Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Yamamoto, Yusuke*; Watanabe, Takahiro; Niwa, Masakazu; Shimada, Koji
JAEA-Testing 2023-003, 67 Pages, 2024/02
A long-term geosphere stability for geological disposal is evaluated by the past geological environmental changes and modern conditions. Stable hydrogen and oxygen isotope ratios (D, O) of geological samples are useful information to estimate the past environmental changes and modern conditions. Recently, the thermal conversion elemental analyzer and isotope ratio mass spectrometer (TC-EA/IRMS) were installed in the Tono Geoscience Center for D and O measurements of geological samples. In this study, we reported analytical methods of D and O using international standard reference materials. In addition, evaluation tests of uncertainty by repeated analyses of the standards were performed using the TC-EA/IRMS. Furthermore, the D and O analyses by the TC- EA/IRMS were also applied to fault rock samples.
Tomita, Ryohei; Tomita, Jumpei; Suzuki, Daisuke; Yasuda, Kenichiro; Miyamoto, Yutaka
Hosha Kagaku, (48), p.1 - 15, 2023/09
Secondary Ion Mass Spectrometry (SIMS) is the method to detect secondary ions produced by the sputtering of primary ions. SIMS is one of effective method to measure isotopic composition of particles containing nuclear material in environmental sample for safeguards. We are a group member of the International Atomic Energy Agency (IAEA)'s network of analytical laboratories and have developed analytical techniques using SIMS and other mass spectrometers for nuclear safeguards. We will introduce the principle of SIMS and analytical techniques developed by our group to measure isotopic composition of uranium particles which having a particle diameter of micron order in environmental sample for safeguards.
Shimada, Asako; Tsukahara, Takehiko*; Nomura, Masao*; Kim, M. S.*; Shimada, Taro; Takeda, Seiji; Yamaguchi, Tetsuji
Journal of Nuclear Science and Technology, 58(11), p.1184 - 1194, 2021/11
Times Cited Count:5 Percentile:65.59(Nuclear Science & Technology)Determining the completeness of nuclear reactor decommissioning is an important step in safely utilizing nuclear power. For example, Cs from the Fukushima Daiichi Nuclear Power Station (FDNPS) accident can be treated as background radioactivity, so determining the origin of Cs is essential. To accomplish this, measuring the Cs/Cs isotope ratio can be useful, so this study optimized a solvent extraction method, with calix[4]arene-bis(t-octylbenzo-crown-6) [BOBCalixC6] in 1-octanol, to purify radioactive Cs, radiocesium, from a solution of major environmental soil elements and mass spectrometry interference elements. This optimized method was applied to Cs purification in soil samples (40 g), and the final solutions contained a total of 10g/ml of the major soil elements and ng/ml concentrations at most of interfering elements. Soil samples collected near the FDNPS were then purified, and the Cs/Cs isotope ratios were measured, using both thermal ionization mass spectrometry (TIMS) and triple quadrupole induced coupled plasma mass spectrometry (ICP-QQQ). The results of each of these measurements were compared, and we found that Cs isotope ratios obtained by TIMS were more precise, by an order of magnitude, while the ICP-QQQ results possessed good abundance sensitivities. A slightly higher Cs/Cs ratio in the northwest area of the FDNPS was observed, while other areas exhibited similar values, all within the measurement error range, which indicated different origins of radiocesium. These results agreed with previously reported Cs/Cs activity distributions, suggesting that this ratio may be useful in identifying radiocesium origins for evaluating future nuclear reactor decommissions.
Sano, Asami; Ito, Shoichi*; Suzumura, Akimasa*; Ueno, Yuichiro*; Yagi, Hikaru*; Inoue, Toru*; Kawazoe, Takaaki*
Koatsuryoku No Kagaku To Gijutsu, 30(2), p.85 - 94, 2020/10
Minerals and rocks exhibit various isotope compositions depending on their origins and histories. In interpreting their isotopic variations, the equilibrium isotope fractionation factor is a key because it depends on the environment parameters such as temperature. Recent studies have shown that the effect of pressure on the isotope fractionation, which was considered negligible compared to temperature, is significant under the conditions of the Earth's interior. In this article we review recent advances in experimental studies to determine the isotope fractionation of iron and hydrogen at high pressure over several GPa, discussing their issues and future perspectives.
