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  1. Nuria Casacuberta on March 8, 2021 at 4:50 pm

    Dear Tazoe,
    thank you so much for putting together this poster.
    Do you think that we can have a good estimate today of the total amount of 90Sr released after 2011? In 2011 we estimated about some TBq of 90Sr that had been released. Do you think we could have a more accurate number today that would also include later releases of 90Sr?
    Also, did TEPCO report any number regarding the 90Sr that may be stored in the tanks today?
    Thank you and best regards,

    • Hirofumi Tazoe on March 10, 2021 at 8:54 pm

      Nuria, Thank you for your question.
      I think there are some issues with improving the Sr-90 emission estimate. Direct leakage events of contaminated water from the reactor buildings from late March to April 2011 are well documented in your study. Regarding the continuous leakage until 2015, I think that the almost same value is reported although it is described in a few studies including my research. However, since these estimates depend on the ratio to radioactive Cs, the contribution of Cs-rich or Sr-rich (for example, treated water stored in the tank) from other than the reactor can increases uncertainty. Moreover, even TEPCO’s data are sampled infrequently, so they have not been able to confirm sporadic emission events. I hope to reconstruct the history on Sr-90 by examining the coastal seawater samples and shell of marine bivalves. For that purpose, the development of analytical methods such as AMS and TIMS may be useful.
      Best regards,
      Hirofumi Tazoe

  2. Nuria Casacuberta on March 12, 2021 at 3:16 am

    Dear Tazoe,
    thank you for your answer and I look forward to see your future studies on this.
    All the best,