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Variance propagation using the VP Code

Description: The VP (Variance Propagation) Code has been developed at Los Alamos in the Safeguards Systems Group to provide offline variance propagation and systems analysis for nuclear material processing facilities. VP provides a flexible, menu-driven user interface. Outputs from the code are in the form of tables and graphs. The code runs on IBM PC or compatible computers. 7 figs.
Date: January 1, 1991
Creator: Kern, E.A.
Partner: UNT Libraries Government Documents Department
open access

Development of an adjoint sensitivity method for site characterization, uncertainty analysis, and code calibration/validation

Description: The adjoint method is applied to groundwater flow-mass transport coupled equations in variably saturated media. The sensitivity coefficients derived by this method can be calculated by a single execution for each performance measure regardless of the number of parameters in question. The method provides an efficient and effective way to rank the importance of the parameters, so that data collection can be guided in support of site characterization programs. The developed code will facilitate th… more
Date: September 1, 1991
Creator: Lu, A.H.
Partner: UNT Libraries Government Documents Department
open access

Experiments for IFR fuel criticality in ZPPR-21

Description: A series of benchmark measurements was made in ZPPR-21 to validate criticality calculations for fuel operations in Argonne's Integral Fast Reactor. Six different mixtures of Pu/U/Zr fuel with a graphite reflector were built and criticality was determined by period measurements. The assemblies were isolated from room return problems by a lithium hydride shield. Analysis was done using a fully-detailed model with the VIM Monte Carlo code and ENDF/B-V.2 data. Sensitivity analysis was used to valid… more
Date: January 1, 1991
Creator: Olsen, D. N.; Collins, P. J. & Carpenter, S. G.
Partner: UNT Libraries Government Documents Department
open access

Effects of lateral separation of oxidic and metallic core debris on the BWR MK I containment drywell floor

Description: In evaluating core debris/concrete interactions for a BWR MK I containment design, it is common practice to assume that at reactor vessel breach, the core debris is homogeneous and of low viscosity, so that it flows through the pedestal doorway and spreads in a radially uniform fashion throughout the drywell floor. In a recent study performed by the NRC-sponsored Severe Accident Sequence Analysis (SASA) program at Oak Ridge National Laboratory, calculations indicate that at reactor vessel botto… more
Date: January 1, 1986
Creator: Hyman, C.R.; Weber, C.F. & Hodge, S.A.
Partner: UNT Libraries Government Documents Department
open access

COMMIX analysis of the Sodium Heated Helical Coil Steam Generator

Description: This paper describes the COMMIX-HCSG computer program and compares predictions to data obtained from performance tests on a 76 MWt Helical Coil Steam Generator (HCSG) test unit. COMMIX-HCSG is a multi-dimensional thermal/hydraulic code that models both steady state and transient operation of an HCSG. The code solves a system of Navier-Stokes continuum equations that have been modified with a combination of volume and directional surface porosities and distributed resistances. This formulation p… more
Date: January 1, 1987
Creator: Kakarala, C. R.; Burge, S. W. & Sha, W. T.
Partner: UNT Libraries Government Documents Department
open access

Assessment of improved fission-product transport models in VICTORIA against the ORNL HI and VI tests

Description: New models for the release of fission-products from fuel have recently been incorporated into a comprehensive code, VICTORIA, for the prediction of radionuclide behavior under severe reactor accident conditions as an alternative to a simple Booth diffusion calculation. It is widely known that the Booth model has severe limitations when used under conditions of changing temperature and power. A new transport model based on a two node diffusive flow formulation has been implemented into VICTORIA.… more
Date: January 1, 1991
Creator: Domagala, P.; Rest, J. & Zawadzki, S.A.
Partner: UNT Libraries Government Documents Department
open access

The Challenges to Coupling Dynamic Geospatial Models

Description: Many applications of modeling spatial dynamic systems focus on a single system and a single process, ignoring the geographic and systemic context of the processes being modeled. A solution to this problem is the coupled modeling of spatial dynamic systems. Coupled modeling is challenging for both technical reasons, as well as conceptual reasons. This paper explores the benefits and challenges to coupling or linking spatial dynamic models, from loose coupling, where information transfer between … more
Date: June 23, 2006
Creator: Goldstein, N
Partner: UNT Libraries Government Documents Department
open access

Improvements in EBR-2 core depletion calculations

Description: The need for accurate core depletion calculations in Experimental Breeder Reactor No. 2 (EBR-2) is discussed. Because of the unique physics characteristics of EBR-2, it is difficult to obtain accurate and computationally efficient multigroup flux predictions. This paper describes the effect of various conventional and higher order schemes for group constant generation and for flux computations; results indicate that higher-order methods are required, particularly in the outer regions (i.e. the … more
Date: January 1, 1991
Creator: Finck, P.J.; Hill, R.N. & Sakamoto, S.
Partner: UNT Libraries Government Documents Department
open access

A comparison between simple and detailed methods for analyzing releases of radionuclides to ground water from low-level waste facilities

