Hydro-thermal performance of unsaturated bentonite-sand buffer material

Yong, Raymond N.; Mohamed, Abdel‐Mohsen O.; Shooshpasha, Issa; Onofrei, C.

doi:10.1016/s0013-7952(96)00115-9

Cited by 20 publications

(7 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The clay will gradually absorb moisture and by swelling and filling the space around it is expected to fill any fractures in the hosting geologic environment. Finally, if a canister develops cracks the clay buffer will prevent water from entering the canister [16][17][18][19][20][21][22][23].…”

Section: The International Experience On Hlw Repositoriesmentioning

confidence: 99%

Geologic environments for nuclear waste repositories

Paleologos¹,

Mohamed²,

Pavlopoulos³

2017

MATEC Web Conf.

View full text Add to dashboard Cite

High-level radioactive waste (HLW) results from spent reactor fuel and reprocessed nuclear material. Since 1957 the scientific consensus is that deep geologic disposal constitutes the safest means for isolating HLW for long timescales. Nuclear power is becoming significant for the Arab Gulf countries as a way to diversify energy sources and drive economic developments. Hence, it is of interest to the UAE to examine the geologic environments currently considered internationally to guide site selection. Sweden and Finland are proceeding with deep underground repositories mined in bedrock at depths of 500m, and 400m, respectively. Equally, Canada's proposals are deep burial in the plutonic rock masses of the Canadian Shield. Denmark and Switzerland are considering disposal of their relative small quantities of HLW into crystalline basement rocks through boreholes at depths of 5,000m. In USA, the potential repository at Yucca Mountain, Nevada lies at a depth of 300m in unsaturated layers of welded volcanic tuffs. Disposal of low and intermediate-level radioactive wastes, as well as the German HLW repository favour structurally-sound layered salt stata and domes. Our article provides a comprehensive review of the current concepts regarding HLW disposal together with some preliminary analysis of potentially appropriate geologic environments in the UAE.

show abstract

Section: The International Experience On Hlw Repositoriesmentioning

confidence: 99%

Geologic environments for nuclear waste repositories

Paleologos¹,

Mohamed²,

Pavlopoulos³

2017

MATEC Web Conf.

View full text Add to dashboard Cite

show abstract

“…Apart from the initial installation cost, the laboratory-based investigations have certain advantages over the field investigations and mock-up tests, such as a precise control over the applied thermal and hydraulic gradients, efficient data monitoring, and a reasonable testing period. In this regard, several small-scale experiments have been performed using a column-type testing device (Cuevas et al 1997;Yong et al 1997;Börgesson et al 2001;Pintado, Ledesma, Lloret 2002;Gatabin and Billaud 2005;Villar, Martín, and Barcala 2005;Åkesson et al 2009;Schanz, Nguyen-Tuan, and Datcheva 2013;Saba et al 2014;Tripathy, Thomas, and Bag 2015). Figure 1B depicts the sectional view of a disposal pit in deep disposal of radioactive waste that links the column-type testing concept (fig.…”

Section: Introductionmentioning

confidence: 99%

A Column-Type Experimental Device for Investigating Coupled Thermo-Hydro-Mechanical Behavior of Expansive Soils

et al. 2021

View full text Add to dashboard Cite

This paper presents a newly designed column-type experimental device for investigating the coupled thermo-hydro-mechanical behavior of expansive soils. Sensors and monitoring instruments facilitated continuous and nondestructive measurements of temperature, relative humidity, water content, and total stresses in both axial and lateral directions at various preselected locations of the device. The design features and calibration of specific accessories are presented. System implementation and validation tests were performed to examine the performance of the device at an elevated temperature. In the context of underground storage of nuclear waste, a test was performed with a compacted Calcigel bentonite-sand mixture (50:50) to investigate the thermo-hydro-mechanical behavior of the material under an applied temperature gradient involving temperatures of 80°C and 20°C at the opposite ends of the sample. The test results highlighted the key features of temperature-driven processes in unsaturated compacted porous media. Thermal loading caused changes in the water content and relative humidity within the sample. During the temperature equilibration period, the thermal dilation phenomenon in the regions closer to the heat source was found to be responsible for the development of axial and lateral stresses in the sample. A longer duration of thermal loading caused volumetric shrinkage of the material, which in turn affected the magnitudes of both axial and lateral stresses.

show abstract

“…Several reduced-scale mockup tests have been performed using the column-type testing devices (e.g., Cuevas et al, 1997;Yong et al, 1997;Börgesson et al, 2001;Pintado et al, 2002;Gatabin and Billaud, 2005;Villar et al, 2005;Åkesson et al, 2009;Schanz et al, 2013;Saba et al, 2014;Tripathy et al, 2015). In the column-type testing concept, the barrier and backfill materials are subjected to repository relevant thermal and hydraulic gradients under K0-condition.…”

Section: Introductionmentioning

confidence: 99%

Swelling behavior of compacted bentonite-sand mixture during water infiltration

Rawat

Baille

Tripathy

2019

Engineering Geology

View full text Add to dashboard Cite

A laboratory-based water infiltration test was conducted with compacted Calcigel bentonite-sand mixture (50:50) at room temperature to mimic the transient hydration of a backfill material in nuclear waste repository conditions. The test was performed with an innovative column-type experimental device, which facilitated the continuous and non-destructive measurements of temperature, relative humidity, water content and total stresses in both axial and lateral direction at various preselected locations along the height of soil sample. The effect of groundwater geochemistry on the bentonite hydration process was not considered in this study. The distilled water was supplied from the bottom-end under 15-kPa hydration pressure for a period of 349 days to mimic the water ingress from the host rock. The test results highlighted the hydration-induced heterogeneity in the material and its effect on the lateral swelling pressure development along the height of soil sample. The axial swelling pressure measurements revealed the factors, which affect the stress-transfer mechanism between both the ends. The simultaneous measurements of relative humidity and water content indicated the porosity redistribution close to the hydration-end during the test.

show abstract

Hydro-thermal performance of unsaturated bentonite-sand buffer material

Cited by 20 publications

References 10 publications

Geologic environments for nuclear waste repositories

Geologic environments for nuclear waste repositories

A Column-Type Experimental Device for Investigating Coupled Thermo-Hydro-Mechanical Behavior of Expansive Soils

Swelling behavior of compacted bentonite-sand mixture during water infiltration

Contact Info

Product

Resources

About