In a small network, clients and servers may all be connected to a single Ethernet without significant performance concerns. As the number of clients on a network grows, the necessity of splitting the network into multiple sub-networks, each with a manageable number of clients, becomes clear. Less obvious is what to do with the servers. Group file servers on subnets and multihomed servers offer only partial solutions -- many other types of servers do not lend themselves to a decentralized model, and tend to collect on another, well-connected but overloaded Ethernet. The higher speed of FDDI seems to offer an easy solution, but in practice both expense and interoperability problems render FDDI a poor choice. Ethernet switches appear to permit cheaper and more reliable networking to the servers while providing an aggregate network bandwidth greater than a simple Ethernet. This paper studies the evolution of the server networks at SLAC. Difficulties encountered in the deployment of FDDI are described, as are the tools and techniques used to characterize the traffic patterns on the server network. Performance of Ethernet, FDDI, and switched Ethernet networks is analyzed, as are reliability and maintainability issues for these alternatives. The motivations for re-designing the SLAC …

The results of a research program conducted by Brookhaven National Laboratory (BNL) to evaluate and develop polymer concrete (PC) materials, which can be used as an alternative material of construction to conventional steel-reinforced portland cement concrete (PCC) within the steam distribution system of Consolidated Edison Company of New York (Con Ed), are presented. Three fiber-reinforced PC systems were identified and evaluated in a series of laboratory and in situ field tests. Based upon the results of these tests preliminary design studies were performed by BNL and the Con Ed Civil Design Division to determine the necessary floor slab, wall and roof thicknesses required to replace a typical steel reinforced PCC manhole with a fiber-reinforced PC manhole.

Enclosed are proceedings of the workshop on Internal Dosimetry held on Atlanta, Georgia in April 1992. The recommendations from the Workshop were considered by the CIRRPC Subpanel on Occupational Radiation Protection Research in identifying those areas to be undertaken by individual Federal Agencies or in cooperative efforts. This document presents summaries of the following sessions: A.1 Applications and limitations of ICRP and other metabolic models, A.2 Applications and implementation of proposed ICRP lung model, A.3 Estimates of intake from repetitive bioassay data, A.4 Chelation models for plutonium urinalysis data, B.1 Transuranium/uranium registry data, B.2 Autopsy tissue analysis, B.3 Bioassay / Whole body counting, B.4 Data base formatting and availability, C.1 An overview of calculational techniques in use today, C.2 The perfect code, C.3 Dose calculations based on individuals instead of averages, C.4 From macro dosimetry to micro dosimetry.

There has been debate over effectiveness of groundwater pump and treat remediation. The goal of the following discussion is to present evidence from a tracer test that illustrates the difficulty in removing contaminants from fractured shale that is typical of portions of the DOE-Oak Ridge Reservation (ORR). This report provides a brief prelude to more detailed analysis that is in progress. Attempts to remediate groundwater contamination with pump and treat technology have been hampered by difficulties in removing contaminants in slow flow zones. There is interest in using this remediation method on the ORR because it is an existing technology. However, this setting provides a rather extreme contrast between fast flow zones (fractures) and slow flow zones (the matrix surrounding the fractures). Over the past few years, the authors have begun to develop an understanding of how contaminants move in fractures and how contaminant exchange between the fracture and matrix occurs. In particular, they have evidence from a long term tritium tracer test that has direct bearing on potential success or failure of pump and treat remediation in fractured rocks.

It is shown that, for an idealized rotor with identical magnetic bearings of negligible mass, precession and rotation are decoupled from the center-of-mass motion so that stabilization of whirl instabilities can be designed independent of tilt. The bearing torques that cause whirl also apply torques on the free-body- rotational motion in a tilted state. The rotational equations of motion including these torques are given in the paper. An approximate solution for a special case suggests the possibility of tilt instability above a critical frequency.

Powder compositions in the series La{sub 1-x}A{sub x}Co{sub 1-y}Fe{sub y}O{sub 3-{delta}} (A = Sr, Ca) have been prepared by a combustion synthesis method. Sintering of pressed powders produced high-density test specimens with the perovskite structure. The specimens exhibited high electrical conductivities with appreciable oxygen-ion conductivity that increased with Co content for the compositions studied. Oxygen permeation studies showed a significant flux of oxygen that increased with temperature for specimens in a P(O{sub 2}) gradient with no applied field. Thermogravimetric studies of the La{sub 1-x}Sr{sub x}Co{sub 0.2}Fe{sub 0.8}O{sub 3-{delta}} system indicated a reversible mass loss with increasing temperature that increased with Sr content.

