A zone plate capable of focusing hard x-rays to less than 1 {mu}m spot size is designed and specified. This design is based on the state-of-art fabrication technology available today. This zone plate consists of Cu/Al layers sputtered alternatively on a round stainless steel core. Parameters of this zone plate are given. The focal length f is given for 8Kev x-rays and the thickness is optimized for focusing efficiency of the same x-ray energy.

Axial loads on plugs or seals in an underground repository due to gas, water pressures and temperature changes induced subsequent to waste and plug emplacement lead to shear stresses at the plug/rock contact. Therefore, the bond between the plug and rock is a critical element for the design and effectiveness of plugs in boreholes, shafts or tunnels. This study includes a systematic investigation of the bond strength of cementitious borehole plugs in welded tuff. Analytical and numerical analysis of borehole plug-rock stress transfer mechanics is performed. The interface strength and deformation are studied as a function of Young`s modulus ratio of plug and rock, plug length and rock cylinder outside-to-inside radius ratio. The tensile stresses in and near an axially loaded plug are analyzed. The frictional interface strength of an axially loaded borehole plug, the effect of axial stress and lateral external stress, and thermal effects are also analyzed. Implications for plug design are discussed. The main conclusion is a strong recommendation to design friction plugs in shafts, drifts, tunnels or boreholes with a minimum length to diameter ratio of four. Such a geometrical design will reduce tensile stresses in the plug and in the host rock to a level …

Strontium isotope studies of carbonates from soils, veins, eolian dust and Paleozoic basement samples near Crater Flat, southwest of Yucca Mountain, provide evidence for the origins of these materials. Vein and soil carbonates have nearly identical ranges of {sup 87}Sr/{sup 86}Sr ratios at the lower end of the pedogenic range. The average {sup 87}Sr/{sup 86}Sr of Paleozoic basement from Black Marble Hill is similar to the {sup 87}Sr/{sup 86}Sr in the eolian dust, perhaps indicating a local source for this material. Possible spring deposits have generally higher {sup 87}Sr/{sup 86}Sr than the other carbonates. These data are compared with similar data from areas east of Yucca Mountain. 7 refs., 5 figs.

Thermal and mechanical models for intact and jointed rock mass behavior are being developed, verified, and validated at Sandia National Laboratories for the Yucca Mountain Site Characterization Project. Benchmarking is an essential part of this effort and is one of the tools used to demonstrate verification of engineering software used to solve thermomechanical problems. This report presents the results of the third (and final) phase of the first thermomechanical benchmark exercise. In the first phase of this exercise, nonlinear heat conduction code were used to solve the thermal portion of the benchmark problem. The results from the thermal analysis were then used as input to the second and third phases of the exercise, which consisted of solving the structural portion of the benchmark problem. In the second phase of the exercise, a linear elastic rock mass model was used. In the third phase of the exercise, two different nonlinear jointed rock mass models were used to solve the thermostructural problem. Both models, the Sandia compliant joint model and the RE/SPEC joint empirical model, explicitly incorporate the effect of the joints on the response of the continuum. Three different structural codes, JAC, SANCHO, and SPECTROM-31, were used with the above models …

Daniel B. Stephens and Associates, Inc. (DBS&A) was requested by LANL to perform laboratory analysis for properties of Tuff samples, as outlined in Subcontract No. 9-XT1-X1785-1. The scope of work included conducting the following tasks Sample preparation; Dry bulk density and calculated porosity; Saturated hydraulic conductivity; Moisture characteristics; Air permeability; and Particle density.

This invention is comprised of a high speed door assembly, comprising an actuator cylinder and piston rods, a pressure supply cylinder and fittings, an electrically detonated explosive bolt, a honeycomb structured door, a honeycomb structured decelerator, and a structural steel frame encasing the assembly to close over a 3 foot diameter opening within 50 milliseconds of actuation, to contain hazardous materials and vapors within a test fixture.

Borehole geophysical logging for site characterization in the volcanic rocks at the proposed nuclear waste repository at Yucca Mountain, Nevada, requires data collection under rather unusual conditions. Logging tools must operate in rugose, dry holes above the water table in the unsaturated zone. Not all logging tools will operate in this environment, therefore; careful consideration must be given to selection and calibration. A sample suite of logs is presented that demonstrates correlation of geological formations from borehole to borehole, the definition of zones of altered mineralogy, and the quantitative estimates of rock properties. We show the results of an exploratory calculation of porosity and water saturation based upon density and epithermal neutron logs. Comparison of the results with a few core samples is encouraging, particularly because the logs can provide continuous data in boreholes where core samples are not available. 9 refs., 4 figs.

