Adaptive Mesh Refinement (AMR) in conjunction with high order upwind finite difference methods has been used effectively on a variety of problems. In this paper we discuss an implementation of an AMR finite difference method that solves the equations of gas dynamics with two material species in three dimensions. An equation for the evolution of volume fractions augments the gas dynamics system. The material interface is preserved and tracked from the volume fractions using a piecewise linear reconstruction technique. 14 refs., 4 figs.

Dissolution of Rocky Flats Pu alloys and Pu metal using a nested insert'' configuration (One Well Insert (S-3352) inside the Mk-42 Insert) will require a Nuclear Safety Study, a major assumption of which will be that the annular dissolver is well-mixed. The well-mixed'' assumption was theoretically and experimentally supported for alloy dissolution using the Three Well Insert, but the present situation differs significantly. In the former case, the insert was directly exposed to the agitation induced by air sparging; in the case under consideration, the One Well Insert would be shielded by the Mk-42 Insert. In an effort to determine if the nested insert'' approach should be pursued, the past studies and technical literature have been surveyed and an attempt made to predict the extent of mixing and bulk circulation for a nested insert'' configuration in the presence of air sparging.

Dissolution of Rocky Flats Pu alloys and Pu metal using a ``nested insert`` configuration (One Well Insert (S-3352) inside the Mk-42 Insert) will require a Nuclear Safety Study, a major assumption of which will be that the annular dissolver is well-mixed. The ``well-mixed`` assumption was theoretically and experimentally supported for alloy dissolution using the Three Well Insert, but the present situation differs significantly. In the former case, the insert was directly exposed to the agitation induced by air sparging; in the case under consideration, the One Well Insert would be shielded by the Mk-42 Insert. In an effort to determine if the ``nested insert`` approach should be pursued, the past studies and technical literature have been surveyed and an attempt made to predict the extent of mixing and bulk circulation for a ``nested insert`` configuration in the presence of air sparging.

Grazing incidence metal mirrors (GIMMs) are examined to replace dielectric mirrors for the final elements in a laser beam line for an inertial confinement fusion reactor. For a laser driver with a wavelength from 250 to 500 nm in a 10-ms pulse, irradiated mirrors made of Al, Al alloys, or Mg were found to have calculated laser damage limits of 0.3--2.3 J/cm{sup 2} of beam energy and neutron lifetime fluence limits of over 5 {times} 10{sup 20} 14 MeV n/cm{sup 2} when used at grazing incidence and operated at room temperature or at 77 K. A final focusing system including mirrors made of Al alloy 7475 at room temperature or at liquid nitrogen temperatures used with a driver which delivers 5 MJ of beam energy in 32 beams would require 32 mirrors of roughly 10 m{sup 2} each. This chapter includes calculations of damage limits for GIMMs and discusses critical issues relevant to the integrity and lifetime of such mirrors in a reactor environment. The reflectivities of various metals are calculated from measured optical constants at room temperature and at cryogenic temperatures for 250- to 500-nm light at both normal and grazing incidence. Then, for the mirrors in a representative …

We examined the effects of total body exposure of BCF1 mice to {gamma}-rays (300 cGy) in modulating expression of cellular oncogenes in both gut and liver tissues. We selected specific cellular oncogenes (c-fos, c-myc, c-src, and c-H-ras), based on their normal expression in liver and gut tissues from untreated mice. As early as 5 min. following whole body exposure of BCF1 mice to {gamma}-rays we detected induction of mRNA specific for c-src and c-H-ras in both liver and gut tissues. c-fos RNA was slightly decreased in accumulation in gut but was unaffected in liver tissue from irradiated mice relative to untreated controls. c-myc mRNA accumulation was unaffected in all tissues examined. These experiments document that modulation of cellular oncogene expression can occur as an early event in tissues following irradiation and suggest that this modulation may play a role in radiation-induced carcinogenesis.

