Impacts of Hydrologic and Geochemical Uncertainty on Predicting Uranium Migration at the Hanford 300 Area
Abstract
In modeling the uranium migration within the Integrated Field Research Challenge (IFRC) site at the Hanford 300 Area, the model simulations are affected by both the hydrologic and geochemical uncertainties. This study investigates the propagation of both types of uncertainty in the simulation of a uranium desorption experiment using a Monte-Carlo framework. The hydrologic uncertainty arises from estimating the transient flow boundary conditions induced by the dynamics in the Columbia River and the underlying heterogeneous hydraulic conductivity field, while the geochemical uncertainty is a result of limited knowledge in the geochemical reaction processes that take place in field and heterogeneity in source terms and reaction coefficients. We also evaluated the effectiveness of various conditioning data in reducing the uncertainty in the simulated uranium plume. For example, identifying the optimal boundary condition and estimating the 3D hydraulic conductivity field through inversion of concurrent conservative tracer test, and exploring the possibility of including the geophysical and geochemical data available at the site to characterize hydrologic and geochemical heterogeneities. The multi-realization capability of the parallel simulator, PFLOTRAN, enables this computationally demanding task to be completed within a reasonable turn-around time.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2011
- Bibcode:
- 2011AGUFM.H13B1206C
- Keywords:
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- 1829 HYDROLOGY / Groundwater hydrology;
- 1869 HYDROLOGY / Stochastic hydrology;
- 1873 HYDROLOGY / Uncertainty assessment