The high-level nuclear waste regulations pertaining to gaseous release of carbon-14 from a repository should be changed to allow greater release, for several reasons. Some of them are as follows. First, the total amount of carbon-14 that would be placed in a repository is small compared to that produced naturally in the atmosphere by cosmic rays. Second, the dose that would result to an individual from total release of repository carbon-14 would be very small compared to that from natural radiation sources and would be well below the ``Below Regulatory Concern`` criterion. Third, the limits on gaseous carbon-14 release from a repository have been set unreasonably low compared to the limits set for carbon-14 release from other fuel cycle facilities. Fourth, the additional cost for waste packages to attempt to meet the regulations for carbon-14 release would likely be of the order of a billion dollars or more, too high to be justified by the small reduction in dose that might result. 32 refs.

Separate abstracts have been prepared for the papers presented at the meeting on nuclear facility air cleaning technology in the following specific areas of interest: air cleaning technologies for the management and disposal of radioactive wastes; Canadian waste management program; radiological health effects models for nuclear power plant accident consequence analysis; filter testing; US standard codes on nuclear air and gas treatment; European community nuclear codes and standards; chemical processing off-gas cleaning; incineration and vitrification; adsorbents; nuclear codes and standards; mathematical modeling techniques; filter technology; safety; containment system venting; and nuclear air cleaning programs around the world. (MB)

The pore structure and mineralogy of Topopah Spring Tuff are heterogeneous on scales less than one cm. This heterogeneity creates spatial variation in transport rates for aqueous actinide species both on the scale of tenths of microns and the scale of mm. The volumetric distribution of fluid paths having very different tortuosity, and potentially differing surface mineralogy and sorptive properties, must be considered in order to provide realistic predictions of transport rates. In addition, size and speciation of actinides in solution must be characterized since coexisting species can diffuse at different rates through the porous material due to both filtration effects and differences in sorption onto exposed mineral surfaces. 11 refs., 8 figs., 2 tabs.

The atmospheric corrosion of oxygen-free copper (CDA-102), 70/30 copper-nickel (CDA-715), and 7% aluminum bronze (CDA-613) in an irradiated moist air environment was investigated. Experiments were performed in both dry and 40% RH (@90{degree}C) air at temperatures of 90 and 150{degree}C. Initial corrosion rates were determined based on a combination of weight gain and weight loss measurements. Corrosion products observed were identified. These experiments support efforts by the Yucca Mountain Project (YMP) to evaluate possible metallic barrier materials for nuclear waste containers. 8 refs., 1 fig., 2 tabs.

As part of the code development and modeling work being carried out to characterize the flow in the unsaturated zone at Yucca Mountain, Nevada, capillary hysteresis models simulating the history-dependence of the characteristic curves have been developed. The objective of the work has been both to develop the hysteresis models, as well as to obtain some preliminary estimates of the possible hysteresis effects in the fractured rocks at Yucca Mountain given the limitations of presently available data. Altogether three different models were developed based on work of other investigators reported in the literature. In these three models different principles are used for determining the scanning paths: in model (1) the scanning paths are interpolated from tabulated first-order scanning curves, in model (2) simple interpolation functions are used for scaling the scanning paths from the expressions of the main wetting and main drying curves and in model (3) the scanning paths are determined from expressions derived based on the dependent domain theory of hysteresis.

A family of finite element computer programs has been developed at Sandia National Laboratories (SNL) most recently, NORIA-SP. The original NORIA code solves a total of four transport equations simultaneously: liquid water, water vapor, air, and energy. Consequently, use of NORIA is computer-intensive. Since many of the applications for which NORIA is used are isothermal, we decided to ``strip`` the original four-equation version, leaving only the liquid water equation. This single-phase version is NORIA-SP. The primary intent of this document is to provide the user of NORIA-SP an accurate user`s manual. Consequently, the reader should refer to the NORIA manual if additional detail is required regarding the equation development and finite element methods used. The single-equation version of the NORIA code (NORIA-SP) has been used most frequently for analyzing various hydrological scenarios for the potential underground nuclear waste repository at Yucca Mountain in western Nevada. These analyses are generally performed assuming a composite model to represent the fractured geologic media. In this model the material characteristics of the matrix and the fractures are area weighted to obtain equivalent material properties. Pressure equilibrium between the matrix and fractures is assumed so a single conservation equation can be solved. NORIA-SP is structured …

