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Title: Gas release from bedded rock salt a canary sings of fracture.

Abstract

Abstract not provided.

Authors:
; ;
Publication Date:
Research Org.:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Org.:
USDOE National Nuclear Security Administration (NNSA)
OSTI Identifier:
1429782
Report Number(s):
SAND2017-5538J
653873
DOE Contract Number:
AC04-94AL85000
Resource Type:
Program Document
Country of Publication:
United States
Language:
English

Citation Formats

Bauer, Stephen J., W. Payton Gardner, University of Montana, and Hyunwoo Lee, University of New Mexico. Gas release from bedded rock salt a canary sings of fracture.. United States: N. p., 2017. Web.
Bauer, Stephen J., W. Payton Gardner, University of Montana, & Hyunwoo Lee, University of New Mexico. Gas release from bedded rock salt a canary sings of fracture.. United States.
Bauer, Stephen J., W. Payton Gardner, University of Montana, and Hyunwoo Lee, University of New Mexico. Mon . "Gas release from bedded rock salt a canary sings of fracture.". United States. doi:.
@article{osti_1429782,
title = {Gas release from bedded rock salt a canary sings of fracture.},
author = {Bauer, Stephen J. and W. Payton Gardner, University of Montana and Hyunwoo Lee, University of New Mexico},
abstractNote = {Abstract not provided.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Mon May 01 00:00:00 EDT 2017},
month = {Mon May 01 00:00:00 EDT 2017}
}

Program Document:
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  • Abstract not provided.
  • Mined salt from the underground facility at the Waste Isolation Pilot Plant (WIPP) Project is a candidate material for use as backfill around the waste packages and in the underground openings during and after the operational phase. We have conducted a series of hydrostatic and triaxial compression experiments on the time-dependent compaction behavior of crushed salt under nominally dry, damp,'' (0.5-5 wt % added water), and brine-saturated conditions. Though the compaction of dry crushed salt is very slow in the laboratory, damp salt is likely to compact as rapidly as the mine walls can converge. Drained tests on brine-saturated crushedmore » salt indicate that, though effects associated with saturation do retard consolidation rates slightly, high fractional densities ({ge}0.95) can still be obtained on laboratory times scales at pressures below lithostatic at the WIPP. Triaxial compression experiments indicate that small deviatoric stresses have little impact on consolidation rates. Micromechanical models for the compaction of dry and damp crushed salt, based on isostatic hot-pressing models, are discussed. 14 refs., 4 figs.« less
  • A research program is proposed to investigate the behavior of salt when subjected to thermal loads like those that would be present in a high-level waste repository. This research would build upon results of decades of previous salt repository program efforts in the US and Germany and the successful licensing and operation of a repository in salt for disposal of defense transuranic waste. The proposal includes a combination of laboratory-scale investigations, numerical simulations conducted to develop validated models that could be used for future repository design and safety case development, and a thermal field test in an underground salt formationmore » with a configuration that replicates a small portion of a conceptual repository design. Laboratory tests are proposed to measure salt and brine properties across and beyond the range of possible repository conditions. Coupled numerical models will seek to describe phenomenology (thermal, mechanical, and hydrological) observed in the laboratory tests. Finally, the field test will investigate many phenomena that have been variously cited as potential issues for disposal of thermally hot waste in salt, including buoyancy effects and migration of pre-existing trapped brine up the thermal gradient (including vapor phase migration). These studies are proposed to be coordinated and managed by the Carlsbad Field Office of DOE, which is also responsible for the operation of the Waste Isolation Pilot Plant (WIPP) within the Office of Environmental Management. The field test portion of the proposed research would be conducted in experimental areas of the WIPP underground, far from disposal operations. It is believed that such tests may be accomplished using the existing infrastructure of the WIPP repository at a lower cost than if such research were conducted at a commercial salt mine at another location. The phased field test is proposed to be performed over almost a decade, including instrumentation development, several years of measurements during heating and then subsequent cooling periods, and the eventual forensic mining back of the test bed to determine the multi-year behavior of the simulated waste/rock environment. Funding possibilities are described, and prospects for near term start-up are discussed. Mining of the access drifts required to create the test area in the WIPP underground began in November 2011. Because this mining uses existing WIPP infrastructure and labor, it is estimated to take about two years to complete the access drifts. WIPP disposal operations and facility maintenance activities will take priority over the SDI field test area mining. Funding of the SDI proposal was still being considered by DOE's Offices of Environmental Management and Nuclear Energy at the time this paper was written, so no specific estimates of the progress in 2012 have been included. (authors)« less
  • At the Asse salt mine in Germany a test field has been operating since September 1990 for the purpose of demonstrating the practicability of the direct disposal of spent fuel elements in drifts. According to the concept for direct disposal of spent fuel, disposal casks called Pollux will be emplaced on the floor of the drifts backfilled with salt afterwards. The main objectives of this test are studies on the thermal and thermomechanical effects in the backfilled drifts and in the surrounding rock due to the power output of the spent fuel in the casks. The temperatures at the surfacemore » of the electrically heated mock-ups of the Pollux-casks increased up to 210 C after five months and then gradually decrease. Determinations of the initial stress state in the test field were carried out by overcoming and slot cutting techniques before the test drifts were opened. After the beginning of heating the casks, the rock stresses increased rapidly related to the temperature at the specific location and later on decreased slowly. Deformation measurements are performed in the host rock using multi-point extensometers and closure gauges for measuring the closure of the test drifts in the heated as well as in the unheated areas. Specially designed equipment was used to observe the settling of the backfill. In the period of about 4 years, the convergence of the backfilled drifts accelerated enormously and caused backfill pressures up to 1.8 MPa. The concentrations of the main components carbon dioxide, hydrogen, and methane in the pore volume of the backfill were analyzed.« less
  • Geologic and geohydrologic data for the Paradox Basin have been used to simulate movement of ground water and radioacrtive contaminants from a hypothetical nuclear reactor spent fuel repository after an assumed accidental release. The pathlines, travel times and velocity of the ground water from the repository to the discharge locale (river) were determined after the disruptive event by use of a two-dimensional finite difference hydrologic model. The concentration of radioactive contaminants in the ground water was calculated along a series of flow tubes by use of a one-dimensional mass transport model which takes into account convection, dispersion, contaminant/media interactions andmore » radioactive decay. For the hypothetical site location and specific parameters used in this demonstration, it is found that Iodine-129 (I-129) is tthe only isotope reaching the Colorado River in significant concentration. This concentration occurs about 8.0 x 10/sup 5/ years after the repository has been breached. This I-129 ground-water concentration is about 0.3 of the drinking water standard for uncontrolled use. The groundwater concentration would then be diluted by the Colorado River. None of the actinide elements reach more than half the distance from the repository to the Colorado River in the two-million year model run time. This exercise demonstrates that the WISAP model system is applicable for analysis of contaminant transport. The results presented in this report, however, are valid only for one particular set of parameters. A complete sensitivity analysis must be performed to evaluate the range of effects from the release of contaminants from a breached repository.« less