Confirmatory analyses were performed to examine the adequacy of the 105-K Reactor Tank Bottom Supports. The supports were reviewed for updated loads from a separate confirmatory calculation for the reactor tank and bottom tubesheet. The lower supports were found to be adequate for the current loading even with conservatisms applied to allow for analysis of the nonlinear friction/gapped support design.

Digital mammography offers the promise of significant advances in early detection of breast cancer. Our overall goal is to design a digital system which improves upon every aspect of current mammography technology: the x-ray source, detector, visual presentation of the mammogram and computer-aided diagnosis capabilities. This paper will discuss one part of our whole-system approach -- the development of a computer algorithm using gray-scale morphology to automatically analyze and flag microcalcifications in digital mammograms in hopes of reducing the current percentage of false-negative diagnoses, which is estimated at 20%. The mammograms used for developing this ``mammographers assistant`` are film mammograms which we have digitized at either 70 {mu}m or 35 {mu}m per pixel resolution with 4096 (12 bits) of gray level per pixel. For each potential microcalcification detected in these images, we compute a number of features in order to distinguish between the different kinds of objects detected.

The Automated Fuel Element Closure Welding System is a robotic device that will load and weld top end plugs onto nuclear fuel elements in a highly radioactive and inert gas environment. The system was developed at Argonne National Laboratory-West as part of the Fuel Cycle Demonstration. The welding system performs four main functions, it (1) injects a small amount of a xenon/krypton gas mixture into specific fuel elements, and (2) loads tiny end plugs into the tops of fuel element jackets, and (3) welds the end plugs to the element jackets, and (4) performs a dimensional inspection of the pre- and post-welded fuel elements. The system components are modular to facilitate remote replacement of failed parts. The entire system can be operated remotely in manual, semi-automatic, or fully automatic modes using a computer control system. The welding system is currently undergoing software testing and functional checkout.

This paper presents a Dynamic Node Architecture (DNA) scheme to optimize the architecture of backpropagation Artificial Neural Networks (ANNs). This network scheme is used to develop an ANN based diagnostic adviser capable of identifying the operating status of a nuclear power plant. Specifically, a root'' network is trained to diagnose if the plant is in a normal operating condition or not. In the event of an abnormal condition, and other classifier'' network is trained to recognize the particular transient taking place. these networks are trained using plant instrumentation data gathered during simulations of the various transients and normal operating conditions at the Iowa Electric Light and Power Company's Duane Arnold Energy Center (DAEC) operator training simulator.

We investigated the electronic and structural properties of low-dimensional materials and explored the structure-property correlations governing their physical properties. Progress was made on how to interpret the scanning tunneling microscopy and atomic force microscopy images of layered materials and on how to account for charge density wave instabilities in 2-D metals. Materials studied included transition metal chalcogenides, transition metal halides, organic conducting salts, Mo bronzes, A[sub 2]PdH[sub 2], fullerenes, squarate tetrahydrate polymers Fe, Cu(C[sub 4]O[sub 4])4[center dot]H[sub 2]O, BEDT salts, etc.

Data on rapidity distributions of protons from the three AGS experiments E-814, E-810 and E-802 are compared on a common base to enlarge the rapidity coverage. Together they provide a unique opportunity to study the proton distributions in relativistic heavy ion reactions over the full rapidity range. Systematics of the rapidity density distributions are presented as function of centrality and mass of colliding system. Considerable stopping is achieved for the heaviest system studied, Au+Au, thus giving the means to study high-density effects in nuclear matter.

This project's objective is to improve our understanding of the generation, recombination, and transport of carriers within III-V homo- and heterostructures. The research itself consists of fabricating and characterizing solar cell building blocks'' such as junctions and heterojunctions as well as basic measurements of material parameters. A significant effort is also being directed at characterizing loss mechanisms in high-quality, III-V solar cells fabricated in industrial research laboratories throughout the United States. The project's goal is to use our understanding of the device physics of high-efficiency cell components to maximize cell efficiency. A related goal is the demonstration of new cell structures fabricated by molecular beam epitaxy (MBE). The development of measurement techniques and characterization methodologies is also a project objective. This report describes our progress during the fifth and final year of the project. During the past five years, we've teamed a great deal about heavy doping effects in p[sup +] and n[sup +] GaAs and have explored their implications for solar cells. We have developed an understanding of the dominant recombination losses in present-day, high-efficiency cells. We've learned to appreciated the importance of recombination at the perimeter of the cell and have developed techniques for chemically passivating such edges. …

