Four fault tolerant architectures were evaluated for their potential reliability in service as control systems of nuclear power plants. The reliability analyses showed that human- and software-related common cause failures and single points of failure in the output modules are dominant contributors to system unreliability. The four architectures are triple-modular-redundant (TMR), both synchronous and asynchronous, and also dual synchronous and asynchronous. The evaluation includes a review of design features, an analysis of the importance of coverage, and reliability analyses of fault tolerant systems. An advantage of fault-tolerant controllers over those not fault tolerant, is that fault-tolerant controllers continue to function after the occurrence of most single hardware faults. However, most fault-tolerant controllers have single hardware components that will cause system failure, almost all controllers have single points of failure in software, and all are subject to common cause failures. Reliability analyses based on data from several industries that have fault-tolerant controllers were used to estimate the mean-time-between-failures of fault-tolerant controllers and to predict those failures modes that may be important in nuclear power plants. 7 refs., 4 tabs.

This report discusses: Cryogenic technology; polymer shell fabrication; glass shell fabrication and characterization; coating technology; development of characterization techniques; laser technology; and plasma research and instrumentation.

The objective of this training is to: describe the responsibilities, resources, and goals of the Emergency Operations Center and be able to evaluate and interpret this information to best direct and allocate emergency, plant, and other resources to protect life and the Paducah Gaseous Diffusion Plant.

Purpose of the Phase I effort was to demonstrate feasibility of the fuel cell/battery system for powering a small bus (under 30 ft or 9 m) on an urban bus route. A brassboard powerplant was specified, designed, fabricated, and tested to demonstrate feasibility in the laboratory. The proof-of-concept bus, with a powerplant scaled up from the brassboard, will be demonstrated under Phase II.

Annual report providing tabular statistical information about motor vehicle accidents in rural areas of Texas during calendar year 1989, with data broken out by various criteria including number of persons, locations, types of accidents, time of day, and other factors.

Annual report providing tabular statistical information about motor vehicle accidents in Texas during calendar year 1989, with data broken out by various criteria including number of persons, locations, types of accidents, time of day, and other factors.

Annual report providing tabular statistical information about motor vehicle accidents that involved motorcycles in Texas during calendar year 1989, with data broken out by various criteria including number of persons, locations, types of accidents, time of day, and other factors.

Annual report providing tabular statistical information about motor vehicle accidents that directly or indirectly involved school buses in Texas during calendar year 1989, with data broken out by various criteria including number of persons, locations, types of accidents, time of day, and other factors.

The objectives of this study are to determine the intrinsic kinetics and the product layer diffusion rate by minimizing the resistances to gas-phase pore diffusion, and eliminating complications due to pore filling. In the report, a grain model was used to introduce the various potentially rate-limiting processes. It was compared with results obtained with a distributed pore model by Bhatia Perlmutter (1981). Comparing the predicted behavior of the surface areas with conversion, it was even possible to compare experimental results with other models. The conclusion of this study was that, even thought the kinetic parameters obtained with different samples differed much more if product layer diffusion assumed rate-limiting rather than the surface reaction, the shape of the predicted curve approached the experimental findings so much better, that product layer diffusion is indeed most likely to be rate-limiting. (VC)

The objectives of this study are to determine the intrinsic kinetics and the product layer diffusion rate by minimizing the resistances to gas-phase pore diffusion, and eliminating complications due to pore filling. In the report, a grain model was used to introduce the various potentially rate-limiting processes. It was compared with results obtained with a distributed pore model by Bhatia & Perlmutter (1981). Comparing the predicted behavior of the surface areas with conversion, it was even possible to compare experimental results with other models. The conclusion of this study was that, even thought the kinetic parameters obtained with different samples differed much more if product layer diffusion assumed rate-limiting rather than the surface reaction, the shape of the predicted curve approached the experimental findings so much better, that product layer diffusion is indeed most likely to be rate-limiting. (VC)

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Jim Mattox, regarding a legal question submitted for clarification: Status of contract jailers for certain purposes (RQ-1871)

The objectives of this contract are to discover and evaluate the catalytic properties of novel homogeneous, heterogeneous, or combination catalytic systems for the production of alcohol fuel extenders from syngas, to evaluate analytically and on the bench scale novel reactor concepts for use in converting syngas to liquid fuel products, and to develop on the bench scale the best combination of chemistry, reactor, and total process configuration to achieve the minimum product cost for conversion of syngas to liquid fuel products. Methanol production and heterogeneous catalysis utilizing transition elements supported on metal oxides with spinel structure are discussed. 12 figs., 16 tabs.

It is worth considering an experiment on a sum resonance. I will give an analytic treatment of a third-order sum resonance. The treatment parallels that in LS-132 for the Walkinshaw difference resonance. Although the algebra is essentially the same as for the difference resonance, the sum resonance appears to have a richer structure.

Compilation of monthly reports from departments in the city of San Antonio, Texas providing statistics, project updates, and other information about services and activities. This is the report for the Historic Review Board for June 1990.

Newsletter of the Texas Bureau of Disease Control and Epidemiology discussing the news, activities, and events of the organization and other information related to health in Texas.

