Description

Radioactive waste disposal in salt depends on the beneficial sealing properties of salt in the far-field. The excavation damaged zone (EDZ) is a halo of higher-permeability, higher-porosity, and reduced brine saturation compared to the far-field that surrounds excavations in the underground. The properties of the EDZ evolve with time (e.g. damage accumulation and “healing”) and change with heating and cooling, due to thermal expansion and thermal pressurization. This DECOVALEX-2027 BATS2 task is a continuation of Task E from DECOVALEX-2023 (Kuhlman et al., 2024).

Experimental Data

The brine availability test in salt (BATS) task is centered around data collected from both historical and ongoing experiments in the underground at the Waste Isolation Pilot Plant (WIPP) near Carlsbad, New Mexico. The task seeks to simulate observed thermal-hydrogeological-mechanical (THM) responses observed in boreholes completed in bedded salt at WIPP. The BATS2 experiment has been collecting data since 2022 (Kuhlman et al., 2023).

Approach

The task will be divided into five tasks, building up in scope and complexity.

Step 0: Modeling heat conduction during three equal-length tests at three different power levels (200 W, 400 W and 500 W).

Step 1: Including the effects of one or more salt-specific brine sources in numerical models (fluid inclusions and saturated clay).

Step 2: Modeling gas migration and tracer test data between boreholes under both ambient and heated conditions.

Step 3: Modeling brine production during two different length heater tests (5 weeks and 8 weeks) at the same power level.

Step 4: Scaling up BATS2 results to repository-scale relevance (cross-collaboration with Salt PA task), including drift-scale EDZ migration of brine, which may be an initial condition for PA models.

Participating Groups

• Netherlands: COVRA
• Germany: BGR and GRS
• USA: Department Of Energy (Sandia, Los Alamos, and Lawrence Berkeley National Laboratories)

Further Information

For further information, please contact the task leader, Kristopher Kuhlman.

Sandia National Laboratories is a multimission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.

References

1. Kuhlman, K., M. Mills, R. Jayne, E. Matteo, C. Herrick, M. Nemer, Y. Xiong, C. Choens, M. Paul, C. Downs, P. Stauffer, H. Boukhalfa, E. Guiltinan, T. Rahn, S. Otto, J. Davis, D. Eldridge, A. Stansberry, Rutqvist, Y. Wu, H. Tounsi, M. Hu, S. Uhlemann & J. Wang, 2023. Brine Availability Test in Salt (BATS) FY23 Update, (88 p.) SAND2023–08820RR. Albuquerque, NM: Sandia National Laboratories
2. Kuhlman, K.L., J. Bartol, S. Benbow, M. Bourret, O. Czaikowski, E. Guiltinan, K. Jantschik, R. Jayne, S. Norris, J. Rutqvist, H. Shao, P. Stauffer, H. Tounsi & C. Watson, 2024. Synthesis of Results for Brine Availability Test in Salt (BATS) DECOVALEX-2023 Task E, Geomechanics for Energy and the Environment (accepted).