No abstract available

[en] Three sites, the Palo Duro Basin in Texas, the Paradox Basin in Utah, and the Richton Dome in Mississippi, are being investigated by the US Department of Energy for high-level radioactive-waste disposal in mined, deep geologic repositories in salt. This report delineates the use of regulatory, engineering, and performance assessment information to establish the technical basis for controlled area requirements. Based on the size of the controlled area determined, plus that of the geologic repository operations area, recommendations of possible land control or ownership area requirements for each locale are provided. On a technical basis, the following minimum land control or ownership requirements are recommended, assuming repository operations area of 2240 ac (907 ha), or 3.5 mi² (9.1 km²): Palo Duro Basin - 4060 ac (1643 ha), or 6.3 mi² (16.4 km²); Paradox Basin - 4060 ac (1643 ha), or 6.3 mi² (16.4 km²); and Richton Dome - 5000 ac (2024 ha), or 7.8 mi² (20.2 km²). Of the factors used to determine the technically based recommendations, one was found to dominate each locale. For the Palo Duro and Paradox Basins, the dominant factor was the need to limit potential radionuclide release by ground-water flow to the accessible environment. For the Richton Dome, the dominant factor was the need to limit the potential effects of solution mining on dome and repository integrity

[en] Numerical calculations have been carried out for gas-particle confined turbulent flows using a recently developed two-phase turbulence closure model. The present modeling scheme utilizes Eulerian formulations of the transport equations and accounts for the combined effects of interphase slip and turbulent dispersion of particles. A multiple-scale turbulence model is used for the turbulent field modeling of the underlying fluid flow. For the particle size and particle loading considered in this study, the fluid turbulence transport equations must be modified to include the damping effects of particles. Predictions and comparisons are made in the fully developed gas-solid pipe flow and the confined particle-laden jet. Numerical results are in reasonably good agreement with the published experimental information. 36 references

[en] A type of nanocrystalline Mg₂Ni_0.75Cr_0.25/TiO₂ composite was prepared by ball-milling alloy with different amounts of (0.5, 1.5, 2.5 wt%) TiO₂ nanoparticles. The microstructures of the nanocomposites were examined by XRD and TEM. The effects of the addition of transition metal oxide TiO₂ nanoparticles on the absorption and desorption properties of the nanocrystalline Mg₂Ni_0.75Cr_0.25 alloy were investigated. The TiO₂ nanoparticles could act as catalyst and the nanocomposites showed rapid absorption and desorption kinetics and good thermodynamic properties. The absorption temperatures of the nanocomposites were greatly decreased and the rates of hydriding were increased. In comparison with the nanocrystalline Mg₂Ni_0.75Cr_0.25 alloy, the enthalpy of hydride formation for the nanocomposite was small, but the absorption capacity was reduced

[en] Measurements of ³He sorption by C₆₀/C₇₀ fullerene crystals show unusual behavior. At low sorption levels the authors find the isotherms ordered in such a way that the higher the temperature the lower the sorption. This is as expected for surface sorption. At a partial pressure of about 0.1 however this order is reversed with the highest temperature isotherms showing a large excess sorption, equivalent at the largest to about 2 atoms of ³He per fullerene molecule. The authors interpret this behavior as intercalation in the fullerene lattice. they find that this takes place reversibly with no hysteresis. Similar behavior has also been found for ⁴He. When viewed as function of the difference in the chemical potential between full and partial saturation, Δμ, the isotherms collapse on a universal curve for Δμ≤-8 K. This is also similar to the behavior of ⁴He

