Title: Sedimentation and remobilization of radiocesium in the coastal area of Ibaraki, 70 km south of the Fukushima Dai-ichi Nuclear Power Plant
Authors: Shigeyoshi Otosaka and Takuya Kobayashi, Research Group for Environmental Science, Japan Atomic Energy Agency
Date: 13 November 2012
The accident of TEPCO’s Fukushima Dai-ichi Nuclear Power Plant (1FNPP) released a large amount of anthropogenic radionuclides into the environment, and is still affecting people who are living in the surrounding regions. MEXT (2011a) reported that significant concentrations of anthropogenic radionuclides, such as iodine-131, cesium-134 (134Cs), cesium-137 (137Cs), tellurium-129m, silver-110m, niobium-95, and antimony-125, were detected from seabed sediments off the eastern regions of the main island of Japan. Since most of the short-lived radionuclides decayed to a level below the detection limit, two isotopes of radiocesium, 134Cs and 137Cs, have been considered as the major radionuclides that should be monitored [...]
Niobium: 95Nb is the decay product of 95Zr (64 days), so disappearance of 95Nb in used nuclear fuel is slower than would be expected from its own 35 day halflife alone. Tiny amounts of the other isotopes may be produced as direct fission products.
Published: November 17th, 2012 at 11:16 am ET