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Kuwata, Haruka*; Tazoe, Hirofumi*; Kranrod, C.*; Fujiwara, Kenso; Terashima, Motoki; Matsueda, Makoto; Hirao, Shigekazu*; Akata, Naofumi*
Radiation Protection Dosimetry, 198(13-15), p.1014 - 1018, 2022/09
Times Cited Count：0 Percentile：0.01(Environmental Sciences)
Reactions to Achieve Mass-spectrometric Discrimination in Simultaneous Plutonium-isotope Speciation with Inductively Coupled Plasma-Tandem Mass SpectrometryMatsueda, Makoto; Kawakami, Tomohiko*; Koarai, Kazuma; Terashima, Motoki; Fujiwara, Kenso; Iijima, Kazuki; Furukawa, Makoto*; Takagai, Yoshitaka*
Chemistry Letters, 51(7), p.678 - 682, 2022/07
Times Cited Count：6 Percentile：58.73(Chemistry, Multidisciplinary)New methodology for a simultaneous isotope speciation of various Pu isotopes without complicated isobaric interferences is developed by using inductively coupled plasma-mass spectrometry (ICP-MS). In analyzing ICP tandem MS (ICP-MS/MS), CO gas reactions in a dynamic reaction cell (DRC) almost eliminated the background noise intensity produced by isobaric interference from isotopes originating from actinides such as Am, Cm, and U at the locations (m/z) of significant Pu isotopes (
Pu, 
Pu, 
Pu, 
Pu, 
Pu).
Kusano, Kanya*; Ichimoto, Kiyoshi*; Ishii, Mamoru*; Miyoshi, Yoshizumi*; Yoden, Shigeo*; Akiyoshi, Hideharu*; Asai, Ayumi*; Ebihara, Yusuke*; Fujiwara, Hitoshi*; Goto, Tadanori*; et al.
Earth, Planets and Space (Internet), 73(1), p.159_1 - 159_29, 2021/12
Times Cited Count：6 Percentile：49.29(Geosciences, Multidisciplinary)The PSTEP is a nationwide research collaboration in Japan and was conducted from April 2015 to March 2020, supported by a Grant-in-Aid for Scientific Research on Innovative Areas from the Ministry of Education, Culture, Sports, Science and Technology of Japan. It has made a significant progress in space weather research and operational forecasts, publishing over 500 refereed journal papers and organizing four international symposiums, various workshops and seminars, and summer school for graduate students at Rikubetsu in 2017. This paper is a summary report of the PSTEP and describes the major research achievements it produced.
Sr in hard tissue samplesKoarai, Kazuma; Matsueda, Makoto; Aoki, Jo; Yanagisawa, Kayo*; Fujiwara, Kenso; Terashima, Motoki
KEK Proceedings 2021-2, p.140 - 145, 2021/12
Strontium-90 and Y, its daughter nuclide, adverse effects on the bone marrow. Monitoring of Sr in the bones have been required after the Fukushima-Daiichi Nuclear Power Plant accident. However, conventional radioactivity measurement method for Sr requires a complicated separation of Y and a time-consuming measurement. ICP-MS system has been applied to Sr concentration survey of water, soil, and edible part of fish. We developed measurement method of Sr with ICP-MS and applied the method for cattle bones. We determined Sr in the hard tissues of animals that collected in the Fukushima prefecture. Limit of detection in the measurement was 19 Bq/kg.
Sr in cattle bone and tooth samples by inductively coupled plasma mass spectrometryKoarai, Kazuma; Matsueda, Makoto; Aoki, Jo; Yanagisawa, Kayo*; Terashima, Motoki; Fujiwara, Kenso; Kino, Yasushi*; Oka, Toshitaka; Takahashi, Atsushi*; Suzuki, Toshihiko*; et al.
