Quantification of water content across a cement-clay interface using high resolution neutron radiography
Quantification of water content across a cement-clay interface using high resolution neutron radiography
复制标题
使用高分辨率中子射线照相术量化水泥-粘土界面的水含量
DOI：
10.1016/j.phpro.2015.07.073
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
S. Churakov
中科院分区：
文献类型：
--
作者：
A. Shafizadeh;T. Gimmi;L. R. Loon;A. Kaestner;E. Lehmann;U. Maeder;S. Churakov
在许多放射性废物储存库的设计中，水泥和粘土将直接接触。水泥和粘土之间的地球化学对比将导致跨界面的质量通量，从而导致这两种材料的结构和输运性质的改变，这可能会影响多屏障系统的性能。我们提出了一种实验方法来研究水泥-粘土相互作用的细胞，以适应小样本的水泥和粘土。该电池的设计允许在原位测量水含量的样品，使用中子射线照相和测量的传输参数，使用通过扩散示踪剂实验。高分辨率中子射线照相实验的目的是监测含水量（孔隙度）的变化及其空间范围。几个不断发展的水泥-粘土界面的中子射线照片提供了定量数据，可以解决样品域内的局部水含量。在目前的工作中，我们探讨了有关各种输入参数和有关的应用图像校正程序的派生水含量的不确定性。测量条件的时间变化造成了±0.1（m3/m3）量级的含水量的绝对不确定性，这无法通过校正程序完全解释。通过对具有不同的、不变的水含量的两个样本区域进行特定校准，可以导出两个图像之间的水含量的较小的相对变化。
In many designs for radioactive waste repositories, cement and clay will come into direct contact. The geochemical contrast between cement and clay will lead to mass fluxes across the interface, which consequently results in alteration of structural and transport properties of both materials that may affect the performance of the multi-barrier system. We present an experimental approach to study cement-clay interactions with a cell to accommodate small samples of cement and clay. The cell design allows both in situ measurement of water content across the sample using neutron radiography and measurement of transport parameters using through-diffusion tracer experiments. The aim of the high-resolution neutron radiography experiments was to monitor changes in water content (porosity) and their spatial extent. Neutron radiographs of several evolving cement-clay interfaces delivered quantitative data which allow resolving local water contents within the sample domain. In the present work we explored the uncertainties of the derived water contents with regard to various input parameters and with regard to the applied image correction procedures. Temporal variation of measurement conditions created absolute uncertainty of the water content in the order of ±0.1 (m3/m3), which could not be fully accounted for by correction procedures. Smaller relative changes in water content between two images can be derived by specific calibrations to two sample regions with different, invariant water contents.