Pure and Applied Geophysics

, Volume 171, Issue 3, pp 645-667

First online:

Analysis of Radionuclide Releases from the Fukushima Dai-ichi Nuclear Power Plant Accident Part II

  • Pascal AchimAffiliated withCEA, DAM, DIF Email author 
  • , Marguerite MonfortAffiliated withCEA, DAM, DIF
  • , Gilbert Le PetitAffiliated withCEA, DAM, DIF
  • , Philippe GrossAffiliated withCEA, DAM, DIF
  • , Guilhem DouyssetAffiliated withCEA, DAM, DIF
  • , Thomas TaffaryAffiliated withCEA, DAM, DIF
  • , Xavier BlanchardAffiliated withCEA, DAM, DIF
  • , Christophe MoulinAffiliated withCEA, DAM, DIF

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The present part of the publication (Part II) deals with long range dispersion of radionuclides emitted into the atmosphere during the Fukushima Dai-ichi accident that occurred after the March 11, 2011 tsunami. The first part (Part I) is dedicated to the accident features relying on radionuclide detections performed by monitoring stations of the Comprehensive Nuclear Test Ban Treaty Organization network. In this study, the emissions of the three fission products Cs-137, I-131 and Xe-133 are investigated. Regarding Xe-133, the total release is estimated to be of the order of 6 × 1018 Bq emitted during the explosions of units 1, 2 and 3. The total source term estimated gives a fraction of core inventory of about 8 × 1018 Bq at the time of reactors shutdown. This result suggests that at least 80 % of the core inventory has been released into the atmosphere and indicates a broad meltdown of reactor cores. Total atmospheric releases of Cs-137 and I-131 aerosols are estimated to be 1016 and 1017 Bq, respectively. By neglecting gas/particulate conversion phenomena, the total release of I-131 (gas + aerosol) could be estimated to be 4 × 1017 Bq. Atmospheric transport simulations suggest that the main air emissions have occurred during the events of March 14, 2011 (UTC) and that no major release occurred after March 23. The radioactivity emitted into the atmosphere could represent 10 % of the Chernobyl accident releases for I-131 and Cs-137.


Fukushima Dai-ichi accident atmospheric transport modeling source terms evaluation Cs-137 I-131 Xe-133 CTBTO