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3-D magnetic field calculations for wiggglers using MAGNUS-3D

Description: The recent but steady trend toward increased magnetic and geometric complexity in the design of wigglers and undulators, of which tapered wigglers, hybrid structures, laced electromagnetic wigglers, magnetic cladding, twisters and magic structures are examples, has caused a need for reliable 3-D computer models and a better understanding of the behavior of magnetic systems in three dimensions. The capabilities of the MAGNUS-3D Group of Programs are ideally suited to solve this class of problems and provide insight into 3-D effects. MAGNUS-3D can solve any problem of Magnetostatics involving permanent magnets, linear or nonlinear ferromagnetic materials and electric conductors of any shape in space. The magnetic properties of permanent magnets are described by the complete nonlinear demagnetization curve as provided by the manufacturer, or, at the user's choice, by a simpler approximation involving the coercive force, the residual induction and the direction of magnetization. The ferromagnetic materials are described by a magnetization table and an accurate interpolation relation. An internal library with properties of common industrial steels is available. The conductors are independent of the mesh and are described in terms of conductor elements from an internal library.
Date: January 1, 1988
Creator: Pissanetzky, S. & Tompkins, P.
Partner: UNT Libraries Government Documents Department

1994 MCAP annual report

Description: VELCOR is an integrated, engineering-level computer code that models the progression of severe accidents in light water reactor (LWR) nuclear power plants. The entire spectrum of severe accident phenomena, including reactor coolant system and containment thermal-hydraulic response, core heatup, degradation and relocation, and fission product release and transport is treated in MELCOR in a unified framework for both boiling water reactors (BWRs) and pressurized water reactors (PWRs). Its current uses include the estimation of severe accident source terms and their sensitivities and uncertainties in a variety of applications. Independent assessment efforts have been successfully completed by the US and international MELCOR user communities. Most of these independent assessment efforts have been conducted to support the needs and fulfill the requirements of the individual user organizations. The resources required to perform an extensive set of model and integral code assessments are large. A prudent approach to fostering code development and maturation is to coordinate the individual assessment efforts of the MELCOR user community. While retaining individual control over assessment resources, each organization using the MELCOR code could work with the other users to broaden assessment coverage and minimize duplication. In recognition of these considerations, the US Nuclear Regulatory Commission (US NRC) has initiated the MELCOR Cooperative Assessment Program (MCAP), a vehicle for coordinating and standardizing the assessment practices of the various MELCOR users. In addition, the user community will have a forum to better communicate lessons learned regarding MELCOR applications, capabilities, and user guidelines and limitations and to provide a user community perspective on code development needs and priorities. This second Annual Report builds on the foundation laid with the first Annual Report.
Date: April 1, 1995
Creator: Harmony, S.C. & Boyack, B.E.
Partner: UNT Libraries Government Documents Department

3D simulation studies of tokamak plasmas using MHD and extended-MHD models

Description: The M3D (Multi-level 3D) tokamak simulation project aims at the simulation of tokamak plasmas using a multi-level tokamak code package. Several current applications using MHD and Extended-MHD models are presented; high-{beta} disruption studies in reversed shear plasmas using the MHD level MH3D code, {omega}{sub *i} stabilization and nonlinear island rotation studies using the two-fluid level MH3D-T code, studies of nonlinear saturation of TAE modes using the hybrid particle/MHD level MH3D-K code, and unstructured mesh MH3D{sup ++} code studies. In particular, three internal mode disruption mechanisms are identified from simulation results which agree well with experimental data.
Date: January 1997
Creator: Park, W.; Chang, Z.; Fredrickson, E.; Fu, G. Y.; Pomphrey, N.; Strauss, H. R. et al.
Partner: UNT Libraries Government Documents Department

