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Kim, M.; Yoshimura, Kazuya; Sakuma, Kazuyuki; Malins, A.*; Abe, Tomohisa; Nakama, Shigeo; Machida, Masahiko; Saito, Kimiaki
Journal of Environmental Radioactivity, 294, p.107931_1 - 107931_8, 2026/03
Times Cited Count:0This study quantitatively evaluated the effects of non-decontamination human activities, such as traffic, on ambient dose rates in residential areas near the Fukushima Daiichi Nuclear Power Plant through field measurements and simulations. Field surveys showed that areas with higher traffic had greater reductions in
Cs deposition, suggesting that vehicular movement may enhance cesium weathering. Monte Carlo simulations using 3D-ADRES confirmed that human activities accelerate the decrease in ambient dose rates on paved surfaces, with reductions of up to approximately 50%. These results indicate that non-decontamination human activities significantly contribute to lowering ambient dose rates.
Ji, Y.-Y.*; Ji, W.*; Kim, K.*; Kim, M. J.*; Ochi, Kotaro; Morishita, Yuki; Sanada, Yukihisa
Radiation Physics and Chemistry, 244, p.113781_1 - 113781_12, 2026/02
Times Cited Count:0UAV-based airborne gamma-ray spectrometry enables rapid radiation mapping, but accurate estimation of ground-level ambient dose rates is difficult because of altitude attenuation, detector field-of-view effects, heterogeneous contamination, and terrain variability. We developed a practical method combining hovering-flight calibration and ground-based validation near the Fukushima Daiichi Nuclear Power Plant. Altitude correction factors were derived using a dual-exponential model and compared with tripod and backpack measurements. Results showed that heterogeneous contamination and terrain introduce systematic biases if correction factors are derived under non-uniform conditions, while calibration at uniform sites improves agreement. The proposed approach demonstrates that UAV airborne surveys can reliably estimate spatial dose-rate distributions when site-dependent corrections are applied.
Kim, M.
Kankyo Sozo Senta Chosa Kenkyu Seika Hokokusho, Heisei 27-Nendo (2015)
Reiwa 6-Nendo (2024) (Internet), P. 31, 2025/10
3D-Air Dose Rate Evaluation System has been developed that can accurately estimate complex spatial dose rate distributions due to radiation emitted into the environment. The applicability of the system was examined, and the results of the analysis and measurements were in general agreement.
Kim, Y. S.*; Kang, T.*; Hong, S.-K.*; Brechtl, J.*; Lebyodkin, M.*; Cheng, Y.-H.*; Huang, E.-W.*; Liaw, P. K.*; Harjo, S.; Gong, W.; et al.
Acta Materialia, 292, p.120970_1 - 120970_16, 2025/06
Times Cited Count:8 Percentile:91.77(Materials Science, Multidisciplinary)Sugita, Yutaka; Ono, Hirokazu; Beese, S.*; Pan, P.*; Kim, M.*; Lee, C.*; Jove-Colon, C.*; Lopez, C. M.*; Liang, S.-Y.*
Geomechanics for Energy and the Environment, 42, p.100668_1 - 100668_21, 2025/06
Times Cited Count:3 Percentile:72.90(Energy & Fuels)The international cooperative project DECOVALEX 2023 focused on the Horonobe EBS experiment in the Task D, which was undertaken to study, using numerical analyses, the thermo-hydro-mechanical (or thermo-hydro) interactions in bentonite based engineered barriers. One full-scale in-situ experiment and four laboratory experiments, largely complementary, were selected for modelling. The Horonobe EBS experiment is a temperature-controlled non-isothermal experiment combined with artificial groundwater injection. The Horonobe EBS experiment consists of the heating and cooling phases. Six research teams performed the THM or TH (depended on research team approach) numerical analyses using a variety of computer codes, formulations and constitutive laws.
Cho, S. H.*; Cho, S. W.*; Lv, Z.*; Sekine, Yurina; Liu, S.*; Zhou, M.*; Nuxoll, R. F.*; Kanatzidis, E. E.*; Ghaffari, R.*; Kim, D.*; et al.
