Development of 129I-AMS system at MALT and measurements of 129I concentrations in several Japanese soils

The I-129 AMS system at MALT (Micro Analysis Laboratory, Tandem accelerator, The University of Tokyo) was reconfigured to use a gas ionization detector and achieved a background I-129/I-127 < 3 x 10(-14). A procedure for separating iodine from soil samples was developed and validated using IAEA standard reference material IAEA-375 (Chernobyl soil). The method was applied to analyze I-129/I-127 ratios as well as I-129 concentrations in several Japanese soils. The I-129/I-127 ratios of the measured surface soils are in the range of the order of 10(-10)-10(-7). The highest ratio was found in a sample collected in the vicinity of a nuclear fuel reprocessing plant. (c) 2007 Elsevier B.V. All rights reserved.