3D simulation studies of tokamak plasmas using MHD and extended-MHD models

Description: The M3D (Multi-level 3D) tokamak simulation project aims at the simulation of tokamak plasmas using a multi-level tokamak code package. Several current applications using MHD and Extended-MHD models are presented; high-{beta} disruption studies in reversed shear plasmas using the MHD level MH3D code, {omega}{sub *i} stabilization and nonlinear island saturation of TAE mode using the hybrid particle/MHD level MH3D-K code, and unstructured mesh MH3D{sup ++} code studies. In particular, three internal mode disruption mechanisms are identified from simulation results which agree which agree well with experimental data.
Date: December 31, 1996
Creator: Park, W.; Chang, Z.; Fredrickson, E. & Fu, G.Y.
Partner: UNT Libraries Government Documents Department

Acceptance test report MICON software exhaust fan control

Description: This test procedure specifies instructions for acceptance testing of software for exhaust fan control under Project ESPT (Energy Savings Performance Contract). The software controls the operation of two emergency exhaust fans when there is a power failure. This report details the results of acceptance testing for the MICON software upgrades. One of the modifications is that only one of the emergency fans will operate at all times. If the operating fan shuts off or fails, the other fan will start and the operating fan will be stopped.
Date: June 12, 1998
Creator: Keck, R.D.
Partner: UNT Libraries Government Documents Department

Acceptance test report MICON software exhaust fan control modifications

Description: This report documents the results the acceptance test HNF-4108 which verifies the MICON program changes for the new automatic transfer switch ATS-2 alarms, the Closed Loop Cooling isolator status, the CB-3 position alarm, the alarms for the new emergency fan damper backup air compressor, and the generator sequencer logic.
Date: May 20, 1999
Creator: SILVAN, G.R.
Partner: UNT Libraries Government Documents Department

Accident sequences simulated at the Juragua nuclear power plant

Description: Different hypothetical accident sequences have been simulated at Unit 1 of the Juragua nuclear power plant in Cuba, a plant with two VVER-440 V213 units under construction. The computer code MELCOR was employed for these simulations. The sequences simulated are: (1) a design-basis accident (DBA) large loss of coolant accident (LOCA) with the emergency core coolant system (ECCS) on, (2) a station blackout (SBO), (3) a small LOCA (SLOCA) concurrent with SBO, (4) a large LOCA (LLOCA) concurrent with SBO, and (5) a LLOCA concurrent with SBO and with the containment breached at time zero. Timings of important events and source term releases have been calculated for the different sequences analyzed. Under certain weather conditions, the fission products released from the severe accident sequences may travel to southern Florida.
Date: August 1, 1998
Creator: Carbajo, J.J.
Partner: UNT Libraries Government Documents Department

Accident simulation and consequence analysis in support of MHTGR safety evaluations

Description: This paper summarizes research performed at Oak Ridge National Laboratory (ORNL) to assist the Nuclear Regulatory Commission (NRC) in preliminary determinations of licensability of the US Department of Energy (DOE) reference design of a standard modular high-temperature gas-cooled reactor (MHTGR). The work described includes independent analyses of core heatup and steam ingress accidents, and the reviews and analyses of fuel performance and fission product transport technology.
Date: January 1, 1991
Creator: Ball, S.J.; Wichner, R.P.; Smith, O.L.; Conklin, J.C. (Oak Ridge National Lab., TN (United States)) & Barthold, W.P. (Barthold Associates, Inc., Knoxville, TN (United States))
Partner: UNT Libraries Government Documents Department

Accounting for time-varying vadose-zone water fluxes caused by infiltration caps using the MEPAS transport, exposure, and risk assessment model