Three main issues giving purpose to our visit to CERN, ESRF and DESY were to: assess the current thinking at CERN on whether Eta, the gas desorption coefficient, would continue to decrease with continued with continued beam cleaning, determine if the time between NEG reconditioning could be expanded, and acquire a knowledge of the basic fabrication processes and techniques for producing beam vacuum chambers of copper.

The general objective of this project is the investigation of phase equilibria for complex fluids using a novel methodology, Monte Carlo simulation in the Gibbs ensemble. The methodology enables the direct determination of the properties of two coexisting fluid phases (e.g. a liquid at equilibrium with its vapor) from a single computer experiment, and is applicable to multicomponent systems with arbitrary equilibrium constraints imposed. The specific goals of this work are to adapt the Gibbs technique to (a) highly asymmetric mixtures with large differences in size and potential energies of interaction (b) chain molecules and (c) ionic systems. Significant progress has been made in all three areas. In this paper, we will briefly describe the progress made in each area, using the same numbering scheme for the tasks as in the original proposal.

Early in 1985, Sam Berk of the Office of Fusion Energy, US Department of Energy, suggested that the development and validation of 3-D eddy current codes would benefit from the compilation of benchmark problems that could be used to validate the codes and from a series of workshops for the comparison of solution methods and codes. (Two years later, at the first International Symposium on Fusion Nuclear Technology in Tokyo, Sam Berk proposed the acronym TEAM for the workshops.) At a three-day planning meeting at Argonne National Laboratory (ANL) in November 1985, eleven participants from five countries defined the goals, format, schedule and problems for the workshops. The ultimate goal is to show the effectiveness of numerical techniques and associated computer codes in solving electromagnetic field problems, and to gain confidence in their predictions. The workshops should also provide cooperation between workers, leading to an interchange of ideas. This note reviews the three cycles of workshops and the problems.

A weekly publication, the Texas Register serves as the journal of state agency rulemaking for Texas. Information published in the Texas Register includes proposed, adopted, withdrawn and emergency rule actions, notices of state agency review of agency rules, governor's appointments, attorney general opinions, and miscellaneous documents such as requests for proposals. After adoption, these rulemaking actions are codified into the Texas Administrative Code.

At our Nova laser facility, the temporal history of incident and reflected laser energy is recorded on LLNL optical streak cameras. Currently, six cameras are used to record the incident 1.06-{mu}m, incident 0.35{mu}m power of each of the ten Nova beams. Each camera records seven multiplexed signals: typically one signal from each of five beam lines, a fiducial pulse, and time mark generator signal. The optical signals are transported to the camera through optical fibers. The output end of each fiber is placed in the slit plane of the camera. The light exiting the fiber is focused to the streak camera photocathode by the streak camera relay lens. One camera can record a signal from each of the ten Nova beams plus a fiducial and time mark generator signal if the number of multiplexed channels can be increased from seven to twelve. This would allow one camera to record the same data that currently requires two cameras. At a savings of $150 per camera/CCD system, this represents a savings of $450K. Additionally, camera/CCD maintenance and operation complexity would be cut in half and three streak cameras would be freed for use in other experiments. Recent laboratory measurements suggest that the …

Based on results of testing eight solids removal technologies and one pretreatment option, it is recommended that a centrifugal ultrafilter and polymeric ultrafilter undergo further testing as possible alternatives to the Norton Ceramic filters. Deep bed filtration should be considered as a third alternative, if a backwashable cartridge filter is shown to be inefficient in separate testing.

Based on results of testing eight solids removal technologies and one pretreatment option, it is recommended that a centrifugal ultrafilter and polymeric ultrafilter undergo further testing as possible alternatives to the Norton Ceramic filters. Deep bed filtration should be considered as a third alternative, if a backwashable cartridge filter is shown to be inefficient in separate testing.

This document reports the progress made during the first six months of the current three-year DOE grant on Artificially Structured Magnetic Materials.'' However, because some of the results of our previous three-year DOE grant on Artificially Structured Superconductors'' continue to emerge, both topics are addressed in this Progress Report. This report describes progress with DOE funding during the current calendar year; description of the research to be conducted during the remaining six months of the current grant year; a description of the status of the graduate students working on this research; lists of the invited talks, seminars and colloquia, of other recognition of our research, and of the publications crediting DOE sponsorship; and a summary of current and pending federal support. Since the research proposed to be conducted during the next 2 1/2 years is described in detail in our DOE proposal, it is only briefly reviewed here.

The invention consists of an improved method for the preparation of single phase, fine grained ceramic materials from precursor powder mixtures where at least one of the components of the mixture is an alkali earth carbonate. The process consists of heating the precursor powders in a partial vacuum under flowing oxygen and under conditions where the partial pressure of CO{sub 2} evolved during the calcination is kept to a very low level relative to the oxygen. The process has been found particularly suitable for the preparation of high temperature copper oxide superconducting materials such as YBa{sub 2}Cu{sub 3}O{sub x} ``123`` and YBa{sub 2}Cu{sub 4}O{sub 8} ``124``.