Current Status of the Post Boiling Transition Research in Japan Integrity Evaluation of Nuclear Fuel Assemblies after Boiling Transition and Development of Rewetting Correlations

Takashi Hara, Shinya Mizokami, Yoshiro Kudo, Seiichi Komura, Yoshifumi Nagata, Shinichi Morooka

Research output: Contribution to journalArticle

9 Citations (Scopus)


Development of rewetting correlation formula was the key to predict fuel-cladding temperature after Boiling Transition (BT). Japanese BWR utilities and vendors performed some tests of rewetting and made two rewetting correlation formulas. The effect on fuel integrity after BT depends on temperature of fuel rod and time of dryout. Main cause of losing fuel integrity during BWR's Anticipated Operational Occurrences (AOO) after BT is embrittlement of the claddings due to oxidation. Ballooning of fuel rod is excepted because its pressure boundary isn't broken. In Japan, the Standards Committee of Atomic Energy Society of Japan (AESJ) is making post BT standard. This standard provides guidelines based on the latest knowledge to judge fuel integrity in case of BT and the validity of reusing the fuel assembly that experienced BT in BWRs.

Original languageEnglish
Pages (from-to)852-861
Number of pages10
JournalJournal of Nuclear Science and Technology
Issue number10
Publication statusPublished - 2003 Oct
Externally publishedYes



  • Boiling transition
  • Dryout
  • Fuel cladding temperature
  • Fuel integrity
  • Japan
  • Rewet

ASJC Scopus subject areas

  • Nuclear Energy and Engineering

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