For the calendar year 1990, the Southern Great Basin seismic network (SGBSN) recorded about 1050 earthquakes in the SGB, as compared to 1190 in 1989. Local magnitudes, M{sub L}, ranged from 0.0 for various earthquakes to 3.2 for an earthquake on April 3, 1990 5:47:58 UTC, 37.368{degrees} North, 117.358{degrees} West, Mud Lake, Nevada quadrangle. 95% of those earthquakes have the property, M{sub L} {le} 2.4. Within a 10 km radius of the center of Yucca Mountain, the site of a potential national, high-level nuclear waste repository, one earthquake with M{sub L} = 0.6 was recorded at 40-Mile Wash. The estimated depth of focus of this earthquake is 3.8 km below sea level. Other, smaller events may have also occurred in the immediate vicinity of Yucca Mountain, but would have been below the detection threshold (M{sub L}{approx}0.0 at Yucca Mountain). Focal mechanisms are computed for seventeen earthquakes in the Nevada Test Site (NTS) and in the SGB west of the NTS for the year 1990. Solutions are mostly strike-slip, although normal slip is observed for a hypocenter at Stonewall Flat, Nevada, and reverse slip is observed for a hypocenter at Tucki Mountain, California. The average direction of the focal mechanism P-axes …

Advective and diffusive migration experiments (within the Dynamic Transport Column Experiments and Diffusion Studies of the Yucca Mountain Site Characterization Project) involve utilizing crushed material, intact, and fractured tuff in order to test and improve (if necessary) transport models by experimentally observing the migration of sorbing and non-sorbing radionuclides on a laboratory scale. Performing a validation of the sorption data obtained with batch techniques (within the Batch Sorption Study) is an integral part of the mission of the Dynamic Transport Column Experiments and Diffusion Studies. In this paper the work scope of the radionuclide migration laboratory experiments (as they apply to validation of batch sorption data) is reviewed.

The present plan for disposal of high-level radioactive waste in the US is to seal it in containers before emplacement in a geologic repository. A proposed site at Yucca Mountain, Nevada, is being evaluated for its suitability as a geologic repository. The containers will probably be made of either an austenitic or a copper-based alloy. Models of alloy degradation are being used to predict the long-term performance of the containers under repository conditions. The models are of uniform oxidation and corrosion, localized corrosion, and stress corrosion cracking, and are applicable to worst-case scenarios of container degradation. This paper reviews several of the models.

This final report represents a summary of data and interpretations obtained from the Prototype Engineered Barrier System Field Test (PEBSFT) performed in G-Tunnel within the Nevada Test Site. The PEBSFT was conducted to evaluate the applicability of measurement techniques, numerical models, and procedures developed for future field tests that will be conducted in the Exploratory Studies Facilities (ESF) at Yucca Mountain. The primary objective of the test was to provide a basis for determining whether tests planned for the ESF have the potential to be successful. Chapter 1 on high frequency electromagnetic tomography discusses the rock mass electromagnetic permittivity and attenuation rate changes that were measured to characterize the water distribution in the near field of a simulated waste container. The data are used to obtain quantitative estimates of how the moisture content in the rock mass changes during heating and to infer properties of the spatial variability of water distribution, leading to conclusions about the role of fractures in the system. Chapter 2 discusses the changes in rock moisture content detected by the neutron logging probe. Chapter 3 permeability tests discusses the characterization of the in-situ permeability of the fractured tuff around the borehole. The air permeability testing apparatus, …

Native Americans` concerns arising from the possibility of establishment of a nuclear repository for high level wastes at Yucca Mountain fall principally into two main categories. First, the strongest objection to the repository comes from traditional Western Shoshones. Their objections are based on a claim that the Western Shoshones still own Yucca Mountain and also on the assertion that putting high level nuclear wastes into the ground is a violation of their religious views regarding nature. Second, there are several reservations around the Yucca Mountain site that might be affected in various ways by building of the repository. There is a question about how many such reservations there are, which can only be decided when more information is available. This report discusses two questions: the bearing of the continued vigorous assertion by traditionalist Western Shoshones of their land claim; and the extent to which Nevada state and local governments are able to understand and represent Indian viewpoints about Yucca Mountain.

