Sheppard S C, Sheppard M I, Tait J C, Sanipelli B L
ECOMatters Inc., 24 Aberdeen Avenue, P.O. Box 430, Pinawa, Manitoba, Canada R0E 1L0.
J Environ Radioact. 2006;89(2):115-37. doi: 10.1016/j.jenvrad.2006.03.003. Epub 2006 Jun 8.
There is a continual supply of new experimental data that are relevant to the assessment of the potential impacts of nuclear fuel waste disposal. In the biosphere, the traditional assessment models are data intensive, and values are needed for several thousand parameters. This is augmented further when measures of central tendency, statistical dispersion, correlations and truncations are required for each parameter to allow probabilistic risk assessment. Recent reviews proposed values for 10-15 key element-specific parameters relevant to (36)Cl, (129)I, (222)Rn, (226)Ra, (237)Np and (238)U, and some highlights from this data update are summarized here. Several parameters for Np are revised downward by more than 10-fold, as is the fish/water concentration ratio for U. Soil solid/liquid partition coefficients, Kd, are revised downward by 10-770-fold for Ra. Specific parameters are discussed in detail, including degassing of I from soil; sorption of Cl in soil; categorization of plant/soil concentration ratios for U, Ra and Np; Rn transfer from soil to indoor air; Rn degassing from surface water; and the Ca dependence of Ra transfers.
有源源不断的新实验数据与核燃料废物处置潜在影响的评估相关。在生物圈中，传统评估模型数据需求量大，需要数千个参数的值。当为进行概率风险评估而要求对每个参数给出集中趋势、统计离散度、相关性和截断值的度量时，数据需求量进一步增加。最近的综述提出了与（36）氯、（129）碘、（222）氡、（226）镭、（237）镎和（238）铀相关的10 - 15个关键元素特定参数的值，此处总结了该数据更新的一些要点。镎的几个参数向下修订了超过10倍，铀的鱼/水浓度比也是如此。镭的土壤固/液分配系数Kd向下修订了10 - 770倍。具体参数将详细讨论，包括碘从土壤中的脱气；氯在土壤中的吸附；铀、镭和镎的植物/土壤浓度比的分类；氡从土壤向室内空气的转移；地表水的氡脱气；以及镭转移对钙的依赖性。
