday.

Hidehiko Nishiyama of the Nuclear and Industrial Safety Agency said the level of radioactive iodine-131 spiked to 6,500 times the legal limit, up from 1,100 times over the limit the day before. Levels of cesium-134 and cesium-137 rose nearly fourfold.

The rise could have been caused by the installation Thursday of steel panels intended to contain the radiation, which may have stirred up stagnant waste in the area, Nishiyama said, adding the increase in iodine, which has a relatively short eight-day half-life, could signal a possible new leak.

"We want to determine the origin and contain the leak, but I must admit that tracking it down is difficult," he said.

Tokyo Electric Power Co. also began dumping sandbags filled with zeolite, a mineral that absorbs radioactive cesium, into the sea in areas heavily contaminated with radiation to reduce the spread of contaminants.

Tepco released three 100-kg bags of zeolite and sand into the sea near the Fukushima plant and additional bags will be released, Nishiyama said. (read more)