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Title: A massively parallel algorithm for the collision probability calculations in the Apollo-II code using the PVM library

Conference ·
OSTI ID:459277
 [1]
  1. Centre d`Etudes de Saclay, Gif sur Yvette (France)

The collision probability method in neutron transport, as applied to 2D geometries, consume a great amount of computer time, for a typical 2D assembly calculation about 90% of the computing time is consumed in the collision probability evaluations. Consequently RZ or 3D calculations became prohibitive. In this paper the author presents a simple but efficient parallel algorithm based on the message passing host/node programmation model. Parallelization was applied to the energy group treatment. Such approach permits parallelization of the existing code, requiring only limited modifications. Sequential/parallel computer portability is preserved, which is a necessary condition for a industrial code. Sequential performances are also preserved. The algorithm is implemented on a CRAY 90 coupled to a 128 processor T3D computer, a 16 processor IBM SPI and a network of workstations, using the Public Domain PVM library. The tests were executed for a 2D geometry with the standard 99-group library. All results were very satisfactory, the best ones with IBM SPI. Because of heterogeneity of the workstation network, the author did not ask high performances for this architecture. The same source code was used for all computers. A more impressive advantage of this algorithm will appear in the calculations of the SAPHYR project (with the future fine multigroup library of about 8000 groups) with a massively parallel computer, using several hundreds of processors.

OSTI ID:
459277
Report Number(s):
CONF-950420-; TRN: 97:007172
Resource Relation:
Conference: International conference on mathematics and computations, reactor physics, and environmental analyses, Portland, OR (United States), 30 Apr - 4 May 1995; Other Information: PBD: 1995; Related Information: Is Part Of Proceedings of the international conference on mathematics and computations, reactor physics, and environmental analyses. Volume 1 and 2; PB: 1629 p.
Country of Publication:
United States
Language:
English

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