Teruyuki Nakajima
Teruyuki Nakajima : The Accidents at Fukushima Dai-Ichi
http://www.whoi.edu/page.do?pid=108196&cl=87413&article=141569&tid=5122
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Nuclear Watch: Fukushima high Iodine 131 lvls fission reactions for weeks or months 10/27/2014
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http://www.ied.tsukuba.ac.jp/hydrogeo/isetr/ISETRen/paper/geochem46-2.pdf
福島第一原子力発電所の事故により放出された放射性物質の大気中での動態
鶴田治雄＊・中島映至＊
（2012年6月1日受付，2012年6月11日受理）
Radioactive materials in the atmosphere released by the accident of the Fukushima Daiichi Nuclear Power Plant
Haruo TSURUTA＊ and Teruyuki NAKAJIMA＊
＊ Atmosphere and Ocean Research Institute, The University of Tokyo
5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8568, Japan
線量率や大気降下物などの様々なモニタリングデータ
をはじめ，多くの研究機関が独自に調査した結果を含
めて，膨大なデータが，それぞれのホームページなど
で公表されている。そこで，それらのデータをもと
に，放射性物質の放出率推定，放射性物質の原発周辺
での挙動，そして広域汚染の概要，最後に，その後の
大気中での放射性物質の長期変化を中心に，これまで
にわかったことをまとめて，陸域を対象として，本総
説で報告する。なお本稿は，最新のデータを盛り込む
ため，最近の学会・シンポジウム等で発表されたデー
タも多く含めており，学術論文以外からの引用が多い
こと，また，使用した多くのデータはそれぞれの機関
のHP に掲載されているので文献に引用していないこ
と，をお許し頂きたい。
２．福島第一原子力発電所からの放射性物質
の放出量推定
原発事故により，大気中に放出された放射性物質量
の時間変化は，対象領域が25 km×25 km で設定され
た緊急時迅速放射能影響予測ネットワークシステム，
いわゆるSPEEDI（The System for Prediction of Environmental
Emergency Dose Information）（MEXT,
2007）や，さらに広域で放射性物質量を予測可能に
するために，日本原子力研究開発機構（JAEA）が開
発したWSPEEDI-II（Worldwide Version of System
for Prediction of Environmental Emergency Dose
Information-II）（Terada et al., 2008）と，空間放射
線量率やダストサンプリングによるヨウ素―131とセ
シウム―137の大気中の放射能濃度を用いて推定され
た（Chino et al., 2011; Katata et al., 2011）。その
後，原子炉で起こった事象からの放出量推定も一部取
り入れられており（Katata et al., 2012; Terada et al.,
2012），それらをとりまとめたもの（茅野，2012）
を，Fig. 1に示す。放出率が一定の期間は，用いた大
気観測データの時間分解能に依存しているところが大
きい。ヨウ素―131とセシウム―137の放出率比は，3月
Fig. 1 Summary of estimated release rates of 131I and137Cs into the atmosphere after the
Fukushima Daiichi Nuclear Power Plant accident (Chino, 2012) (This figure is quoted
from the website of JAEA Open Workshop, 2012).
100 鶴田治雄・中島映至
==============================================
Nuclear Watch: Fukushima high Iodine 131 lvls fission reactions for weeks or months 10/27/2014
2014/10/27 に公開
Watch: Nuclear experts confront Japanese scientists — IAEA says Fukushima reactors “might still be active” long after meltdowns — “Changes completely” our idea of what happened — “Very surprised… extremely high” Iodine-131 levels — Means fission reactions lasted for weeks or months
Teruyuki Nakajima,University of Tokyo and Science Council of Japan (emphasis added): International Expert #1 (at 38:10): My name is [inaudible] from the International Atomic Energy Agency’s marine laboratory in Monaco. I have a question regarding the Iodine-131. We were very surprised that the Iodine-131 was still discharged at very high levels in July [2011]. We had a lot of discussion about what would be the reason… You’d expect that, according to the shorter half life for Iodine-131, this would decrease much, much stronger — much faster… My briefings to member states of the IAEA was that we would expect within a few weeks there would be no more Iodine-131, but this was not true. This was still measured at high, extremely high levels in July and August of 2011. I wrote in my statement given out by the IAEA, that the reactors might still be active. There was a big discussion about this… Nakajima: Yeah, I think the reactors still emitted the materials in… not sure about July… we have soil measurement in June, I think that still we observed Iodine-131 from the soil measurement. If that is terminated in April, we wouldn’t measure that at this point, but we still had that measurement. And still, the data are not totally thoroughly investigated. We have several remaining data we need to look at. Some people have those data, so we need to dig this kind of data set. Also, monitoring post, we had [problems?] as I told, we couldn’t use, but some are surviving and not rescued. Recently that kind of data is coming in, so we will see that data for Iodine-131… International Expert #2 (at 43:45): I’m sorry, but I’d like to go back to the question of my colleague from the IAEA. If I understand correctly, the question is not whether… in July or August, there still were releases of Iodine. If that is the case, it would change completely the picture about the accident. That was the question that was never clarified, either by TEPCO or by [inaudible]. Nakajima: There’s some evidence [of the reactors] releasing radiogenic gas… International Expert #2: The basic question is the following — several weeks after Chernobyl it was crystal clear there were no more releases of Iodine. If that’s not crystal clear at Fukushima, this means several weeks or months after the accident there were fission reactions. That’s the question. This question was presented, as my colleague said, at several meetings of the IAEA and that was never made clear?… That is an important question because it would change the composition of the releases… International Expert #3 (at 46:45): I also want to [inaudible] the data. I agree with him about the calculation… Iodine had been measured in such amounts in July… Iodine from those same samples — that would allow you [Nakajima] to actually check whether this is satisfied by resuspension, as you claim…. Observations make clear, [Iodine-131 is too high by] orders of magnitude, even in the best cases — and that’s a lot… Nakajima: We have all the data but I haven’t checked Iodine-131… But, still, we are making the data set… Maybe I could check with my file data… (Lights go on) Further questions? OK, well, thank you very much. Sorry.
