skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: APOLLO: a general code for transport, slowing-down and thermalization calculations in heterogeneous media

Conference ·
OSTI ID:4392112

From national topical meeting on mathematical models and computational techniques for analysis of nuclear systems; Ann Arbor, Michigan, USA (8 Apr 1973). In mathematical models and computational techniques for analysis of nuclear systems. APOLLO calculates the space-and-energy-dependent flux for a one dimensional medium, in the multigroup approximation of the transport equation. For a one dimensional medium, refined collision probabilities have been developed for the resolution of the integral form of the transport equation; these collision probabilities increase accuracy and save computing time. The interaction between a few cells can also be treated by the multicell option of APOLLO. The diffusion coefficient and the material buckling can be computed in the various B and P approximations with a linearly anisotropic scattering law, even in the thermal range of the spectrum. Eventually this coefficient is corrected for streaming by use of Benoist's theory. The self-shielding of the heavy isotopes is treated by a new and accurate technique which preserves the reaction rates of the fundamental fine structure flux. APOLLO can perform a depletion calculation for one cell, a group of cells or a complete reactor. The results of an APOLLO calculation are the space-and-energy-dependent flux, the material buckling or any reaction rate; these results can also be macroscopic cross sections used as input data for a 2D or 3D depletion and diffusion code in reactor geometry. 10 references. (auth)

Research Organization:
Centre d'Etudes Nucleaires, Saclay, France; American Nuclear Society. Michigan Section
NSA Number:
NSA-29-007172
OSTI ID:
4392112
Report Number(s):
CONF-730414-P1
Resource Relation:
Conference: National topical meeting on mathematical models and computational techniques for analysis of nuclear systems, Ann Arbor, Michigan, USA, 8 Apr 1973; Other Information: Orig. Receipt Date: 30-JUN-74; Related Information: Mathematical models and computational techniques for analysis of nuclear systems
Country of Publication:
Country unknown/Code not available
Language:
English