Title: Verification of a Triga Mark III MCNP model for neutron flux calculations

Authors: Arturo Delfín Loya; Samuel Vargas-Escamilla; Armando Miguel Gómez-Torres; Edmundo Del Valle Gallegos

Addresses: Instituto Nacional de Investigaciones Nucleares, Department of Nuclear Systems, Carretera Mexico-Toluca s/n, La Marquesa, Ocoyoacac, C.P. 52750, Mexico ' Instituto Nacional de Investigaciones Nucleares, Department of Nuclear Systems, Carretera Mexico-Toluca s/n, La Marquesa, Ocoyoacac, C.P. 52750, Mexico ' Instituto Nacional de Investigaciones Nucleares, Department of Nuclear Systems, Carretera Mexico-Toluca s/n, La Marquesa, Ocoyoacac, C.P. 52750, Mexico ' Escuela Superior de Física y Matemáticas, Instituto Politécnico Nacional, México, D.F., Mexico

Abstract: One of the concerns of any fuel configuration change in a research reactor is the ability to produce the same neutron flux. For assessing the impact of fuel changes in the Triga Mark III Mexican research reactor, a detailed model was developed with MCNP-5. The verification was done comparing the fluxes obtained with the ones of the manufacturer. Relative errors in the order of 1% were found in the irradiation core facilities. Using the same model but with the 17th core configuration, the neutron flux was calculated. Neutron flux differences between the initial and the 17th configuration are presented and discussed. Total flux calculated at the irradiation facilities was fitted into correlations providing a valuable way to predict neutron flux as function of height. The developed model can be used to evaluate further changes like the one done in 2012 in which the HEU fuel was replaced with LEU.

Keywords: Triga Mark III reactor; irradiation facilities; neutron flux calculations; MCNP; Monte Carlo N-Particle Transport Codes; fuel changes; nuclear reactors; nuclear energy; nuclear power; modelling; nuclear fuel; fuel elements; low enriched uranium; high enriched uranium.

DOI: 10.1504/IJNEST.2016.077480

International Journal of Nuclear Energy Science and Technology, 2016 Vol.10 No.2, pp.146 - 163

Received: 04 Mar 2016
Accepted: 03 Apr 2016
Published online: 03 Jul 2016 *

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