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Improvements in release probability by using an overpack. [Obsolete munitions]

Description: An analysis was performed to determine the probability of an unconfined release of hazardous material as a consequence of being involved in a severe transportation accident. Two packaging scenarios were considered: (1) material was palletized and placed in a standard aluminum sided trailer, and (2) the same material was placed in an overpackage. In addition to truck, both rail and air transport were also considered. Several release categories were defined ranging from minor to very large, and the effectiveness of the overpackage to reduce the probability of unconfined release was evaluated for each type of release category. The results are applicable to the transport of radioactive materials in similar overpackages. The potential accident scenarios for a pallet of obsolete munitions were identified using a fault-free methodology.
Date: January 1, 1986
Creator: Rhyne, W.R.; Ashwood, T.L. & Shappert, L.B.
Partner: UNT Libraries Government Documents Department
open access

Automated Monte Carlo biasing for photon-generated electrons near surfaces.

Description: This report describes efforts to automate the biasing of coupled electron-photon Monte Carlo particle transport calculations. The approach was based on weight-windows biasing. Weight-window settings were determined using adjoint-flux Monte Carlo calculations. A variety of algorithms were investigated for adaptivity of the Monte Carlo tallies. Tree data structures were used to investigate spatial partitioning. Functional-expansion tallies were used to investigate higher-order spatial representations.
Date: September 1, 2009
Creator: Franke, Brian Claude; Crawford, Martin James & Kensek, Ronald Patrick
Partner: UNT Libraries Government Documents Department
open access

Transport data libraries for incident proton and neutron energies to 100 MeV

Description: A joint effort between the Applied Nuclear Science and Radiation Transport groups at Los Alamos has begun to develop and implement proton, neutron, and photon transport libraries for incident energies up to 100 MeV. The major steps involved in this effort are: (1) development of evaluated (ENDF/B) data formats appropriate for higher energies; (2) extension of low-energy nuclear physics theoretical models for applicability up to 100 MeV; (3) calculation and evaluation of nuclear data in ENDF/B-VI format for appropriate materials up to 100 MeV; (4) development of processing code capabilities to handle the higher energy data; and (5) development of the appropriate interfaces and code patches for use of data in transport codes such as MCNP. In this paper we mainly discuss the development of the basic transport data library, items (2) and (3) above, and summarize the remaining activities. 14 refs.
Date: January 1, 1989
Creator: Young, P. G.; Arthur, E. D.; Bozoian, M.; England, T. R.; Hale, G. M.; LaBauve, R. J. et al.
Partner: UNT Libraries Government Documents Department
open access

On Carrier Facilitated Transport Through Membranes

Description: Facilitated transport is a process, whereby the diffusion of a solute across a membrane is chemically enhanced. In this report an analysis is given of a facilitated transport system involving a volatile species A which reacts with a nonvolatile carrier species B to form the nonvolatile product AB.
Date: June 1980
Creator: Kaper, H. G.; Leaf, G. K. & Matkowsky, Bernard J.
Partner: UNT Libraries Government Documents Department
open access

Low-temperature charge transport in Ga-acceptor nanowires implanted by focused-ion beams

Description: Ga-acceptor nanowires were embedded in crystalline Si using focused-ion beams. The dc current-voltage characteristics of these wires after annealing are highly nonlinear at low temperatures, and a threshold voltage of less than 50 mV is observed independent of Ga+ dosage and implant beam overlap. These features suggest a Coulomb blockade transport mechanism presumably caused by a network of Ga precipitates in the substrate. This granular scenario is further supported by measurements of gated nanowires. Nanowires with metallic conductance at low temperatures could be achieved by reducing the current density of the focused-ion beams.
Date: July 31, 2007
Creator: Schenkel, Thomas; Robinson, S.J.; Perkins, C.L.; Tucker, J.R.; Schenkel, T.; Wang, X.W. et al.
Partner: UNT Libraries Government Documents Department
open access

Finite element method for solving neutron transport problems

Description: A finite element method is introduced for solving the neutron transport equations. Our method falls into the category of Petrov-Galerkin solution, since the trial space differs from the test space. The close relationship between this method and the discrete ordinate method is discussed, and the methods are compared for simple test problems.
Date: March 21, 1984
Creator: Ferguson, J.M. & Greenbaum, A.
Partner: UNT Libraries Government Documents Department
open access

