Three-dimensional thermomechanical modelling of high-level waste emplacement in a salt dome

2013 ◽  
pp. 647-652 ◽  
Author(s):  
S Heusermann ◽  
R Eickemeier ◽  
H Nipp ◽  
S Fahland
Keyword(s):  
Three Dimensional ◽  
Salt Dome ◽  
High Level Waste ◽  
High Level

Long-Term Radioactivity Release from Solidified High-Level Waste - Part II Parametric Study of Waste form Properties, Temperature and Time

1982 ◽  
Vol 15 ◽  
Author(s):  
Friedrich K. Altenhein ◽  
Werner Lutze ◽  
Rodney C. Ewing
Keyword(s):  
Parametric Study ◽  
Computer Code ◽  
Salt Dome ◽  
Waste Form ◽  
Glass Block ◽  
High Level Waste ◽  
Surface Layers ◽  
History Of ◽  
High Level

The computer code QTERM has been used to calculate the total released activity from a single glass block when in contact with brine in a salt dome repository as a function of: (1) waste form properties, (2) leaching mechanisms, (3) retention or precipitation of specific radionuclides in surface layers, (4) thermal history of the repository and (5) decreasing activity as a function of time.

Long Term Crystallization Behavior of Glasses at Temperatures T < Tg

1988 ◽  
Vol 127 ◽  
Author(s):  
A. D. Stalios ◽  
R. De Batist ◽  
P. Van Iseghem
Keyword(s):  
Volume Fraction ◽  
Three Dimensional ◽  
Mathematical Expression ◽  
Time Limit ◽  
Minimum Time ◽  
High Level Waste ◽  
System A ◽  
Time Period ◽  
The Times ◽  
High Level

ABSTRACTBoulos et al. [1], derived a mathematical expression predicting the minimum time needed for a glassy system to experience fractional crystallization, not exceeding a few volume percent at temperatures lower than the glass transition temperature, T. The range of applicability of this expression is extended to include crystallization processes governed by either homogeneous or heterogeneous nucleation and by diffusion controlled one-, two-, and three-dimensional crystal growth. This study demonstrates that the Boulos et al. expression is fairly independent of the nucleation, growth habit and dimensionality of the crystallization process. Moreover, the inherent theoretical as well as experimental limitations of the technique are reviewed and discussed.The calculation for evaluating this minimum time limit has been applied for an alkali ferrisilicate alpha-waste reference glass. It is found that, for this system, a barely observable crystallized volume fraction (less than 5 % vol) will be reached at 25°C only after storage for more than 10 years. This time period is certainly beyond the times to be considered for evaluations of geological disposal. In addition some preliminary calculations of the minimum time limit for two types of borosilicate high level waste glass forms (HLW) are presented. These indicate safe time limits of the order of 10–100 years at 450°C, suggesting that crystallization effects cannot be ignored if the assumptions made in the calculations are valid.

The Isolation Capability of a Salt Dome Utilized for High-Level Waste Disposal

1981 ◽  
Vol 11 ◽  
Author(s):  
J. Hamstra
Keyword(s):  
Waste Disposal ◽  
Salt Dome ◽  
High Level Waste ◽  
High Level

The overall objective of disposal of high-level and alpha bearing wastes in deep geologic formations is to isolate these wastes from the biosphere for such a period of time that a subsequent future release of radionuclides from the buried wastes will not result in undue radiation exposures to man.

Performance Assessment with Realistic Data for a Hypothetical High-Level Waste Repository in A Salt Dome

1988 ◽  
Vol 127 ◽  
Author(s):  
R.-P. Hirsekorn ◽  
R. Storck
Keyword(s):  
Salt Dome ◽  
High Level Waste ◽  
Model Parameters ◽  
Dose Rates ◽  
Best Estimate ◽  
Time Histories ◽  
Sensitivity Studies ◽  
High Level ◽  
Physical And Chemical ◽  
Realistic Data

ABSTRACTIn the frame of the European R&D program on “Management and Storage of Radioactive Waste” assessments for HLW repositories in different geological formations have been performed with realistic data. Part of this action was the discussion of altered evolution scenarios for a repository in a salt dome.For the considered HLW repository a combined altered evolution scenario with brine intrusion via the main anhydrite vein and brine intrusion from undetected brine pockets has been considered. For this scenario limited intrusions of brine at very early times are assumed, which inundate boreholes and parts of the repository. Radionuclides are leached out of the waste forms and contaminate the brine. At later times brine intrusion via the main anhydrite is assumed to take place. Under certain conditions contact between both amounts of brine is possible, and contaminated brine reaches the overburden. Here, the radionuclides are swept away with the groundwater flow.Decisive for the transport of radionuclides from the repository to the geosphere are several interacting effects (e.g. convergence, permeability, pressure) which determine the movement of brine through the drifts and seal-ings. For the parameters involved in the modelling of physical and chemical effects as realistic data as available (best estimate) were used. Local sensitivity studies show that with the best estimate values for some parameters the combined intrusion scenario is just at the transition point between release and no release.Results are obtained showing time histories for the decrease of the voids in the repository, release rates for relevant nuclides injected into the overburden, and for dose rates. Dependences on the model parameters are discussed and most relevant parameters are identified.

