2002 Technical Reports
Centrifuge modeling of LNAPL movement in the vadose zone
Hideo Nakajima
University of California, Davis, Davis, CA
Thesis
Thesis availabe from the UC Davis library.
2002 Initial Assessments for B-BX-BY Field Investigation Report(FIR): Numerical Simulations
V. L. Freedman, M. D. Williams, C. R. Cole, M. D. White, M. P. Bergeron
Pacific Northwest National Lab, Richland, WA
PNNL-13949, Pacific Northwest National Lab, Richland, WA, 2002.
Summary
Pacific Northwest National Laboratory, supporting CH2MHILL Hanford Group, Inc. (CHG) in their preparation of a Field Investigative Report (FIR) for the Hanford Site Single-Shell Tank (SST) Waste Management Area (WMA) B-BX -BY, executed a suite of numerical simulations of flow and solute transport to predict the performance of surface barriers for reducing long-term risks from potential groundwater contamination at the WMA. The scope and parametric data for these simulations were defined by a CHG Modeling Data Package. This report documents the simulation of 14 cases involving two-dimensional cross sections through the B-BX-BY WMA. Two cross-sections were constructed for this analysis: the fIrst was through the BX WMA from Tanks BX-l08 to BX-l02 for investigating past leaks; the second was through trench B-38 to simulate discharge from the B trenches. The simulations were used to investigate the impact of surface barriers, water-line leaks, and placement of inventories for the transporting fluid (i.e., water), meteoric recharge and partitioning between the aqueous and sorbed phases. Three transported solutes were considered: uranium-238 (U-238), technetium-99 (Tc-99), and nitrate (NO3).
Estimating field-scale hydraulic parameters of heterogeneous soils using a combination of parameter scaling and inverse methods
Zhang, Z.F., A.L. Ward, G.W. Gee.
Pacific Northwest National Lab, Richland, WA
PNNL-14109, Pacific Northwest National Lab, Richland, WA, 2002.
Summary
As the Hanford Site transitions into remediation of contaminated soil waste sites and tank farm closure, more information is needed about the transport of contaminants as they move through the vadose zone to the underlying water table. The hydraulic properties must be characterized for accurate simulation of flow and transport. This characterization includes the determination of soil texture types, their three-dimensional distribution, and the parameterization of each soil texture. This document describes a method to estimate the soil hydraulic parameter using the parameter scaling concept (Zhang et al. 2002) and inverse techniques. To this end, the Groundwater Protection Program Science and Technology Project funded vadose zone transport field studies, including an analysis of the results to estimate field-scale hydraulic parameters for modeling.