A tutorial presentation is made on topics related to the measurement of charged particle beam currents. The fundamental physics of electricity and magnetism pertinent to the problem is reviewed. The physics is presented with a stress on its interpretation from an electrical circuit theory point of view. The operation of devices including video pulse current transformers, direct current transformers, and gigahertz bandwidth wall current style transformers is described. Design examples are given for each of these types of devices. Sensitivity, frequency response, and physical environment are typical parameters which influence the design of these instruments in any particular application. Practical engineering considerations, potential pitfalls, and performance limitations are discussed.

Mechanical design features of the reactor chamber for the HYLIFE-II inertial confinement fusion power plant are presented. A combination of oscillating and steady, molten salt streams (Li{sub 2}BeF{sub 4}) are used for shielding and blast protection of the chamber walls. The system is designed for a 6 Hz repetition rate. Beam path clearing, between shots, is accomplished with the oscillating flow. The mechanism for generating the oscillating streams is described. A design configuration of the vessel wall allows adequate cooling and provides extra shielding to reduce thermal stresses to tolerable levels. The bottom portion of the reactor chamber is designed to minimize splash back of the high velocity (>12 m/s) salt streams and also recover up to half of the dynamic head. Cost estimates for a 1 GWe and 2 GWe reactor chamber are presented.

The authors propose a concept of thermonuclear fusion reactor in which the plasma pressure is balanced by direct gas-wall interaction in a high-pressure vessel. The energy confinement is achieved by means of the self-contained toroidal magnetic configuration sustained by an external current drive or charged fusion products. This field structure causes the plasma pressure to decrease toward the inside of the discharge and thus it should be magnetohydrodynamically stable. The maximum size, temperature and density profiles of the reactor are estimated. An important feature of confinement physics is the thin layer of cold gas at the wall and the adjacent transitional region of dense arc-like plasma. The burning condition is determined by the balance between these nonmagnetized layers and the current-carrying plasma. They suggest several questions for future investigation, such as the thermal stability of the transition layer and the possibility of an effective heating and current drive behind the dense edge plasma. The main advantage of this scheme is the absence of strong external magnets and, consequently, potentially cheaper design and lower energy consumption.

This report is the second in a series examining the risks for the high level waste (HLW) storage facilities at the Hanford Site. The first phase of the HTF PSA effort addressed risks from Tank 101-SY, only. Tank 101-SY was selected as the initial focus of the PSA because of its propensity to periodically release (burp) a mixture of flammable and toxic gases. This report expands the evaluation of Tank 101-SY to all 177 storage tanks. The 177 tanks are arranged into 18 farms and contain the HLW accumulated over 50 years of weapons material production work. A centerpiece of the remediation activity is the effort toward developing a permanent method for disposing of the HLW tank`s highly radioactive contents. One approach to risk based prioritization is to perform a PSA for the whole HLW tank farm complex to identify the highest risk tanks so that remediation planners and managers will have a more rational basis for allocating limited funds to the more critical areas. Section 3 presents the qualitative identification of generic initiators that could threaten to produce releases from one or more tanks. In section 4 a detailed accident sequence model is developed for each initiating event group. …

Photon production data have been acquired in the incident neutron energy range, 1 < E{sub n} < 400 MeV, for a number of target nuclei, gamma-ray energy ranges, and reactions, using the continuous-energy neutron beam of the WNR facility at Los Alamos. Gamma-ray production measurements using high resolution Ge detectors have been employed for gamma-rays in the energy range, 0.1 < E{sub {gamma}} < 10 MeV. These measurements allow identification of reactions from the known energies of the gamma-ray transitions between low-lying states in the final nucleus. Some of the targets studied include: N, O, Al, Na, {sup 56}Fe, and {sup 207,208}Pb. These data are useful both for testing nuclear reaction models at intermediate energies and for numerous applied purposes. BGO detectors do not have the good energy resolution of Ge detectors, but have much greater detection efficiency for gamma rays with energies greater than a few MeV. We have used an array of 5 BGO detectors to measure cross sections and angular distributions for photon production from C and N. A large, well-shielded BGO detector has been used to measure fast neutron capture in the giant resonance region with a maximum gamma-ray energy of 52 MeV. We present results …

