Geochemistry Technical Basis Document

Geochemical and Isotopic Evaluation of Groundwater Movement in Corrective Action Unit 97: Yucca Flat/Climax Mine, Nevada Test Site, Nevada, Rev. No.: 0

“…The methodology used in this investigation follows the basic format described in Benedict et al (2003) and is summarized below:…”

“…Initially, geochemical modeling of Yucca Flat groundwater movement examined the conservative, or non-reactive, species to identify potential groundwater source areas, flow paths, and mixing relationships (Benedict et al, 2003). Preliminary conceptual models were developed from a combination of stable isotope and Cl data.…”

“…The resulting dataset presented here reflects the highest quality data that are presently available. The flow path and travel time evaluations developed from these data are based on methodologies described in the Geochemistry Technical Basis Document for the UGTA Project (Benedict et al, 2003).…”

Phase II Corrective Action Investigation Plan for Corrective Action Units 101 and 102: Central and Western Pahute Mesa, Nevada Test Site, Nye County, Nevada, Revision 2

“…The experiments demonstrated the significance of aquifer material properties on the observed RN transport behavior and the importance of a combination of studies to reduce transport modeling uncertainties. (Benedict et al, 2003) This document presents a methodology in which data can more effectively contribute to the development, calibration, and verification of groundwater flow and solute transport models for the UGTA Project as it relates to the PM/OV flow system. Three chapters comprise: (1) an introduction to the geochemical parameters, (2) a methodology for using these parameters to define geochemical conceptual models, and (3) a description of the process that defines how the conceptual models are reconciled with hydraulic and hydrogeologic data and how they are used to verify flow and transport models.…”

Phase II Groundwater Flow Model of Corrective Action Unit 98: Frenchman Flat, Nevada Test Site, Nye County, Nevada, Rev. No.: 0

“…More discussion of the available groundwater geochemistry data for the Frenchman Flat CAU is also provided in SNJV (2004d; Section 10.0). The approach used for these evaluations was consistent with that described in the Geochemistry Technical Basis Document (Benedict et al, 2003). Viable flow paths were first identified using conservative tracers and evaluated further using strontium (Sr) data and NETPATH (Plummer et al, 1994) and PHREEQC (Parkhurst and Appelo, 1999) final water compositions along a flow path, and to calculate groundwater mixing ratios and apparent groundwater travel times (Hershey et al, 2005).…”