TY - JOUR
T1 - New highly radioactive particles derived from Fukushima Daiichi Reactor Unit 1
T2 - Properties and environmental impacts
AU - Morooka, Kazuya
AU - Kurihara, Eitaro
AU - Takehara, Masato
AU - Takami, Ryu
AU - Fueda, Kazuki
AU - Horie, Kenji
AU - Takehara, Mami
AU - Yamasaki, Shinya
AU - Ohnuki, Toshihiko
AU - Grambow, Bernd
AU - Law, Gareth T.W.
AU - Ang, Joyce W.L.
AU - Bower, William R.
AU - Parker, Julia
AU - Ewing, Rodney C.
AU - Utsunomiya, Satoshi
N1 - Funding Information:
The authors are grateful to Dr. Watanabe for her assistance on SEM analyses at the Center of Advanced Instrumental Analysis, Kyushu University. This study is partially supported by JST Initiatives for Atomic Energy Basic and Generic Strategic Research and by a Grant-in-Aid for Scientific Research (KAKENHI) from the Japan Society for the Promotion of Science ( 16K12585 , 16H04634 , No. JP26257402 ). The findings and conclusions of the authors of this paper do not necessarily state or reflect those of the JST. We thank Diamond Light Source for beamtime NT21246-9, U.K.
Funding Information:
The authors are grateful to Dr. Watanabe for her assistance on SEM analyses at the Center of Advanced Instrumental Analysis, Kyushu University. This study is partially supported by JST Initiatives for Atomic Energy Basic and Generic Strategic Research and by a Grant-in-Aid for Scientific Research (KAKENHI) from the Japan Society for the Promotion of Science (16K12585, 16H04634, No. JP26257402). The findings and conclusions of the authors of this paper do not necessarily state or reflect those of the JST. We thank Diamond Light Source for beamtime NT21246-9, U.K.
Publisher Copyright:
© 2021 Elsevier B.V.
PY - 2021/6/15
Y1 - 2021/6/15
N2 - A contaminated zone elongated toward Futaba Town, north-northwest of the Fukushima Daiichi Nuclear Power Plant (FDNPP), contains highly radioactive particles released from reactor Unit 1. There are uncertainties associated with the physio-chemical properties and environmental impacts of these particles. In this study, 31 radioactive particles were isolated from surface soils collected 3.9 km north-northwest of the FDNPP. Two of these particles have the highest particle-associated 134+137Cs activity ever reported for Fukushima (6.1 × 105 and 2.5 × 106 Bq per particle after decay-correction to March 2011). The new, highly-radioactive particle labeled FTB1 is an aggregate of flaky silicate nanoparticles with an amorphous structure containing ~0.8 wt% Cs, occasionally associated with SiO2 and TiO2 inclusions. FTB1 likely originates from the reactor building, which was damaged by a H2 explosion, after adsorbing volatilized Cs. The 134+137Cs activity in the other highly radioactive particle labeled FTB26 exceeded 106 Bq. FTB26 has a glassy carbon core and a surface that is embedded with numerous micro-particles: Pb–Sn alloy, fibrous Al-silicate, Ca-carbonate or hydroxide, and quartz. The isotopic signatures of the micro-particles indicate neutron capture by B, Cs volatilization, and adsorption of natural Ba. The composition of the micro-particles on FTB26 reflects the composition of airborne particles at the moment of the H2 explosion. Owing to their large size, the health effects of the highly radioactive particles are likely limited to external radiation during static contact with skin; the highly radioactive particles are thus expected to have negligible health impacts for humans. By investigating the mobility of the highly radioactive particles, we can better understand how the radiation dose transfers through environments impacted by Unit 1. The highly radioactive particles also provide insights into the atmospheric conditions at the time of the Unit 1 explosion and the physio-chemical phenomena that occurred during reactor meltdown.
AB - A contaminated zone elongated toward Futaba Town, north-northwest of the Fukushima Daiichi Nuclear Power Plant (FDNPP), contains highly radioactive particles released from reactor Unit 1. There are uncertainties associated with the physio-chemical properties and environmental impacts of these particles. In this study, 31 radioactive particles were isolated from surface soils collected 3.9 km north-northwest of the FDNPP. Two of these particles have the highest particle-associated 134+137Cs activity ever reported for Fukushima (6.1 × 105 and 2.5 × 106 Bq per particle after decay-correction to March 2011). The new, highly-radioactive particle labeled FTB1 is an aggregate of flaky silicate nanoparticles with an amorphous structure containing ~0.8 wt% Cs, occasionally associated with SiO2 and TiO2 inclusions. FTB1 likely originates from the reactor building, which was damaged by a H2 explosion, after adsorbing volatilized Cs. The 134+137Cs activity in the other highly radioactive particle labeled FTB26 exceeded 106 Bq. FTB26 has a glassy carbon core and a surface that is embedded with numerous micro-particles: Pb–Sn alloy, fibrous Al-silicate, Ca-carbonate or hydroxide, and quartz. The isotopic signatures of the micro-particles indicate neutron capture by B, Cs volatilization, and adsorption of natural Ba. The composition of the micro-particles on FTB26 reflects the composition of airborne particles at the moment of the H2 explosion. Owing to their large size, the health effects of the highly radioactive particles are likely limited to external radiation during static contact with skin; the highly radioactive particles are thus expected to have negligible health impacts for humans. By investigating the mobility of the highly radioactive particles, we can better understand how the radiation dose transfers through environments impacted by Unit 1. The highly radioactive particles also provide insights into the atmospheric conditions at the time of the Unit 1 explosion and the physio-chemical phenomena that occurred during reactor meltdown.
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U2 - 10.1016/j.scitotenv.2021.145639
DO - 10.1016/j.scitotenv.2021.145639
M3 - Article
C2 - 33940743
AN - SCOPUS:85101037363
SN - 0048-9697
VL - 773
JO - Science of the Total Environment
JF - Science of the Total Environment
M1 - 145639
ER -