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Sr/Y inside the Fukushima Daiichi Nuclear Power Station Unit 3 reactor building using a liquid light guide Cherenkov counterTerasaka, Yuta; Sato, Yuki; Furuta, Yoshihiro*; Kubo, Shin*; Ichiba, Yuta*
Nuclear Instruments and Methods in Physics Research A, 1070(2), p.170021_1 - 170021_9, 2025/01
Times Cited Count：0 Percentile：0.00(Instruments & Instrumentation)Miura, Taito*; Miyamoto, Shintoro*; Maruyama, Ippei*; Aili, A.*; Sato, Takumi; Nagae, Yuji; Igarashi, Go*
Case Studies in Construction Materials, 21, p.e03571_1 - e03571_14, 2024/12
Times Cited Count：0 Percentile：0.00(Construction & Building Technology)
Sm synchrotron-radiation-based M
ssbauer spectroscopy of Sm-based heavy fermion compoundsTsutsui, Satoshi; Higashinaka, Ryuji*; Mizumaki, Masaichiro*; Kobayashi, Yoshio*; Nakamura, Jin*; Ito, Takashi; Yoda, Yoshitaka*; Matsuda, Tatsuma*; Aoki, Yuji*; Sato, Hideyuki*
Interactions (Internet), 245(1), p.9_1 - 9_10, 2024/12
Iwami, Satone*; Yamashita, Takuma*; Mitsuyasu, Yusuke*; Ono, Kenta*; Oka, Toshitaka; Takahashi, Atsushi*; Kino, Yasushi*; Sekine, Tsutomu*; Shimizu, Yoshinaka*; Chiba, Mirei*; et al.
KEK Proceedings 2024-6, p.91 - 95, 2024/12
We aim to improve the detection limit of the ESR dosimetry method. In this study, the saturation behavior of each radical was investigated by varying the microwave power during ESR measurement. Based on the difference in spin relaxation time between carbonate radicals and native radicals, it is expected that the signal-to-noise ratio improves and the detection limit can be lowered when the microwave power is increased to 4.0 mW.
Yamashita, Takuma*; Iwami, Satone*; Mitsuyasu, Yusuke*; Ono, Kenta*; Oka, Toshitaka; Takahashi, Atsushi*; Kino, Yasushi*; Sekine, Tsutomu*; Shimizu, Yoshinaka*; Chiba, Mirei*; et al.
KEK Proceedings 2024-6, p.85 - 90, 2024/12
To clarify the radiation effects of the accident at the TEPCO's Fukushima Daiichi NPP on living organisms, it is important to accurately estimate the dose to each individual. We have developed a multi-component analysis program using random number optimization to extract only the components derived from carbonate radicals from the ESR spectra.
Sato, Tatsuhiko; Hashimoto, Shintaro; M
rquez Damin, J. I.*; Niita, Koji*
Nuclear Instruments and Methods in Physics Research B, 557, p.165535_1 - 165535_8, 2024/12
Times Cited Count：0 Percentile：0.00(Instruments & Instrumentation)Ogawa, Tatsuhiko; Hirata, Yuho; Matsuya, Yusuke; Kai, Takeshi; Sato, Tatsuhiko; Iwamoto, Yosuke; Hashimoto, Shintaro; Furuta, Takuya; Abe, Shinichiro; Matsuda, Norihiro; et al.
EPJ Nuclear Sciences & Technologies (Internet), 10, p.13_1 - 13_8, 2024/11
The latest updates on PHITS, a versatile radiation transport code, focusing specifically on track-structure models are presented. Track structure calculations are methods used to simulate the movement of charged particles while explicitly considering each atomic reaction. Initially developed for radiation biology, these calculation methods aimed to analyze the radiation-induced damage to DNA and chromosomes. Several track-structure calculation models, including PHITS-ETS, PHITS-ETS for Si, PHITS-KURBUC, ETSART, and ITSART, have been developed and implemented to PHITS. These models allow users to study the behavior of various particles at the nano-scale across a wide range of materials. Furthermore, potential applications of track-structure calculations have also been proposed so far. This collection of track-structure calculation models, which encompasses diverse conditions, opens up new avenues for research in the field of radiation effects.
