【摘要】 深地层埋藏是目前首选的核废料处置方案。由于放射性核素的长半衰期和辐照导致的某些不可预见性因素，我们需要根据天然类似物研究的成果与理论分析和实验结果综合评估和预测核废料处置场的安全性。铜、铁等自然金属类似物的研究指出，壁厚１０ｃｍ的铜质包装在几十万年内都不会破裂；一定厚度的铁质容器至少也能保证核废料在１０００年内不与地下水接触。由于膨润土具有遇水即胀的特点和吸附阳离子的能力，因此是一种常用的核废料回填材料，然而其膨胀和吸附性在温度高于１００℃时可能会受到影响，因此，核废料处置场的设计温度最好在１００℃以下。铀在还原性环境中以ＵＯ２形式存在时溶解极低，实际上不迁移；但在氧化性环境下以Ｕ６＋形式存在时就变得很活泼。辐照可能会造成局部的氧化环境导致Ｕ的迁移，但围岩和回填材料中的还原性物质又会将Ｕ６＋还原为Ｕ４＋从而使铀的迁移限制在几米的距离之内．理论上，可以根据发生过地下水蚀变的类似地质体的水／岩比等参数计算Ｓｒ、Ｃｓ等元素的迁移，从而估算核废料中重要核素９０Ｓｒ和１３７Ｃｓ的迁移量；核废料中其他放射性核素碍、镎、钚和超铀元素在自然界中含量太低，无法直接测量，但它们的地球化学性质与稀土和铀钍等元素相近，因此可根据后?更多还原

【Abstract】 It is still the best way to disposal the nuclear waste in deep earth. The security of thewaste repository should be sythesize predicted and appraised by both theoretical analyse andprance results of the nature analogue study. The copper waste canisters with walls 10 cm thickwould not be breached in several handred thousand years since the nature copper is know inmany ore deposits; the estimated alteration rates suggest that the corrosion would not breachthe planned thick-walled iron canisters for at least a thousand years. Even has the ability toswell on contact with water and strong sorptive capacity for canons, the bentonite, which wasoften designed for backfill materials around the waste canisters, is still questionable for whetherit will retain these properties in a repository during the long times and high temperature required for high level radioactive waste isolation. The using of bentbnite seems only fully justified under the environment with the temperature below 100℃. Being in the form of UO2 atthe reducing condition, the uranium has very low solubility, practically no movement at all;but it is very activity in the form of U6+at oxidizing environment. Uranium may be oxidizedby the radiation of the nuclear waste in an limited field and also can be reduced by the countryrocks and back fill materials soon, so it’s movement can be trapped in a few meters. Themovement amounts of some important nuclides, such as 90Sr and137Cs, can be analogous evaluted using water/rock ratio and other parameters to calculate the amounts of Sr and Cs at analtered geological pluton. The nature contents of other nuclides, such as To, NP, Pn andTRU, are too low to be surveied directly, but their geochemical characters are near that ofthe REE, U and Th, so the movement amounts of the former can be estimated by the calculated results of the later, even this estimated is still very uncertainly.更多还原