Lab on a Chip, 25(7), p.1647 - 1655, 2025/04
Times Cited Count:10 Percentile:98.65(Biochemical Research Methods)Amino acids are essential for protein synthesis and metabolic processes in support of homeostatic balance and healthy body functions. This study quantitatively investigates eccrine sweat as a significant channel for loss of amino acids during exercise, to improve an understanding of amino acid turnover and to provide feedback to users on the need for supplement intake. The measurement platform consists of a soft, skin-interfaced microfluidic system for real-time analysis of amino acid content in eccrine sweat. This system relies on integrated fluorometric assays and smartphone-based imaging techniques for quantitative analysis.
Kim, M.*; Lee, C.*; Sugita, Yutaka; Kim, J.-S.*; Jeon, M.-K.*
Geomechanics for Energy and the Environment, 41, p.100628_1 - 100628_9, 2025/03
Times Cited Count:1 Percentile:51.47(Energy & Fuels)This study investigates the impact of primary variables selection on the modeling of non-isothermal two-phase flow, by using the numerical work on the full-scale Engineered Barrier System (EBS) experiment conducted at Horonobe URL as part of the DECOVALEX-2023 project. A validated numerical model is employed to simulate the coupled thermo-hydrological behavior of heterogeneous porous media within the EBS. Two different primary variable schemes are compared in discretizing the governing equations, revealing significant difference in results.

Chung, J.-H.*; Kwangwoo, S.*; Yokoo, Tetsuya R.; Ueta, Daichi*; Imai, Masaki; Kim, H.-S.; Kiem, D. H.; Han, M. J.*; Shamoto, Shinichi
Scientific Reports (Internet), 15, p.5978_1 - 5978_10, 2025/02
Times Cited Count:1 Percentile:53.65(Multidisciplinary Sciences)
signatures in two-dimensional cone beam interferometrySarenac, D.*; Gorbet, G.*; Clark, C. W.*; Cory, D. G.*; Ekinci, H.*; Henderson, M. E.*; Huber, M. G.*; Hussey, D. S.*; Kapahi, C.*; Kienzle, P. A.*; et al.
Physical Review Research (Internet), 6(3), p.L032054_1 - L032054_8, 2024/09
Machida, Masahiko; Yamada, Susumu; Kim, M.; Tanaka, Satoshi*; Tobita, Yasuhiro*; Iwata, Ayako*; Aoki, Yuto; Aoki, Kazuhisa; Yanagisawa, Kenichi*; Yamaguchi, Takashi; et al.
RIST News, (70), p.3 - 22, 2024/09
Inside the Fukushima Daiichi Nuclear Power Plant (1F), there are many locations with high radiation levels due to contamination by radioactive materials that leaked from the reactor. These pose a significant obstacle to the smooth progress of decommissioning work. To help solve this issue, the Japan Atomic Energy Agency (JAEA), under a subsidy from the Ministry of Economy, Trade, and Industry's decommissioning and contaminated water management project, is conducting research and development on digital technologies to improve the radiation environment inside the decommissioning site. This project, titled "Development of Technology to Improve the Environment Inside Reactor Buildings (Enhancing Digital Technology for Environment and Source Distribution to Reduce Radiation Exposure)," began in April of FY 2023. In this project, the aim is to develop three interconnected systems: FrontEnd, Pro, and BackEnd. The FrontEnd system, based on the previously developed 3D-ADRES-Indoor (prototype) from FY 2021-2022, will be upgraded to a high-speed digital twin technology usable on-site. The Pro system will carry out detailed analysis in rooms such as the new office building at 1F, while the BackEnd system will serve as a database to centrally manage the collected and analyzed data. This report focuses on the FrontEnd system, which will be used on-site. After point cloud measurement, the system will quickly create a 3D mesh model, estimate the radiation source from dose rate measurements, and refine the position and intensity of the estimated source using recalculation techniques (re-observation instructions and re-estimation). The results of verification tests conducted on Unit 5 are also presented. Furthermore, the report briefly discusses the future research and development plans for this project.
