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Thermionic system evaluation test (TSET) facility construction: A United States and Russian effort

Description: The Thermionic System Evaluation Test (TSET) is a ground test of an unfueled Russian TOPAZ-II in-core thermionic space reactor powered by electric heaters. The facility that will be used for testing of the TOPAZ-II systems is located at the New Mexico Engineering Research Institute (NMERI) complex in Albuquerque, NM. The reassembly of the Russian test equipment is the responsibility of International Scientific Products (ISP), a San Jose, CA, company and Inertek, a Russian corporation, with support provided by engineers and technicians from Phillips Laboratory (PL), Sandia National Laboratories (SNL), Los Alamos National Laboratory (LANL), and the University of New Mexico (UNM). This test is the first test to be performed under the New Mexico Strategic Alliance agreement. This alliance consist of the PL, SNL, LANL, and UNM. The testing is being funded by the Strategic Defense Initiative Organization (SDIO) with the PL responsible for project execution.
Date: January 1, 1992
Creator: Wold, S.K.
Partner: UNT Libraries Government Documents Department

An efficient parallel algorithm for matrix-vector multiplication

Description: The multiplication of a vector by a matrix is the kernel computation of many algorithms in scientific computation. A fast parallel algorithm for this calculation is therefore necessary if one is to make full use of the new generation of parallel supercomputers. This paper presents a high performance, parallel matrix-vector multiplication algorithm that is particularly well suited to hypercube multiprocessors. For an n x n matrix on p processors, the communication cost of this algorithm is O(n/[radical]p + log(p)), independent of the matrix sparsity pattern. The performance of the algorithm is demonstrated by employing it as the kernel in the well-known NAS conjugate gradient benchmark, where a run time of 6.09 seconds was observed. This is the best published performance on this benchmark achieved to date using a massively parallel supercomputer.
Date: March 1, 1993
Creator: Hendrickson, B.; Leland, R. & Plimpton, S.
Partner: UNT Libraries Government Documents Department

Elastic dynamics of a complete wind turbine structure: Theoretical development

Description: This paper develops a pseodo-linear formulation of the equations of motion for analyzing elastic bodies which undergo large rotations relative to one another with an emphasis on its application to HAWTs. This procedure greatly simplifies the computational aspects of the solution algorithm over the nonlinear alternatives and should yield a significant improvement in computer speed. Additional speed can be achieved by ordering the nodes such that a minimum bandwidth can be realized (leading to approximately 64 multiplications per degree of freedom per solution step). The formulation utilizes a set of nested moving coordinate systems, each of which is loosely tied to one of the elastic bodies such that the displacements in the body relative to its coordinate system remain small. The formulation also includes a scheme for handling the nonlinear geometric stiffness that occurs in the blades as a result of the centrifugal loads in a pseudo-linear fashion.
Date: January 1, 1992
Creator: Lobitz, D.W.; Arguello, J.G. & Veers, P.S.
Partner: UNT Libraries Government Documents Department

Downhole material injector for lost circulation control

Description: This invention is comprised of an apparatus and method for simultaneously and separately emplacing two streams of different materials through a drillstring in a borehole to a downhole location for lost circulation control. The two streams are mixed outside the drillstring at the desired downhole location and harden only after mixing for control of a lost circulation zone.
Date: January 1, 1991
Creator: Glowka, D.A.
Partner: UNT Libraries Government Documents Department

A methodology for estimating the residual contamination contribution to the source term in a spent-fuel transport cask