This project`s objective is to improve our understanding of the generation, recombination, and transport of carriers within III-V homo- and heterostructures. The research itself consists of fabricating and characterizing solar cell ``building blocks`` such as junctions and heterojunctions as well as basic measurements of material parameters. A significant effort is also being directed at characterizing loss mechanisms in high-quality, III-V solar cells fabricated in industrial research laboratories throughout the United States. The project`s goal is to use our understanding of the device physics of high-efficiency cell components to maximize cell efficiency. A related goal is the demonstration of new cell structures fabricated by molecular beam epitaxy (MBE). The development of measurement techniques and characterization methodologies is also a project objective. This report describes our progress during the fifth and final year of the project. During the past five years, we`ve teamed a great deal about heavy doping effects in p{sup +} and n{sup +} GaAs and have explored their implications for solar cells. We have developed an understanding of the dominant recombination losses in present-day, high-efficiency cells. We`ve learned to appreciated the importance of recombination at the perimeter of the cell and have developed techniques for chemically passivating such edges. …

In space-charge dominated beams the nonlinear space-charge forces produce a filamentation pattern, which results in a 2-component beam consisting of an inner core and an outer halo. The halo is very prominent in mismatched beams, and the potential for accelerator activation is of concern for a next generation of cw, high-power proton linacs that could be applied for intense neutron generators to process nuclear materials. We present new results about beam halo and the evolution of space-charge dominated beams from multiparticle simulation of initial laminar beams in a uniform linear focusing channel, and from a model consisting of single particle interactions with a uniform-density beam core. We study the energy gain from particle interactions with the space-charge field of the core, and we identify the resonant characteristic of this interaction as the basic cause of the separation of the beam into the two components. We identify three different particle-trajectory types, and we suggest that one of these types may lead to continuous halo growth, even after the halo is removed by collimators.

In space-charge dominated beams the nonlinear space-charge forces produce a filamentation pattern, which in projection to the 2-D phase spaces results in a 2-component beam consisting of an inner core and a diffuse outer halo. The beam-halo is of concern for a next generation of cw, high-power proton linacs that could be applied to intense neutron generators for nuclear materials processing. The author describes what has been learned about beam halo and the evolution of space-charge dominated beams using numerical simulations of initial laminar beams in uniform linear focusing channels. Initial results are presented from a study of beam entropy for an intense space-charge dominated beam.

We have built, installed and tested a pinger for use as a general diagnostic at the Los Alamos Proton Storage Ring (PSR). Two 4-m-long parallel-plate electrodes with a plate spacing of 10.2 cm provide kicks of up to 1.1 mrad. A pair of solid-state pulsers may be operated in a single-pulse mode for beam pinging (tune measurements) or in a burst mode at up to 700 kHz pulse rates for beam sweeping. During our 1992 operating period we used the pinger for beam sweeping, for beam shaking, for measuring the tune shift, and we have used it as an ion chamber. Using the pinger as an ion chamber during production conditions has yielded some surprising results.

This paper describes the Beam Position Monitor (BPM) data acquisition scheme for the Advanced Photon Source (APS) storage ring. The storage ring contains 360 beam position monitors distributed around its 1104-meter circumference. The beam position monitor data acquisition system is capable of making turn-by-turn measurements of all BPMs simultaneously. It is VXI-based with each VXI crate containing the electronics for 9 BPMS. The VXI Local Bus is used to provide sustained data transfer rates of up to 13 mega-transfers per second to a scanner module. The system provides single-bunch tracking, bunch-to-bunch measurements, fast digital-averaged positions, beam position history buffering, and synchronized multi-turn measurements. Data is accessible to the control system VME crates via an MXI bus. Dedicated high-speed ports are provided to supply position data to beam orbit feedback systems.

A logarithmic-ratio beam position monitor (BPM) circuit has been designed that operates directly from radio frequency- signals in the 100-MHz to 500-MHz frequency range. The circuit uses four logarithmic amplifiers, a pair for each channel. One amplifier per channel receives its signal input directly from a BPM electrode while the second amplifier receives the same signal attenuated by 7-dB. The two outputs of each channel are summed together and the composite video outputs are applied to a differencing amplifier. The net result is the logarithmic-ratio position measurement derived from the two input rf signals. Paralleling the pairs of outputs from the amplifiers provides measurement accuracy that is comparable to other circuit techniques used for position measurement.