Peri
ez, R.*; Bezhenar, R.*; Maderych, V.*; Brovchenko, I.*; Liptak, L.*; Kobayashi, Takuya; Min, B.-I.*; Suh, K. S.*; Little, A.*; Iosjpe, M.*; et al.
IAEA-TECDOC-2060, 55 Pages, 2024/07
This publication describes the work undertaken by Working Group 7, Assessment of Fate and Transport of Radionuclides Released in the Marine Environment of the IAEA's Modelling and Data for Radiological Impact Assessments (MODARIA II) programme (2016-2019). In MODARIA II, the degree of complexity of the models used was increased in order to effectively consider additional processes, specifically uptake by biota, and the spatiotemporal scales of the simulations were also expanded.
Kim, J.*; Thompson, B. R.*; Tominaga, Taiki*; Osawa, Takahito; Egami, Takeshi*; F
rster, S.*; Ohl, M.*; Senses, E.*; Faraone, A.*; Wagner, N. J.*
ACS Macro Letters (Internet), 13(6), p.720 - 725, 2024/06
Times Cited Count:4 Percentile:39.84(Polymer Science)The Rouse dynamics of polymer chains in model nanocomposite PolyEthylene Oxide (PEO)/Silica NanoParticles (NPs) was investigated using QuasiElastic Neutron Scattering (QENS). The apparent Rouse rate of the polymer chains decreases as the particle loading increases. However, there is no evidence of an immobile segment population on the probed time scale of tens of ps. The slowing down of the dynamics is interpreted in terms of modified Rouse models for the chains in the NP inter-phase region. Thus, two chain populations, one bulk like and the other characterized by a suppression of Rouse modes, are identified. The spatial extent of the interphase region is estimated to be about twice the adsorbed layer thickness, or about 2 nm. These findings provide a detailed description of the suppression of the chain dynamics on the surface of NPs. These results are relevant insights on surface effects and confinement and provide a foundation for the understanding of the rheological properties of Polymer NanoComposites (PNCs) with well-dispersed NPs.
Kim, M.; Yoshimura, Kazuya; Sakuma, Kazuyuki; Malins, A.*; Abe, Tomohisa; Nakama, Shigeo; Machida, Masahiko; Saito, Kimiaki
Kankyo Hoshano Josen Gakkai-Shi, 12(2), p.39 - 53, 2024/04
More than ten years have passed since the accident at TEPCO's Fukushima Daiichi Nuclear Power Station. But with the progress of decontamination, the evacuation order has been lifted and the return of residents is still ongoing. Under these circumstances, in order to quantitatively evaluate the effect of decontamination activities and cultivation on air dose rate reduction, a detailed environmental model was constructed using 3D-ADRES for a real area located in the Okuma town, Fukushima prefecture. Monte Carlo simulations were performed using the model to calculate realistic distributions of radioactive Cs based on measurement results and air dose rates reflecting changes over time. As a result, the distribution of air dose rates at 100 cm above ground level in the target area according to decontamination and cultivation activities was calculated. The calculated air dose rates reproduced the measured values well, and were confirmed to be appropriate as a method for evaluating the effects of decontamination and cultivation activities. This method is expected to serve as a reference for further decontamination management measures to reduce the air dose rate in the difficult-to-return zone, where entry is still restricted.

Linh, B. D.*; Corsi, A.*; Gillibert, A.*; Obertelli, A.*; Doornenbal, P.*; Barbieri, C.*; Duguet, T.*; G
mez-Ramos, M.*; Holt, J. D.*; Hu, B. S.*; et al.