Numerical and Experimental Investigations on the Time Dependent Behaviour of a Salt Dome With a High-Level Waste Repository

1983 ◽  
Vol 26 ◽  
Author(s):  
Jan Prij ◽  
Leo H. Vons
Keyword(s):  
Elevated Temperatures ◽  
Salt Dome ◽  
Time Dependent ◽  
High Level Waste ◽  
Experimental Investigations ◽  
Time Dependent Behaviour ◽  
High Level ◽  
Hlw Repository ◽  
Dependent Behaviour

ABSTRACTResults are presented of in-situ measurements, performed in a 300 m deep dry-drilled borehole, in the ASSEmine. Convergence measurements at ambient as well as elevated temperatures and pressure measurements at elevated temperatures are discussed. Creep equations derived from these experiments are used for the numerical analysis of the time dependent behaviour of a salt dome with a HLW repository. The analyses show that the total stresses in the salt remain compressive with deviatoric components smaller than 3 MPa.

Application of the Monte Carlo Method in the Performance Assessment of a Hypothetical HLW Repository in Salt

1988 ◽  
Vol 127 ◽  
Author(s):  
Alexander Nies
Keyword(s):  
Monte Carlo ◽  
Safety Assessment ◽  
Salt Dome ◽  
High Level Waste ◽  
Parameter Uncertainties ◽  
Output Uncertainty ◽  
The Monte Carlo Method ◽  
Waste Repository ◽  
High Level ◽  
Hlw Repository

ABSTRACTRecent advances in complementing the capabilities of our safety assessment code development allow for an explicit investigation of the consequences of parameter uncertainties by Monte Carlo simulation of the disposal system. The implemented methods aire described and applied to impact assessment of a brine intrusion scenario on a high level waste repository in a salt dome. Results display the strong effect of parameter uncertainties on the analysis results. With help of several sensitivity estimators input parameters are ranked according to their influence on output uncertainty.

scholarly journals Near-Field Thermal-Hydrological Behavior for Alternative Repository Designs at Yucca Mountain

1996 ◽  
Vol 465 ◽  
Author(s):  
Thomas A. Buscheck ◽  
John J. Nitao ◽  
Lawrence D. Ramspott
Keyword(s):  
Liquid Phase ◽  
Relative Humidity ◽  
Near Field ◽  
Three Dimensional ◽  
Yucca Mountain ◽  
Point Load ◽  
High Level Waste ◽  
Line Load ◽  
Large Variability ◽  
High Level

ABSTRACTThree-dimensional calculations that explicitly represent a realistic mixture of waste packages (WPs) are used to analyze decay-heat-driven thermal-hydrological behavior around emplacement drifts in a potential high-level waste facility at Yucca Mountain. Calculations, using the NUFT code, compare two fundamentally different ways that WPs can be arranged in the repository, with a focus on temperature, relative humidity, and liquid-phase flux on WPs. These quantities strongly affect WP integrity and the mobilization and release of radionuclides from WPs. Point-load spacing, which places the WPs roughly equidistant from each other, thermally isolates WPs from each other, causing large variability in temperature, relative humidity, and liquid-phase flux along the drifts. Line-load spacing, which places WPs nearly end to end in widely spaced drifts, results in more locally intensive and uniform heating along the drifts, causing hotter, drier, and more uniform conditions. A larger and more persistent reduction in relative humidity on WPs occurs if the drifts are backfilled with a low-thermal-conductivity granular material with hydrologie properties that minimize moisture wicking.

Interactions between the co-located intermediate-level waste/low-level waste and high-level waste/spent fuel components of a geological disposal facility

2012 ◽  
Vol 76 (8) ◽  
pp. 3475-3482 ◽  
Author(s):  
T. W. Hicks ◽  
S. Watson ◽  
S. Norris ◽  
G. Towler ◽  
D. Reedha ◽  
...  
Keyword(s):  
Radioactive Waste ◽  
Three Dimensional ◽  
White Paper ◽  
Intermediate Level ◽  
High Level Waste ◽  
Spent Fuel ◽  
Geological Disposal ◽  
Disposal Facility ◽  
Three Dimensional Models ◽  
High Level

AbstractThe 2008 UK government White Paper, published as part of the Managing Radioactive Waste Safety programme, identified benefits to disposing of all of the UK's higher activity wastes at the same site. That is, a single geological disposal facility (GDF) could be constructed that consists of a module for low- and intermediate-level waste, and a module for high-level waste and spent fuel.A safety case for a co-located GDF will have to consider the extent to which evolving thermo-hydro-mechanical-chemical and gas (THMCG) conditions in and around one module may affect conditions in the other module, including the extent to which barrier performance and radionuclide migration behaviour could be altered. Several research projects have been undertaken on behalf of Radioactive Waste Management Directorate aimed at understanding and evaluating the THMCG interactions that might occur during the disposal facility operational and post-closure phases.This paper describes research on THMCG interactions between disposal modules based on illustrative GDF designs for different host rock environments. Interactions were evaluated using simple analytical solutions and detailed three-dimensional models. The analyses demonstrated that interactions can be controlled by design constraints.

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