HR: 1340h
AN: H13A-1317    [Abstracts]
TI: Evaluation of Alternatives to the Southwest No-Flow Boundary Condition in the Culebra at the Waste Isolation Pilot Plant
AU: Beauheim, R L
EM: rlbeauh@sandia.gov
AF: Repository Performance Department, Sandia National Laboratories, 4100 National Parks Highway, Carlsbad, NM 88220
AU: * Klise, K A
EM: kaklise@sandia.gov
AF: Geohydrology Department, Sandia National Laboratories, PO Box 5800, MS0735 , Albuquerque, NM 87185
AB: The Culebra Dolomite within the Rustler Formation at the Waste Isolation Pilot Plant (WIPP) has been identified as a potential pathway for radionuclide migration to the environment. Water level measurements indicate a groundwater divide exists within the Culebra southwest of the WIPP site. This project evaluates the influence of the boundary condition used to represent the groundwater divide on the estimated solute travel time from the center of the WIPP repository to the site boundary. The southwest boundary condition is presently represented by a no-flow boundary extending southeast from a potash tailings pile in Nash Draw. Alternative conceptualization of this boundary is desired as the groundwater divide could be a result of infiltration where the Culebra is unconfined. In this regard, alternate boundary conceptualizations include (1) fixed heads along the structural high in the Culebra in the southwest region and (2) moving the no-flow boundary to the west in order to include recharge where the Culebra is unconfined. For each change, stochastic inverse calibration of the Culebra transmissivity fields to both steady-state heads obtained during calendar year 2000 and to a series of transient responses to various hydraulic tests over a period of 11 years is carried out. Preliminary results from 15 realizations of the base transmissivity field show that solute travel time within the WIPP site is responsive to the alternate conceptualizations of the groundwater divide within the Culebra Dolomite. This research is funded by WIPP programs administered by the Office of Environmental Management (EM) of the U.S. Department of Energy. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.
DE: 1829 Groundwater hydrology
DE: 1869 Stochastic hydrology
DE: 1875 Vadose zone
SC: Hydrology [H]
MN: Fall Meeting 2005