Impacts of 240Pu self-shielding effect and uncertainties of σ(n,γ) at resonance energy on the reactivity controllability in HTGR inert matrix fuel

Abstract

The resonance (n,γ) reaction of Pu is one of dominant phenomena to the self-shielding effect and the reactivity controllability in plutonium fuel for high temperature gas cooled reactors (HTGRs) aiming to deep-burning. Impacts of the mitigation of the self-shielding effect and nuclear data uncertainties for the resonance (n,γ) reaction of Pu on the reactivity controllability were investigated for various fuel design using MVP code. k∞ decreased from 1.3 to 1.05 and reactivity fluctuation decreased from 30% to 6% in the proposed inert matrix fuel (IMF) design with a dilution of the TRU oxide kernel and the neutron spectrum control because of mitigation of Pu self-shielding effect at 1.056-eV.