Journal of Analytical Atomic Spectrometry, 36(8), p.1678 - 1682, 2021/08
Times Cited Count：5 Percentile：54.36(Chemistry, Analytical)Rapid analysis of Sr in bone and tooth samples of cattle were achieved by an inductively coupled plasma mass spectrometry (ICP-MS) coupled with mass shift and solid phase extraction techniques. Limit of detection (LOD) in the ICP-MS measurement of 0.1 g samples was lower than that of the radioactivity measurement. Analytical time of the ICP-MS method was reduced from 20 days to 11 hours, compared with the radiometric method. Therefore, the ICP-MS method can be rapid and useful procedure of Sr in small bone and tooth samples derived from terrestrial animals.
Matsueda, Makoto; Yanagisawa, Kayo*; Koarai, Kazuma; Terashima, Motoki; Fujiwara, Kenso; Abe, Hironobu; Kitamura, Akihiro; Takagai, Yoshitaka*
ACS Omega (Internet), 6(29), p.19281 - 19290, 2021/07
Times Cited Count：2 Percentile：14.19(Chemistry, Multidisciplinary)Online solid-phase extraction-inductively coupled plasma-quadrupole mass spectrometry with oxygen dynamic reaction cell (online SPE-ICP-MS-DRC) was shown to be a thorough automatic analytical system, circumventing the need for human handling. At three stepwise separations (SPE-DRC-Q mass filters), we showed that interference materials allowed the coexistence of abundance ratios of 1.5
10
for 
Tc/Mo. Using this optimized system, a detection limit of Tc was 9.3 pg/L (5.9 mBq/L) for a 50 mL injection and sequential measurements were undertaken at a cycle of 24 min/sample.
Aoki, Jo; Matsueda, Makoto; Koarai, Kazuma; Terashima, Motoki; Fujiwara, Kenso; Abe, Hironobu
JAEA-Research 2021-002, 20 Pages, 2021/05
JAEA-Research-2021-002.pdf:2.75MB
In order to analyze extremely low concentrations of 
I in environmental samples by ICP-MS with high sensitivity and rapidity, it is necessary to remove interfering elements (Na, Mg, K, Ca, Mo, Cd and In) using a pretreatment method with Solid-phase Extraction Resin. Anion Exchange Resins with amino groups have been widely used as Solid-phase Extraction Resins, while Ag+ Supported Resins have also been widely used in recent years. It is necessary to optimize the pretreatment technique based on characteristics of the resins. In this study, we compared in terms of separation of I from matrix elements (Na, Mg, K, Ca, Mo, Cd and In) for DOWEX1-X8, AG 1-X8 and CL Resin, and investigated their suitability for ICP-MS analysis of I in environmental samples. The results of adsorption and elution experiments showed that all resins examined uptake and elute I quantitatively. CL Resin showed the highest removal performance of interfering elements, with 3.1% of Mo remaining, but other interfering elements were removed below the detection limit of ICP-MS. However, the Mo remained after the CL Resin treatment could interfere the ICP-MS measurement of I, based on the consideration of ratio of I and Mo. The eluate from CL Resin was treated with a Cation exchange resin (DOWEX 50WX8). As a result, Mo in the eluate was removed by up to 98% and the interference from Mo was reduced to measurable level. Therefore, the pretreatment method using CL Resin in combination with DOWEX 50WX8 is effective for ICP-MS analysis of I at extremely low concentrations (background level).
Takeda, Tetsuaki*; Inagaki, Yoshiyuki; Aihara, Jun; Aoki, Takeshi; Fujiwara, Yusuke; Fukaya, Yuji; Goto, Minoru; Ho, H. Q.; Iigaki, Kazuhiko; Imai, Yoshiyuki; et al.
High Temperature Gas-Cooled Reactors; JSME Series in Thermal and Nuclear Power Generation, Vol.5, 464 Pages, 2021/02
As a general overview of the research and development of a High Temperature Gas-cooled Reactor (HTGR) in JAEA, this book describes the achievements by the High Temperature Engineering Test Reactor (HTTR) on the designs, key component technologies such as fuel, reactor internals, high temperature components, etc., and operational experience such as rise-to-power tests, high temperature operation at 950
C, safety demonstration tests, etc. In addition, based on the knowledge of the HTTR, the development of designs and component technologies such as high performance fuel, helium gas turbine and hydrogen production by IS process for commercial HTGRs are described. These results are very useful for the future development of HTGRs. This book is published as one of a series of technical books on fossil fuel and nuclear energy systems by the Power Energy Systems Division of the Japan Society of Mechanical Engineers.
