First phase of small diameter heater experiments in tuff
As part of the Nevada Nuclear Waste Storage Investigations (NNWSI) project, we have undertaken small diameter heater experiments in the G-Tunnel Underground Facility on the Nevada Test Site (NTS). These experiments are to evaluate the thermal and hydrothermal behavior which might be encountered if heat producing nuclear waste were disposed of in welded and nonwelded tuffs. The two Phase I experiments discussed have focused on vertical borehole emplacements. In each experiment, temperatures were measured along the surface of the 10.2-cm-dia heater and the 12.7-cm-dia boreholes. For each experiment, measurements were compared with computer model representations. Maximum temperatures reached were: 196{sup 0}C for the welded tuff after 21 days of operations at 800W and 173{sup 0}C for the nonwelded tuff after 35 days of operations at 500W. Computed results indicate that the same heat transfer model (includes conduction and radiation only) can describe the behavior of both tuffs using empirical techniques to describe pore water vaporization. Hydrothermal measurements revealed heat-indiced water migration. Results indicated that small amounts of liquid water migrated into the welded tuff borehole early in the heating period. Once the rock-wall temperatures exceeded 94{sup 0}C, in both tuffs, there was mass transport of water vapor as evidence indicated condensation cooler regions. Borehole pressures remained essentially ambient during the thermal periods.
- Research Organization:
- Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
- DOE Contract Number:
- AC04-76DP00789
- OSTI ID:
- 59854
- Report Number(s):
- CONF-830605-10; ON: DE86009490
- Resource Relation:
- Conference: 24. symposium on rock mechanics, College Station, TX (United States), 20-23 Jun 1983; Other Information: PBD: 1983
- Country of Publication:
- United States
- Language:
- English
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