Applied technology legend removed per DOE/HQ on April 3, 2002

Laboratory data are presented on the effect of constant-temperature aging on the apparent thermal conductivity of polyurethane foam insulation for refrigerators and freezers. The foam specimens were blown with HCFC-141b and with three of its potential replacements--HFC-134a, HFC-245fa, and cyclopentane. Specimens were aged at constant temperatures of 90 F, 40 F, and {minus}10 F. Thermal conductivity measurements were made on two types of specimens: full-thickness simulated refrigerator panels containing foam enclosed between solid plastic sheets, and thin slices of core foam cut from similar panels. Results are presented for the first year of a multi-year study for the full-thickness panels and for about 1-1/2 years of aging for the core-foam specimens.

Alternative LEU Designs for the FRM-II have been developed by the RERTR Program at Argonne National Laboratory (ANL) at the request of an FRM-II Expert Group established by the German Federal Government in January 1999 to evaluate the options for using LEU fuel instead of HEU fuel in cores with power levels of 20 MW. The ANL designs would use the same building structure and maintain as many of the HEU design features as practical. The range of potential LEU fuels was expanded from previous studies to include already-tested silicide fuels with uranium densities up to 6.7 g/cm{sup 3} and the new U-Mo fuels that show excellent prospects for achieving uranium densities in the 8-9 g/cm{sup 3} range. For each of the LEU cores; the design parameters were chosen to match the 50 day cycle length of the HEU core and to maximize the thermal neutron flux in the Cold Neutron Source and beam tubes. The studies concluded that an LEU core with a diameter of about 29 cm instead of 24 cm in HEU design and operating at a power level of 20 MW would have thermal neutron fluxes that are 0.85 times that of the HEU design at …

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Weekly newspaper from Alvin, Texas that includes local, state, and national news along with advertising.

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The ATLAS facility (Argonne Tandem-Linac Accelerator System) is located at the Argonne National Laboratory. The facility is a tool used in nuclear and atomic physics research, which focuses primarily on heavy-ion physics. The accelerator as well as its control system are evolutionary in nature, and consequently, continue to advance. In 1998 the most recent project to upgrade the ATLAS control system was completed. This paper briefly reviews the upgrade, and summarizes the configuration and features of the resulting control system.

Monthly newsletter discussing news and activities related to the Atmospheric Radiation Measurement Program, articles about weather and atmospheric phenomena, and other related topics.

Current hexahedral mesh generation techniques rely on a set of meshing tools, which when combined with geometry decomposition leads to an adequate mesh generation process. Of these tools, sweeping tends to be the workhorse algorithm, accounting for at least 50% of most meshing applications. Constraints which must be met for a volume to be sweepable are derived, and it is proven that these constraints are necessary but not sufficient conditions for sweepability. This paper also describes a new algorithm for detecting extruded or sweepable geometries. This algorithm, based on these constraints, uses topological and local geometric information, and is more robust than feature recognition-based algorithms. A method for computing sweep dependencies in volume assemblies is also given. The auto sweep detect and sweep grouping algorithms have been used to reduce interactive user time required to generate all-hexahedral meshes by filtering out non-sweepable volumes needing further decomposition and by allowing concurrent meshing of independent sweep groups. Parts of the auto sweep detect algorithm have also been used to identify independent sweep paths, for use in volume-based interval assignment.

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Other written product issued by the General Accounting Office with an abstract that begins "GAO commented on the U.S. Trade Deficit Review Commission's authority to compensate an executive level IV Export-Import Bank employee that it would like detailed to it to serve as its executive director. The Commission's statute provides authority to appoint staff without regard to civil service laws and regulations, but it limits the compensation the Commission may pay to executive schedule level. To detail the employee under the Economy Act with full reimbursement to the Bank would violate the pay limitation. However, the Commission's statute also provides authority for any federal employee to be detailed to the Commission without reimbursement and without loss of civil service status or privilege. To avoid violating the compensation limitation, the Commission proposes to reimburse the Bank for the employee's compensation at the level V rate, with the Bank providing the amount over level V. Since this arrangement appears to satisfy the language and intent of the pay limitation and the detail provisions, GAO has no objection."