Sr in hard tissue samplesKoarai, Kazuma; Matsueda, Makoto; Aoki, Jo; Yanagisawa, Kayo*; Fujiwara, Kenso; Terashima, Motoki; Kitamura, Akihiro; Abe, Hironobu
KEK Proceedings 2020-4, p.180 - 185, 2020/11
Strontium-90 and Y, its daughter nuclide, adverse effects on the bone marrow. Monitoring of Sr in the bones have been required after the Fukushima-Daiichi Nuclear Power Plant accident. However, conventional radioactivity measurement method for Sr requires a complicated separation of Y and a time-consuming measurement. ICP-MS system has been applied to Sr concentration survey of water, soil, and edible part of fish. We applied the ICP-MS system for the bones for the first time. In this study, reference bone (JSAC 0785 fish bone) was used as measurement samples. Sample preparation of the bone was performed using a microwave digestion instrument. After sample preparation, Sr was determined using ICP-MS system with cascade separation steps based on on-line column separation and oxygen reaction. Strontium-90 in the bones was successfully separated from Ca, Ba, Y, Zr, Fe, Se, and Ge, which interfered in ICP-MS measurement, in the separation steps.
pellets for Mo-99 production, 2Nishikata, Kaori; Ishida, Takuya; Yonekawa, Minoru; Kato, Yoshiaki; Kurosawa, Makoto; Kimura, Akihiro; Matsui, Yoshinori; Tsuchiya, Kunihiko; Sano, Tadafumi*; Fujihara, Yasuyuki*; et al.
KURRI Progress Report 2014, P. 109, 2015/07
As one of effective applications of the Japan Materials Testing Reactor (JMTR), JAEA has a plan to produce Mo by (n,
) method ((n,)Mo production), a parent nuclide of 
Tc. In this study, preliminary irradiation test was carried out with the high-density molybdenum trioxide (MoO) pellets in the hydraulic conveyer (HYD) of the Kyoto University Research Reactor (KUR) and the Tc solution extracted from Mo was evaluated. After the irradiation test of the high-density MoO pellets in the KUR, Tc was extracted from the Mo solution and the recovery rate of Tc achieved the target values. The Tc solution also got the value that satisfied the standard value for Tc radiopharmaceutical products by the solvent extraction method.
Shibata, Masahiro; Sawada, Atsushi; Tachi, Yukio; Makino, Hitoshi; Wakasugi, Keiichiro; Mitsui, Seiichiro; Kitamura, Akira; Yoshikawa, Hideki; Oda, Chie; Ishidera, Takamitsu; et al.
JAEA-Research 2014-030, 457 Pages, 2015/03
JAEA-Research-2014-030.pdf:199.23MB
JAEA and NUMO have conducted a collaborative research work which is designed to enhance the methodology of repository design and post-closure performance assessment in preliminary investigation stage. With regard to (1) study on rock suitability in terms of hydrology, based on some examples of developing method of hydro-geological structure model, acquired knowledge are arranged using the tree diagram, and model uncertainty and its influence on the evaluation items were discussed. With regard to (2) study on scenario development, the developed approach for "defining conditions" has been reevaluated and improved from practical viewpoints. In addition, the uncertainty evaluation for the effect of use of cementitious material, as well as glass dissolution model, was conducted with analytical evaluation. With regard to (3) study on setting radionuclide migration parameters, based on survey of precedent procedures, multiple-approach for distribution coefficient of rocks was established, and the adequacy of the approach was confirmed though its application to sedimentary rock and granitic rock. Besides, an approach for solubility setting was developed including the procedure of selection of solubility limiting solid phase. The adequacy of the approach was confirmed though its application to key radionuclides.
