scholarly journals Evaluation of Gas Migration and Rock Damage Characteristics for Underground Nuclear Waste Storage Based on a Coupled Model

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Yi Xue ◽  
Faning Dang ◽  
Fang Shi ◽  
Rongjian Li ◽  
Zhengzheng Cao
Keyword(s):  
Nuclear Waste ◽  
Sedimentary Rock ◽  
Damage Model ◽  
Mechanical Damage ◽  
Coupled Model ◽  
Nuclear Waste Repository ◽  
Gas Migration ◽  
Nuclear Waste Storage ◽  
Deformation And Failure ◽  
Waste Repository

In the deep geological repository of nuclear waste, the corrosion of waste generates gas, which increases the storage pressure, changes the properties of the rock strata, and affects the stability of nuclear waste repository. Therefore, it is of great importance to understand the gas migration in the engineering barrier and the potential impact on its integrity for the safety assessment of nuclear waste repository. A hydro-mechanical-damage model for analyzing gas migration in sedimentary rocks is established in this paper. On the basis of which, a set of coupled formulas for the coupling of gas migration in rock mass is established. The model considers the characteristics of gas migration in sedimentary rock, especially the microcracks caused by the degradation of elastic modulus and damage, and the coupling between the rock deformation and failure of fractures. The numerical simulation of gas injection test is beneficial to understand the mechanism of gas migration process in sedimentary rock.

Geochemical Performance Evaluation and Characterization of a Potential Cementitious Repository Sealing Material for Application in the Topopah Spring Tuff Nnwsi Investigations

1984 ◽  
Vol 44 ◽  
Author(s):  
Barry E. Scheetz ◽  
Della M. Roy
Keyword(s):  
Portland Cement ◽  
Nuclear Waste ◽  
Host Rock ◽  
Nuclear Waste Repository ◽  
Nuclear Waste Storage ◽  
Welded Tuff ◽  
Waste Repository ◽  
Sealing Materials ◽  
Repository Sealing ◽  
Topopah Spring Tuff

AbstractPreliminary geochemical evaluations of some portland cement based materials have been made in Nevada Nuclear Waste Storage Investigations (NNWSI), for possible nuclear waste repository sealing applications in welded tuff focused in the Yucca Mountain area. Portland cement based sealing materials have been evaluated in the NNWSI for possible sealing applications in a nuclear waste repository in the Topopah Spring tuff member. Cementitious sealing materials developed for long-term stability should be as nearly as possible in thermodynamic equilibrium with the host rock, or any disequilibrium should not have negative impact upon the integrity of the host rock. A primary step in achieving this equilibrium condition is to minimize the chemical potential between the sealant and the host rock. Two different approaches were evaluated to achieve this compatibility. The one approach utilized indigenous materials for the formulation of the concrete and the other utilized reactive admixtures to adjust the bulk chemical composition of the concrete formulation to approximate the local rock bulk chemistry. Testing of both formulations at conditions that represented the maximum credible temperature and pressure conditions of a repository were completed and show that the use of an indigenous tuff in the formulation without adjusting the matrix chemistry caused alterations which might compromise the performance of the concrete. In contrast, the chemically adjusted cementitious formulation exhibited minimal alteration in the J-13 groundwater of the designed test.

scholarly journals Effect of damage on gas seepage mechanism in coal seam based on a coupled model

2019 ◽  
Vol 23 (3 Part A) ◽  
pp. 1323-1328
Author(s):  
Yi Xue ◽  
Zhengzheng Cao ◽  
Faning Dang ◽  
Songhe Wang ◽  
Mingming He ◽  
...  
Keyword(s):  
Coal Seam ◽  
Gas Adsorption ◽  
Damage Model ◽  
Mechanical Damage ◽  
Coupled Model ◽  
Gas Migration ◽  
Initial Stage ◽  
Coal Deformation ◽  
Gas Seepage ◽  
Coal Damage

Damage has a significant impact on gas migration in coal seam. In this paper, a coupled hydraulic-mechanical-damage model is established, which takes into account the coupling relationship among coal damage, gas seepage and coal deformation. The simulation results show that the damage of coal body has little effect on seepage characteristic in the initial stage, but the influence of damage on gas seepage is increasing with the increase of time. Both the distribution of gas pressure and the gas adsorption content of coal body have a significant change.

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