The goal is, using a very large passive array, to determine the performance limits of a detector. The signal of interest is narrowband with a Gaussian envelope, and the contaminating noise is multivariate Class-A. Two different multivariate models for the Class A family are presented. One of the models is appropriate for array processing applications. The data is spatially dependent and temporally independent. It is shown, in the spatially independent case, that the Chernoff approximation does closely approximate the performance of the optimal detector. It is shown the approximation improves as the number of samples increases. Unfortunately, it is also shown that the Chernoff approximation requires numerical evaluation of a M-dimensional integral. For the application here, M may be as large as 150, ruling out this approach. Two alternative approaches are examined. First, approximating the Class A model by a Gaussian model is shown to result in a poor approximation. Second, the exact likelihood ratio is approximated by a piece-wise function. While the approximation can be done with very good accuracy, the bound must be evaluated numerically. 10 refs., 11 figs.

The following messages were taken from Inter-office Electronic Mail and provide perspective on the DOE FAST site survey. The key issue is that WSRC analytical groups have been unable to state when processes will be operated and what the exact requirements will be for characterizing materials from those processes when they do start. What results is a uncertainty at the site in the actual analytical work load. Although Donnan refers to the original survey data, one update was submitted to the needs requirements in the fall of 90. However that update was not as complete as the one given below. I have identified some of the people using brackets.

The objective of this project is to design a conceptual slurry reactor for two indirect liquefaction applications; production of methanol and production of hydrocarbon fuels via Fischer-Tropsch route. The work will be accomplished by the formulation of reactor models for both the processes and use computer simulation. Process data, kinetic and thermodynamic data, heat and mass transfer data and hydrodynamic data will be used in the mathematical models to describe the slurry reactor for each of the two processes. The cost of current vapor phase reactor systems will be compared with cost estimated for the slurry reactor systems. For the vapor phase systems, upstream and downstream processing equipments may have to be included during cost analysis for a meaningful cost comparison.

Atmospheric transport and diffusion models have been developed for real-time calculations of the location and concentration of toxic or radioactive materials during an accidental release at the Savannah River Site (SRS). These models are based Gaussian distributions and have been incorporated into an automated menu-driven program called the WIND (Weather INformation and Display) system. The WIND system atmospheric models employ certain assumptions that allow the computations of the ground-level concentration of toxic or radioactive materials to be made quickly. Gaussian models, such as PF/PL and 2DPUF, suffer from serious limitations including the inability to represent recirculation of pollutants in complex terrain, the use of one stability class at a given time to represent turbulent mixing over heterogeneous terrain, and the use of a wind field computed at only one height in the atmosphere. These limitations arise because the fundamental conservation relations of the atmosphere have been grossly simplified. Three-dimensional coupled atmospheric-dispersion models are not limited by the over-simplifications of the Gaussian assumption and have been used in the past to predict the transport of pollutants in a variety of atmospheric circulations. The disadvantage of these models is that they require large amounts of computational time; however, technology has progressed enough …

Atmospheric transport and diffusion models have been developed for real-time calculations of the location and concentration of toxic or radioactive materials during an accidental release at the Savannah River Site (SRS). These models are based Gaussian distributions and have been incorporated into an automated menu-driven program called the WIND (Weather INformation and Display) system. The WIND system atmospheric models employ certain assumptions that allow the computations of the ground-level concentration of toxic or radioactive materials to be made quickly. Gaussian models, such as PF/PL and 2DPUF, suffer from serious limitations including the inability to represent recirculation of pollutants in complex terrain, the use of one stability class at a given time to represent turbulent mixing over heterogeneous terrain, and the use of a wind field computed at only one height in the atmosphere. These limitations arise because the fundamental conservation relations of the atmosphere have been grossly simplified. Three-dimensional coupled atmospheric-dispersion models are not limited by the over-simplifications of the Gaussian assumption and have been used in the past to predict the transport of pollutants in a variety of atmospheric circulations. The disadvantage of these models is that they require large amounts of computational time; however, technology has progressed enough …

This publication provides monthly statistics at the national, Census division, and state levels for net generation, fuel consumption, fuel stocks, quantity and quality of fuel, cost of fuel, electricity sales, revenue, and average revenue per kilowatthour of electricity sold. Data on net generation, fuel consumption, fuel stocks, quantity and cost of fuel are also displayed at the North American Electric Reliability Council (NERC) region level. Additionally, statistics at the company and plant level are published in the EPM on capability of new plants, net generation, fuel consumption, fuel stocks, quantity and quality of fuel, and cost of fuel. 4 figs., 63 tabs.

