INCREASE OF I-129 IN THE ENVIRONMENT

The long-life fission product I-129 is released continuously into the environment by nuclear fuel reprocessing plants. The annual I-129 depo sition rate has been measured with accelerator mass spectrometry (AMS) in an Alpine ice core covering the years from 1950 to 1980. These mea surements show, that even at sites not in the vicinity of reprocessing plants, an increase in I-129 can be observed. Today's fall-out of I-1 29 is even larger than the fall-out from nuclear weapons tests in the 1960s. Different sources of anthropogenic I-129 and the impact on the natural iodine reservoirs are discussed. The results are compared to c alculations with a box transport model.