Spatial distributions of radionuclides deposited onto ground soil around the Fukushima Dai-ichi Nuclear Power Plant and their temporal change until December 2012

Satoshi Mikami; Takeshi Maeyama; Yoshifumi Hoshide; Ryuichi Sakamoto; Shoji Sato; Naotoshi Okuda; Stéphanie Demongeot; Rodolfo Gurriaran; Yoshitomo Uwamino; Hiroaki Kato; Mamoru Fujiwara; Tetsuro Sato; Hiroshi Takemiya; Kimiaki Saito

doi:10.1016/j.jenvrad.2014.09.010

Spatial distributions of radionuclides deposited onto ground soil around the Fukushima Dai-ichi Nuclear Power Plant and their temporal change until December 2012

J Environ Radioact. 2015 Jan:139:320-343. doi: 10.1016/j.jenvrad.2014.09.010. Epub 2014 Oct 11.

Authors

Affiliations

¹ Fukushima Environmental Safety Center, Sector of Fukushima Research and Development, Japan Atomic Energy Agency, 2-2-2, Uchisaiwai-cho, Chiyoda, Tokyo, 100-8577, Japan. Electronic address: mikami.satoshi@jaea.go.jp.
² General Analysis Division, Japan Chemical Analysis Center, 295-3, Sanno-cho, Inage, Chiba, Chiba, 263-0002, Japan. Electronic address: t-maeyama@jcac.or.jp.
³ Division of Emergency Preparedness Technology, Nuclear Safety Technology Center, 5-1-3-101, Hakusan, Bunkyo, Tokyo, 112-8604, Japan. Electronic address: yoshi-hoshide@nustec.or.jp.
⁴ Institute of Radiation Measurements, 2-4 Shirane, Shirakata, Tokai-mura, Naka, Ibaraki, 319-1106, Japan. Electronic address: r.sakamoto@irm.or.jp.
⁵ Radioactive Analysis Division, Japan Chemical Analysis Center, 295-3, Sanno-cho, Inage, Chiba, Chiba, 263-0002, Japan. Electronic address: s-sato@jcac.or.jp.
⁶ Division of Emergency Preparedness Technology, Nuclear Safety Technology Center, 5-1-3-101, Hakusan, Bunkyo, Tokyo, 112-8604, Japan. Electronic address: okuda@nustec.or.jp.
⁷ Emergency Response, Radiation Protection Division, Institute of Radioprotection and Nuclear Safety, BP 17, Fontenay-aux-Roses, 92262, France. Electronic address: stephanie.demongeot@irsn.fr.
⁸ Environment, Radiation Protection Division, Institute of Radioprotection and Nuclear Safety, Bat 501, Bois des Rames, Orsay, 91400, France. Electronic address: rodolfo.gurriaran@irsn.fr.
⁹ Safety Management Group, Nishina Center for Accelerator-Based Science, RIKEN, 2-1, Hirosawa, Wako, Saitama, 351-0198, Japan. Electronic address: uwamino@riken.jp.
¹⁰ Center for Research in Isotopes and Environmental Dynamics, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8577, Japan. Electronic address: hiros980@ies.life.tsukuba.ac.jp.
¹¹ Research Center for Nuclear Physics, Osaka University, 10-1, Mihogaoka, Ibaraki, Osaka, 567-0047, Japan. Electronic address: fujiwara@rcnp.osaka-u.ac.jp.
¹² Hitachi Solutions East Japan, Ltd., NBF Sendai Honcho Bldg, 2-16-10 Honcho, Aoba-ku, Sendai, 980-0014, Japan. Electronic address: tetsuro.sato.aj@hitachi-solutions.com.
¹³ Center for Computational Science & e-Systems, Japan Atomic Energy Agency, 5-1-5, Kashiwanoha, Kashiwa, Chiba, 277-8587, Japan. Electronic address: takemiya.hiroshi@jaea.go.jp.
¹⁴ Fukushima Environmental Safety Center, Sector of Fukushima Research and Development, Japan Atomic Energy Agency, 2-2-2, Uchisaiwai-cho, Chiyoda, Tokyo, 100-8577, Japan. Electronic address: kimiaki.saito@jaea.go.jp.

PMID: 25307776
DOI: 10.1016/j.jenvrad.2014.09.010

Abstract

Spatial distributions and temporal changes of radioactive fallout released by the Fukushima Dai-ichi Nuclear Power Plant accident have been investigated by two campaigns with three measurement schedules. The inventories (activities per unit area) of the radionuclides deposited onto ground soil were measured using portable gamma-ray spectrometers at nearly 1000 locations (at most) per measurement campaign. Distribution maps of the inventories of (134)Cs, (137)Cs, and (110m)Ag as of March, September, and December 2012 were constructed. No apparent temporal change of the radionuclide inventories was observed from March to December 2012. Weathering effects (e.g., horizontal mobility) were not noticeable during this period. Spatial dependence in the ratios of (134)Cs/(137)Cs and (110m)Ag/(137)Cs were observed in the Tohoku and Kanto regions. The detailed maps of (134)Cs and (137)Cs as of September 2012 and December 2012 were constructed using the relationship between the air dose rate and the inventory.

Keywords: Distribution; Fukushima; In situ measurement; Inventory; Portable gamma-ray spectrometer; Temporal change.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Cesium Radioisotopes / analysis
Fukushima Nuclear Accident*
Geographic Mapping
Japan
Nuclear Power Plants
Radiation Monitoring
Radioactive Fallout / analysis*
Radioisotopes / analysis*
Seasons
Silver / analysis*
Soil Pollutants, Radioactive / analysis*
Spectrometry, Gamma

Substances

Cesium Radioisotopes
Radioactive Fallout
Radioisotopes
Soil Pollutants, Radioactive
Silver