This report presents guidelines for estimating operating costs for use in benchmarking US Department of Energy (DOE) low-level mixed waste thermal treatment systems. The guidelines are based on operating cost experience at the DOE Toxic Substances Control Act (TSCA) mixed waste incinerator at the K-25 Site at Oak Ridge. In presenting these guidelines, it should be made clear at the outset that it is not the intention of this report to present operating cost estimates for new technologies, but only guidelines for estimating such costs.

Scenarios and computer codes used to evaluate intrusion scenarios at different DOE sites are compared and discussed. The purpose of the comparison is to identify differences in the approaches and areas where approaches could be made more consistent without ignoring the need to consider legimate site-specific differences, The comparison is comprised of two steps: (1) benchmarking of CENII and PATHRAE (the two most commonly used codes at DOE sites), and (2) comparison of assumed values for selected input parameters from:scenarios used at the different sites. The results of the benchmarking and parameter comparisons identify fundamental differences in the default assumptions used in the computer codes, as well as differences in the approaches used at the different sites. GENII and PATHRAE are applied to a variety of sites within DOE and other regulatory environments, differences in default assumptions identified in these comparisons are discussed for users to consider when they apply the codes. Furthermore, differences in assumptions made at the different sites disposing of low-level radioactive wastes within Department of Energy are identified to provide an example of how the Performance Assessment Task Team is working to ensure consistent interpretation of performance assessment results.

This report discusses the following topics on future hadron facilities: Workshop on future hadron facilities in the US; 30 {times} 30 TeV-summary report; A high luminosity, 2 {times} 2 TeV collider in the tevatron tunnel; magnets working group; cryogenics discussion; vacuum report; antiproton source production; injector working group; interaction region working group; lattice/beam dynamics working group; LEBT for high-luminosity colliders; some notes on long-range beam-beam effects for the 2TeV collider; synchrotron radiation masks for high energy proton accelerators. Emittance preservation in a proton synchrotron; beam-beam interaction effects on betatron tunes; analytic solutions for phase trombone modules; and chromatic corrections of RHIC when one or two insertions is at {Beta}* = 0.5m.

This document presents the Preliminary Safety Evaluation for Project W-320, Tank 241-C-106 Waste Retrieval Sluicing System (WRSS). The US DOE has been mandated to develop plans for response to safety issues associated with the waste storage tanks at the Hanford Site, and to report the progress of implementing those plans to Congress. The objectives of Project W-230 are to design, fabricate, develop, test, and operate a new retrieval system capable of removing a minimum of about 75% of the high-heat waste contained in C-106. It is anticipated that sluicing operations can remove enough waste to reduce the remaining radiogenic heat load to levels low enough to resolve the high-heat safety issue as well as allow closure of the tank safety issue.

Studies of Rocky Mountain area petroleum product availability with reduced refining capacity in Petroleum Administration for Defense IV (PADD IV, part of the Rocky Mountain area) have been performed with the Oak Ridge National Laboratory Refinery Yield Model, a linear program which has been updated to blend gasolines to satisfy constraints on emissions of nitrogen oxides and winter toxic air pollutants. The studies do not predict refinery closures in PADD IV. Rather, the reduced refining capacities provide an analytical framework for probing the flexibility of petroleum refining and distribution for winter demand conditions in the year 2000. Industry analysts have estimated that, for worst case scenarios, 20 to 35 percent of PADD IV refining capacity could be shut-down as a result of clean air and energy tax legislation. Given these industry projections, the study scenarios provide the following conclusions: The Rocky Mountain area petroleum system would have the capability to satisfy winter product demand with PADD IV refinery capacity shut-downs in the middle of the range of industry projections, but not in the high end of the range of projections. PADD IV crude oil production can be maintained by re-routing crude released from PADD IV refinery demands to satisfy increased …

Optical prossesses in nanostructured fractal composites are shown to be strongly enhanced. The enhancement occurs because of a localization of dipolar eigenmodes in subwavelength areas.

