辐射环境评价中的干沉积问题

考虑到在辐射环境评价中使用ＮＲＣ耗减曲线和沉积曲线时存在的问题，以及流出物粒径分布的影响，本文用国内实测的３种粒径分布粒子的干沉积速度用源耗减模式计算了烟羽残留份额和相对干沉积率，并分别与ＮＲＣ的结果进行了比较。结果表明，本文计算的３种模态粒子的烟羽残留份额曲线和相对干沉积率曲线与都ＮＲＣ的结果有明显的差别。在辐射环境评价中要充分考虑流出物的粒径分布，谨慎选择沉积速度。

SOME ASPECTS OF DRY DEPOSITION IN RADIATION ENVIRONMENTAL ASSESSMENT

Taking account of the issue resulted from using NRC's (America Nuclear Regulatory Commision) plume depletion curves and deposition curves for radiation environmental assessment, as well as the effect of particle size distribution of effluents, this paper calculates the residual fraction of plume and the relative dry deposition rate with source depletion model employing the dry deposition velocities which was measured in our country for three modes particles (Altken mode, accumulation mode and the coarse mode), and the results for the three mode particles are respectively compared with NRC's results. The results show that there are a obvious differences between them. However, the particle size distribution of effluents should be taken into consideration adequately and the deposition velocities should prudently be selected in Radiation environmental assessment. (