The diffusion of iodine (labeled with ¹²⁵I^-) in compacted Beishan granite (BsG) was investigated using the in-diffusion capillary method at pH ~2.0 to ~11.0 under oxygen and irradiation conditions. With the advantages of simple and easy operation of the capillary diffusion devices, this work makes a preliminary investigation on the irradiation condition that cannot be performed by the traditional diffusion experiment. In this study, D_a values of ¹²⁵I as a tracer in the form of iodide were determined to investigate and assess the influence of irradiation and oxygen conditions, which must be considered in-situ environment of the geologic repository. The results indicate that capillary method is a simple and efficient method to study the diffusion behavior of radionuclides, which is a relatively feasible to quickly obtain the diffusion coefficient, especially for some special conditions, e.g., oxygen and irradiation conditions. The diffusion results showed that D_a values of ¹²⁵I^- range from 1.4 × 10^-10 to 1.5 × 10^-9 m²∙s^-1, which was much faster than other nuclides, such as ⁷⁹Se (10^-11 m²∙s^-1). The batch adsorption experiments in this paper and related studies showed that the sorption could be neglected, i.e., ¹²⁵I^- is a weak adsorbent nuclide. Its diffusion and sorption process were hardly affected by pH、oxygen and irradiation conditions, which is very different from ⁷⁹Se. Besides, ionic strength has a significant impact on the diffusion rate of ¹²⁵I^-, which is closely related to the double electric layer. Overall, this study indicates that natural BsG couldn't greatly attenuate the mobility of ¹²⁵I^- in the deep geologic repository and new retardation method or materials need to be explored.

（标记有碘的扩散¹²⁵我^- ）使用in-扩散毛细管法在pH〜2.0至〜11.0下的氧和照射条件在压实北山花岗岩（BSG）进行了研究。凭借毛细管扩散装置操作简便的优势，这项工作对传统扩散实验无法完成的辐照条件进行了初步研究。在本研究中，D _a值为¹²⁵我以碘化物形式的示踪剂被确定用于调查和评估辐照和氧气条件的影响，这些条件必须考虑到地质处置库的原位环境。结果表明，毛细管法是研究放射性核素扩散行为的一种简单有效的方法，特别是在某些特殊条件下，例如氧气和辐照条件，对于快速获得扩散系数是相对可行的。扩散结果表明，D _a值为¹²⁵ I- ^，范围从1.4×10 ^-10到1.5×10 ^-9  m ² ∙s ^-1，比其他核素（例如⁷⁹）要快得多。Se（10 ^-11  m ² ∙s ^-1）。本文及相关研究的批次吸附实验表明，吸附可以忽略不计，即¹²⁵我^-是一个较弱的吸附剂核素。其扩散和吸附过程几乎不受pH，氧气和辐照条件的影响，这与⁷⁹ Se有很大不同。此外，离子强度对的扩散速度显著影响¹²⁵我^- ，这是密切相关的双电层。总体而言，这项研究表明，天然BsG不能大大减弱¹²⁵ I的迁移率^- 在深部地质库中，需要探索新的减速方法或材料。