The Yucca Mountain Project is considering some type of backfill, possibly emplaced as a capillary barrier, for inclusion in the Engineering Barrier System (EBS) at the potential Yucca Mountain nuclear waste repository site. The performance of capillary barriers in isothermal, low- temperature, environments has been studied extensively (e.g., Ho and Webb, 1998; OZdenburg and Pruess, 1993; Ross, 1990). The performance of capillary barriers in an non-isothermal, high temperature environment, such as during the thermal pulse phase of a nuclear waste repository, has received much less attention. One concern is that the backfill materials may be altered from that of the as-placed material by the hydrothermal regime imposed by the emplacement of waste in the repository, changing hydrologic properties in a way that degrades the performance of the EBS system. This report is a status report on our efforts to address this concern. The work was initiated by SCR #98-76-041 and was authorized to begin at LLNL in summer 1998. This report is organized as follows. In the first part, we discuss our understanding of the relevant issues of backfill performance based on thermal hydrology. We focus here on changes to hydrologic properties, but we recognize that changes to thermal, mechanical …

The Waste Information Requirements Document describes the activities of the Tank Waste Remediation System (TWRS) Characterization Project that provide characterization information on Hanford Site waste tanks. The characterization information is required to perform operations and meet the commitments of TWRS end users. These commitments are derived from the Hanford Federal Facility Agreement and Consent Order, also known as the Tri-Party Agreement; the Recommendation 93-5 Implementation Plan to the Defense Nuclear Facilities Safety Board (DNFSB); and other directives as listed in Section 4.0. This Waste Information Requirement Document applies to Fiscal Years 1997 and 1998 activities. Its contents are based on the best information available in August 1997. The format and content are based on the directions of DOE-RL (Sieracki, 1997) and Fluor Daniel Hanford Incorporated (Umek, 1997). Activities, such as the revision of the Tank Characterization Technical Sampling Basis (Brown et al. 1997), the revision of the data quality objectives (DQOs), issue closures, discussions with Ecology, and management decisions may cause subsequent updates to the Waste Information Requirements Document.

Annual compilation of information and statistics related to educational facilities at public colleges and universities in Texas, including space usage and maintenance, campus planning, and other relevant data.

Both during September 15-30, 1996 and September 15-October 5, 1997, the Environmental Technology Laboratory (ETL) participated in an experiment at the Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) site that was designed to study many of the ways that ARM is measuring water vapor. These experiments, called the Water Vapor Intensive Operating Periods (WVIOPs), produced some results of significant importance to ARM water vapor measurements. We have spent the major portion of this years activities in analyzing results of these experiments, and improving algorithms for improving the measurement of precipitable water vapor (PWV) from instruments available at ARM. The most important ARM instrument for this measurement continues to be the Microwave Radiometer (MWR). Measurements of water vapor at the North Slope of Alaska and Adjacent Arctic Ocean (NSA/AAO) CART site in Barrow, Alaska, area potential problem because of the difficulty of radiosondes to measure low amounts of vapor during cold and extremely dry conditions. The applicability of MWR scaling to radiosondes is questionable because of the low sensitivity of these instrument during dry conditions. It has been suggested by the ARM Instantaneous Radiative Flux Working Group and others that measurements of brightness temperature around 183 GHz could be …

The U.S. Department of Energy (DOE) continues to face a major radioactive waste tank remediation problem with hundreds of waste tanks containing hundreds of thousands of cubic meters of high-level waste (HLW) and transuranic (TRU) waste across the DOE complex. Approximately 80 tanks are known or assumed to have leaked. Some of the tank contents have reacted to form flammable gases, introducing additional safety risks. These tanks must be maintained in a safe condition and eventually remediated to minimize the risk of waste migration and/or exposure to workers, the public, and the environment. However, programmatic drivers are more ambitious than baseline technologies and budgets will support. Science and technology development investments are required to reduce the technical and programmatic risks associated with the tank remediation baselines. The Tanks Focus Area (TFA) was initiated in 1994 to serve as the DOE`s Office of Environmental Management`s (EM`s) national technology development program for radioactive waste tank remediation. The national program was formed to increase integration and realize greater benefits from DOE`s technology development budget. The TFA is responsible for managing, coordinating, and leveraging technology development to support DOE`s four major tank sites: Hanford Site (Washington), Idaho National Engineering and Environmental Laboratory (INEEL) (Idaho), …