DOE transporation programs - computerized techniques

Description: One of the major thrusts of the transportation programs at the Oak Ridge National Laboratory has been the development of a number of computerized transportation programs and data bases. The U.S. Department of Energy (DOE) is supporting these efforts through the Transportation Technology Center at Sandia National Laboratories and the Tranportation Operations and Traffic Management (TOTM) organization at DOE Headquarters. Initially this project was centered upon research activities. However, since these tools provide traffic managers and key personnel involved in preshipment planning with a unique resource for ensuring that the movement of radioactive materials can be properly accomplished, additional interest and support is coming from the operational side of DOE. The major accomplishments include the development of two routing models (one for rail shipments and the other for highway shipments), an emergency response assistance program, and two data bases containing pertinent legislative and regulatory information. This paper discusses the mose recent advances in, and additions to, these computerized techniques and provides examples of how they are used.
Date: January 1, 1983
Creator: Joy, D.S.; Johnson, P.E.; Fore, C.S. & Peterson, B.E.
Partner: UNT Libraries Government Documents Department
open access

Energy Deposition by 45-GeV Photons in H, Be, Al, Cu, and Ta

Description: Electron--photon cascade calculations have been carried out for zero- width beams of 45-GeV photons normally incident on semi-infinite slabs of hydrogen, beryllium, aluminum, copper, and tantalum. The energy deposition is given as a function of both depth and radius in the slabs. (auth)
Date: January 1, 1974
Creator: Alsmiller, R. G., Jr. & Barish, J.
Partner: UNT Libraries Government Documents Department
open access

Angular Distribution of Particles Emerging from a Diffusive Region and its Implications for the Fleck-Canfield Random Walk Algorithm for Implicit Monte Carlo Radiation Transport

Description: We present various approximations for the angular distribution of particles emerging from an optically thick, purely isotropically scattering region into a vacuum. Our motivation is to use such a distribution for the Fleck-Canfield random walk method [1] for implicit Monte Carlo (IMC) [2] radiation transport problems. We demonstrate that the cosine distribution recommended in the original random walk paper [1] is a poor approximation to the angular distribution predicted by transport theory. Then we examine other approximations that more closely match the transport angular distribution.
Date: July 3, 2000
Creator: Cooper, M. A.
Partner: UNT Libraries Government Documents Department
open access

Baseline requirements of the proposed action for the Transportation Management Division routing models

Description: The potential impacts associated with the transportation of hazardous materials are important to shippers, carriers, and the general public. This is particularly true for shipments of radioactive material. The shippers are primarily concerned with safety, security, efficiency, and equipment requirements. The carriers are concerned with the potential impact that radioactive shipments may have on their operations--particularly if such materials are involved in an accident. The general public has also expressed concerns regarding the safety of transporting radioactive and other hazardous materials through their communities. Because transportation routes are a central concern in hazardous material transport, the prediction of likely routes is the first step toward resolution of these issues. In response to these routing needs, several models have been developed over the past fifteen years at Oak Ridge National Laboratory (ORNL). The HIGHWAY routing model is used to predict routes for truck transportation, the INTERLINE routing model is used to predict both rail and barge routes, and the AIRPORT locator model is used to determine airports with specified criteria near a specific location. As part of the ongoing improvement of the US Department of Energy`s (DOE) Environmental Management Transportation Management Division`s (EM-261) computer systems and development efforts, a Baseline Requirements Assessment Session on the HIGHWAY, INTERLINE, and AIRPORT models was held at ORNL on April 27, 1994. The purpose of this meeting was to discuss the existing capabilities of the models and data bases and to review enhancements of the models and data bases to expand their usefulness. The results of the Baseline Requirements Assessment Section will be discussed in this report. The discussions pertaining to the different models are contained in separate sections.
Date: February 1, 1995
Creator: Johnson, P.E. & Joy, D.S.
Partner: UNT Libraries Government Documents Department
open access

US Department of Energy Transportation Programs: computerized techniques

Description: The US Department of Energy is currently sponsoring the development of four specialized transportation programs at Oak Ridge National Laboratory. The programs function as research tools that provide unique computerized techniques for planning the safe shipment of radioactive and hazardous materials. Major achievements include the development of rail and highway routing models, an emergency response assistance program, a data base focusing on legislative requirements, and a resource file identifying key state and local contacts. A discussion of each program and data base is presented, and several examples reflecting each project's applications to the overall DOE transportation program are provided. The interface of these programs offers a dynamic resource of data for use during preshipment planning stages. 9 references, 10 figures, 2 tables.
Date: January 1, 1984
Creator: Joy, D.S.; Johnson, P.E.; Fore, C.S. & Peterson, B.E.
Partner: UNT Libraries Government Documents Department
open access

