压缩对双硫化物通过MX-80顿石扩散传输的影响
F Chowdhury1, T L Rashwan2, P Mondal1
1Department of Civil Engineering, Lassonde School of Engineering, York University, Canada.
Journal of contaminant hydrology
|May 3, 2024
概括
了解二硫化物 (HS-) 运输在高度压缩的土岩 (HCB) 中是核废物处理的关键. 在本托尼特中使用铁的HS-固定限制了其扩散,保护了废燃料容器 (UFC).
科学领域:
- 地质化学 地质化学
- 材料科学 材料科学 材料科学
- 核工程 核工程是指核工程.
背景情况:
- 加拿大深层地质储存库 (DGR) 使用高度紧缩的土矿 (HCB) 来屏蔽使用过的燃料容器 (UFC).
- 微生物生产双硫化物 (HS-) 通过通过HCB扩散,对UFCs造成铜腐蚀的风险.
- 准确预测HS-运输对于评估UFC完整性和存储库安全至关重要.
研究的目的:
- 为了研究二硫化物 (HS-) 在各种干密度下通过MX-80顿石的运输行为.
- 为了探索由于HS相互作用而导致的本托尼特的潜在物理或矿物学变化.
- 确定HS-的有效扩散系数,并评估其在本托尼特矩阵内的固定.
主要方法:
- 通过扩散实验使用MX-80顿石在干密度从1070到1615公斤/米3.5之间进行.
- 扩散后的分析包括化物 (Br-) 扩散试验和拉曼光谱来检查土矿的变化.
- 使用扩展的阿奇定律来估计可访问的毛孔度 (ε).
主要成果:
- 对HS-的有效扩散系数被确定为2.5 × 10−12 m2/s (1330 kg/m3) 和5.0 × 10−12 m2/s (1070 kg/m3).
- 在170天内,在高度压缩的土岩 (1535-1615公斤/立方米) 中没有观察到HS突破.
- 拉曼光谱显示HS-不动化通过与bentonite中的铁反应,形成mackinawite.
结论:
- 在HCB中,HS-运输受到土岩的干密度及其铁含量的显著限制.
- 在本托尼特中通过铁对HS的固定有效地减轻了UFC铜腐蚀的风险.
- 这些发现对于验证深层地质仓库的长期安全性和性能至关重要.
相关概念视频
Unsoundness of Aggregate due to Volume Change
106
Unsoundness in aggregates due to volume changes is primarily caused by the physical alterations aggregates undergo, such as freezing and thawing, thermal changes, and wetting and drying. Unsound aggregates, when subjected to these changes, result in volume change upon disintegration. This, in turn, contributes to the deterioration of concrete, including scaling, pop-outs, and cracking. Particular types of aggregates, such as porous flints, cherts, and those containing clay minerals, are...
106
Porosity in Cement Paste
127
The porosity of concrete is a measure of the void spaces within its structure. These spaces impact its strength and durability significantly. When water and cement interact, a chemical reaction called hydration creates a semi-solid paste. This paste includes combined water, making up approximately 23% of the cement's dry mass, and gel water, which fills minuscule voids known as gel pores, accounting for about 28% of the cement gel volume.
The balance of water to cement in the mix is...
The balance of water to cement in the mix is...
127
Compacting Factor test
140
The compacting factor test is a method used to assess the workability of concrete. It is especially suitable for concrete mixes containing aggregates up to one and a half inches in size. This test involves specialized equipment consisting of two truncated cone-shaped hoppers and a cylinder, all with polished interior surfaces to minimize friction.
The procedure begins by placing concrete into the upper hopper without any compaction. Once filled, the bottom door of this hopper is opened,...
The procedure begins by placing concrete into the upper hopper without any compaction. Once filled, the bottom door of this hopper is opened,...
140
Pore Size Distribution
123
In concrete, the pore size distribution significantly influences the material's properties. Capillary pores, markedly larger than gel pores, form a vast network within partially hydrated cement paste, reducing the concrete's strength and increasing its permeability. This heightened permeability leads to a greater risk of damage from environmental factors like freeze-thaw cycles and chemical attacks, with the extent of vulnerability also being tied to the water-to-cement ratio.
Adequate...
Adequate...
123
Bulk Density of Aggregate
444
Bulk density refers to the mass of aggregate particles that would fill a unit volume. The concept of bulk density originates from the inability to pack aggregate particles in a manner that completely eliminates void spaces. Hence, the term bulk refers to the volume that encompasses both the aggregates and the voids. This measurement is crucial when aggregates are batched by volume and is used to convert quantities by mass to volume.
Most natural mineral aggregates, like sand and gravel,...
Most natural mineral aggregates, like sand and gravel,...
444