A beamline has been designed and assembled to use the ANL Chemistry Division 20-MeV electron linac for the testing of higher-order mode excitation and damping in rf cavities. The beamline consists of two sections (a beam collimating section with a 1.5 inches-OD vacuum line, and a cavity test section with a 3 inches-OD vacuum line), separated by two double aluminum foil windows. The beam diagnostics consist of a stripline beam position monitor, integrating current transformers, fluorescent screens, and a Faraday cup. EPICS (Experimental Physics and Industrial Control System) is used for beamline control, monitoring, and data acquisition. Also described is the diagnostic system used for beam image capture and analysis using EPICS-controlled hardware and PV-WAVE software. The rf cavity measurement will be described in a separate paper.

Waste matrices containing organics, radionuclides, and metals pose difficult problems in waste treatment and disposal when the organic compounds and/or metals are considered to be hazardous. A means of destroying hazardous organic components while safely containing and concentrating metals would be extremely useful in mixed waste volume reduction or conversion to a radioactive-only form. Previous studies have found the DETOX, a patented process utilizing a novel catalytic wet oxidation by iron(III) oxidant, cold have successful application to mixed wastes, and to many other waste types. This paper describes the results of bench scale studies of DETOX applied to the components of liquid mixed wastes, with the goal of establishing parameters for the design of a prototype waste treatment unit. Apparent organic reaction rate orders, and the dependence of apparent reaction rate on the contact area, were measured for vacuum pump oil, scintillation fluids, and trichloroethylene. It was found that reaction rate was proportional to contact area above about 2.% w/w loading of organic. Oxidations in a 4 liter. volume, mixed bench top reactor have given destruction efficiencies of 99.9999+% for common organics. Reaction rates achieved in the mixedbench top reactor were one to two orders of magnitude greater than had …

To satisfy the need for the verification of the computer programs and modeling techniques that will be used to perform the final piping analyses for an advanced boding water reactor standard design, three piping benchmark problems were developed. The problems are representative piping systems subjected to representative dynamic loads with solutions developed using the methods being proposed for analysis for the advanced reactor standard design. It will be required that the combined license holders demonstrate that their solutions to these problems are in agreement with the benchmark problem set. A summary description of each problem and some sample results are included.

Complete eigenvalue spectrum calculations are usually performed for benchmark analysis to compare the accuracy of various approximate methods. In one-speed criticality studies the most accurate methods either rely on analytical techniques (singular eigenfunction) or high order spatial expansion (Carlvik's method). The extension of these techniques to calculate higher order anisotropy is somewhat cumbersome and rarely done in practice. In this paper, a low spatial order technique is examined for its capability to produce accurate benchmark results with higher order of anisotropy. In the past, the use of low order methods were generally discarded for this type of calculation due to the large computer memory and time requirements. With the recent development and availability of greatly improved computing power, these limitations are largely removed and low order spatial approximations may also produce accurate solutions.

Complete eigenvalue spectrum calculations are usually performed for benchmark analysis to compare the accuracy of various approximate methods. In one-speed criticality studies the most accurate methods either rely on analytical techniques (singular eigenfunction) or high order spatial expansion (Carlvik`s method). The extension of these techniques to calculate higher order anisotropy is somewhat cumbersome and rarely done in practice. In this paper, a low spatial order technique is examined for its capability to produce accurate benchmark results with higher order of anisotropy. In the past, the use of low order methods were generally discarded for this type of calculation due to the large computer memory and time requirements. With the recent development and availability of greatly improved computing power, these limitations are largely removed and low order spatial approximations may also produce accurate solutions.

The purpose of this paper is to summarize some initial experiences related to measuring the performance of massively parallel processors (MPPs) at Los Alamos National Laboratory (LANL). Actually, the range of MPP architectures the authors have used is rather limited, being confined mostly to the Thinking Machines Corporation (TMC) Connection Machine CM-2 and CM-5. Some very preliminary work has been carried out on the Kendall Square KSR-1, and efforts related to other machines, such as the Intel Paragon and the soon-to-be-released CRAY T3D are planned. This paper will concentrate more on methodology rather than discuss specific architectural strengths and weaknesses; the latter is expected to be the subject of future reports. MPP benchmarking is a field in critical need of structure and definition. As the authors have stated previously, such machines have enormous potential, and there is certainly a dire need for orders of magnitude computational power over current supercomputers. However, performance reports for MPPs must emphasize actual sustainable performance from real applications in a careful, responsible manner. Such has not always been the case. A recent paper has described in some detail, the problem of potentially misleading performance reporting in the parallel scientific computing field. Thus, in this paper, …

The Hanford Envirorunental Dose Reconstruction (HEDR) project is developing several computer codes to model the airborne release, transport, and envirormental accumulation of radionuclides resulting from Hanford operations from 1944 through 1972. In order to calculate the dose of radiation a person may have received in any given location, the geographic area addressed by the HEDR Project will be divided into a grid. The grid size suggested by the draft requirements contains 2091 units called nodes. Two of the codes being developed are DESCARTES and CIDER. The DESCARTES code will be used to estimate the concentration of radionuclides in environmental pathways from the output of the air transport code RATCHET. The CIDER code will use information provided by DESCARTES to estimate the dose received by an individual. The requirements that Battelle (BNW) set for these two codes were released to the HEDR Technical Steering Panel (TSP) in a draft document on November 10, 1992. This document reports on the preliminary work performed by the code development team to determine if the requirements could be met.