Public information circular for shipments of irradiated reactor fuel. Revision 5

Description: This circular has been prepared in response to numerous requests for information regarding routes used for the shipment of irradiated reactor (spent) fuel subject to regulation by the Nuclear Regulatory Commission (NRC), and to meet the requirements of Public Law 96-295. The NRC staff must approve such routes prior to their first use in accordance with the regulatory provisions of Section 73.37 of 10 CFR Part 73. The information included reflects NRC staff knowledge as of June 1, 1985. Spent fuel shipment routes, primarily for road transportation, but also including one rail route, are indicated on reproductions of DOT road maps. Also included are the amounts of material shipped during the approximate three year period that safeguards regulations for spent fuel shipments have been effective. In addition, the Commission has chosen to provide information in this document regarding the NRC's safety and safeguards regulations for spent fuel shipment as well as safeguards incidents regarding spent fuel shipments (of which none have been reported to date). This additional information is furnished by the Commission in order to convey to the public a more complete picture of NRC regulatory practices concerning the shipment of spent fuel than could be obtained by the publication of the shipment routes and quantities alone.
Date: June 1, 1985
Partner: UNT Libraries Government Documents Department
open access

Escape and transmission probabilities in cylindrical geometry

Description: An improved technique for the generation of escape and transmission probabilities in cylindrical geometry was applied to the existing resonance cross section processing code ROLAIDS. The algorithm of Hwang and Toppel, (ANL-FRA-TM-118) (with modifications) was employed. The probabilities generated were found to be as accurate as those given by the method previously applied in ROLAIDS, while requiring much less computer core storage and CPU time. (RWR)
Date: January 1, 1980
Creator: Bjerke, M.A.
Partner: UNT Libraries Government Documents Department
open access

Transverse centroid oscillations in solenoidially focused beam transport lattices

Description: Linear equations of motion are derived that describe small-amplitude centroid oscillations induced by displacement and rotational misalignments of the focusing solenoids in the transport lattice, dipole steering elements, and initial centroid offset errors. These equations are analyzed in a local rotating Larmor frame to derive complex-variable"alignment functions" and"bending functions" that efficiently describe the characteristics of the centroid oscillations induced by mechanical misalignments of the solenoids and dipole steering elements. The alignment and bending functions depend only on properties of the ideal lattice in the absence of errors and steering and have associated expansion amplitudes set by the misalignments and steering fields. Applications of this formulation are presented for statistical analysis of centroid deviations, calculation of actual lattice misalignments from centroid measurements, and optimal beam steering.
Date: August 1, 2008
Creator: Lund, Steven M.; Wootton, Christopher J. & Lee, Edward P.
Partner: UNT Libraries Government Documents Department
open access

Piecewise linear discretization of Symbolic Implicit Monte Carlo radiation transport in the difference formulation

Description: We describe a Monte Carlo solution for time dependent photon transport, in the difference formulation with the material in local thermodynamic equilibrium (LTE), that is piecewise linear in its treatment of the material state variable. Our method employs a Galerkin solution for the material energy equation while using Symbolic Implicit Monte Carlo (SIMC) to solve the transport equation. In constructing the scheme, one has the freedom to choose between expanding the material temperature, or the equivalent black body radiation energy density at the material temperature, in terms of finite element basis functions. The former provides a linear treatment of the material energy while the latter provides a linear treatment of the radiative coupling between zones. Subject to the conditional use of a lumped material energy in the vicinity of strong gradients, possible with a linear treatment of the material energy, our approach provides a robust solution for time dependent transport of thermally emitted radiation that can address a wide range of problems. It produces accurate results in the diffusion limit.
Date: November 15, 2005
Creator: Brooks III, E D; Szoke, A & Peterson, J L
Partner: UNT Libraries Government Documents Department
open access

Advantages of Analytical Transformations in Monte Carlo Methods for Radiation Transport

Description: Monte Carlo methods for radiation transport typically attempt to solve an integral by directly sampling analog or weighted particles, which are treated as physical entities. Improvements to the methods involve better sampling, probability games or physical intuition about the problem. We show that significant improvements can be achieved by recasting the equations with an analytical transform to solve for new, non-physical entities or fields. This paper looks at one such transform, the difference formulation for thermal photon transport, showing a significant advantage for Monte Carlo solution of the equations for time dependent transport. Other related areas are discussed that may also realize significant benefits from similar analytical transformations.
Date: December 13, 2004
Creator: McKinley, M. S.; Brooks, E. D., III & Daffin, F.
Partner: UNT Libraries Government Documents Department
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