Description: The Multimedia Environmental Pollutant Assessment System (MEPAS) is an objective, scientific methodology to assess and prioritize hazardous chemical and radionuclide waste disposal sites based on a limited amount of site information. The vadose zone/groundwater transport module (RADCON) of MEPAS was enhanced to simulate scenarios where water-infiltration barriers (caps) have been emplaced over contaminated sites. The computer code was modified to accommodate three periods of constant water flux through the vadose zone (i.e., flux with no cap, fully functioning cap, and partially failed cap). The simulation results from test problems where the cap should have no effect essentially duplicated the simulation results from the same test problems evaluated with the earlier (baseline) version of RADCON (which requires a single constant value of water flux). Therefore, MEPAS assessments of baseline (no-cap) scenarios should be the same as they were when the baseline RADCON code was used as the vadose zone/groundwater transport module. As expected, simulations of preliminary test problems where the cap should have an effect showed that peak concentrations arrived at the receptor later and were reduced in magnitude compared to the no-cap case. Simple criteria were derived to indicate the degree to which results could be affected by violation of the assumptions of the conceptual model. However, even when assumptions are violated, errors on the nonconservative side that could occur as the cap fails should be offset by errors on the conservative side that would have already occurred as the cap was emplaced, resulting in simulations that are conservative overall.
Date: October 1, 1993
Creator: Streile, G. P. & Stroh, J. L.
Partner: UNT Libraries Government Documents Department

Activation caused by proton beam losses in Accelerator Production of Tritium LINAC

Description: A variety of accelerator designs are being considered for the Accelerator Production of Tritium (APT) project at Alamos National Laboratory. Because activation of the structural components of the accelerator is considered a major radiation protection issue, we have developed a computational methodology to estimate quantitatively radionuclide inventories and gamma dose rates resulting from accelerator operation. The work presented here illustrates the use of our computational methodology by focusing on the 20 and 100 MeV sections of the Bridge-Coupled Drift Tube LINAC (BCDTL), and the 100 and 1000 MeV sections of the Coupled Cavity LINAC (CCL).
Date: March 1, 1996
Creator: Beard, C.A.; Eaton, S.L.; Daemen, L.L.; Waters, L.S. & Wilson, W.B.
Partner: UNT Libraries Government Documents Department

Advanced alkaline water electrolysis. Task 2 summary report. Model for alkaline water electrolysis systems

Description: Task 2 involved the establishment of an engineering and economic model for the evaluation of various options in water electrolysis. The mode, verification of the specific coding and four case studies are described. The model was tested by evaluation of a nearly commercial technology, i.e., an 80-kW alkaline electrolyte system, operating at 60/sup 0/C, which delivers approximately 255 SLM, hydrogen for applications such as electrical generation cooling or semiconductor manufacturing. The calculated cost of hydrogen from this installed non-optimized case system with an initial cost to the customer of $87,000 was $6.99/Kg H/sub 2/ ($1.67/100 SCF) on a 20-yr levelized basis using 2.5 cents/kWh power costs. This compares favorably to a levelized average merchant hydrogen cost value of $9.11/Kg H/sub 2/ ($2.17/100 SCF) calculated using the same program.
Date: April 1, 1980
Creator: Yaffe, M.R. & Murray, J.N.
Partner: UNT Libraries Government Documents Department

Advanced computer techniques for inverse modeling of electric current in cardiac tissue

Description: For many years, ECG`s and vector cardiograms have been the tools of choice for non-invasive diagnosis of cardiac conduction problems, such as found in reentrant tachycardia or Wolff-Parkinson-White (WPW) syndrome. Through skillful analysis of these skin-surface measurements of cardiac generated electric currents, a physician can deduce the general location of heart conduction irregularities. Using a combination of high-fidelity geometry modeling, advanced mathematical algorithms and massively parallel computing, Sandia`s approach would provide much more accurate information and thus allow the physician to pinpoint the source of an arrhythmia or abnormal conduction pathway.
Date: August 1, 1996
Creator: Hutchinson, S.A.; Romero, L.A. & Diegert, C.F.
Partner: UNT Libraries Government Documents Department