Oxygen in carbonaceous materials is converted to carbon monoxide (CO) by pyrolyzing the material in a stream of oxygen-free helium. The CO is reacted with Ni{sup 63}, a radioactive isotope of nickel, to form nickel tetracarbanyl (Ni{sup 63}(CO){sub 4}) which is carried by the helium stream into a flow-through gas proportional counter. The quantity of Ni(CO){sub 4} is determined by the radioactivity of the gas as measured by the gas proportional counter. After exiting the flow through counter the Ni{sub 63}(CO){sub 4} is destroyed by exposing it to high temperatures. The Ni{sub 63} is retained within the apparatus while the CO is flushed from the system after being oxidized to carbon dioxide (CO{sub 2}). The detection limit is estimated to be less than 1 part per billion oxygen for a 10 mg sample.

Petrologic, bulk chemical and mineralogic data are presented for 19 samples of tuffaceous rocks from core holes UE-25a{number_sign}1, USW G-1, USW GU-3, and USW G-4 at Yucca Mountain, Nevada. The suite of samples contains a wide variety of petrologic types, including zeolitized, glassy, and devitrified tuffs. Data include hand sample and thin section descriptions (with modal analyses for which uncertainties are estimated), and major element analyses with uncertainty estimates. No uncertainties were estimated for qualitative mineral identifications by X-ray diffraction. 5 refs., 1 fig., 4 tabs.

This report was written by the State of Nevada Agency for Nuclear Projects/Nuclear Waste Project Office. This office oversees the nuclear waste activities for the proposed Yucca Mountain high-level waste facility for the state of Nevada. The Yomba Shoshone Reservation socio-economic profile was the basis of this paper. It describes the life and current status of the Shoshone Indians. Population, utilities, education and social services of the Shoshone are examples of the topics which are discussed. It is intended as base-line information only. It eventually summarizes and compares data from the public opinion of the Shoshone about the high level waste repository at Yucca Mountain. (MB)

An apparatus for selecting a single synchrotron pulse from the millions of pulses provided per second from a synchrotron source includes a rotating spindle located in the path of the synchrotron pulses. The spindle has multiple faces of a highly reflective surface, and having a frequency of rotation f. A shutter is spaced from the spindle by a radius r, and has an open position and a closed position. The pulses from the synchrotron are reflected off the spindle to the shutter such that the speed s of the pulses at the shutter is governed by: s=4 {times} {pi} {times} r {times} such that a single pulse is selected for transmission through an open position of the shutter.

The Yucca Mountain Site Characterization Project is evaluating Yucca Mountain in Nye County, Nevada, as a site for a potential high-level nuclear waste repository. Lawrence Livermore National Laboratory is concerned with the development and performance modeling of waste packages for the potential repository. Argonne National Laboratory has performed experimental studies in support of the waste package effort. This effort is currently guided by the Waste Package Plan, which calls for a systems engineering approach to waste package development. Part of this approach involves formulating an approved set of selection criteria to choose the materials to be used in fabricating the waste packages. Technical issues related to the performance of metals in the air/water vapor environment expected in the potential Yucca Mountain repository are discussed. Preliminary experiments, focused on the atmospheric corrosion of copper-based materials, are summarized. These experiments were performed over a broad range of conditions: temperatures between 90 and 150{degrees}C; relative humidities of 0, 15, 40, and 100%; and gamma dose rates between 0.01 and 0.3 Mrad/hr. In irradiated moist air, copper-based materials form cooper oxides and nitrate phases depending on the dose rate, humidity and temperature. The rates of general corrosion increase with temperature, humidity, and dose rate. …

This paper presents a summary of the conduct and findings of the Exploratory Studies Facility Alternatives Study (ESF-AS). The Exploratory Studies Facility (ESF) is being planned for use in the characterization of a site for a potential high-level nuclear waste repository at Yucca Mountain, NV. The purpose of the ESF-AS were to identify and rank order ESF-repository options and to improve understanding of the favorable or unfavorable features of the ESF design. The analysis resulted in the ranking of 34 options, in accordance with the extent to which each option could achieve the objectives. Additional findings regarding design features that were identified as key elements in an option`s ability to provide good overall performance are also discussed.