Description: A performance assessment methodology has been developed for use by the US Nuclear Regulatory Commission in evaluating license applications for low-level waste disposal facilities. The methodology has been designed to be modular in structure, so that either simple or more complex analyses can be used, as appropriate. This paper compares results from a simple ground-water transport analysis implemented in the computer code PAGAN to results from VAM2D, which is used in the methodology for more com… more
Date: January 1, 1991
Creator: Kozak, M.W.
Partner: UNT Libraries Government Documents Department
open access

VENUS-III two-dimensional multi-component thermal hydraulic techniques

Description: In recent analyses of the initiating phase in LMFBR core disruptive accidents the energy deposition rate may not be nearly so high as originally thought and the development of material motion and interaction may take place on a time scale considerably larger than the classic disassembly time scale of milliseconds. This introduces a considerably different twist to the problem and it becomes apparent that processes heretofore ignored, such as differential motion and heat exchange, may become impo… more
Date: January 1, 1979
Creator: Weber, D.P.
Partner: UNT Libraries Government Documents Department
open access

Preparation of delisting petition for SRS (Savannah River Site) raw materials waste sludge---Mixed F006 waste

Description: Waste sludge from the raw materials manufacturing facility at the Savannah River Site contains both hazardous and low-level radioactive components. This waste, which contains electroplating sludge and depleted uranium, is classified as a mixed waste. The objective of the delisting petition is to demonstrate that this waste can be treated/solidified in a cement-based material and disposed of in concrete vaults so that drinking water standards will not be exceeded. Sampling and analytical data wh… more
Date: January 1, 1989
Creator: Langton, C.A.
Partner: UNT Libraries Government Documents Department
open access

Results of Aerosol Code Comparisons With Releases From ACE MCCI Tests

Description: Results of aerosol release calculations by six groups from six countries are compared with the releases from ACE MCCI Test L6. The codes used for these calculations included: SOLGASMIX-PV, SOLGASMIX Reactor 1986, CORCON.UW, VANESA 1.01, and CORCON mod2.04/VANESA 1.01. Calculations were performed with the standard VANESA 1.01 code and with modifications to the VANESA code such as the inclusion of various zirconium-silica chemical reactions. Comparisons of results from these calculations were mad… more
Date: January 1, 1992
Creator: Fink, J. K.; Corradini, M.; Hidaka, A.; Hontanon, E.; Mignanelli, M. A.; Schroedl, E. et al.
Partner: UNT Libraries Government Documents Department
open access

Ground test accelerator control system software

Description: The GTA control system provides an environment in which the automation of a state-of-the-art accelerator can be developed. It makes use of commercially available computers, workstations, computer networks, industrial I/O equipment, and software. This system has built-in supervisory control (like most accelerator control systems), tools to support continuous control (like the process control industry), and sequential control for automatic startup and fault recovery (like few other accelerator co… more
Date: January 1, 1988
Creator: Burczyk, L.; Dalesio, R.; Dingler, R.; Hill, J.; Howell, J. A.; Kerstiens, D. et al.
Partner: UNT Libraries Government Documents Department
open access

Update on the meso-microscale meteorological hierarchy

Description: SIGTRA is designed to define the height of the material layer and provide interpolated mass and energy fluxes to VARYME. It also provides interpolated winds, temperatures, and potential densities at levels within the material layer. VARTRA uses similarity theory surface energy budget considerations, and the VARYME solutions to perturb the SIGMET profiles. It is the principal vehicle for converting the VARYME solutions into wind and temperature profiles and for incorporating the effects of local… more
Date: January 1, 1987
Creator: Williams, M. D.
Partner: UNT Libraries Government Documents Department
open access

IAEA Sodium Void Reactivity Benchmark Calculations

Description: In this paper, the IAEA-1 992 Benchmark Calculation of Sodium Void Reactivity Effect in Fast Reactor Core'' problem is evaluated. The proposed design is a large axially heterogeneous oxide-fueled fast reactor as described in Section 2; the core utilizes a sodium plenum above the core to enhance leakage effects. The calculation methods used in this benchmark evaluation are described in Section 3. In Section 4, the calculated core performance results for the benchmark reactor model are presented;… more
Date: November 1992
Creator: Hill, R. N. & Finck, P. J.
Partner: UNT Libraries Government Documents Department
open access

Evaluation and validation of criticality codes for fuel dissolver calculations

Description: During the past ten years an OECD/NEA Criticality Working Group has examined the validity of criticality safety computational methods. International calculation tools which were shown to be valid in systems for which experimental data existed were demonstrated to be inadequate when extrapolated to fuel dissolver media. The spread of the results in the international calculation amounted to {plus minus} 12,000 pcm in the realistic fuel dissolver exercise n{degrees} 19 proposed by BNFL, and to {pl… more
Date: January 1, 1991
Creator: Santamarina, A.; Smith, H.J. (CEA Centre d'Etudes Nucleaires de Cadarache, 13 - Saint-Paul-lez-Durance (France)) & Whitesides, G.E. (Oak Ridge National Lab., TN (United States))
Partner: UNT Libraries Government Documents Department
open access

