Development of high efficiency containment venting system by using AgX

Tadashi Narabayashi, Yuuhei Sugano, Hiroki Imaeda, Go Chiba, Nobuaki Sato, Koji Endo, Toshiki Kobayashi

Research output: Chapter in Book/Report/Conference proceedingConference contribution

4 Citations (Scopus)


Fukushima Daiichi NPP accident would be terminated, if sufficient accident countermeasures, such as water proof door, mobile power, etc [1, 2]. In case of Europe, it had already installed the heat removal system and filtered containment venting system (FCVS) from the lessons of TMI and Chernobyl Accidents. The new regulatory standard in Japan, the filtered vent system (FCVS) should be installed, and prevent the radioactive material in case of the severe accident and the overpressure breakage prevention of a primary containment vessel (PCV) and also the robustization of the FCVS. The authors examined the severe accident process in the 2nd unit of Fukushima Daiichi NPS, and found the vent by FCVS should be done before water injection into the core. The PCV spray and water injection into the pedestal basement should be also the countermeasures to the severe accident. Countermeasures for an intentional aircraft collision should be installed too. Upon occurrence of a severe accident (SA), vent gas with radioactive fission products is blown out to a scrubbing pool through numerous venturi nozzles. Mist in steam moves upward to a metal fiber filter through a multi-hole baffle plate. After the mist is removed by that filter, radioactive methyl iodine (CH3I) is captured on the surface of a molecular sieve or AgX, made from zeolite particles with silver coating. A FCVS visualized test facility was installed at Hokkaido University. An AgX filter is used down-stream of the scrubbing pool and metal fiver filter. Thickness of AgX filter is very important parameter to obtain enough decontamination factor (DF). The DF for the radioactive iodine exceeds 10,000 at bed depth (AgX filter thickness) greater than 75mm.

Original languageEnglish
Title of host publicationThermal-Hydraulics
PublisherAmerican Society of Mechanical Engineers (ASME)
ISBN (Electronic)9780791850039
Publication statusPublished - 2016
Event2016 24th International Conference on Nuclear Engineering, ICONE 2016 - Charlotte, United States
Duration: 2016 Jun 262016 Jun 30

Publication series

NameInternational Conference on Nuclear Engineering, Proceedings, ICONE


Other2016 24th International Conference on Nuclear Engineering, ICONE 2016
Country/TerritoryUnited States

ASJC Scopus subject areas

  • Nuclear Energy and Engineering


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