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Nagaoka, Mika; Fujita, Hiroki; Aida, Taku*; Guo, H.*; Smith, R. L. Jr.*
Applied Radiation and Isotopes, 168, p.109465_1 - 109465_6, 2021/02
Times Cited Count:0 Percentile:0.01(Chemistry, Inorganic & Nuclear)The radioactivities in the environmental samples are analyzed to monitor the nuclear power facilities. The pretreatment of radioactive nuclides of alpha and beta emitters in the environmental samples is performed with acid to decompose organic matter and extract object nuclide such as Sr, U and Pu. However, the pretreatment methods are time-consuming and used many concentrated acid solutions that are unsafe and hazardous. Therefore, we develop to the new pretreatment method using supercritical water instead of acid. Hydrothermal pretreatment of soils (Andosols) from Ibaraki prefecture (Japan) was used to improve methods for monitoring radioactive Sr and U. Calcined samples were pretreated with subcritical or supercritical water (SCW) followed by extraction with 0.5 M HNO solutions. With SCW pretreatment, recoveries of Sr and U were 70% and 40%, respectively. Experimental recoveries obtained can be described by a linear relationship in water density. The proposed method is robust and can lower environmental burden of routine analytical protocols.
Abe, Tomohisa; Ogiya, Takashi*; Shibata, Katsuya*; Hanawa, Tatsuaki*; Sanada, Yukihisa
JAEA-Data/Code 2020-004, 280 Pages, 2020/08
After the accidents at Fukushima Daiichi Nuclear Power Station (FDNPS), Japan Atomic Energy Agency has carried on survey for distribution situation of radiation materials under the direction of the Ministry of Education, Culture, Sports, Science and Technology (later the Nuclear Regulatory Agency) from June 2011 to FY2019. This report is mainly summarized as data-base of air dose rate, integrated dose and radionuclide concentration of some types of environmental sample (airborne dust, soil, pine needles) in the radiation monitoring in Fukushima Prefecture (20 km far from FDNPS). The results of radiation monitoring were analyzed for temporal change at each measurement site under the unification format. Furthermore, the effective half-life and the dispersion at each location and sample were evaluated based on these big data.
Azami, Kazuhiro*; Otagaki, Takahiro*; Ishida, Mutsushi; Sanada, Yukihisa
Landscape and Ecological Engineering, 14(1), p.3 - 15, 2018/01
Times Cited Count:2 Percentile:11.98(Biodiversity Conservation)Miyahara, Kaname; Ohara, Toshimasa*
Nihon Genshiryoku Gakkai-Shi ATOMO, 59(5), p.282 - 286, 2017/05
This review highlights JAEA and NIES's challenges for enhancing Fukushima environmental resilience based on carrying out multifaceted research working with many public and private sector organizations and academia.
Ohara, Toshimasa*; Miyahara, Kaname
Global Environmental Research (Internet), 20(1&2), p.3 - 13, 2017/03
Toward the environmental regeneration in Fukushima Prefecture and other areas after the Fukushima Daiichi Nuclear Power Station accidents, JAEA and NIES working with many public and private sector organizations and academia have carried out multifaceted research that will help to restore the environment of affected areas. These challenging efforts need to be further strengthened.
Shibata, Katsuyuki; Ebisawa, Katsumi; Abe, Ichiro*; Kuno, Tetsuya; Hori, S.*; Oi, Masahiro*
Proceedings of 12th World Conference in Earthquake Engineering (CD-ROM), 8 Pages, 2000/01
no abstracts in English
; ; Takasaki, Koichi*; ;
JAERI-Review 98-005, 203 Pages, 1998/03
no abstracts in English