Groundwater travel time uncertainty analysis. Sensitivity of results to model geometry, and correlations and cross correlations among input parameters

Technical Report · Fri Mar 01 00:00:00 EST 1985

OSTI ID:5751479

Clifton, P M

This study examines the sensitivity of the travel time distribution predicted by a reference case model to (1) scale of representation of the model parameters, (2) size of the model domain, (3) correlation range of log-transmissivity, and (4) cross correlations between transmissivity and effective thickness. The basis for the reference model is the preliminary stochastic travel time model previously documented by the Basalt Waste Isolation Project. Results of this study show the following. The variability of the predicted travel times can be adequately represented when the ratio between the size of the zones used to represent the model parameters and the log-transmissivity correlation range is less than about one-fifth. The size of the model domain and the types of boundary conditions can have a strong impact on the distribution of travel times. Longer log-transmissivity correlation ranges cause larger variability in the predicted travel times. Positive cross correlation between transmissivity and effective thickness causes a decrease in the travel time variability. These results demonstrate the need for a sound conceptual model prior to conducting a stochastic travel time analysis.

• Research Organization: Rockwell International Corp., Richland, WA (USA). Rockwell Hanford Operations
• DOE Contract Number: AC06-77RL01030
• OSTI ID: 5751479
• Report Number(s): RHO-BW-ST-70P; ON: DE85013499
• Country of Publication: United States
• Language: English

Related Subjects

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
58 GEOSCIENCES
BASALT
FLUID FLOW
GROUND WATER
FLOW MODELS
DATA COVARIANCES
HYDRAULIC CONDUCTIVITY
PERFORMANCE
POROSITY
RADIOACTIVE WASTE FACILITIES
SENSITIVITY
HYDROGEN COMPOUNDS
IGNEOUS ROCKS
MATHEMATICAL MODELS
NUCLEAR FACILITIES
OXYGEN COMPOUNDS
ROCKS
VOLCANIC ROCKS
WATER
053000* - Nuclear Fuels- Environmental Aspects
052002 - Nuclear Fuels- Waste Disposal & Storage
580100 - Geology & Hydrology- (-1989)