The Hanford Envirorunental Dose Reconstruction (HEDR) project is developing several computer codes to model the airborne release, transport, and envirormental accumulation of radionuclides resulting from Hanford operations from 1944 through 1972. In order to calculate the dose of radiation a person may have received in any given location, the geographic area addressed by the HEDR Project will be divided into a grid. The grid size suggested by the draft requirements contains 2091 units called nodes. Two of the codes being developed are DESCARTES and CIDER. The DESCARTES code will be used to estimate the concentration of radionuclides in environmental pathways from the output of the air transport code RATCHET. The CIDER code will use information provided by DESCARTES to estimate the dose received by an individual. The requirements that Battelle (BNW) set for these two codes were released to the HEDR Technical Steering Panel (TSP) in a draft document on November 10, 1992. This document reports on the preliminary work performed by the code development team to determine if the requirements could be met.

The US Department of Energy (DOE), in DOE Order 5400.5 (1990), directs operators of DOE facilities to apply the Best Available Technology (BAT) to control radiological liquid effluents from these facilities when specific conditions are present. DOE has published interim guidance to assist facility operators in knowing when a BAT analysis is needed and how such an analysis should be performed and documented. The purpose of the guidance is to provide a uniform basis in determining BAT throughout DOE and to assist in evaluating BAT determinations during programmatic audits. The BAT analysis process involves characterizing the effluent source; identifying and selecting candidate control technologies; evaluating the potential environmental, operational, resource, and economic impacts of the control technologies; developing an evaluation matrix for comparing the technologies; selecting the BAT; and documenting the evaluation process. The BAT analysis process provides a basis for consistent evaluation of liquid effluent releases, yet allows an individual site or facility the flexibility to address site-specific issues or concerns in the most appropriate manner.

The US Department of Energy (DOE), in DOE Order 5400.5 (1990), directs operators of DOE facilities to apply the Best Available Technology (BAT) to control radiological liquid effluents from these facilities when specific conditions are present. DOE has published interim guidance to assist facility operators in knowing when a BAT analysis is needed and how such an analysis should be performed and documented. The purpose of the guidance is to provide a uniform basis in determining BAT throughout DOE and to assist in evaluating BAT determinations during programmatic audits. The BAT analysis process involves characterizing the effluent source; identifying and selecting candidate control technologies; evaluating the potential environmental, operational, resource, and economic impacts of the control technologies; developing an evaluation matrix for comparing the technologies; selecting the BAT; and documenting the evaluation process. The BAT analysis process provides a basis for consistent evaluation of liquid effluent releases, yet allows an individual site or facility the flexibility to address site-specific issues or concerns in the most appropriate manner.

A helium-jet/tape-transport system is employed in the study of beta-particle and gamma-ray energy spectra of aggregate fission products as a function of time after fission. During the initial nine months of this project we have investigated the following areas: Design, assembly and characterization of a beta-particle spectrometer; Measurement of [sup 235]U(n[sub th]ff) beta spectra for delay times 0.2 s to 12,000 s; Assembly and characterization of a 5 [times] 5 Nal(Tl) gamma-ray spectrometer; Measurement of [sup 235]U(n[sub th]ff) gamma-ray spectra for delay times 0.2s to 1 5,500s; Assembly and characterization of HPGe gamma-ray spectrometer with a Nal(Tl) Compton-and-background-suppression annulus; Measurement of [sup 235]U(n [sub th],ff) high-resolution gamma-ray spectra for delay times 0.6 s to over 100,000 s; Comparison of individual gamma-line intensities with ENDF/B-VI; Adaptation to our computer of unfolding program FERDO for beta and gamma aggregate fission-product energy spectra and development of a spectrum-stripping program for analysis of HPGe gamma-ray spectra; Study of the helium-jet fission-fragment elemental transfer efficiency. This work has resulted in the publication of twelve BAPS abstracts of presentations at scientific meetings. There are currently four Ph.D. and two M.S. candidates working on dissertations associated with the project.