Data collection and field experiments at the Apache Leap research site. Annual report, May 1995--1996

Abstract

This report documents the research performed during the period M a y 1995-May 1996 for a project of the US. Nuclear Regulatory Commission (sponsored contract NRC-04-090-051) by the University of Arizona. The project manager for this research is Thomas J. Nicholson, OtEce of Nuclear Regulatory Research. The objectives of this research were to examine hypotheses and test alternative conceptual models concerning unsaturated flow and transport through fractured rock, and to design and execute confirmatory field and laboratory experiments to test these hypotheses and conceptual models at the Apache Leap Research Site near Superior, Arizona. Each chapter in this report summarizes research related to a specific set of objectives and can be read and interpreted as a separate entity. Topics include: crosshole pneumatic and gaseous tracer field and modeling experiments designed to help validate the applicability of contiuum geostatistical and stochastic concepts, theories, models, and scaling relations relevant to unsaturated flow and transport in fractured porous tuffs; use of geochemistry and aquifer testing to evaluate fracture flow and perching mechanisms; investigations of *Up% fractionation to evaluate leaching selectivity; and transport and modeling of both conservative and nonconservative tracers.