ATTILA: A threedimensional, unstructured tetrahedral mesh discrete ordinates transport code
Abstract
Many applications of radiation transport require the accurate modeling of complex threedimensional geometries. Historically, Monte Carlo codes have been used for such applications. Existing deterministic transport codes were not applied to such problems because of the difficulties of modeling complex threedimensional geometries with rectangular meshes. The authors have developed a threedimensional discrete ordinates (S{sub n}) code, ATTILA, which uses lineardiscontinuous finite element spatial differencing in conjunction with diffusionsynthetic acceleration (DSA) on an unstructured tetrahedral mesh. This tetrahedral mesh capability enables the authors to efficiently model complex threedimensional geometries. One interesting and challenging application of neutron and/or gammaray transport is nuclear welllogging applications. Nuclear welllogging problems usually involve a complex geometry with fixed sources and one or more detectors. Detector responses must generally be accurate to within {approx}1%. The combination of complex threedimensional geometries and high accuracy requirements makes it difficult to perform logging problems with traditional S{sub n} differencing schemes and rectangular meshes. Hence, it is not surprising that deterministic S{sub n} codes have seen limited use in nuclear welllogging applications. The geometric modeling capabilities and the advanced spatial differencing of ATTILA give it a significant advantage, relative to traditional S{sub n} codes, for performing nuclear welllogging calculations.
 Authors:

 Los Alamos National Lab., NM (United States)
 Publication Date:
 OSTI Identifier:
 426394
 Report Number(s):
 CONF961103
Journal ID: TANSAO; ISSN 0003018X; TRN: 96:0063070116
 Resource Type:
 Journal Article
 Journal Name:
 Transactions of the American Nuclear Society
 Additional Journal Information:
 Journal Volume: 75; Conference: Winter meeting of the American Nuclear Society (ANS) and the European Nuclear Society (ENS), Washington, DC (United States), 1014 Nov 1996; Other Information: PBD: 1996
 Country of Publication:
 United States
 Language:
 English
 Subject:
 02 PETROLEUM; 66 PHYSICS; RADIATION TRANSPORT; DISCRETE ORDINATE METHOD; A CODES; MESH GENERATION; FINITE ELEMENT METHOD; RADIOACTIVITY LOGGING
Citation Formats
Wareing, T A, McGhee, J M, and Morel, J E. ATTILA: A threedimensional, unstructured tetrahedral mesh discrete ordinates transport code. United States: N. p., 1996.
Web.
Wareing, T A, McGhee, J M, & Morel, J E. ATTILA: A threedimensional, unstructured tetrahedral mesh discrete ordinates transport code. United States.
Wareing, T A, McGhee, J M, and Morel, J E. Tue .
"ATTILA: A threedimensional, unstructured tetrahedral mesh discrete ordinates transport code". United States.
@article{osti_426394,
title = {ATTILA: A threedimensional, unstructured tetrahedral mesh discrete ordinates transport code},
author = {Wareing, T A and McGhee, J M and Morel, J E},
abstractNote = {Many applications of radiation transport require the accurate modeling of complex threedimensional geometries. Historically, Monte Carlo codes have been used for such applications. Existing deterministic transport codes were not applied to such problems because of the difficulties of modeling complex threedimensional geometries with rectangular meshes. The authors have developed a threedimensional discrete ordinates (S{sub n}) code, ATTILA, which uses lineardiscontinuous finite element spatial differencing in conjunction with diffusionsynthetic acceleration (DSA) on an unstructured tetrahedral mesh. This tetrahedral mesh capability enables the authors to efficiently model complex threedimensional geometries. One interesting and challenging application of neutron and/or gammaray transport is nuclear welllogging applications. Nuclear welllogging problems usually involve a complex geometry with fixed sources and one or more detectors. Detector responses must generally be accurate to within {approx}1%. The combination of complex threedimensional geometries and high accuracy requirements makes it difficult to perform logging problems with traditional S{sub n} differencing schemes and rectangular meshes. Hence, it is not surprising that deterministic S{sub n} codes have seen limited use in nuclear welllogging applications. The geometric modeling capabilities and the advanced spatial differencing of ATTILA give it a significant advantage, relative to traditional S{sub n} codes, for performing nuclear welllogging calculations.},
doi = {},
journal = {Transactions of the American Nuclear Society},
number = ,
volume = 75,
place = {United States},
year = {1996},
month = {12}
}