First-principles modelling of radiation defects in advanced nuclear fuels

E. A. Kotomin, D. Gryaznov, R. W. Grimes, D. Parfitt, Yu F. Zhukovskii, Yu A. Mastrikov, P. Van Uffelen, V. V. Rondinella, R. J.M. Konings

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

We present and discuss the results of the first-principles calculations of Frenkel defects and O impurities in uranium mononitride (UN) perspective for fast reactor nuclear fuels. Special attention is paid to the calculation of defect migration energies. We demonstrate that the interstitialcy mechanism (with the formation of a N-N dumbbell along the [1 1 1] axis) is energetically more favorable than the direct [1 0 0] hops. As a result, for the interstitial N ions we predict a diffusion mechanism similar to that known in isostructural fcc materials with a different chemical nature (KCl, MgO). The calculated effective N charge considerably depends on the ion position and environment (a host lattice site, interstitial or saddle point) which strongly limits the applicability of classical defect modelling based on formal invariant charges. Lastly, the calculated migration energy for the interstitial impurity O ions is quite low (2.84 eV), which indicates their high mobility and ability for reactions with other defects.

Original languageEnglish
Pages (from-to)2671-2675
Number of pages5
JournalNuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms
Volume266
Issue number12-13
DOIs
Publication statusPublished - 1 Jun 2008
Externally publishedYes

Keywords

  • Defect migration
  • First-principles calculations
  • Frenkel defects
  • O impurity
  • Supercell model
  • Uranium mononitride (UN)

ASJC Scopus subject areas

  • Nuclear and High Energy Physics
  • Instrumentation

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