S. Taher Aminfarkhani - Department of Physics, K.N. Toosi University of Technology, P. O. Box ۱۵۸۷۵-۴۴۱۶, Tehran, Iran
Ahmad Lashkari - Nuclear Reactor and Safety School, Nuclear Science and Technology Research Institute (NSTRI), Atomic Energy Organization of Iran, Tehran, Iran
S. Farhad Masoudi - Department of Physics, K.N. Toosi University of Technology, P. O. Box ۱۵۸۷۵-۴۴۱۶, Tehran, Iran

The present work is concerned on neutron flux increasing in Tehran Research Reactor (TRR). TRR is a ۵ MW pool-type research reactor with plate type fuels in which the light water is used as both the coolant and moderator. The main goal of this paper is reaching to the average thermal neutron flux of the order of ۱۰۱۴ #/cm-۲.s-۱ in the central irradiation box. Combination of the TRR power upgrading with the compact core can enable us to reach a neutron flux higher than ۱.۵ × ۱۰۱۴ #/cm-۲.s-۱ without violating the neutronic and thermal-hydraulic safety criteria. The compact core, with ۱۹ and ۵ standard and control fuel elements respectively, is used as a base for the neutronic analyses. Compact core with ۲۶ fuel assemblies fulfilled all neutronic and operation criteria. Considering thermal hydraulic aspect from previous study lets TRR to be upgraded to ۸.۵ MW, resulting in neutron thermal flux greater than ۱.۵ × ۱۰۱۴

TRR, Neutronic Analyses, power upgrading, MTR, CITVAP code