Title: Study on the temperature distributions in fuel assemblies of lead-cooled fast reactors

Authors: Gilberto Espinosa-Paredes; Juan-Luis François; Heriberto Sánchez-Mora; Alejandría D. Pérez-Valseca; Cecilia Martín-del-Campo

Addresses: Área de Ingeniería en Recursos Energéticos, Universidad Autónoma Metropolitana-Iztapalapa, Av. San Rafael Atlixco 186, Col. Vicentina, México DF 09340, México; Facultad de Ingeniería, Universidad Nacional Autónoma de México, Programa de Estancias Sabáticas del CONACyT, Morelos, México ' Departamento de Sistemas Energéticos, Facultad de Ingeniería, Universidad Nacional Autónoma de México, Paseo Cuauhnáhuac 8532, 62550 Jiutepec, Morelos, México ' Área de Ingeniería en Recursos Energéticos, Universidad Autónoma Metropolitana-Iztapalapa, Av. San Rafael Atlixco 186, Col. Vicentina, México DF 09340, México; Departamento de Sistemas Energéticos, Facultad de Ingeniería, Universidad Nacional Autónoma de México, Paseo Cuauhnáhuac 8532, 62550 Jiutepec, Morelos, México ' Área de Ingeniería en Recursos Energéticos, Universidad Autónoma Metropolitana-Iztapalapa, Av. San Rafael Atlixco 186, Col. Vicentina, México DF 09340, México ' Departamento de Sistemas Energéticos, Facultad de Ingeniería, Universidad Nacional Autónoma de México, Paseo Cuauhnáhuac 8532, 62550 Jiutepec, Morelos, México

Abstract: The aim of this paper is to make a comparative study of two concepts of Lead-Cooled Fast Reactor (LFR) fuel assemblies, from a point of view of the thermofluids performance. The sub-channel analysis approach was applied to determine the temperature distribution in the fuel, in the cladding and in the lead-coolant. The mathematical model is fully transient and takes into account the heat transfer in an annular fuel pellet design. The thermofluid is modelled with a mass, energy and momentum balance with thermal expansion effects. The neutronic processes are modelled with point kinetic equations for power generation with feedback fuel temperature and expansion effects. The numerical experiments consider steady-state and transient behaviours. The numerical comparison shows that a hexagonal assembly is an option to compact the size of the LFR core design. This option leads to higher temperature in the fuel and the cladding than in the case of a rectangular assembly design. Results show the LFR with square array is more sensitive to power changes than the hexagonal array at the same nominal power and with the same transient conditions.

Keywords: lead-cooled reactor; fast reactor; ELSY; annular fuel; fuel assembly; sub-channel analysis.

DOI: 10.1504/IJNEST.2017.085776

International Journal of Nuclear Energy Science and Technology, 2017 Vol.11 No.2, pp.183 - 203

Received: 21 Apr 2017
Accepted: 14 Jun 2017

Published online: 12 Aug 2017 *

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