核素迁移延迟系数对环境评价结果的影响

EFFECT OF RETARDATION COEFFICIENT FOR RADIONUCLIDE MIGRATION ON ASSESSMENT RESULTS OF ENVIRONMENTAL IMPACT

环境影响报告书是实施环境影响评价制度的一项重要内容。本文讨论了核素在地质介质迁移研究中所用的延迟系数对下游计算点最大浓度计算结果的影响。实验结果表明 :延迟系数并非常数 ;而计算结果显示 :延迟系数对下游计算点的最大浓度计算结果有较大的影响。如果这些问题得不到足够的注意和应有的解决 ,将可能极大地影响评价结果的保守性 ,从而影响计算结果的可信性。文中指出 ,核素迁移模式中所应用的延迟系数应该由实测得到 ,而不要用某些公式由分配系数推导 ,以免对浓度计算 。

Environmental impact report is an important content in enforcing environmental impact assessment system. Effect of retardation coefficient used in models of radionuclide migration in geological media on the calculated results of maximum concentration of calculated points at the lower reaches is discussed in this paper. It is shown from experimental results that the retardation coefficient is not a constant. And it is shown from calculated results that retardation coefficient obviously affect the calculated results of maximum concentration of calculated point at the lower reaches. Conservation level of the assessment results would considerably be affected, and hence confidence level of results would be affected if the aspects are not paid enough attention and solved. The paper suggests that retardation coefficient used in migration models should directly be obtained by measurement in the field or in column, rather than using the result derived from distribution coefficients according to some formula in order to prevent the nonconservative results. (