Advanced concepts for gamma-ray isotopic analysis and instrumentation

Description: The Safeguards Technology Program at the Lawrence Livermore National Laboratory is developing actinide isotopic analysis technologies in response to needs that address issues of flexibility of analysis, robustness of analysis, ease-of-use, automation and portability. Recent developments such as the Intelligent Actinide Analysis System (IAAS), begin to address these issues. We are continuing to develop enhancements on this and other instruments that improve ease-of-use, automation and portability. Requests to analyze samples with unusual isotopics, contamination, or containers have made us aware of the need for more flexible and robust analysis. We have modified the MGA program to extend its plutonium isotopic analysis capability to samples with greater {sup 241}Am content or U isotopics. We are looking at methods for dealing with tantalum or lead contamination and contamination with high-energy gamma emitters, such as {sup 233}U. We are looking at ways to allow the program to use additional information about the sample to further extend the domain of analyzable samples. These unusual analyses will come from the domain of samples that need to be measured because of complex reconfiguration or environmental cleanup.
Date: July 1, 1994
Creator: Buckley, W. M. & Carlson, J. B.
Partner: UNT Libraries Government Documents Department

Advanced electromagnetic design of cavities for high current accelerators

Description: For high-current accelerators such as those proposed for transmutation technologies or spallation sources, preconstruction numerical modeling has a high importance. Non axisymmetric cavities require a full 3-D modeling. A complex analysis of structures beyond tuning and the calculation of Q and shunt impedance is required and also the interaction with the mechanical properties of the structures has to be taken into account. This paper reports on recent work done at LANL for proposed beam funnels, a new normal-conducting medium-energy structure (CCDTL) and superconducting cavities for medium energy. The electromagnetic calculations have been done with MAFIA, Rel 3.2, the thermal and stress analysis results reported come from the ABAQUS engineering code.
Date: May 1, 1995
Creator: Krawczyk, F.L.
Partner: UNT Libraries Government Documents Department

Advanced methods for the computation of particle beam transport and the computation of electromagnetic fields and beam-cavity interactions. Final report

Description: The University of Maryland Dynamical Systems and Accelerator Theory Group carries out research in two broad areas: the computation of charged particle beam transport using Lie algebraic methods and advanced methods for the computation of electromagnetic fields and beam-cavity interactions. Important improvements in the state of the art are believed to be possible in both of these areas. In addition, applications of these methods are made to problems of current interest in accelerator physics including the theoretical performance of present and proposed high energy machines. The Lie algebraic method of computing and analyzing beam transport handles both linear and nonlinear beam elements. Tests show this method to be superior to the earlier matrix or numerical integration methods. It has wide application to many areas including accelerator physics, intense particle beams, ion microprobes, high resolution electron microscopy, and light optics. With regard to the area of electromagnetic fields and beam cavity interactions, work is carried out on the theory of beam breakup in single pulses. Work is also done on the analysis of the high frequency behavior of longitudinal and transverse coupling impedances, including the examination of methods which may be used to measure these impedances. Finally, work is performed on the electromagnetic analysis of coupled cavities and on the coupling of cavities to waveguides.
Date: November 1, 1992
Creator: Dragt, A. J. & Gluckstern, R. L.
Partner: UNT Libraries Government Documents Department

Advanced methods for the computation of particle beam transport and the computation of electromagnetic fields and beam-cavity interactions. Progress report, August 1992--June 1993

Description: The University of Maryland Dynamical Systems and Accelerator Theory Group has been carrying out long-term research work in the general area of Dynamical Systems with a particular emphasis on applications to Accelerator Physics. This work is broadly divided into two tasks: Charged Particle Beam Transport and the Computation of Electromagnetic Fields and Beam-Cavity Interactions. Each of these tasks is described briefly. Work is devoted both to the development of new methods and the application of these methods to problems of current interest in accelerator physics including the theoretical performance of present and proposed high energy machines. In addition to its research effort, the Dynamical Systems and Accelerator Theory Group is actively engaged in the education of students and postdoctoral research associates.
Date: June 1, 1993
Creator: Dragt, A. J. & Gluckstern, R. L.
Partner: UNT Libraries Government Documents Department

Advective-diffusive/dispersive transport of chemically reacting species in hydrothermal systems. Final report, FY83-85