The USNRC version of the 3D neutron kinetics code, Purdue Advanced Reactor Core Simulator (PARCS), has been coupled to the USNRC thermal-hydraulic (T/H) codes RELAP5 and the consolidated TRAC (merger of TRAC-BF1 and TRAC-PF1). These coupled codes may be used to audit license safety analysis submittals where 3D spatial kinetics and thermal-hydraulic effects are important. The coupling scheme was designed and implemented with emphasis placed on maximizing flexibility while minimizing modifications to the respective codes. In this design, the T/H and neutronic codes function independently and utilize the Parallel Virtual Machine software to communicate with each other through code specific Data Mapping Routines, and a General Interface. RELAP5/PARCS validation results are presented for two NEACRP rod ejection benchmark problems. The validation of TRAC-M/PARCS has only recently been initiated, nonetheless, the capabilities of the coupled code are presented for a typical PWR system/core model.

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The Wigner-Seitz pin-cell approximation has long been applied as a modeling approximation in analysis of UO2 lattice fuel cells. In the past, this approximation has been appropriate for such fuel. However, with increasing attention drawn to mixed-oxide (MOX) fuels with significant plutonium content, it is important to understand the implications of the approximation in a uranium-plutonium matrix. The special geometric capabilities of the deterministic NEWT computer code have been used to assess the adequacy of the Wigner-Seitz cell in such an environment, as part of a larger study of computational aspects of MOX fuel modeling. Results of calculations using various approximations and boundary conditions are presented, and are validated by comparison to results obtained using KENO V.a and XSDRNPM.

A diffusion synthetic acceleration method is developed for the time dependent S{sub N} equations with linear discontinuous finite element time differencing and discontinuous finite element spatial differencing on unstructured grids. Both theoretical and computational results are given which demonstrate the effectiveness and efficiency of the method.

Discontinuous finite element methods for the S{sub N} equations on 3-D unstructured tetrahedral and hexahedral meshes are presented. Solution Techniques including Source Iteration and diffusion-synthetic acceleration are described. Numerical results are presented which demonstrate the accuracy and efficiency of these methods.

A spectral analysis is conducted for the Source Iteration (SI), and Diffusion Synthetic Acceleration (DSA) operators previously formulated for solving the Even-Parity Method (EPM) equations. In order to accommodate material heterogeneity, the analysis is performed for the Periodic Horizontal Interface (PHI) configuration. The dependence of the spectral radius on the optical thickness of the two PHI layers illustrates the deterioration in the rate of convergence with increasing material discontinuity, especially when one of the layers approaches a void. The rate at which this deterioration occurs is determined for a specific material discontinuity in order to demonstrate the conditional robustness of the EPM-DSA iterations. The results of the analysis are put in perspective via numerical tests with the DANTE code (MCGhee, et al., 1997) which exhibits a deterioration in the spectral radius consitent with the theory.

A spectral analysis is conducted for the Source Iteration (SI), and Diffusion Synthetic Acceleration (DSA) operators previously formulated for solving the Even-Parity Method (EPM) equations. In order to accommodate material heterogenity, the analysis is performed for the Periodic Horizontal Interface (PHI) configuration. The dependence of the spectral radius on the optical thickness of the two PHI layers illustrates the deterioration in the rate of convergence with increasing material discontinuity, especially when one of the layers approaches a void. The rate at which this deterioration occurs is determined for a specific material discontinuity in order to demonstrate the conditional robustness of the EPM-DSA iterations. The results of the analysis are put in perspective via numerical tests with the DANTE code (McGhee, et. al., 1997) which exhibits a deterioration in the spectral radius consistent with the theory.

The project was comprised of three main tasks: (1) develop, design, and fabricate 20 sensors; (2) develop, design, and fabricate 5 test instruments; (3) testing and data analysis.

The heat distributions within the components of the target station of the Spallation Neutron Source were calculated using the Monte Carlo codes HETC, LAHET and MCNP to track the cascade of events after the introduction of 1 GeV protons in the mercury target. The boundaries of the model are the proton window and the external reflectors and includes such components as the stainless steel container, the water coolant, the thermal and cold neutron sources and the beam tubes. The calculations show that detailed heat distributions are sensitive to the proton beam profile and the curvature of the surface penetrated by the proton beam.

The Department of Energy (DOE) has prepared an environmental assessment (EA) (DOE/EA-1285) for the proposed repair of the Pond B dam at the Savannah River Site (SRS), located near Aiken, South Carolina. Based on the analyses in the EA, DOE has determined that the proposed action is not a major Federal action significantly affecting the quality of the human environment within the meaning of the National Environmental Policy Act of 1969 (NEPA). Therefore, the preparation of an environmental impact statement (EIS) is not required, and DOE is issuing this Finding of No Significant Impact (FONSI) and Floodplain Statement of Findings.

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