Description: This report describes the ranges of the residual contamination that may build up in spent-fuel transport casks. These contamination ranges are calculated based on data taken from published reports and from previously unpublished data supplied by cask transporters. The data involve dose rate measurements, interior smear surveys, and analyses of water flushed out of cask cavities during decontamination operations. A methodology has been developed to estimate the effect of residual contamination on spent-fuel cask containment requirements. Factors in estimating the maximum permissible leak rates include the form of the residual contamination; possible release modes; internal gas-borne depletion; and the temperature, pressure, and vibration characteristics of the cask during transport under normal and accident conditions. 12 refs., 9 figs., 4 tabs.
Date: September 1, 1991
Creator: Sanders, T.L. (Sandia National Labs., Albuquerque, NM (United States)); Jordan, H. (EG and G Rocky Flats, Inc., Golden, CO (United States). Rocky Flats Plant); Pasupathi, V. (Battelle, Columbus, OH (United States)); Mings, W.J. (USDOE Idaho Field Office, Idaho Falls, ID (United States)) & Reardon, P.C. (GRAM, Inc., Albuquerque, NM (United States))
Partner: UNT Libraries Government Documents Department

Multidimensional spectral load balancing

Description: We describe an algorithm for the static load balancing of scientific computations that generalizes and improves upon spectral bisection. Through a novel use of multiple eigenvectors, our new spectral algorithm can divide a computation into 4 or 8 pieces at once. These multidimensional spectral partitioning algorithms generate balanced partitions that have lower communication overhead and are less expensive to compute than those produced by spectral bisection. In addition, they automatically work to minimize message contention on a hypercube or mesh architecture. These spectral partitions are further improved by a multidimensional generalization of the Kernighan-Lin graph partitioning algorithm. Results on several computational grids are given and compared with other popular methods.
Date: January 1, 1993
Creator: Hendrickson, B. & Leland, R.
Partner: UNT Libraries Government Documents Department

An improved spectral graph partitioning algorithm for mapping parallel computations

Description: Efficient use of a distributed memory parallel computer requires that the computational load be balanced across processors in a way that minimizes interprocessor communication. We present a new domain mapping algorithm that extends recent work in which ideas from spectral graph theory have been applied to this problem. Our generalization of spectral graph bisection involves a novel use of multiple eigenvectors to allow for division of a computation into four or eight parts at each stage of a recursive decomposition. The resulting method is suitable for scientific computations like irregular finite elements or differences performed on hypercube or mesh architecture machines. Experimental results confirm that the new method provides better decompositions arrived at more economically and robustly than with previous spectral methods. We have also improved upon the known spectral lower bound for graph bisection.
Date: September 1, 1992
Creator: Hendrickson, B. & Leland, R.
Partner: UNT Libraries Government Documents Department

An estimate of the cost of electricity production from hot-dry rock

Description: This paper gives an estimate of the cost to produce electricity from hot-dry rock (HDR). Employment of the energy in HDR for the production of electricity requires drilling multiple wells from the surface to the hot rock, connecting the wells through hydraulic fracturing, and then circulating water through the fracture system to extract heat from the rock. The basic HDR system modeled in this paper consists of an injection well, two production wells, the fracture system (or HDR reservoir), and a binary power plant. Water is pumped into the reservoir through the injection well where it is heated and then recovered through the production wells. Upon recovery, the hot water is pumped through a heat exchanger transferring heat to the binary, or working, fluid in the power plant. The power plant is a net 5.1-MW[sub e] binary plant employing dry cooling. Make-up water is supplied by a local well. In this paper, the cost of producing electricity with the basic system is estimated as the sum of the costs of the individual parts. The effects on cost of variations to certain assumptions, as well as the sensitivity of costs to different aspects of the basic system, are also investigated.
Date: January 1, 1993
Creator: Pierce, K.G. (Sandia National Labs., Albuquerque, NM (United States)) & Livesay, B.J. (Livesay Consultants, Inc., Encinitas, CA (United States))
Partner: UNT Libraries Government Documents Department