Oikawa, Kenichi; Matsumoto, Yoshihiro*; Watanabe, Kenichi*; Sato, Hirotaka*; Parker, J. D.*; Shinohara, Takenao; Kiyanagi, Yoshiaki*
Scientific Reports (Internet), 14, p.27990_1 - 27990_11, 2024/11
Times Cited Count：0 Percentile：0.00(Multidisciplinary Sciences)Matsumoto, Yoshihiro*; Oikawa, Kenichi; Watanabe, Kenichi*; Sato, Hirotaka*; Parker, J. D.*; Shinohara, Takenao; Kiyanagi, Yoshiaki*
Journal of Archaeological Science; Reports, 58, p.104729_1 - 104729_10, 2024/10
Machida, Akihiko*; Saito, Hiroyuki*; Sugimoto, Hidehiko*; Hattori, Takanori; Sano, Asami; Endo, Naruki*; Katayama, Yoshinori*; Iizuka, Riko*; Sato, Toyoto*; Matsuo, Motoaki*; et al.
Nature Communications (Internet), 15, p.8861_1 - 8861_2, 2024/10
Times Cited Count：0 Percentile：0.00(Multidisciplinary Sciences)In our previous article (Nature Commun. 5, 5063 (2014)), the site occupancies of D atoms dissolved in an fcc Fe metal lattice were investigated via Rietveld refinement of neutron powder diffraction patterns collected at 988 K and 6.3 GPa. The fcc metal lattice has two interstitial sites available for accommodating D atoms: octahedral and tetrahedral sites. The Rietveld refinement revealed that D atoms occupied mainly the octahedral sites with occupancy of 0.532 and slightly the tetrahedral sites with occupancy of 0.056. Subsequent density-functional-theory (DFT) calculations by Antonov (Phys. Rev. Mater. 2019)) showed that the occupation energy on the tetrahedral site was significantly higher than that on the octahedral site; the tetrahedral site occupation was unlikely to occur even at temperatures as high as 988 K. We reexamined the site occupancies of D-atom by Rietveld refinement including extinction correction. As a result, the octahedral occupancy was increased to 0.60 and the tetrahedral occupancy was reduced to zero. The occupation of only the octahedral site for D atom is consistent with the DFT calculation, although in contrast to the previous results.
Sato, Nobuaki*; Kameo, Yutaka; Sato, Soichi; Kumagai, Yuta; Sato, Tomonori; Yamamoto, Masahiro*; Watanabe, Yutaka*; Nagai, Takayuki; Niibori, Yuichi*; Watanabe, Masayuki; et al.
Introduction to Dismantling and Decommissioning Chemistry, 251 Pages, 2024/09
This book focuses on the dismantling and decommissioning of nuclear facilities and reactors that have suffered severe accidents. In Part 1, we introduce basic aspects ranging from fuel chemistry, analytical chemistry, radiation chemistry, corrosion, and decontamination chemistry to waste treatment and disposal. Then, Part 2 covers the chemistry involved in the decommissioning of various nuclear facilities, and discusses what chemical approaches are necessary and possible for the decommissioning of TEPCO's Fukushima Dai-ichi Nuclear Power Plants, how decommissioning should be carried out, and what kind of research and development and also human resource development are required for this.
Akiba, Hiroshi*; Omasa, Yoshinori*; Kofu, Maiko*; Zhang, M.*; Sato, Shun*; Yamamuro, Osamu*
Journal of the Physical Society of Japan, 93(9), p.091010_1 - 091010_6, 2024/09
Times Cited Count：0 Percentile：0.00(Physics, Multidisciplinary)Lan, Z.*; Arikawa, Yasunobu*; Mirfayzi, S. R.*; Morace, A.*; Hayakawa, Takehito*; Sato, Hirotaka*; Kamiyama, Takashi*; Wei, T.*; Tatsumi, Yuta*; Koizumi, Mitsuo; et al.
Nature Communications (Internet), 15, p.5365_1 - 5365_7, 2024/07
Times Cited Count：2Mochizuki, Akihito; Sato, Toshinori; Wada, Junichi*
JAEA-Research 2024-003, 86 Pages, 2024/06
JAEA-Research-2024-003.pdf:8.13MB
For the geological disposal of high-level radioactive waste, research and studies are being conducted in Japan and abroad to contribute to the mitigation of the upper temperature limit (100
C) in the buffer material assumed in the current disposal system. In this study, uniaxial compression tests under several temperature conditions, some of which exceed 100C, were conducted to understand changes in rock properties under high temperature conditions, using siliceous mudstone (Wakkanai formation) from Horonobe, Hokkaido, as a case study. The uniaxial compressive strength of the rock increased with heating temperature. The uniaxial compressive strength of specimens heated above 100C was comparable to that of specimens desiccated before testing. Mineralogical observations by scanning electron microscopy showed no evidence of alteration of pore structure or minerals, as observed in other rocks in previous studies. In conclusion, the increase in strength of siliceous mudstone with heating temperature observed in this study is considered to be due to the drying of the specimens with heating.