Uesaka, Mitsuru*; Kobayashi, Hitoshi*; Kureta, Masatoshi; Nakatsuka, Shigehiro*; Nishimura, Kazuya*; Igashira, Masayuki*; Hori, Junichi*; Kiyanagi, Yoshiaki*; Tagi, Kazuhiro*; Seki, Toshichika*; et al.
Reviews of Accelerator Science and Technology, 8, p.181 - 207, 2015/00
We choose nuclear data and nuclear material inspection for energy application and nondestructive testing of explosive and hidden nuclear materials for security application. 90 keV electrostatic accelerators of deuterium are commercially available for nondestructive testing. For nuclear data measurement, electrostatic ion accelerators and L-band and S-band electron linear accelerators (linac) are used for the neutron source. Compact or mobile X-band electron linac neutron sources are under development. Compact proton linac neutron source is used for nondestructive testing especially water in solids. Several efforts for more neutron intensity using proton and deuteron accelerators are also introduced.
pellets for Mo-99 productionNishikata, Kaori; Ishida, Takuya; Yonekawa, Minoru; Kato, Yoshiaki; Kurosawa, Makoto; Kimura, Akihiro; Matsui, Yoshinori; Tsuchiya, Kunihiko; Sano, Tadafumi*; Fujihara, Yasuyuki*; et al.
KURRI Progress Report 2013, P. 242, 2014/10
As one of effective applications of the Japan Materials Testing Reactor (JMTR), JAEA has a plan to produce Mo-99 (Mo) by (n,) method ((n,)Mo production), a parent nuclide of Tc. In this study, preliminary irradiation tests were carried out with the high-density MoO pellets in the KUR and the Mo production amount was evaluated between the calculation results and measurement results.
Shibata, Masahiro; Sawada, Atsushi; Tachi, Yukio; Hayano, Akira; Makino, Hitoshi; Wakasugi, Keiichiro; Mitsui, Seiichiro; Oda, Chie; Kitamura, Akira; Osawa, Hideaki; et al.
JAEA-Research 2013-037, 455 Pages, 2013/12
JAEA-Research-2013-037.pdf:42.0MB
Following FY2011, JAEA and NUMO have conducted a collaborative research work which is designed to enhance the methodology of repository design and performance assessment in preliminary investigation stage. With regard to (1) study on rock suitability in terms of hydrology, the tree diagram of methodology of groundwater travel time has been extended for crystalline rock, in addition, tree diagram for sedimentary rock newly has been organized. With regard to (2) study on scenario development, the existing approach has been improved in terms of a practical task, and applied and tested for near field focusing on the buffer. In addition, the uncertainty of some important processes and its impact on safety functions are discussed though analysis. With regard to (3) study on setting radionuclide migration parameters, the approaches for parameter setting have been developed for sorption for rocks and solubility, and applied and tested through parameter setting exercises for key radionuclides.
Yoshikawa, Hideki; Iijima, Kazuki; Sasamoto, Hiroshi; Fujiwara, Kenso; Mitsui, Seiichiro; Kitamura, Akira; Kurikami, Hiroshi; Tokizawa, Takayuki; Yui, Mikazu; Nakayama, Shinichi
Materials Research Society Symposium Proceedings, Vol.1518, p.269 - 275, 2013/10
Following the release of radionuclides into the environment as a result of the accident at Fukushima Daiichi Nuclear Power Plant, Japan Atomic Energy Agency (JAEA) had to develop an immediate and effective method of reducing the dose rate received by students in school facilities. A demonstration of a reducing method was carried out by JAEA at a junior high school ground and kindergarten yard in the center of Fukushima-city. Dose rates of the released radionuclides are largely controlled by the ground level contamination and accumulation of mainly cesium-137 (
Cs) and cesium-134 (
Cs) in populated areas. An effective means of reducing dose rate was to remove the surface soil and to bury it on-site under fresh uncontaminated soil or soil collected under deep depth at the site for shielding. The dose rate at1 m above ground level was reduced from 2.5 
Sv/h to 0.15 Sv/h.
collisions at 
= 200 and 62.4 GeVAdare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Yasuyuki*; Al-Bataineh, H.*; Alexander, J.*; Aoki, Kazuya*; Aphecetche, L.*; Armendariz, R.*; et al.