Fiber-optic shock position sensor

Description: This report describes work performed for the development of a fiber-optic shock position sensor used to measure the location of a shock front in the neighborhood of a nuclear explosion. Such a measurement would provide a hydrodynamic determination of nuclear yield. The original proposal was prompted by the Defense Nuclear Agency's interest in replacing as many electrical sensors as possible with their optical counterparts for the verification of a treaty limiting the yield of a nuclear device used in underground testing. Immunity to electromagnetic pulse is the reason for the agency's interest; unlike electrical sensors and their associated cabling, fiber-optic systems do not transmit to the outside world noise pulses from the device containing secret information.
Date: March 1, 1993
Creator: Weiss, J.D.
Partner: UNT Libraries Government Documents Department

A source-term method for determining spent-fuel transport cask containment requirements: Executive summary

Description: This Executive Summary presents the methodology for determining containment requirements for spent-fuel transport casks under normal and hypothetical accident conditions. Three sources of radioactive material are considered: (1) the spent fuel itself, (2) radioactive material, referred to as CRUD, attached to the outside surfaces of fuel rod cladding, and (3) residual contamination adhering to interior surfaces of the cask cavity. The methodologies for determining the concentrations of freely suspended radioactive materials within a spent-fuel transport cask for these sources are discussed in much greater detail in three companion reports: A Method for Determining the Spent-Fuel Contribution to Transport Cask Containment Requirements,'' Estimate of CRUD Contribution to Shipping Cask Containment Requirements,'' and A Methodology for Estimating the Residual Contamination Contribution to the Source Term in a Spent-Fuel Transport Cask.'' Examples of cask containment requirements that combine the individually determined containment requirements for the three sources are provided, and conclusions from the three companion reports to this Executive Summary are presented.
Date: February 1, 1993
Creator: Sanders, T.L.; Seager, K.D. (Sandia National Labs., Albuquerque, NM (United States)) & Reardon, P.C. (GRAM, Inc., Albuquerque, NM (United States))
Partner: UNT Libraries Government Documents Department

Preliminary nuclear safety assessment of the NEPST (Topaz II) space reactor program

Description: The United States (US) Strategic Defense Initiative Organization (SDIO) decided to investigate the possibility of launching a Russian Topaz II space nuclear power system. A preliminary nuclear safety assessment was conducted to determine whether or not a space mission could be conducted safely and within budget constraints. As part of this assessment, a safety policy and safety functional requirements were developed to guide both the safety assessment and future Topaz II activities. A review of the Russian flight safety program was conducted and documented. Our preliminary nuclear safety assessment included a number of deterministic analyses, such as; neutronic analysis of normal and accident configurations, an evaluation of temperature coefficients of reactivity, a reentry and disposal analysis, an analysis of postulated launch abort impact accidents, and an analysis of postulated propellant fire and explosion accidents. Based on the assessment to date, it appears that it will be possible to safely launch the Topaz II system in the US with a modification to preclude water flooded criticality. A full scale safety program is now underway.
Date: January 1, 1993
Creator: Marshall, A.C.
Partner: UNT Libraries Government Documents Department

The status of the US VAWT program

Description: Vertical axis wind turbine (VAWT) technology in the United States started in the early 1970s directly from the original work in Canada. The close, and very productive relationships among laboratories, universities and industry have continued since that time. This paper briefly discusses the significant technical progress and rather dramatic programmatic changes that have occurred in the past 18 to 24 months on the US side of the border. 20 refs., 14 figs.
Date: January 1, 1991
Creator: Dodd, H.M.; Berg, D.E.; Ashwill, T.D.; Sutherland, H.J. & Schluter, L.L.
Partner: UNT Libraries Government Documents Department

