核设施事故条件下环境中氚的迁移

Transfer of Tritium in the Environment from Nuclear Facilities after Accidental Releases

核电厂释放的3H是公众剂量的主要贡献核素之一,应该考虑事故情况下气态氚释放对公众造成的辐射剂量。目前,IAEA启动EMRAS II项目对核设施事故条件下氚的释放和迁移机理进行了初步研究。研究结果表明:事故情况下不同时段氚的剂量贡献与其存在形态有关,其中HTO造成的主要是短期剂量贡献,OBT则是产生长期的剂量贡献,食入贮存较长时间的植物产品,会产生更强的剂量;土壤途径和大气途径为氚产生剂量的主要途径,有机物中氚的合成速率成为事故下氚释放产生剂量的最重要因素。

^3H is one of the main contribution radionuc lides to the public dose , thus the public radiation dose from 3H after accidental releases from the nuclear facilities should be considered. IAEA stared the EMRAS Ⅱ project to run researches onllie mechanisms for^3 H transfer in the environment. The conclusion indicated that different mechanisms occurred at different segments, with HTO contributing a big part of the dose in the short term while OBT in the longer terms. This effect was reinforced by the consumption of plant products , which were stored for many months after harvest. It was also interest ing to note that the soil pathway seemed to be as important as the air pathway. The incorporation rate of tritium in organic materials was the single most important parameter in determining the dose after an accidental release of tritium to the atmosphere.