Damping measurements using operational data

Description: We have measured modal damping using strain-gauge data from an operating wind turbine. Previously, such measurements were difficult and expensive. Auto-correlation and cross-correlation functions of the strain-gauge data have been shown to consist of decaying sinusoids which correspond to the modal frequencies and damping ratios of the wind turbine. We have verified the method by extracting damping values from an analytically generated data set. Actual operating response data from the DOE/Sandi… more
Date: January 1, 1991
Creator: James, G.H.; Carne, T.G. & Veers, P.S.
Partner: UNT Libraries Government Documents Department
open access

Thermal reactor design for a neutron scattering source facility

Description: The purpose of this paper is to present conclusions drawn from preliminary neutronic calculations and to present a possible reactor design configuration capable of meeting the above thermal flux level, flux location, and lifetime requirements. (JDB)
Date: January 1, 1985
Creator: Worley, B. A.; Difilippo, F. C. & Vondy, D. R.
Partner: UNT Libraries Government Documents Department
open access

Intelligent System Controller for remote systems

Description: The US Department of Energy's Office of Technology Development (OTD) has sponsored the development of the Generic Intelligent System Controller (GISC) for application to the clean up of hazardous waste sites. Of primary interest to the OTD is the development of technologies which result in faster, safer, and cheaper cleanup of hazardous waste sites than possible using conventional approaches. An objective of the GISC development project is to achieve these goals by developing a modular robotics… more
Date: January 1, 1992
Creator: Harrigan, R.W.
Partner: UNT Libraries Government Documents Department
open access

IAEA sodium void reactivity benchmark calculations

Description: In this paper, the IAEA-1 992 ``Benchmark Calculation of Sodium Void Reactivity Effect in Fast Reactor Core`` problem is evaluated. The proposed design is a large axially heterogeneous oxide-fueled fast reactor as described in Section 2; the core utilizes a sodium plenum above the core to enhance leakage effects. The calculation methods used in this benchmark evaluation are described in Section 3. In Section 4, the calculated core performance results for the benchmark reactor model are presente… more
Date: December 1, 1992
Creator: Hill, R. N. & Finck, P. J.
Partner: UNT Libraries Government Documents Department
open access

Greek research reactor performance characteristics after addition of beryllium reflector and LEU fuel

Description: The GRR-1 is a 5-MW pool-type, light-water-moderated and-cooled reactor fueled with MTR-type fuel elements. Recently received Be reflector blocks will soon be added to the core to add additional reactivity until fresh LEU fuel arrives. REBUS-3 xy fuel cycle analyses, using burnup dependent cross sections, were performed to assist in fuel management decisions for the water- and Be-reflected HEU nonequilibrium cores. Cross sections generated by EPRI-CELL have been benchmarked to identical VIM Mon… more
Date: December 31, 1992
Creator: Deen, J. R.; Snelgrove, J. L. & Papastergiou, C.
Partner: UNT Libraries Government Documents Department
open access

VIM Monte Carlo versus CASMO comparisons for BWR advanced fuel designs

Description: Eigenvalues and two-dimensional fission rate distributions computed with the CASMO-3G lattice physics code and the VIM Monte Carlo Code are compared. The cases assessed are two advanced commercial BWR pin bundle designs. Generally, the two codes show good agreement in K{sub inf}, fission rate distributions, and control rod worths.
Date: March 1, 1994
Creator: Pallotta, A. S. & Blomquist, R. N.
Partner: UNT Libraries Government Documents Department
open access

Time-dependent numerical simulation of vertical cavity lasers

Description: To simulate vertical cavity surface emitting lasers (VCSELs), the authors are developing a three-dimensional, time-dependent field-gain model with absorption in bulk dielectric regions and gain in quantum well regions. Since the laser linewidth is narrow, the bulk absorption coefficient is assumed to be independent of frequency with a value determined by the material and the lattice temperature. In contrast, the frequency-dependent gain regions must be solved consistently in the time domain. Tr… more
Date: December 31, 1994
Creator: Thode, L. E.; Csanak, G.; So, L. L.; Kwan, T. J. T. & Campbell, M.
Partner: UNT Libraries Government Documents Department
open access

Analysis of EBR-II neutron and photon physics by multidimensional transport-theory techniques

Description: This paper contains a review of the challenges specific to the EBR-II core physics, a description of the methods and techniques which have been developed for addressing these challenges, and the results of some validation studies relative to power-distribution calculations. Numerical tests have shown that the VARIANT nodal code yields eigenvalue and power predictions as accurate as finite difference and discrete ordinates transport codes, at a small fraction of the cost. Comparisons with contin… more
Date: March 1, 1994
Creator: Jacqmin, R. P.; Finck, P. J. & Palmiotti, G.
Partner: UNT Libraries Government Documents Department
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