Steady-state hydroxide, pH, carbonate and bicarbonate levels have been estimated for supernatant liquids during sludge washing and storage. These compositions were needed in order to prepare synthetic solutions for determining inhibitor requirements. The steady-state pH was plotted versus the nitrate concentration and fitted to a logarithmic expression of the form, pH = 10.23 [times] [NO[sub 3][minus]][sup 0.0178] where [NO[sub 3][minus]] is the concentration of nitrate in moles/liter. Similar expressions were also developed for calculating the concentrations of carbonate and bicarbonate as a function of the nitrate concentration.

Steady-state hydroxide, pH, carbonate and bicarbonate levels have been estimated for supernatant liquids during sludge washing and storage. These compositions were needed in order to prepare synthetic solutions for determining inhibitor requirements. The steady-state pH was plotted versus the nitrate concentration and fitted to a logarithmic expression of the form, pH = 10.23 {times} [NO{sub 3}{minus}]{sup 0.0178} where [NO{sub 3}{minus}] is the concentration of nitrate in moles/liter. Similar expressions were also developed for calculating the concentrations of carbonate and bicarbonate as a function of the nitrate concentration.

Over the last few years, Bonneville has been addressing this need and has developed numerous ways of acquiring resources. Four of these Approaches, the Competitive Acquisition, Billing Credits, and Targeted Acquisition Programs, and the Cowlitz Falls Hydroelectric Project, were the subject of this evaluation project. Each Approach is currently in different stages of a process, and Bonneville felt it was an appropriate time that an evaluation be conducted. The purpose of this evaluation is to analyze the various Approaches` processes, to learn what`s working and what`s not, and to offer recommendations as to how Bonneville might improve their resources acquisition efforts. The evaluation was conducted with no preconceived biases.

This report describes the first small-scale explosion experiments with aerated grout (i.e., YTONG). Apart from data referring to crater depth and volume versus depth of burst (DOB), isobaric DOB curves in the range of 1.5 psi {le} p {le} 15 psi were established. The comparison with previous HOB values shows that the ground range to a given overpressure is considerably reduced with increasing depth of burst. The authors plan to continue the airblast investigations with different types of soil materials.

The first series of experiments using the Nova laser to investigate mix at an interface between different materials has been completed. Mix was induced by a shock crossing the interface and initiating a Richtmyer-Meshkov instability. Both low and high Atwood number targets were used and the results compare favorably with simulations using a k{var epsilon} mix model. These experiments pave the way for new designs which should provide data needed to develop mix models with predictive capabilities. 9 refs., 8 figs.

The third hypervariable domain (V3) of the human immunodeficiency virus type-1 (HIV-1) envelope protein (env) can serve as an epitope for potent type-specific neutralizing antibodies (NAbs) -- thus short peptides predicted on the most commonly found variants of the antigenic tip of the V3 loop have been considered as potential candidates for an HIV peptide vaccine. To evaluate the extent of intrapatient variation in the immunogenic crest of the V3 loop, sequence sets were analyzed from individuals for whom multiple V3 sequences were available. Several strategies for selecting the best sets of hexapeptides to represent the variable tip of the V3 loop were considered and their effectiveness was evaluated by comparing them with the sequence sets from individuals. Most individuals carried at least one, and frequently many, variants that did not match any of the sequences from among the ten most common hexapeptides. Intrapatient viral sequence variation was increased by including sequences derived from brain biopsy specimens as well as from blood. Additionally, sequences obtained from brain specimens of different individuals had common elements which were not conserved in the corresponding blood samples, suggesting that certain amino acids in the V3 loop may be requisite for viral propagation in the …