Teruyuki Nakajima,University of Tokyo and Science Council of Japan (emphasis added): International Expert #1 (at 38:10): My name is [inaudible] from the International Atomic Energy Agency’s marine laboratory in Monaco. I have a question regarding the Iodine-131. We were very surprised that the Iodine-131 was still discharged at very high levels in July [2011]. We had a lot of discussion about what would be the reason… You’d expect that, according to the shorter half life for Iodine-131, this would decrease much, much stronger — much faster… My briefings to member states of the IAEA was that we would expect within a few weeks there would be no more Iodine-131, but this was not true. This was still measured at high, extremely high levels in July and August of 2011. I wrote in my statement given out by the IAEA, that the reactors might still be active. There was a big discussion about this… Nakajima: Yeah, I think the reactors still emitted the materials in… not sure about July… we have soil measurement in June, I think that still we observed Iodine-131 from the soil measurement. If that is terminated in April, we wouldn’t measure that at this point, but we still had that measurement. And still, the data are not totally thoroughly investigated. We have several remaining data we need to look at. Some people have those data, so we need to dig this kind of data set. Also, monitoring post, we had [problems?] as I told, we couldn’t use, but some are surviving and not rescued. Recently that kind of data is coming in, so we will see that data for Iodine-131… International Expert #2 (at 43:45): I’m sorry, but I’d like to go back to the question of my colleague from the IAEA. If I understand correctly, the question is not whether… in July or August, there still were releases of Iodine. If that is the case, it would change completely the picture about the accident. That was the question that was never clarified, either by TEPCO or by [inaudible]. Nakajima: There’s some evidence [of the reactors] releasing radiogenic gas… International Expert #2: The basic question is the following — several weeks after Chernobyl it was crystal clear there were no more releases of Iodine. If that’s not crystal clear at Fukushima, this means several weeks or months after the accident there were fission reactions. That’s the question. This question was presented, as my colleague said, at several meetings of the IAEA and that was never made clear?… That is an important question because it would change the composition of the releases… International Expert #3 (at 46:45): I also want to [inaudible] the data. I agree with him about the calculation… Iodine had been measured in such amounts in July… Iodine from those same samples — that would allow you [Nakajima] to actually check whether this is satisfied by resuspension, as you claim…. Observations make clear, [Iodine-131 is too high by] orders of magnitude, even in the best cases — and that’s a lot… Nakajima: We have all the data but I haven’t checked Iodine-131… But, still, we are making the data set… Maybe I could check with my file data… (Lights go on) Further questions? OK, well, thank you very much. Sorry.
=====================================================
http://www.ied.tsukuba.ac.jp/hydrogeo/isetr/ISETRen/paper/geochem46-2.pdf
福島第一原子力発電所の事故により放出された放射性物質の大気中での動態
鶴田治雄＊・中島映至＊
（2012年6月1日受付，2012年6月11日受理）
Radioactive materials in the atmosphere released by the accident of the Fukushima Daiichi Nuclear Power Plant
Haruo TSURUTA＊ and Teruyuki NAKAJIMA＊
＊ Atmosphere and Ocean Research Institute, The University of Tokyo
5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8568, Japan
線量率や大気降下物などの様々なモニタリングデータ
をはじめ，多くの研究機関が独自に調査した結果を含
めて，膨大なデータが，それぞれのホームページなど
で公表されている。そこで，それらのデータをもと
に，放射性物質の放出率推定，放射性物質の原発周辺
での挙動，そして広域汚染の概要，最後に，その後の
大気中での放射性物質の長期変化を中心に，これまで
にわかったことをまとめて，陸域を対象として，本総
説で報告する。なお本稿は，最新のデータを盛り込む
ため，最近の学会・シンポジウム等で発表されたデー
タも多く含めており，学術論文以外からの引用が多い
こと，また，使用した多くのデータはそれぞれの機関
のHP に掲載されているので文献に引用していないこ
と，をお許し頂きたい。
２．福島第一原子力発電所からの放射性物質
の放出量推定
原発事故により，大気中に放出された放射性物質量
の時間変化は，対象領域が25 km×25 km で設定され
た緊急時迅速放射能影響予測ネットワークシステム，
いわゆるSPEEDI（The System for Prediction of Environmental
Emergency Dose Information）（MEXT,
2007）や，さらに広域で放射性物質量を予測可能に
するために，日本原子力研究開発機構（JAEA）が開
発したWSPEEDI-II（Worldwide Version of System
for Prediction of Environmental Emergency Dose
Information-II）（Terada et al., 2008）と，空間放射
線量率やダストサンプリングによるヨウ素―131とセ
シウム―137の大気中の放射能濃度を用いて推定され
た（Chino et al., 2011; Katata et al., 2011）。その
後，原子炉で起こった事象からの放出量推定も一部取
り入れられており（Katata et al., 2012; Terada et al.,
2012），それらをとりまとめたもの（茅野，2012）
を，Fig. 1に示す。放出率が一定の期間は，用いた大
気観測データの時間分解能に依存しているところが大
きい。ヨウ素―131とセシウム―137の放出率比は，3月
Fig. 1 Summary of estimated release rates of 131I and137Cs into the atmosphere after the
Fukushima Daiichi Nuclear Power Plant accident (Chino, 2012) (This figure is quoted
from the website of JAEA Open Workshop, 2012).
100 鶴田治雄・中島映至
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