Moderator temperature effects on reactivity of HEU core of MNSR

In this article we report on analyses that were performed to investigate the influence of cross section differences among libraries released by various centers on reactivity of Miniature Neutron Source Reactors. The 3D model of the core was developed with WIMS-D and PRIDE codes and six cross section libraries were used including JENDL-3.2, JEF-2.2, JEFF-3.3, ENDF/B-VI and ENDF/B-VII, and IAEA library. It was observed that all the libraries predict the reactivity within 10%, with IAEA library giving minimum reactivity worth, and JEF-2.2 data library resulted in highest worth.

► The MNSR core was analyzed to see the cross section effects on moderator temperature coefficient of reactivity.
► WIMS-D code was used for cell calculations.
► The 3D diffusion theory code PRIDE was first validated using IAEA benchmark problem and then used for analysis of MNSR.
► The differences among results for various libraries were discussed.