Yamano, Hidemasa; Takano, Kazuya; Kurisaka, Kenichi; Kikuchi, Shin; Kondo, Toshiki; Umeda, Ryota; Sato, Rika; Shirakura, Shota*
Dai-28-Kai Doryoku, Enerugi Gijutsu Shimpojiumu Koen Rombunshu (Internet), 5 Pages, 2024/06
This project studies investigation on safety design guideline and risk assessment technology for sodium-cooled fast reactor with the molten-salt heat storage system, development of evaluation method for heat transferring performance between sodium and molten-salt and improvement of the performance, and evaluation of chemical reaction characteristic between sodium and molten-salt and improvement of its safety. This paper describes the effect of sodium-molten salt heat transfer tube failure in addition to the project overview and progress.
Kikuchi, Shin; Sato, Rika; Kondo, Toshiki; Umeda, Ryota; Yamano, Hidemasa
Dai-28-Kai Doryoku, Enerugi Gijutsu Shimpojiumu Koen Rombunshu (Internet), 4 Pages, 2024/06
no abstracts in English
Sato, Ikken; Yoshikawa, Shinji; Yamashita, Takuya; Shimomura, Kenta; Cibula, M.*; Mizokami, Shinya*
Nuclear Engineering and Design, 422, p.113088_1 - 113088_24, 2024/06
Times Cited Count：0 Percentile：0.00(Nuclear Science & Technology)Ishikawa, Akihisa; Koba, Yusuke*; Furuta, Takuya; Chang, W.*; Yonai, Shunsuke*; Matsumoto, Shinnosuke*; Hashimoto, Shintaro; Hirai, Yuta*; Sato, Tatsuhiko
Radiological Physics and Technology, 17(2), p.553 - 560, 2024/06
Be and 
Al under direct muon-induced spallation in granite quartz and its implications for past high-energy cosmic ray fluxesSakurai, Hirohisa*; Kurebayashi, Yutaka*; Suzuki, Soichiro*; Horiuchi, Kazuho*; Takahashi, Yui*; Doshita, Norihiro*; Kikuchi, Satoshi*; Tokanai, Fuyuki*; Iwata, Naoyoshi*; Tajima, Yasushi*; et al.
Physical Review D, 109(10), p.102005_1 - 102005_18, 2024/05
Times Cited Count：0 Percentile：0.00(Astronomy & Astrophysics)Secular variations of galactic cosmic rays (GCRs) are inseparably associated with the galactic activities and should reflect the environments of the local galactic magnetic field, interstellar clouds, and nearby supernova remnants. The high-energy muons produced in the atmosphere by high-energy GCRs can penetrate deep underground and generate radioisotopes in the rock. As long lived radionuclides such as Be and Al have been accumulating in these rocks, concentrations of Be and Al can be used to estimate the long-term variations in high-energy muon yields, corresponding to those in the high-energy GCRs over a few million years. This study measured the production cross sections for muon induced Be and Al by irradiating positive muons with the momentum of 160 GeV/c on the synthetic silica plates and the granite core at the COMPASS experiment line in CERN SPS. In addition, it the contributions of the direct muon spallation reaction and the nuclear reactions by muon-induced particles on the production of long lived radionuclides in the rocks were clarified.
Sr in highly radioactive aqueous samples via conversion to a kinetically stable 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid complex followed by concentration-separation-fractionation based on capillary electrophoresis-liquid scintillationOuchi, Kazuki; Haraga, Tomoko; Hirose, Kazuki*; Kurosawa, Yuika*; Sato, Yoshiyuki; Shibukawa, Masami*; Saito, Shingo*
Analytica Chimica Acta, 1298, p.342399_1 - 342399_7, 2024/04
Times Cited Count：1 Percentile：63.46(Chemistry, Analytical)Given that conventional methods of high-dose sample analysis pose substantial exposure risks and generate large amounts of secondary radioactive waste, faster procedures allowing for decreased radiation emission are highly desirable. To address this need, we developed a Sr
quantitation technique that is based on liquid scintillation counting-coupled capillary transient isotachophoresis (ctITP) with two-point detection and relies on the rapid concentration, separation, and fractionation of 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA)-complexed Sr in a single run. This method, which allows for the handling of high-dose radioactive specimens at the microliter level and is substantially faster than conventional ion-exchange protocols, was used to selectively quantify Sr in real high-dose waste. The successful concentration-separation in ctITP was ascribed to the inertness of the Sr-DOTA complex to dissociation.