Description: A general formulation of multi-phase fluid flow coupled to chemical reactions was developed based on a continuum description of porous media. A preliminary version of the computer code MCCTM was constructed which implemented the general equations for a single phase fluid. The computer code MCCTM incorporates mass transport by advection-diffusion/dispersion in a one-dimensional porous medium coupled to reversible and irreversible, homogeneous and heterogeneous chemical reactions. These reactions include aqueous complexing, oxidation/reduction reactions, ion exchange, and hydrolysis reactions of stoichiometric minerals. The code MCCTM uses a fully implicit finite difference algorithm. The code was tested against analytical calculations. Applications of the code included investigation of the propagation of sharp chemical reaction fronts, metasomatic alteration of microcline at elevated temperatures and pressures, and ion-exchange in a porous column. Finally numerical calculations describing fluid flow in crystalline rock in the presence of a temperature gradient were compared with experimental results for quartzite.
Date: June 20, 1986
Creator: Lichtner, P.C. & Helgeson, H.C.
Partner: UNT Libraries Government Documents Department

Air ingression calculations for selected plant transients using MELCOR

Description: Two sets of MELCOR calculations have been completed studying the effects of air ingression on the consequences of various severe accident scenarios. One set of calculations analyzed a station blackout with surge line failure prior to vessel breach, starting from nominal operating conditions; the other set of calculations analyzed a station blackout occurring during shutdown (refueling) conditions. Both sets of analyses were for the Surry plant, a three-loop Westinghouse PWR. For both accident scenarios, a basecase calculation was done, and then repeated with air ingression from containment into the core region following core degradation and vessel failure. In addition to the two sets of analyses done for this program, a similar air-ingression sensitivity study was done as part of a low-power/shutdown PRA, with results summarized here; that PRA study also analyzed a station blackout occurring during shutdown (refueling) conditions, but for the Grand Gulf plant, a BWR/6 with Mark III containment. These studies help quantify the amount of air that would have to enter the core region to have a significant impact on the severe accident scenario, and demonstrate that one effect, of air ingression is substantial enhancement of ruthenium release. These calculations also show that, while the core clad temperatures rise more quickly due to oxidation with air rather than steam, the core also degrades and relocates more quickly, so that no sustained, enhanced core heatup is predicted to occur with air ingression.
Date: January 1, 1994
Creator: Kmetyk, L. N.
Partner: UNT Libraries Government Documents Department

Air quality modeling for emergency response applications. [MATHEW; ADPIC; FEM3]

Description: The three-dimensional diagnostic wind field model (MATHEW) and the particle-in-cell transport and diffusion model (ADPIC) are used by the Atmospheric Release Advisory Capability (ARAC) for real-time assessments of the consequences from accidental releases of radioactivity into the atmosphere. For the dispersion of hazardous heavier-than-air gases, a time-dependent, three-dimensional finite element model (FEM3) is used. These models have been evaluated extensively against a wide spectrum of field experiments involving the release of chemically inert tracers or heavier-than-air gases. The results reveal that the MATHEW/ADPIC models are capable of simulating the spatial and temporal distributions of tracer concentration to within a factor of 2 for 50% of the measured tracer concentrations for near surface releases in relatively flat terrain and within a factor of 2 for 20% of the comparisons for elevated releases in complex terrain. The FEM3 model produces quite satisfactory simulations of the spatial and temporal distributions of heavier-than-air gases, typically within a kilometer of the release point. The ARAC consists of a centralized computerized emergency response system that is capable of supporting up to 100 sites and providing real-time predictions of the consequence of transportation accidents that may occur anywhere. It utilizes pertinent accident information, local and regional meteorology, and terrain as input to the MATHEW/ADPIC models for the consequence analysis. It has responded to over 150 incidents and exercises over the past decade.
Date: December 1, 1985
Creator: Gudiksen, P.H.; Chan, S.T.; Knox, J.B.; Dickerson, M.H. & Lange, R.
Partner: UNT Libraries Government Documents Department

