Calculation of oxygen potential change of irradiated UO2 and UO2-PuO2 mixed oxide fuels using the intra-cation complex model

Takeo Fujino, Nobuaki Sato, Toshiyuki Yamashita, Kinji Ouchi

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)


The oxygen potential change of irradiated uranium dioxide and urania-plutonia mixed oxide fuels, which is caused by the formation of solid solutions of some fission product metals with the fuel oxides, was calculated using the intra-cation complex model. It assumes weak-bound complexes between the cations of relatively positive and negative charges with respect to U4+. Partial molar entropy of oxygen, Δ S ̄O2, was derived by differentiating the logarithm of the number of ways of arranging the cationic defects and complexes over the cation sublattices. The fission product metals which dissolve into the fuel matrix were classified into +2, +3 and +4 valence state ion groups, and their effect on Δ G ̄O2 was clarified in the equations of Δ G ̄O2 representation. Comparison of the calculated results with the Δ G ̄O2 values for irradiated fuels as well as for the fuels containing some fission product simulant cations revealed that agreement was good, showing that the Δ G ̄O2 change on irradiation can be expressed as a function of M3+ fraction.

Original languageEnglish
Pages (from-to)70-80
Number of pages11
JournalJournal of Nuclear Materials
Issue numberC
Publication statusPublished - 1993 May 2

ASJC Scopus subject areas

  • Nuclear and High Energy Physics
  • Materials Science(all)
  • Nuclear Energy and Engineering

Fingerprint Dive into the research topics of 'Calculation of oxygen potential change of irradiated UO<sub>2</sub> and UO<sub>2</sub>-PuO<sub>2</sub> mixed oxide fuels using the intra-cation complex model'. Together they form a unique fingerprint.

Cite this