Taguchi, Shigeo; Miyauchi, Hironari*; Horigome, Kazushi; Yamamoto, Masahiko; Kuno, Takehiko
Bunseki Kagaku, 67(11), p.681 - 686, 2018/11
In thermal ionization mass spectrometry, de-gassing is one of the important treatments to release impurities of filaments and to minimize the influence of background. In this work, the effect of the surface change in the tungsten filament induced by the conductively heating treatment on uranium isotopic (U/U) measurement has been investigated. It was found that the conductively heating treatment of the filament has the effect of smoothing the surface of the filament and also has the effect of improving the deposition of the sample on the filament surface. As a result of either these effects, the precision of uranium isotopic (U/U) measurement was improved.
Esaka, Fumitaka; Yasuda, Kenichiro; Suzuki, Daisuke; Miyamoto, Yutaka; Magara, Masaaki
Talanta, 165, p.122 - 127, 2017/04
Times Cited Count:15 Percentile:52.34(Chemistry, Analytical)The isotope ratios of Pu/Pu, Pu/Pu, Pu/Pu, and Pu/Pu were measured for individual Pu and U-Pu mixed oxide particles by a combination of alpha spectrometry and inductively coupled plasma mass spectrometry (ICP-MS). As a consequence, we were able to determine the Pu/Pu, Pu/Pu, and Pu/Pu isotope ratios with ICP-MS after particle dissolution and chemical separation of uranium, plutonium and americium with UTEVA resins. Furthermore, Pu/Pu isotope ratios were able to be calculated by using both the Pu/(Pu+Pu) activity ratios that had been measured through alpha spectrometry and the Pu/Pu isotope ratios determined through ICP-MS. Therefore, the combined use of alpha spectrometry and ICP-MS is useful in determining plutonium isotope ratios, including Pu/Pu, in individual U-Pu mixed oxide particles.
Esaka, Fumitaka; Suzuki, Daisuke; Miyamoto, Yutaka; Magara, Masaaki
Journal of Radioanalytical and Nuclear Chemistry, 306(2), p.393 - 399, 2015/11
Times Cited Count:6 Percentile:45.92(Chemistry, Analytical)An analytical technique was developed by a combination of single particle dissolution, chemical separation of uranium, plutonium and americium with extraction chromatography using UTEVA resins and measurement with inductively coupled plasma mass spectrometry (ICP-MS). This method was applied to plutonium isotope ratio analysis of individual U-Pu particles with U/Pu ratios ranging from 1 to 70. Consequently, Pu/Pu, Pu/Pu and Pu/Pu isotope ratios were successfully determined, while it was impossible to determine Pu/Pu ratios due to the high process blank values on m/z 238.
Kokubu, Yoko; Yasuda, Kenichiro; Magara, Masaaki; Miyamoto, Yutaka; Sakurai, Satoshi; Usuda, Shigekazu; Yamazaki, Hideo*; Yoshikawa, Shusaku*
Journal of Radioanalytical and Nuclear Chemistry, 273(1), p.183 - 186, 2007/07
Times Cited Count:7 Percentile:47.34(Chemistry, Analytical)no abstracts in English
Kokubu, Yoko; Yasuda, Kenichiro; Magara, Masaaki; Miyamoto, Yutaka; Sakurai, Satoshi; Usuda, Shigekazu; Yamazaki, Hideo*; Mitamura, Muneki*; Yoshikawa, Shusaku*
Journal of Geosciences, Osaka City University, 50, p.7 - 13, 2007/03
no abstracts in English
Hayakawa, Takehito; Iwamoto, Nobuyuki; Shizuma, Toshiyuki; Kajino, Toshitaka*; Umeda, Hideyuki*; Nomoto, Kenichi*
European Physical Journal A, 27(S1), p.123 - 128, 2006/03
Times Cited Count:0 Percentile:0.01(Physics, Nuclear)no abstracts in English
Magara, Masaaki
Kaku Busshitsu Kanri Senta Nyusu, 34(11), P. 18, 2005/11
no abstracts in English
Kitamura, Toshikatsu; Kabuto, Shoji*; Suzuki, Takashi; Amano, Hikaru; Kitada, Yoshinobu*; Watanabe, Yukiya*
Dai-17-Kai Tandemu Kasokuki Oyobi Sono Shuhen Gijutsu No Kenkyukai Hokokushu, p.52 - 55, 2004/12
no abstracts in English
Esaka, Fumitaka; Watanabe, Kazuo; Fukuyama, Hiroyasu; Onodera, Takashi; Esaka, Konomi; Magara, Masaaki; Sakurai, Satoshi; Usuda, Shigekazu
Journal of Nuclear Science and Technology, 41(11), p.1027 - 1032, 2004/11
Times Cited Count:60 Percentile:95.56(Nuclear Science & Technology)A new particle recovery method and a sensitive screening method were developed for subsequent isotope ratio analysis of uranium particles in safeguards swipe samples. The particles in the swipe sample were recovered onto a carrier by means of vacuum suction 8211; impact collection method. When grease coating was applied to the carrier, the recovery efficiency was improved to 48 %, which is superior to that of conventionally-used ultrasoneration method. Prior to isotope ratio analysis with secondary ion mass spectrometry (SIMS), total reflection X-ray fluorescence spectrometry (TXRF) was applied to screen the sample for the presence of uranium particles. By the use of Si carriers in TXRF analysis, the detection limit of 22 pg was achieved for uranium. By combining these methods with SIMS, the isotope ratios of U/U for individual uranium particles were efficiently determined.