Human event observations in the individual plant examinations

Description: A major objective of the Nuclear Regulatory Commission`s (NRC) Individual Plant Examination (IPE) Insights Program is to identify the important determinants of core damage frequency (CDF) for the different reactor and containment types and plant designs as indicated in the IPEs. The human reliability analysis (HRA) is a critical component of the probabilistic risk assessments (PRAS) which were done for the IPES. The determination and selection of human actions for incorporation into the event and fault tree models and the quantification of their failure probabilities can have an important impact on the resulting estimates of CDF and risk. Therefore, two important goals of the NRCs IPE Insights Program are (1) to determine the extent to which human actions and their corresponding failure probabilities influenced the results of the IPEs and (2) to identify which factors played significant roles in determining the differences and similarities in the results of the HRA analyses across the different plants. To obtain the relevant information, the NRC`s IPE database, which contains information on plant design, CDF, and containment performance obtained from the IPES, was used in conjunction with a systematic examination of the HRA analyses and results from the IPES. Regarding the extent to which the results of the HRA analyses were significant contributors to the plants` CDFs, examinations of several different measures indicated that while individual human actions could have important influences on CDF for particular initiators, the HRA results did not appear to be the most significant driver of plant risk (CDF). Another finding was that while there were relatively wide variations in the calculated human error probabilities (HEPs) for similar events across plants, there was no evidence for any systematic variation as a function of the HRA methods used in the analyses.
Date: January 1, 1995
Creator: Forester, J.
Partner: UNT Libraries Government Documents Department

Characteristics and control response of the TOPAZ II Reactor System Real-time Dynamic Simulator

Description: A dynamic simulator of the TOPAZ II reactor system has been developed for the Nuclear Electric Propulsion Space Test Program. The simulator combines first-principle modeling and empirical correlations in its algorithm to attain the modeling accuracy and computational through-put that are required for real-time execution. The overall execution time of the simulator for each time step is 15 ms when no data is written to the disk, and 18 ms when nine double precision data points are written to the disk once in every time step. The simulation program has been tested and it is able to handle a step decrease of $8 worth of reactivity. It also provides simulations of fuel, emitter, collector, stainless steel, and ZrH moderator failures. Presented in this paper are the models used in the calculations, a sample simulation session, and a discussion of the performance and limitations of the simulator. The simulator has been found to provide realistic real-time dynamic response of the TOPAZ II reactor system under both normal and casualty conditions.
Date: November 12, 1993
Creator: Kwok, K. S.
Partner: UNT Libraries Government Documents Department

Thermochemical data for CVD modeling from ab initio calculations

Description: Ab initio electronic-structure calculations are combined with empirical bond-additivity corrections to yield thermochemical properties of gas-phase molecules. A self-consistent set of heats of formation for molecules in the Si-H, Si-H-Cl, Si-H-F, Si-N-H and Si-N-H-F systems is presented, along with preliminary values for some Si-O-C-H species.
Date: December 31, 1993
Creator: Ho, P. & Melius, C. F.
Partner: UNT Libraries Government Documents Department

First-principles calculations for AlN, GaN, and InN: Bulk and alloy properties

Description: First-principles density-functional calculations utilizing ab initio pseudopotentials and plane-wave expansions are used to determine lattice parameters, bulk moduli, and band structures for AlN, GaN and InN. It is found that large numbers of plane waves are necessary to resolve the nitrogen 2p wave functions and that explicit treatment of the gallium 3d and indium 4d electrons is important for an accurate description of GaN and InN. Several properties of ternary zinc-blende alloys are determined including their bond-length and bond-angle relaxation and their energy-gap bowing parameters. The similarity of the calculated zinc-blende and wurtzite direct gaps also allows estimates to be made of the energy gap versus composition for wurtzite alloys.
Date: February 1, 1995
Creator: Wright, A. F. & Nelson, J. S.
Partner: UNT Libraries Government Documents Department

Results and insights from the low power and shutdown Level 1 PRA of the Grand Gulf Nuclear Power Station

Description: The US Nuclear Regulatory Commission`s Office of Nuclear Regulatory Research has undertaken a two-phase project to analyze the frequencies, consequences, and risk of accidents occurring during modes of operation other than full power (i.e., low power and shutdown (LP&S) conditions). The Phase 1 work represented a ``coarse screening`` of all identified modes of operation. The results were used to identify which set of plant operating conditions would be subjected to a detailed analysis during Phase 2. This paper presents an overview of the results from the current Phase 2 effort to identify and quantify the various accident sequences that can lead to severe core damage. This overview encompasses the detailed analysis of potential accidents that could occur at the Grand Gulf Nuclear Power Plant while in the Cold Shutdown Phase [Plant Operational State (POS) 5] of a refueling outage.
Date: November 1, 1993
Creator: Whitehead, D. W.; Staple, B. D.; Daniel, S. L.; Darby, J.; Miller, S.; Forester, J. et al.
Partner: UNT Libraries Government Documents Department

