Evaluation of the Air-Vegetation-Milk Pathway for 131I at the Quad Cities Nuclear Power Station

摘要

The results of a field evaluation of the release and environmental behavior of airborne (131)I released from the two-unit Quad Cities Nuclear Power Station during June--October 1974 are reported. Release rates of (131)I in gaseous effluents from the two boiling water reactors (BWRs) were measured continuously for more than four months. The effluent sampling system distinguished four chemical species of airborne (131)I: activity associated with particulates, elemental iodine (I2), hypoiodous acid (HOI), and organic iodides. Environmental measurements were delayed by the arrival of fallout from nuclear weapons testing at Lop Nor, Peoples Republic of China. Radioiodine was measured in ambient air, deposition collectors, pasture vegetation, and cows' milk at two locations near the station. The results of these measurements provided a basis for comparison with environmental transport models that predict air, vegetation, and milk concentrations of (131)I in the critical exposure pathway. In addition to the monitoring at the two main sites, vegetation was sampled at three other locations and air samples were collected at two other locations to provide more data for comparisons. Detailed measurement results are presented and compared with predictions of the models described in NRC Regulatory Guides 1.111 and 1.109. The behavior of fallout (131)I from tests at Lop Nor and from French nuclear testing at Mururoa in the South Pacific, observed during parts of the study, is also discussed.