[en] Subpart G ''Quality Assurance'' of 10 CFR Part 60 requires that the US Department of Energy (DOE) apply a quality assurance program to ''all systems, structures, and components important to safety'' and to ''design and characterization of barriers important to waste isolation.'' In April 1986, DOE's Office of Geologic Repositories (OGR) issued general guidance for formulating a list of such systems, structures, and components---the Q-list. This guidance called for the use of probabilistic risk assessment (PRA) techniques to identify Q-list items. In this report, PRA techniques are applied to the underground facilities and systems described in the conceptual design report for the Salt Repository Project (SRP) in Deaf Smith County, Texas. Based on probability and dose consequence calculations, no specific items were identified for the Q-list. However, evaluation of the analyses indicated that two functions are important in precluding off-site releases of radioactivity: disposal container integrity; and isolation of the underground facility by the heating, ventilation, and air conditioning (HVAC) systems. Items related to these functions are recommended for further evaluation as the repository design progresses. 13 refs., 20 figs

[en] The US Department of Energy (DOE) Office of Geologic Repositories (OGR) has provided general guidance to project offices for formulating a quality control list (Q-list). A Q-list is a list of structures, systems, components, and related activities subjected to 10 CFR Part 70 Subpart G ''Quality Assurance'' requirements. The OGR guidance requires the application of probabilistic risk assessment (PRA) techniques, including a master logic diagram and event trees. A Salt Repository Project (SRP) Q-List Working Group was established to implement the risk assessment techniques. The working group is composed of individuals of diverse backgrounds including repository design, PRA, consequence analysis, and licensing. It includes representatives from the Office of Nuclear Waste Isolation, Battelle Columbus Division, Fluor Technology, Inc., and Morrison-Knudsen Engineers. The work was initiated in October 1986 and completed within six months. This report presents the analyses done during this period. Results of the analyses were provided as input to the Site Characterization Plan Conceptual Design Report (SCP-CDR). This work also confirms parallel exploratory shaft facility analyses regarding the ''important to safety'' requirements specified by 10 CFR Part 60. 30 refs., 20 figs., 26 tabs

[en] A method of medical diagnosis of toxic elements, using a neutron beam from a mobile nuclear reactor to perform partial-body in-vivo prompt gamma-ray activation technique, has been developed. Both neutron and gamma-ray dose equivalents in an irradiated phantom and around medical researchers were measured and evaluated. Neutron flux at various kinetic energies was measured using an activation foil technique, and the neutron dose equivalents at tissues of risk inside the irradiated phantom were calculated by neutron transport code. Gamma-ray dose equivalents inside the irradiated phantom and around the nuclear reactor were measured by thermoluminescent dosimeters. The risk associated with the neutron and gamma radiation dose equivalents received by both the irradiated phantom and medical researchers were evaluated in detail. The radiation safety of the in-vivo medical diagnosis using the mobile nuclear reactor, under the context of radiation protection guidelines, is discussed

[en] A multigrid relaxation method is applied to a pressure-based implicit procedure to solve unseady, incompressible Navier-Stokes equations. The present multigrid method is a Correction Scheme according to Brandt. This method is used to solve the scalar matrices resulting from the finite-volume formulation and uses flux averaging as the restriction operator. The accuracy and computational efficiency are demonstrated with a steady state driven cavity flow and an unsteady flow over a circular cylinder case. The results are compared with single grid results using the OrthoMin conjugate gradient method and experimental data. 24 refs

[en] The authors present sorption measurements for ³He and ⁴He in the temperature range of 1.5 K to 4.1 K, and for ²⁰Ne in the temperature range of 22 K to 27 K by crystals of C₆₀, C₇₀ and crystals of the mixture of these two molecules, 80% C₆₀, 20% C₇₀. They analyze these data by taking into account the non-ideality of the gas in equilibrium with the adsorbate. The authors calculate chemical potentials and isosteric heats. They find that there is no obvious evidence of intercalation of helium in these crystals at low temperatures. At higher temperatures there are some anomalies in the helium isotherms, and indication of excess sorption. The isosteric heat shows a minimum in this region which can be interpreted as penetration of the helium into a region of repulsive potential. The authors also find that levels of sorption, at the same chemical potential difference from saturation, are higher for ⁴He than for ³He. They are also higher for ⁴He on C₇₀ than for the other crystals. For neon this work is concentrated around the triple point. The authors find that the isotherms indicate the formation of liquid or solid films. Below the triple point, and above a few atomic layers, the neon film does not grow uniformly