Development of high efficiency filtered containment venting system by using two-phase flow technology and AGX

Tadashi Narabayashi, Naoto Kitahara, Yuuhei Sugano, Go Chiba, Nobuaki Sato

Research output: Contribution to conferencePaperpeer-review

Abstract

Fukushima Daiichi NPP accident would be terminated, if sufficient accident countermeasures, such as water proof door, mobile power, etc1, 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 enhance the robustness of the FCVS against intentional aircraft-attack. 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
Publication statusPublished - 2017
Event17th International Topical Meeting on Nuclear Reactor Thermal Hydraulics, NURETH 2017 - Xi'an, Shaanxi, China
Duration: 2017 Sep 32017 Sep 8

Other

Other17th International Topical Meeting on Nuclear Reactor Thermal Hydraulics, NURETH 2017
Country/TerritoryChina
CityXi'an, Shaanxi
Period17/9/317/9/8

ASJC Scopus subject areas

  • Nuclear Energy and Engineering
  • Instrumentation

Fingerprint

Dive into the research topics of 'Development of high efficiency filtered containment venting system by using two-phase flow technology and AGX'. Together they form a unique fingerprint.

Cite this