Physical Review C, 109(3), p.034312_1 - 034312_15, 2024/03
Times Cited Count:3 Percentile:62.30(Physics, Nuclear)no abstracts in English
TaS
Park, P.*; Cho, W.*; Kim, C.*; An, Y.*; Avdeev, M.*; Iida, Kazuki*; Kajimoto, Ryoichi; Park, J.-G.*
Physical Review B, 109(6), p.L060403_1 - L060403_7, 2024/02
Times Cited Count:19 Percentile:87.36(Materials Science, Multidisciplinary)Watabe, Hiroshi*; Sato, Tatsuhiko; Yu, K. N.*; Zivkovic, M.*; Krstic, D.*; Nikezic, D.*; Kim, K. M.*; Yamaya, Taiga*; Kawachi, Naoki*; Tanaka, Hiroki*; et al.
Radiation Protection Dosimetry, 200(2), p.130 - 142, 2024/02
Times Cited Count:2 Percentile:30.64(Environmental Sciences)Previously, we have developed DynamicMC for modelling relative movement of ORNL phantom in a radiation field for MCNP. Using this software, 3-dimensional dose distributions in a phantom irradiated by a certain mono-energetic source can be deduced through its graphical user interface (GUI). In this study, we extended DynamicMC to be used in combination with the PHITS by providing it with a higher flexibility for dynamic movement for a less sophisticated anthropomorphic phantom. We anticipate that the present work and the developed open-source tools will be in the interest of nuclear radiation physics community for research and teaching purposes.
Kim, G.*; Cho, S.-M.*; Im, S.*; Suh, H.*; Morooka, Satoshi; Shobu, Takahisa; Kanematsu, Manabu*; Machida, Akihiko*; Bae, S.*
Construction and Building Materials, 411, p.134529_1 - 134529_18, 2024/01
Times Cited Count:15 Percentile:73.73(Construction & Building Technology)
TaS
Park, P.*; Cho, W.*; Kim, C.*; An, Y.*; Kang, Y.-G.*; Avdeev, M.*; Sibille, R.*; Iida, Kazuki*; Kajimoto, Ryoichi; Lee, K. H.*; et al.
Nature Communications (Internet), 14, p.8346_1 - 8346_9, 2023/12
Times Cited Count:52 Percentile:91.64(Multidisciplinary Sciences)Kim, M.; Malins, A.*; Machida, Masahiko; Yoshimura, Kazuya; Saito, Kimiaki; Yoshida, Hiroko*
Nihon Genshiryoku Gakkai Wabun Rombunshi (Internet), 22(4), p.156 - 169, 2023/11
Dose reduction factor of a Japanese house is important information in the external exposure estimation of returning residents. In 2019, a total of 19 wooden houses were surveyed in Iitate Village and Namie Town using a gamma plotter that can continuously measure the air dose rate. In addition, the characteristics of the reduction factor were investigated from the measured air dose rate. In the vicinity of houses, uncontaminated areas exist underneath houses and, the ratio of paved surfaces such as asphalt roads is relatively high; furthermore, the pavement has a tendency for the radiation source to decay quickly. Therefore, the air dose rate near the house showed a relatively low value in common at all sites. Air dose rates above unpaved surfaces showed higher values and larger variations than those above paved surfaces within a radius of 50 m form the center of a house. The reduction factor was widely distributed even for one house, if the ratio of every air dose rate observed inside and outside the house is considered. It is suggested that a realistic reduction factor may not be obtained when the reduction factor is obtained based on the measured values at a small number of points that do not have the representativeness of the radiation field to be measured.
Yang, D. S.*; Wu, Y.*; Kanatzidis, E. E.*; Avila, R.*; Zhou, M.*; Bai, Y.*; Chen, S.*; Sekine, Yurina; Kim, J.*; Deng, Y.*; et al.
Materials Horizons, 10(11), p.4992 - 5003, 2023/09
Times Cited Count:25 Percentile:85.01(Chemistry, Multidisciplinary)This paper presents a set of findings that enhances the performance of these systems through the use of microfluidic networks, integrated valves and microscale optical cuvettes formed by three-dimensional printing in hard/soft hybrid materials systems, for accurate spectroscopic and fluorometric assays. Field studies demonstrate the capability of these microcuvette systems to evaluate the concentrations of copper, chloride, and glucose in sweat, along with the sweat pH, with laboratory grade accuracy and sensitivity.