Esaka, Fumitaka; Watanabe, Kazuo; Magara, Masaaki; Usuda, Shigekazu
Instrumentation Science & Technology, 32(2), p.103 - 114, 2004/03
The capability of secondary ion mass spectrometry (SIMS) for lead isotope ratio measurements of individual particles has been demonstrated by measuring lead-containing particles in three kinds of environmental certified reference materials (CRMs): urban particulate matter, vehicle exhaust particulates and coal fly ash. The isotope ratios of Pb/Pb and Pb/Pb for the individual particles on the carrier were determined by SIMS. The relative standard deviations of the lead isotope ratios were less than 1.6 % for all particles measured. It was demonstrated that the results of the lead isotope ratios were clearly distinguished among the three samples. Moreover, the particles in the vehicle exhaust particulate sample were classified into two groups according to lead isotope ratios. The results indicated that the present SIMS technique can provide detailed information with regard to the origin and the transportation of individual particles.
Esaka, Fumitaka
Bunseki, 2003(11), p.688 - 691, 2003/11
Isotope ratio measurement for individual particles containing uranium in swipe samples taken at nuclear facilities is a powerful tool to verify the absence of undeclared nuclear activities. In order to develop the analysis technique, we have investigated a series of methods: particle recovery from the swipe sample, particle screening and isotope ratio analysis for individual particles. As the result, the 235U/238U ratio was determined with the relative standard deviation within 2.0 % for the particle with a diameter of 1 um.
Usuda, Shigekazu
Kagaku To Kyoiku, 51(10), p.612 - 613, 2003/10
no abstracts in English
Takahashi, Masato; Magara, Masaaki; Sakurai, Satoshi; Kurosawa, Setsumi; Esaka, Fumitaka; Taguchi, Takuji; Takai, Konomi; Fukuyama, Hiroyasu; Lee, C. G.; Yasuda, Kenichiro; et al.
Dai-23-Kai Kaku Busshitsu Kanri Gakkai Nihon Shibu Nenji Taikai Rombunshu, 8 Pages, 2002/09
Based on the strengthen safeguard program of the IAEA to detect undeclared nuclear activities, the method of precise and accurate isotope ratio determination for uranium and plutonium in the environmental samples (cotton swipes) has been developed at JAERI. The samples should be treated in clean environment in order to secure the analytical reliability by eliminating external contamination from the samples containing trace amount of uranium and plutonium. Since the measurement by ICP-MS is favorable to bulk analysis from view points of analytical capacity and operation simplicity, we have studied sample preparation procedures for the trace amount of uranium and plutonium to be applied to ICP-MS. Up to the present, interfering factors involved during analytical processes and the ICP-MS measurement of uranium and plutonium were examined. As a result, uranium and plutonium isotope measurement more than 100 pg and 100 fg, respectively, became possible at JAERI clean facility. At presentation, other progress in the development will be reported.
Magara, Masaaki; Sakakibara, Takaaki; Kurosawa, Setsumi; Takahashi, Masato; Sakurai, Satoshi; Hanzawa, Yukiko; Esaka, Fumitaka; Watanabe, Kazuo; Usuda, Shigekazu
Journal of Analytical Atomic Spectrometry, 17(9), p.1157 - 1160, 2002/09
Times Cited Count:11 Percentile:44.18(Chemistry, Analytical)no abstracts in English
Sakurai, Satoshi; Hanzawa, Yukiko; Magara, Masaaki; Usuda, Shigekazu; Watanabe, Kazuo; Adachi, Takeo
Kuki Seijo, 39(6), p.404 - 410, 2002/03
no abstracts in English
Esaka, Fumitaka; Magara, Masaaki; Hanzawa, Yukiko; Sakurai, Satoshi; Taguchi, Takuji; Takai, Konomi; Sakakibara, Takaaki; Kurosawa, Setsumi; Takahashi, Masato; Yasuda, Kenichiro; et al.
Dai-22-Kai Kaku Busshitsu Kanri Gakkai Nihon Shibu Nenji Taikai Rombunshu, 8 Pages, 2001/11
no abstracts in English