Development of a mitigation system against hydrogen-air deflagrations in nuclear power plants

Hiroyasu Saitoh, Teruhito Otsuka, Norihiko Yoshikawa, Nozomu Kanno, Seiji Takanashi, Yousuke Oozawa, Masahiro Hirata, Masayuki Takeshita, Kenji Sakuragi, Sayuri Kurihara, Yuichiro Tsunashima, Naohito Aoki, Kento Tanaka

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)


A novel mitigation system against hydrogen-air deflagrations in nuclear power plant buildings is proposed and developed through a series of field experiments using explosion vessels of different volume sizes. The mitigation system is installed on the outer surface of the vessels, and it comprises flame arrester and explosion air bag. The flame arrester is made by stacking 10–20 sheets of fine-mesh wire screens, and the air bag is connected for holding explosion gas. The successful mitigation mechanism is the sequence of pressure-rise reduction by the air bag expansion, flame quenching by the flame arrester, and the slow burning of the gas mixture sucked from the air bag back into the vessel due to the negative pressure caused by the rapid condensation of water vapor inside the vessel. Necessary conditions for the successful mitigation system are discussed, and the practical unit size of flame arrester sheet is recommended.

Original languageEnglish
Pages (from-to)9-16
Number of pages8
JournalJournal of Loss Prevention in the Process Industries
Publication statusPublished - 2019 Jul


  • Deflagration
  • Flame arrester
  • Hydrogen explosion
  • Mitigation
  • Nuclear power plant
  • Severe accident

ASJC Scopus subject areas

  • Control and Systems Engineering
  • Food Science
  • Chemical Engineering(all)
  • Safety, Risk, Reliability and Quality
  • Energy Engineering and Power Technology
  • Management Science and Operations Research
  • Industrial and Manufacturing Engineering


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