Investigating Possibilities of fuelling NIRR-1 with Low Enriched Uranium Silicide-Aluminum Dispersion Fuels

Abstract

In the last quarter of 2018, low enriched uranium dioxide fuel with zirconium alloy cladding was used successfully to convert the core of NIRR-1 from HEU to LEU fuel and the removed core returned to the country of origin. The objective of this study was to investigate the possibility of fueling the same system with alternate LEU fuel for future replacement of the current fuel, without any unacceptable compromise in reactor performance. Having more than one fuel options available for the same reactor system will present Nigeria an opportunity of making good economic decisions at the end of the cycle of the current LEU fuel. The performance of low enriched uranium silicide aluminum dispersion fuels in the core of NIRR-1 has been investigated and the results were identical with that of similar studies conducted elsewhere for generic MNSR system. Some of the calculated reactor parameters using this alternate LEU fuel were closely identical with that of the old HEU core. The computer software selected for this studies were the SCALE code system and the VENTURE PC. While the SCALE code system was employed to generate a properly averaged multigroup cross section library for the investigated LEU core models for NIRR-1 system, the VENTURE PC was utilized to give criticality information, few group fluxes and power density distributions within the core of the modeled system.Keywords— Reactor, Reactivity, Fuel, Enriched, Silicide