Physical Review C, 83(6), p.064903_1 - 064903_29, 2011/06
Times Cited Count：184 Percentile：99.45(Physics, Nuclear)Transverse momentum distributions and yields for 
, and 
in collisions at = 200 and 62.4 GeV at midrapidity are measured by the PHENIX experiment at the RHIC. We present the inverse slope parameter, mean transverse momentum, and yield per unit rapidity at each energy, and compare them to other measurements at different collisions. We also present the scaling properties such as 
and 
scaling and discuss the mechanism of the particle production in collisions. The measured spectra are compared to next-to-leading order perturbative QCD calculations.
and Au+Au collisions at 
= 200 GeVAdare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Yasuyuki*; Al-Bataineh, H.*; Alexander, J.*; Aoki, Kazuya*; Aphecetche, L.*; Aramaki, Y.*; et al.
Physical Review C, 83(4), p.044912_1 - 044912_16, 2011/04
Times Cited Count：9 Percentile：49.6(Physics, Nuclear)Measurements of electrons from the decay of open-heavy-flavor mesons have shown that the yields are suppressed in Au+Au collisions compared to expectations from binary-scaled collisions. Here we extend these studies to two particle correlations where one particle is an electron from the decay of a heavy flavor meson and the other is a charged hadron from either the decay of the heavy meson or from jet fragmentation. These measurements provide more detailed information about the interaction between heavy quarks and the quark-gluon matter. We find the away-side-jet shape and yield to be modified in Au+Au collisions compared to collisions.
Morita, Yoshimune*; Kamiya, Chiho*; Sasaki, Toshinori*; Miyagi, Toyohiko*; Sugai, Toshihiko; Yanagida, Makoto*; Furusawa, Akira*; Fujiwara, Osamu*
Kikan Chirigaku, 62(4), p.195 - 210, 2010/12
It is assumed that the variation of temperature and the precipitation with the climate change may affect geological environment such as the subsurface water flow. Therefore, as well as global climate change from the past to the present, investigation technology to grasp local climate change is indispensable. A palynological study was carried out using the sediment core taken from the Okute Basin, located in the northeast of Mizunami Underground Research Laboratory. As a result, it was appeared that in a interglacial epoch, there was much precipitation around this area, and that in a glacial epoch, became colder and more arid, compared with Kinki region in the same latitude. This shows that the modern analog method with pollen data from the sediment of the inland basin is effective technique to estimate a local climate change.
Li, T.*; Garg, U.*; Liu, Y.*; Marks, R.*; Nayak, B. K.*; Madhusudhana Rao, P. V.*; Fujiwara, Mamoru*; Hashimoto, Hisanobu*; Nakanishi, Kosuke*; Okumura, Shun*; et al.
Physical Review C, 81(3), p.034309_1 - 034309_11, 2010/03
Times Cited Count：107 Percentile：97.52(Physics, Nuclear)Nakayama, Shinichi; Nagasaki, Shinya*; Inagaki, Yaohiro*; Oe, Toshiaki*; Sasaki, Takayuki*; Sato, Seichi*; Sato, Tsutomu*; Tanaka, Satoru*; Tochiyama, Osamu*; Nagao, Seiya*; et al.
JAEA-Conf 2007-003, 120 Pages, 2007/03
JAEA-Conf-2007-003.pdf:53.18MB
The 1st information exchange meeting on Radioactive Waste Disposal Research Network was held in Nuclear Science Research Institute of Japan Atomic Energy Agency on August 4, 2006. Radioactive Waste Disposal Research Network was established by under Interorganization Atomic Energy Research Program of Japan Atomic Energy Agency, and the objective is to bring both research infrastructures and human expertise in Japan to an adequate performance level, thereby contributing to the development of the fundamental research area in the field of radioactive waste disposal. This lecture material is a collection of research presentations and discussions during the information exchange meeting.
