Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Nagai, Haruyasu; Furuta, Yoshihiro*; Nakayama, Hiromasa; Satoh, Daiki
Journal of Nuclear Science and Technology, 16 Pages, 2023/00
A novel monitoring method for the quantitative visualization of 3D distribution of a radioactive plume and source term estimation of released radionuclides is proposed and its feasibility is demonstrated by preliminary test. The proposed method is the combination of gamma-ray imaging spectroscopy with the Electron Tracking Compton Camera (ETCC) and real-time high-resolution atmospheric dispersion simulation based on 3D wind observation with Doppler lidar. The 3D distribution of a specific radionuclide in a target radioactive plume is inversely reconstructed from line gamma-ray images from each radionuclide by several ETCCs located around the target by harmonizing with the air concentration distribution pattern of the plume predicted by real-time atmospheric dispersion simulation. A prototype of the analysis method was developed, showing a sufficient performance in several test cases using hypothetical data generated by numerical simulations of atmospheric dispersion and radiation transport.
Wada, Yuki*; Matsumoto, Takahiro*; Enoto, Teruaki*; Nakazawa, Kazuhiro*; Yuasa, Takayuki*; Furuta, Yoshihiro*; Yonetoku, Daisuke*; Sawano, Tatsuya*; Okada, Go*; Nanto, Hidehito*; et al.
Physical Review Research (Internet), 3(4), p.043117_1 - 043117_31, 2021/12
Tsuchiya, Harufumi; Enoto, Teruaki*; Wada, Yuki*; Furuta, Yoshihiro; Nakazawa, Kazuhiro*; Yuasa, Takayuki*; Umemoto, Daigo*; Makishima, Kazuo*; GROWTH collaboration*
Proceedings of Science (Internet), 358, p.1163_1 - 1163_6, 2021/07
Satoh, Daiki; Nakayama, Hiromasa; Furuta, Takuya; Yoshihiro, Tamotsu*; Sakamoto, Kensaku
PLOS ONE (Internet), 16(1), p.e0245932_1 - e0245932_26, 2021/01
Times Cited Count：2 Percentile：48.75(Multidisciplinary Sciences)In this study, we developed a simulation code named SIBYL, which estimates external gamma-ray doses at ground level from radionuclides distributed nonuniformly in atmosphere and on ground. SIBYL can combine with the local-scale atmospheric dispersion model LOHDIM-LES, and calculate the dose distributions according to the map of the activity concentrations simulated by LOHDIM-LES. To apply the SIBYL code to emergency responses of nuclear accidents, the time-consuming three-dimensional radiation transport simulations were performed in advance using the general-purpose Monte Carlo code PHITS, and then the results were compiled to the database for the SIBYL's dose calculations. Moreover, SIBYL can consider the dose attenuation by obstacles and the changes of terrain elevations. To examine the accuracy of SIBYL, typical five cases including 
Kr emission from a ventilation shaft and 
Cs dispersion inside urban area were investigated. The results of SIBYL agreed within 10% with those of PHITS at the most of target locations. Furthermore, the calculation speed was approximately 100 times faster than that of PHITS.
Wada, Yuki*; Enoto, Teruaki*; Nakazawa, Kazuhiro*; Odaka, Hirokazu*; Furuta, Yoshihiro; Tsuchiya, Harufumi
Journal of Geophysical Research; Atmospheres, 125(20), 17 Pages, 2020/10
Times Cited Count：2 Percentile：14.18(Meteorology & Atmospheric Sciences)Wada, Yuki*; Enoto, Teruaki*; Nakazawa, Kazuhiro*; Yuasa, Takayuki*; Furuta, Yoshihiro; Odaka, Hirokazu*; Makishima, Kazuo*; Tsuchiya, Harufumi
Journal of Geophysical Research; Atmospheres, 125(20), p.e2020JD033194_1 - e2020JD033194_15, 2020/10
Times Cited Count：2 Percentile：14.18(Meteorology & Atmospheric Sciences)Yuasa, Takayuki*; Wada, Yuki*; Enoto, Teruaki*; Furuta, Yoshihiro; Tsuchiya, Harufumi; Hisadomi, Shohei*; Tsuji, Yuna*; Okuda, Kazufumi*; Matsumoto, Takahiro*; Nakazawa, Kazuhiro*; et al.
Progress of Theoretical and Experimental Physics (Internet), 2020(10), p.103H01_1 - 103H01_27, 2020/10
Times Cited Count：11 Percentile：75.1(Physics, Multidisciplinary)Wada, Yuki*; Nakazawa, Kazuhiro*; Enoto, Teruaki*; Furuta, Yoshihiro; Yuasa, Takayuki*; Makishima, Kazuo*; Tsuchiya, Harufumi
Physical Review D, 101(10), p.102007_1 - 102007_6, 2020/05
Times Cited Count：1 Percentile：10.29(Astronomy & Astrophysics)Morishita, Yuki; Usami, Hiroshi; Furuta, Yoshihiro; Aoki, Katsunori; Tsurudome, Koji; Hoshi, Katsuya; Torii, Tatsuo
Radiation Protection Dosimetry, 189(2), p.172 - 181, 2020/04
Times Cited Count：0 Percentile：0.01(Environmental Sciences)We developed a remote continuous air monitoring (RCAM) system. The RCAM system consisted of a personal air monitor and a robot. The personal air monitor (poCAMon, SARAD, Germany) had a 400 mm
ion-injected silicon detector and a membrane air filter with 25 mm-diameter. The personal air monitor provides the alpha energy spectra for any measurement time interval. Demonstration measurements were taken underground at the Mizunami Underground Research Laboratory (MIU) and at a poorly ventilated concrete building. The RCAM system was remotely operated and successfully measured the 
Rn progeny even though the relative humidity (RH) was almost 100%. In the measured alpha spectra, the peaks of 
Po (6.0 MeV alpha) and 
Po (7.7 MeV alpha) were clearly identified. Our developed monitor is promising for alpha dust monitoring in a high gamma-ray environment or contaminated areas where a worker cannot safely physically enter.