Los Alamos MAWST software layered on Westinghouse Savannah River Company`s nuclear materials accountability system

Description: The Los Alamos Safeguards Systems Group`s Materials Accounting With Sequential Testing (MAWST) computer program was developed to fulfill DOE Order 5633.3B requiring that inventory-difference control limits be based on variance propagation or any other statistically valid technique. Westinghouse Savannah River Company (WSRC) developed a generic computerized accountability system, NucMAS, to satisfy accounting and reporting requirements for material balance areas. NucMAS maintains the calculation methods and the measurement information required to compute nuclear material transactions in elemental and isotopic masses by material type code. The Safeguards Systems Group designed and implemented to WSRC`s specifications a software interface application, called NucMASloe. It is a layered product for NucMAS that automatically formats a NucMAS data set to a format compatible with MAWST and runs MAWST. This paper traces the development of NucMASloe from the Software Requirements through the testing and demonstration stages. The general design constraints are described as well as the difficulties encountered on interfacing an external software product (MAWST) with an existing classical accounting structure (NucMAS). The lessons learned from this effort, the design, and some of the software are directly applicable to the Local Area Network Material Accountability System (LANMAS) being sponsored by DOE.
Date: September 1, 1995
Creator: Whitty, W.J.; Smith, J.E. & Davis, J.M. Jr.
Partner: UNT Libraries Government Documents Department

Alpha-like calculations with MCNP

Description: Alpha (time-absorption eigenvalue) calculations are not an explicit calculational option in MCNP. Nevertheless, it is possible to perform alpha calculations with MCNP. Such calculations are presently either very inefficient or require special coding or cross section library modifications. However, alpha-like calculations can easily be performed with MCNP using the KCODE option with neutron energy- or time-cutoffs. These approximate alpha-like calculations are described and tested.
Date: November 1, 1997
Creator: Parsons, D.K.
Partner: UNT Libraries Government Documents Department

Alternate fluid to improve energy efficiency of supercritical water oxidation process

Description: This report discusses the replacement of water by carbon dioxide in both the quench stream and the supercritical water oxidation (SCWO) reactor feed in order to reduce the energy utilization in the process. FLUENT was used to generate the input requirements and ASPEN PLUS was used to model the SCWO process. Simulations were made for normal MODAR operating conditions (baseline case) and two other cases replacing water by carbon dioxide. The basis for and assumptions used in the simulation are given. Economic evaluations were made and costs were compared with the baseline case and a case with 60% replacement of water by carbon dioxide. The equipment cost is almost the same. However, the case with replacement of water by carbon dioxide reduces the energy requirement in the end process by a factor of three, which is a significant energy savings in the operation. Also, the injection of carbon dioxide into the SCWO reactor feed is expected to reduce corrosion and makes salt particles non-sticky. However, these advantages need to be confirmed by experiment.
Date: March 1, 1996
Creator: Oh, C.H.
Partner: UNT Libraries Government Documents Department

AMPX-77 Phase 1 certification package

Description: The AMPX-77 Phase 1 modules have been certified. AMPX-77 is a modular code system for generating coupled multigroup neutron-gamma cross section libraries from Evaluated Nuclear Data Files (ENDF/B). All basic cross-section data are input from the formats used by the ENDF/B, and output can be obtained from a variety of formats, included in its own internal and very general formats, along with a variety of other useful formats used by major transport, diffusion theory, and Monte Carlo codes. Processing is provided for both neutron and gamma-ray data. The AMPX-77 code system will be used at SRS to perform critical calculations related to nuclear criticality safety. The AMPX-77 modular codes system contains forty-seven separate modules. For the certification process, the 47 modules have been divided into three groups or phases. This Certification Package is for the Phase 1 modules: BONAMI, LAPHNGAS, MALOCS, NITAWL, ROLAIDS, SMUG, and XSDRNPM.
Date: March 1, 1994
Creator: Niemer, K. A.
Partner: UNT Libraries Government Documents Department