To obtain in situ measurements of the rheological properties within tank 241-SY-101, this document will implement the test strategy defined in PNLMIT-041994, acquisition and Reduction of Data Obtained in Tank SY-101 with the Ball Rheometer. Instructions for all sequences are defined within the procedure. All safety requirements as defined in LA-UR-92-3196, A Safety Assessment for Proposed Mixing Operations to Mitigate Episodic Gas Releases in Tank 241-101-SY have been implemented into this procedure.

An important variable controlling the critical current density (J{sub c}) of Ag-sheathed BSCCO-2223 tapes is the degree of phase purity of the reacted tapes. Most correlations between J{sub c} and microstructure show that it is highly desirable to reduce the amount of non-superconducting second phases to as low a level as practical. In recent studies of the influence of cooling rate after the final reaction, we find contradictions to this general rule. The J{sub c} (77 K, 0 T) of so-called {open_quotes}one-powder{close_quotes} tapes can be raised by as much as 50% (from -8,000 A/cm{sup 2} to 12,000 A/cm{sup 2}) by slow cooling in 7.5%O{sub 2} at 0.05{degrees}C/min, even though large 2212 grains are usually seen in the slowly cooled microstructure. However, the higher J{sub c} of the slow-cooled state does correlate with a sharper T{sub c} transition. Experiments with {open_quotes}two-powder{close_quotes} tapes have produced similar results. These apparently anomalous results emphasize the important role played by the connectivity of the polycrystalline core in determining J{sub c}.

This document is the first part of a three-part report describing the analysis and characterization of double shell tank 241-AP-108 which is located at the Hanford Reservation.This document is the analytical laboratory data package entitled `Analysis and Characterization of Double Shell Tank 241-AP-108` which contains a case sampling history, the sampling protocols, the analytical procedures, sampling and analysis quality assurance and quality control measures, and chemical analysis results for samples obtained from the tank.

We demonstrate epitaxial growth of the bcc transition metals Nb, Mo, Fe, and Cr via sputtering onto single crystal MgO substrates. The epitaxial growth orientations are (011), (112) and (001) when grown onto MgO (111), (011) and (001), respectively. Further we demonstrate that under appropriate growth conditions, superlattices of these materials (e.g., Fe/Cr, Fe/V and Mo/V) can be grown with the same epitaxial order as the films.

This report describes a new flexible technology which is now available to design sensor and control networks based on a protocol embedded in an intelligent communications processor. The flexibility allows a system designer and/or a technical installer to make appropriate tradeoffs among simplicity, functionality, and cost in the design of network nodes and their installation. This is especially important in designing an installation scenario for the safeguards network. The network technology permits several choices of installations with the same basic node hardware. A pre-installed network offers maximum simplicity and no flexibility since it will operate as programmed during manufacture or the pre-installation setup and checkout. At the other end of the spectrum, a network can be installed using network management software and a computer. The combination of the network management software and computer hardware is generally referred to as a Network Management Tool (NMT). The NMT option offers full flexibility to change the network during or after installation. Different NMT can provide different degrees of complexity depending upon the applications and the amount of changes that need to be made during installation.

This report describes a project to develop tools for evaluating solar heating and cooling systems. Current work on this project has been to validate the Florida Solar Energy Center`s (FSEC) models of the Solahart 302K and 302K-AS systems to prepare a rating for the Sacramento Municipal Utility District`s rebate program for solar domestic hot water heaters. A preliminary rating has been issued by FSEC and updated ratings will be released as necessary. Two of the problems that were mentioned in the August/September report are addressed and a tank heat loss test is discussed. Work continues on improving and validating the models.

Many computer programs and a variety of models exist for the design of accelerator lattices and the correction of errors. Many physicists contributed to this work by developing codes to suit a variety of machines. At present, we are integrating some of these codes into a unified framework to design and control any type of machine. We will refer to this system of interactive accelerator design, control, and analysis codes as the All-In-One Modeling system (AIM). This paper will explore the utilities of AIM for future accelerator modeling and control. As an example, we will describe a procedure to produce both a linear and a nonlinear model for SPEAR.