Pages: 362-369

Authors: Atta Muhammad, Masood Iqbal, Tayyab Mahmood

Abstract

Utilizing low enriched uranium silicide fuel (U₃Si₂-Al) of existing uranium density (3.285 g/cm³), different core configurations have been studied in search of an equilibrium core with an improved performance for the Pakistan Research Reactor-1. Furthermore, we have extended our analysis to the performance of higher density silicide fuels with a uranium density of 4.0 and 4.8 U g/cm³. The criterion used in selecting the best performing core was that of “unit flux time cycle length per ²³⁵U mass per cycle”.
In order to analyze core performance by improving neutron moderation, utilizing higher-density fuel, the effect of the coolant channel width was also studied by reducing the number of plates in the standard/control fuel element. Calculations employing computer codes WIMSD/4 and CITATION were performed. A ten energy group structure for fission neutrons was used for the generation of microscopic cross-sections through WIMSD/4. To search the equilibrium core, two-dimensional core modelling was performed in CITATION. Performance indicators have shown that the higher-density uranium silicide-fuelled core (U density 4.8 g/cm³) without any changes in standard/control fuel elements, comprising of 15 standard and 4 control fuel elements, is the best performing of all analysed cores.

 

Key words: research reactor, reactor fuel, MTR-PC26 package, WIMS/D4, CITATION

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