Concentrations of iodine-129 in coastal surface sediments around spent nuclear fuel reprocessing plant at Rokkasho, Japan, during and after its test operation

摘要

Concentrations of I-129 in coastal surface sediment samples from the east coast of Aomori, Japan, 2-65 km away from the wastewater outlet of the nuclear fuel reprocessing plant at Rokkasho, Japan, were measured from 2006 to 2010. No clear effect on I-129/I-127 atom ratios in marine sediments was observed, although I-129 was discharged from the plant, during its test operation using actual spent fuel, mainly between 2006 and 2008. The ratio in sediments collected at a fishing port at the mouth of a brackish lake increased in 2007, showing that the I-129 migrated from the lake to the port.