Accurate prediction of the subsurface transport of iodine species is important for the assessment of long-term nuclear waste repository performance, as well as monitoring compliance with the Comprehensive Nuclear-Test-Ban Treaty, given that radioiodine decays into radioxenon. However, the transport of iodine through intact geologic media is not well understood, compromising our ability to assess risk associated with radioiodine migration. The current study's goal is to quantify the matrix diffusion of iodine species through saturated volcanic rock, with particular attention paid to the redox environment and potential speciation changes. Diffusion experiments were run for iodide through lithophysae-rich lava, lithophysae-poor lava, and welded tuff, whereas iodate diffusion was studied through welded tuff. Iodine transport was compared with a conservative tracer, HDO, and effective diffusion coefficients were calculated. Likely due to a combination of size and anion exclusion effects, iodine species diffused more slowly than the conservative tracer through all rock types tested. Furthermore, oxidation of iodide to iodate was observed in the lithophysae-poor lava, affecting transport. Results provide much needed data for subsurface transport models that predict radioiodine migration from underground sources, and indicate the pressing need for geochemical and redox interactions to be incorporated into these models.

鉴于放射性碘会降解成放射性氙，准确预测碘物种的地下运输对评估长期核废料储存库的性能以及监测对《全面禁止核试验条约》的遵守情况至关重要。但是，人们对通过完整地质介质进行碘运输的了解还不够，这损害了我们评估与放射性碘迁移有关的风险的能力。当前的研究目标是量化碘通过饱和火山岩的基质扩散，尤其要注意氧化还原环境和潜在的形态变化。通过富含岩藻石的熔岩，贫岩藻石的熔岩和焊接凝灰岩进行了碘的扩散实验，而通过焊接凝灰岩研究了碘酸盐的扩散。将碘转运与保守示踪剂HDO进行比较，并计算出有效扩散系数。可能由于大小和阴离子排斥效应的共同作用，在所有测试的岩石类型中，碘物质的扩散速度都比保守示踪剂慢。此外，在贫岩岩浆熔岩中观察到碘化物氧化为碘酸盐，影响了运输。结果为地下运输模型提供了急需的数据，这些模型预测了地下地下放射性碘的迁移，并表明迫切需要将地球化学和氧化还原相互作用纳入这些模型。此外，在贫岩藻的熔岩中观察到碘化物氧化为碘酸盐，影响了运输。结果为地下运输模型提供了急需的数据，这些模型预测了地下地下放射性碘的迁移，并表明迫切需要将地球化学和氧化还原相互作用纳入这些模型。此外，在贫岩岩浆熔岩中观察到碘化物氧化为碘酸盐，影响了运输。结果为地下运输模型提供了急需的数据，这些模型预测了地下地下放射性碘的迁移，并表明迫切需要将地球化学和氧化还原相互作用纳入这些模型。