Ceramic Plugs for Deep Borehole Seals - 17316
- Olympic Research, Inc. (United States)
- Battelle, Columbus, Ohio 43201 (United States)
- Arnold Hydrogeology Consulting (United States)
- South Dakota School of Mines and Technology (United States)
In the deep borehole nuclear waste disposal concept, waste packages are emplaced deep in crystalline rock formations under conditions of high pressures, high mineral content water, and elevated temperatures. Well seals and plugs must perform for thousands of years. A novel ceramic plug system under development capitalizes on the thermal energy of thermite mixtures and engineered additives to react and form ceramic-like plugs in place with favorable structural, flow, and geochemical properties. Depending on the ingredients, the reaction can produce aluminosilicates, plagioclase feldspars, or other combinations in crystalline or amorphous forms. Normative mineralogy techniques were applied to predict product mineralogy and evaluate compatibility with host rocks, and showed they are comparable to igneous rock analogs. The results support a tentative geochemical compatibility between these formulations and granitic host rock. Because the reaction produces a significant amount of thermal energy, the thermal/structural/fluid response of the plug and surrounding media was evaluated with the FEHM code. Temperatures near the plug/rock interface are estimated to peak at less than 600 deg. C and cool to near ambient temperature within a day. Rock stresses resulting from the thermal pulse are predicted to be similar to the unconfined compressive strength of granites, and generally lower than triaxial test results. Entrained fluid expansion due to heating was shown to be lower than failure stresses. Little or no failure in the surrounding media would be expected due to the plug formation process. The present efforts are focused on refining the material formulations, evaluating the geochemical and mechanical interactions between the plug and host rock, and testing the plug formation process in scaled granite and basalt masses. (authors)
- Research Organization:
- WM Symposia, Inc., PO Box 27646, 85285-7646 Tempe, AZ (United States)
- OSTI ID:
- 22802345
- Report Number(s):
- INIS-US-19-WM-17316; TRN: US19V0356046739
- Resource Relation:
- Conference: WM2017: 43. Annual Waste Management Symposium, Phoenix, AZ (United States), 5-9 Mar 2017; Other Information: Country of input: France; 12 refs.; available online at: http://archive.wmsym.org/2017/index.html
- Country of Publication:
- United States
- Language:
- English
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