Core damage frequency observations and insights of LWRs based on the IPEs

Description: Seventy-eight plants are expected to submit Individual Plant Examinations (IPEs) for severe accident vulnerabilities to the U.S. Nuclear Regulatory Commission (NRC). The majority of the plants have elected to perform full Level 1 probabilistic risk assessments (PRAs) to meet the intent of the IPES. Because of this, it is possible to compare the results from the IPE submittals to determine general observations and {open_quotes}lessons learned{close_quotes} from the IPES. The IPE Insights Program is performing this evaluation, and preliminary results are presented in this paper. The core damage frequency and core damage sequences are identified and compared for pressurized water reactors and boiling water reactors. Examination of the results indicates that variations among plant results are due to a combination of actual plant design/operational features and analysis approaches. The findings are consistent with previous NRC studies, such as WASH-1400 and NUREG-1 150.
Date: January 1, 1995
Creator: Dingman, S. E.; Camp, A. L.; Drouin, M. T.; Kolaczkowski, A.; Darby, J.; LaChance, J. L. et al.
Partner: UNT Libraries Government Documents Department

Stability and precipitation kinetics in Si{sub 1{minus}y}C{sub y}/Si and Si{sub 1{minus}x{minus}y}Ge{sub x}C{sub y}/Si heterostructures prepared by solid phase epitaxy

Description: This study investigates the stability of metastable Si{sub 1{minus}y}C{sub y}/Si heterostructures during rapid thermal annealing (RTA) over a temperature range of 1,000--1,150 C. Heterostructures of Si{sub 1{minus}y}C{sub y}/Si and Si{sub 1{minus}x{minus}y}Ge{sub x}C{sub y}/Si (x {equals} 0.77, Y {<=} .0014) were formed by solid phase epitaxy from C implanted, preamorphized substrates using a 30 minute 700 C anneal in N{sub 2}. The occupancy of C in substitution lattice sites was monitored by Fourier Transform Infrared Absorption spectroscopy. The layer strain was monitored by rocking curve X-ray diffraction and the structural changes in the layers were determined using plan-view and X-sectional transmission electron microscopy (TEM). For anneals of 1,150 C or above, all the substitutional C was lost from the Si lattice after 30 seconds. TEM verified that the strain relaxation was the result of C precipitating into highly aligned {beta}SiC particles rather than by the formation of extended defects. No nucleation barrier was observed for the loss of substitutional C. Preliminary results will also be discussed for Si{sub 1{minus}x{minus}y}Ge{sub x}C{sub y}/Si heterostructures where there is the additional factor of the competition between strain energy and the chemical driving forces.
Date: December 31, 1993
Creator: Strane, J. W.; Picraux, S. T.; Stein, H. J.; Lee, S. R.; Candelaria, J.; Theodore, D. et al.
Partner: UNT Libraries Government Documents Department

Pulsed power systems for environmental and industrial applications

Description: The development of high peak power simulators, laser drivers, free electron lasers, and Inertial Confinement Fusion drivers is being extended to high average power short-pulse machines with the capabilities of performing new roles in environmental cleanup and industrial manufacturing processes. We discuss a new class of short-pulse, high average power accelerator that achieves megavolt electron and ion beams with 10`s of kiloamperes of current and average power levels in excess of 100 KW. Large treatment areas are possible with these systems because kilojoules of energy are available in each output pulse. These systems can use large area x-ray converters for applications requiring greater depth of penetration such as food pasteurization and waste treatment. The combined development of this class of accelerators and applications, at Sandia National Laboratories, is called Quantum Manufacturing.
Date: December 31, 1993
Creator: Neau, E. L.
Partner: UNT Libraries Government Documents Department

