Computational Study of 19.75% UO2 Fuel for the Core Conversion of Nigeria Research Reactor-1 (NIRR-1) from HEU to LEU

Abstract

SCALE 6.1 code system and VENTURE-PC code system has been used for the core conversion of Miniature Neutron Source Reactor (MNSR) from Highly Enriched Uranium (HEU) system (90.2% enriched UAl 4 fuel) to Low Enriched Uranium (LEU) system (19.75% enriched UO 2 -zircaloy-4 fuel). All other structure materials and dimensions of HEU and LEU cores are the same except the increase in the fuel cell diameters for the proposed LEU core. Results obtained show that the peak power density of 4.310033 Watts/cc, maximum neutron density of 6.94535e-6 n/cc, total control rod worth of ሺ723 േ 0.049ሻ pcm, clean cold core excess reactivity of ሺ404 േ 0.009ሻ pcm, k ୣ of ሺ1.0119634 േ 0.0072434ሻ , shutdown margin of ሺ319 േ 0.1003ሻ pcm and neutron flux profile of ሺ1.24 ൈ 10 ଵଶ േ 0.11ሻ ncm ିଶ s ିଵ for the potential LEU core are slightly greater than those of the

Depletion Analysis of the Nigerian Research Reactor Fuel with 19.75% Enriched UO2 Material

“…The current Highly Enriched Uranium (HEU) Nigeria Research Reactor-1 (NIRR-1) has a tank-in-pool structural configuration and a nominal thermal power rating of 31.1 kW [1]. The current core of the reactor is a 230 x 230 mm square cylinder and fueled by using U-Al4 enriched to 90.2% [6]. The computer code selected to perform these depletion/burnup calculations for the current NIRR-1 core is the VENTURE PC [7].…”