Helium behavior in oxide nuclear fuels: First principles modeling

D. Gryaznov, Sergey Rashkeev, E. A. Kotomin, E. Heifets, Y. Zhukovskii

Research output: Contribution to journalArticle

26 Citations (Scopus)

Abstract

UO2 and (U, Pu)O2 solid solutions (the so-called MOX) nowadays are used as commercial nuclear fuels in many countries. One of the safety issues during the storage of these fuels is related to their self-irradiation that produces and accumulates point defects and helium therein. We present density functional theory (DFT) calculations for UO2, PuO2 and MOX containing He atoms in octahedral interstitial positions. In particular, we calculated basic MOX properties and He incorporation energies as functions of Pu concentration within the spin-polarized, generalized gradient approximation (GGA) DFT calculations. We also included the on-site electron correlation corrections using the Hubbard model (in the framework of the so-called DFT + U approach). We found that PuO2 remains semiconducting with He in the octahedral position while UO2 requires a specific lattice distortion. Both materials reveal a positive energy for He incorporation, which, therefore, is an exothermic process. The He incorporation energy increases with the Pu concentration in the MOX fuel.

Original languageEnglish
Pages (from-to)3090-3094
Number of pages5
JournalNuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms
Volume268
Issue number19
DOIs
Publication statusPublished - 1 Oct 2010
Externally publishedYes

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Keywords

  • Actinide oxide
  • Correlation correction
  • DFT
  • Incorporation energy

ASJC Scopus subject areas

  • Instrumentation
  • Nuclear and High Energy Physics

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