Wada, Yuki*; Enoto, Teruaki*; Nakamura, Yoshitaka*; Morimoto, Takeshi*; Sato, Mitsuteru*; Ushio, Tomoo*; Nakazawa, Kazuhiro*; Yuasa, Takayuki*; Yonetoku, Daisuke*; Sawano, Tatsuya*; et al.
Journal of Geophysical Research; Atmospheres, 125(4), p.e2019JD031730_1 - e2019JD031730_11, 2020/02
Times Cited Count：19 Percentile：86.25(Meteorology & Atmospheric Sciences)Wada, Yuki*; Enoto, Teruaki*; Nakazawa, Kazuhiro*; Furuta, Yoshihiro; Yuasa, Takayuki*; Nakamura, Yoshitaka*; Morimoto, Takeshi*; Matsumoto, Takahiro*; Makishima, Kazuo*; Tsuchiya, Harufumi
Physical Review Letters, 123(6), p.061103_1 - 061103_6, 2019/08
Times Cited Count：28 Percentile：88.95(Physics, Multidisciplinary)Wada, Yuki*; Enoto, Teruaki*; Nakamura, Yoshitaka*; Furuta, Yoshihiro; Yuasa, Takayuki*; Nakazawa, Kazuhiro*; Morimoto, Takeshi*; Sato, Mitsuteru*; Matsumoto, Takahiro*; Yonetoku, Daisuke*; et al.
Communications Physics (Internet), 2(1), p.67_1 - 67_9, 2019/06
Times Cited Count：35 Percentile：91.86(Physics, Multidisciplinary)Wada, Yuki*; Bowers, G. S.*; Enoto, Teruaki*; Kamogawa, Masashi*; Nakamura, Yoshitaka*; Morimoto, Takeshi*; Smith, D.*; Furuta, Yoshihiro*; Nakazawa, Kazuhiro*; Yuasa, Takayuki*; et al.
Geophysical Research Letters, 45(11), p.5700 - 5707, 2018/06
Times Cited Count：23 Percentile：79.11(Geosciences, Multidisciplinary)Enoto, Teruaki*; Wada, Yuki*; Furuta, Yoshihiro*; Nakazawa, Kazuhiro*; Yuasa, Takayuki*; Okuda, Kazufumi*; Makishima, Kazuo*; Sato, Mitsuteru*; Sato, Yosuke*; Nakano, Toshio*; et al.
Nature, 551(7681), p.481 - 484, 2017/11
Times Cited Count：99 Percentile：97.56(Multidisciplinary Sciences)Tsuchiya, Harufumi; Enoto, Teruaki*; Wada, Yuki*; Furuta, Yoshihiro*; Nakazawa, Kazuhiro*; Yuasa, Takayuki*; Okuda, Kazufumi*; Makishima, Kazuo*; Sato, Mitsuteru*; Sato, Yosuke*; et al.
no journal, ,
no abstracts in English
Kaburagi, Masaaki; Sato, Yuki; Morishita, Yuki; Usami, Hiroshi; Terasaka, Yuta; Furuta, Yoshihiro; Torii, Tatsuo
no journal, ,
The 45th annual Waste Management Symposium in a forum for discussing and seeking safe and cost-effective solutions to managing and dispositioning radioactive waste and decommissioning nuclear facilities is hold, JAEA participates in it as the exhibitor. This is the introduction of the radiation imaging technology, which is one of the R&D of the acceleration of the decommissioning of the TEPCO's Fukushima Daiichi Nuclear Station.
Nakayama, Hiromasa; Satoh, Daiki; Furuta, Yoshihiro; Nagai, Haruyasu
no journal, ,
We have been developing a method for estimating radionuclide concentration distributions in the atmosphere and release amount by combining atmospheric dispersion simulations with radiation measuring. This method has high potential to improve reliability of the simulation accuracy by incorporating the obtained release amount and concentration distributions near a source point into atmospheric dispersion simulations. Because there are no real data on radionuclide concentrations, we have a plan to calculate the test data on radionuclide concentration distributions in the atmosphere by computational simulation and validate the estimation method. In this study, we report the method for calculating them used for the test data.
Nagai, Haruyasu; Tanimori, Toru*; Nakayama, Hiromasa; Satoh, Daiki; Furuta, Yoshihiro
no journal, ,
no abstracts in English
Furuta, Yoshihiro; Satoh, Daiki; Nakayama, Hiromasa; Nagai, Haruyasu; Tanimori, Toru*
no journal, ,
In the CLADS subsidy project, we are developing an estimation method of concentration distribution and release amount of radiative nuclide by reverse-analyzing images of gamma-ray emitted by radionuclide discharged into the atmosphere obtained by an Electron Tracking Compton Camera (ETCC). It improves the estimation accuracy of atmospheric dispersion to use the concentration distribution and release amount of radionuclide calculated by this method as input data to the dispersion calculation. We simulated virtual gamma-ray images and response matrices for the development and verification of reverse analysis method. We report on simulation of these virtual gamma-ray images and construction of the response matrices.
Usami, Hiroshi; Morishita, Yuki; Furuta, Yoshihiro; Aoki, Katsunori; Tsurudome, Koji; Hoshi, Katsuya; Torii, Tatsuo
no journal, ,
no abstracts in English
Nagai, Haruyasu; Furuta, Yoshihiro*; Satoh, Daiki; Nakayama, Hiromasa
no journal, ,
no abstracts in English
