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Journal of Radioanalytical and Nuclear Chemistry

, Volume 295, Issue 3, pp 1709–1714 | Cite as

Radon concentration of outdoor air: measured by an ionization chamber for radioisotope monitoring system at radioisotope institute

  • Yukari Tajika
  • Yumi Yasuoka
  • Hiroyuki Nagahama
  • Toshiyuki Suzuki
  • Yoshimi Homma
  • Tetsuo Ishikawa
  • Shinji Tokonami
  • Takahiro Mukai
  • Miroslaw Janik
  • Atsuyuki Sorimachi
  • Masahiro Hosoda
Article

Abstract

Gas-flow ionization chambers for radioisotope (RI) monitoring systems at RI institutes throughout Japan are commonly used to measure RIs which leak from the RI institutes. Before the Japan’s 2011 Tohoku earthquake [11 March 2011, moment magnitude (M w) 9.0], ionization current data measured with a gas-flow ionization chamber at the RI institute of Fukushima Medical University were found to change. The question we must raise is whether the variation ionization current can be considered to the variation of outdoor radon concentration. The conversion factors (from ionization current to radon concentration in air) of the gas-flow ionization chamber can be obtained by measuring four levels of radon concentration (outdoor air, indoor air, high level and radon-free gas) with an AlphaGUARD monitor and the chamber itself. The two gas-flow ionization chambers consist of the air intake and terminal exhaust duct of the RI institute. It was found that the radon concentration in the exhaust air was the same as that in the air intake. This study provided evidence that variations of outdoor radon concentration could be determined using gas-flow ionization chambers for RI monitoring systems.

Keywords

Radon concentration Ionization chambers Outdoor air  Correction factor 

Notes

Acknowledgments

We would like to thank Ms. Marina Thuge and Ms. Shoko Miyamoto of Kobe Pharmaceutical University for discussions about this study.

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Copyright information

© Akadémiai Kiadó, Budapest, Hungary 2012

Authors and Affiliations

  • Yukari Tajika
    • 1
  • Yumi Yasuoka
    • 2
  • Hiroyuki Nagahama
    • 3
  • Toshiyuki Suzuki
    • 4
  • Yoshimi Homma
    • 4
  • Tetsuo Ishikawa
    • 5
  • Shinji Tokonami
    • 6
  • Takahiro Mukai
    • 1
    • 2
  • Miroslaw Janik
    • 5
  • Atsuyuki Sorimachi
    • 6
  • Masahiro Hosoda
    • 6
  1. 1.Department of Biophysical ChemistryKobe Pharmaceutical UniversityKobeJapan
  2. 2.Institute of Radioisotope ResearchKobe Pharmaceutical UniversityKobeJapan
  3. 3.Fault and Geodynamics Research Group, Division of GeoEnvironmental Sciences, Department of Earth Science, Graduate School of ScienceTohoku UniversitySendaiJapan
  4. 4.Fukushima Medical UniversityFukushimaJapan
  5. 5.National Institute of Radiological SciencesChibaJapan
  6. 6.Hirosaki UniversityHirosakiJapan

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