The National Center for Advanced Information Components Manufacturing: Program update

Description: The National Center for Advanced Information Components Manufacturing (NCAICM) Projects focus on manufacturing processes, materials, user facilities, standard tools, and equipment for large area emissive flat panel displays and microelectronics. Two types of projects are funded: (1) precompetitive projects done at the Center, and (2) joint industry/national laboratory projects, which may carry intellectual property rights, where the work will be done at the appropriate industry or laboratory site. A summary of the NCAICM Projects will be presented.
Date: February 1, 1994
Creator: Jorgensen, J. & McBurnett, S.
Partner: UNT Libraries Government Documents Department

MELCOR 1.8.2 assessment: The DF-4 BWR Damaged Fuel experiment

Description: MELCOR is a fully integrated, engineering-level computer code being developed at Sandia National Laboratories for the USNRC, that models the entire spectrum of severe accident phenomena in a unified framework for both BWRs and PWRs. As a part of an ongoing assessment, program, MELCOR has been used to model the ACRR in-pile DF-4 Damaged Fuel experiment. DF-4 provided data for early phase melt progression in BWR fuel assemblies, particularly for phenomena associated with eutectic interactions in the BWR control blade and zircaloy oxidation in the canister and cladding. MELCOR provided good agreement with experimental data in the key areas of eutectic material behavior and canister and cladding oxidation. Several shortcomings associated with the MELCOR modeling of BWR geometries were found and corrected. Twenty-five sensitivity studies were performed on COR, HS and CVH parameters. These studies showed that the new MELCOR eutectics model played an important role in predicting control blade behavior. These studies revealed slight time step dependence and no machine dependencies. Comparisons made with the results from four best-estimate codes showed that MELCOR did as well as these codes in matching DF-4 experimental data.
Date: October 1, 1993
Creator: Tautges, T. J.
Partner: UNT Libraries Government Documents Department

Risk perspectives for TOPAZ II flight mission

Description: The purpose of this paper is to present a preliminary estimate of the nuclear-related public health risk presented by launching and operating the Russian TOPAZ II space reactor as part of the Nuclear Electric Propulsion Space Test Program (NEPSTP). This risk is then compared to the risks from the operation of commercial nuclear power reactors and previously planned and/or launched space nuclear power missions. For the current mission profile, the initial estimate of the risk posed by launching and operating TOPAZ II is significantly less (at least two orders of magnitude) than that estimated for prior space nuclear missions. Even allowing for the large uncertainties in this estimate, it does not appear that the NEPSTP mission will present a significant health risk to the public.
Date: November 1, 1993
Creator: Payne, A. C. Jr. & Haskin, F. E.
Partner: UNT Libraries Government Documents Department

Synthesis and characterization of novel spiro penta- and hexacoordinate anionic polysiliconate and polygermylate ionomers derived from the condensation of ({plus_minus}) 5,5{prime}, 6,6{prime} - Tetrahydroxy-1,1{prime} - spiro-bis(Indane) with trialkoxysilanes, tetraalkoxysilanes, and trialkoxygermanes

Description: Synthesis of hybrid organic-inorganic materials with ionic functionality within the polymer backbone has been achieved. A new family of hypervalent spiro anionic polysiliconates and polygermylates has been prepared. These materials were shown to be thermally stable to moderate temperatures and are completely air and moisture stable. Analysis by solution and solid state NMR verified the presence of the hypervalent functionality. We are currently examining the effect that alteration of the condensing reagent and/or the counterion may have on bulk properties of the ionomeric material.
Date: December 1, 1993
Creator: Small, J. H.; Shea, K. J.; Loy, D. A. & Jamison, G. M.
Partner: UNT Libraries Government Documents Department