Geostatistical estimation of elevations within the Cohassett flow at the reference repository location
Geostatistical methods are used to estimate positions and associated uncertainties of key horizons in the Cohassett flow to define the probability that repository tunnels for a given design will maintain appropriate vertical distances from either the flow top or flow bottom. Because specific requirements for waste emplacement, haulage, and drainage result in repository tunnels that do not precisely follow the geologic structure, structural attitude and thickness of the Cohassett flow interior are key factors in repository placement. The Cohassett flow structural attitude was estimated by ordinary kriging of top-of-basalt borehole data, thus providing more elevation control than deeper horizons. Estimation standard deviations were calculated to determine the uncertainty of the estimates. Using these standard deviations and planned repository elevations, an assessment was made as to how well the proposed repository workings would ''fit'' in the Cohassett flow given an 80% confidence criterion. Regions where the repository did not satisfy the criterion were identified, and can be used to locate sites for additional geologic borehole drilling to reduce uncertainties. Evaluation of optional drilling plans revealed that a combination of deep and shallow boreholes would produce greatest reduction in standard deviations (uncertainty) for a given drilling budget. 4 refs., 24 figs.
- Research Organization:
- Rockwell International Corp., Richland, WA (USA). Rockwell Hanford Operations
- DOE Contract Number:
- AC06-77RL01030
- OSTI ID:
- 6205781
- Report Number(s):
- RHO-BW-CR-155-P; ON: DE87013005
- Country of Publication:
- United States
- Language:
- English
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12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
BASALT
COMPARATIVE EVALUATIONS
DESIGN
HANFORD RESERVATION
IGNEOUS ROCKS
MANAGEMENT
MATHEMATICAL MODELS
NATIONAL ORGANIZATIONS
RADIOACTIVE WASTE DISPOSAL
ROCKS
SHAFT EXCAVATIONS
UNDERGROUND DISPOSAL
US DOE
US ERDA
US ORGANIZATIONS
VOLCANIC ROCKS
WASTE DISPOSAL
WASTE MANAGEMENT