The third hypervariable domain (V3) of the human immunodeficiency virus type-1 (HIV-1) envelope protein (env) can serve as an epitope for potent type-specific neutralizing antibodies (NAbs) -- thus short peptides predicted on the most commonly found variants of the antigenic tip of the V3 loop have been considered as potential candidates for an HIV peptide vaccine. To evaluate the extent of intrapatient variation in the immunogenic crest of the V3 loop, sequence sets were analyzed from individuals for whom multiple V3 sequences were available. Several strategies for selecting the best sets of hexapeptides to represent the variable tip of the V3 loop were considered and their effectiveness was evaluated by comparing them with the sequence sets from individuals. Most individuals carried at least one, and frequently many, variants that did not match any of the sequences from among the ten most common hexapeptides. Intrapatient viral sequence variation was increased by including sequences derived from brain biopsy specimens as well as from blood. Additionally, sequences obtained from brain specimens of different individuals had common elements which were not conserved in the corresponding blood samples, suggesting that certain amino acids in the V3 loop may be requisite for viral propagation in the …

Department of Energy and Nuclear Regulatory Commission regulations governing material control and accountability in nuclear facilities have become more restrictive in the past decade, especially in areas that address the insider threat. As the insider threat receives greater credibility, regulations have been strengthened to increase the probability of detecting insider activity and to prevent removal of a significant quantity of Special Nuclear Material (SNM) from areas under control of the protective force.

The technology being proposed by LLNL is an Active and Passive Computed Tomography (A P CT) Drum Scanner for contact-handled (CH) wastes. It combines the advantages offered by two well-developed nondestructive assay technologies: gamma-ray spectrometry and computed tomography (CT). Coupled together, these two technologies offer to nondestructively and quantitatively characterize mixed- wastes forms. Gamma-ray spectroscopy uses one or more external radiation detectors to passively and nondestructively measure the energy spectrum emitted from a closed container. From the resulting spectrum one can identify most radioactivities detected, be they transuranic isotopes, mixed-fission products, activation products or environmental radioactivities. Spectral libraries exist at LLNL for all four. Active (A) or transmission CT is a well-developed, nondestructive medical and industrial technique that uses an external-radiation beam to map regions of varying attenuation within a container. Passive (P) or emission CT is a technique mainly developed for medical application, e.g., single-photon emission CT. Nondestructive industrial uses of PCT are under development and just coming into use. This report discuses work on the A P CT Drum Scanner at LLNL.

The applicability of electrostatic particle-in-cell (PIC) methods for the simulation of magnetically-confined fusion plasmas is investigated. The aspects of the PIC methodology which allow one to accurately model the representative charge separations found in hot fusion plasmas with far fewer simulation particles are discussed. The number of simulation particles required to resolve the collective effects of interest (such as the ambipolar potential) above the statistical fluctuations is also analyzed. 8 refs., 1 fig.

Models of plasma injection (creation) and charged/neutral atomic physics which are suitable for incorporation into particle simulation codes are described. Both planar and distributed source injection models are considered. Results obtained from planar injection into a collisionless plasma-sheath region are presented. The atomic physics package simulates the charge exchange and impact ionization interactions which occur between charged particles and neutral atoms in a partially-ionized plasma. These models are applicable to a wide range of problems, from plasma processing of materials to transport in the edge region of a tokamak plasma. 18 refs., 6 figs.

This specification documents the gas tungsten arc (GTA) welding process and production weld acceptance criteria requirements for the MC4163. This document is written specifically to apply to the welds on the MC4163 and is not to be used as a general gas tungsten arc welding specification. All sections of this specification must be complied with unless specifically exempted in writing. There are a total of five welds with three different joint designs required to fabricate the MC4163. In the order of fabrication they are (1) initiator closure disc, (2) nozzle to case girth welds, two and, (3) nozzle closure disc welds, two. This specification will only address the nozzle to case girth welds and the nozzle closure disc welds.

A conceptual design is discussed for a fusion rocket propulsion system based on the magnetic dipole configuration. The dipole is found to have features well suited to space applications. Example parameters are presented for a system producing a specific power of 1 kW/kg, capable of interplanetary flights to Mars in 90 days and to Jupiter in a year, and of extra-solar-system flights to 1000 astronomical units (the Tau mission) in 20 years. This is about 10 times better specific power toward 10 kW/kg are discussed, as in an approach to implementing the concept through proof-testing on the moon. 21 refs., 14 figs., 2 tabs.