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Esaka, Fumitaka; Suzuki, Daisuke; Magara, Masaaki
Analytical Chemistry, 87(5), p.3107 - 3113, 2015/03
Times Cited Count：13 Percentile：44.45(Chemistry, Analytical)The analysis of uranium particles in environmental samples taken from nuclear facilities is a useful tool to unveil undeclared nuclear activities related to the production of nuclear weapons. An efficient method to analyze isotope ratios of individual uranium particles is thermal ionization mass spectrometry (TIMS) combined with a fission track technique. A drawback in the fission track-TIMS technique is so-called particle-mixing. Here, some uranium particles are measured as a single particle and an averaged isotope ratio is obtained, which may lead to misunderstanding conclusions for source identification. In the present study, micro-sampling under a scanning electron microscope has been added to the procedure of the fission track-TIMS technique. The analysis of a mixed sample containing uranium particles in SRM 950a and CRM U100 materials indicated that the problem of particle mixing was almost avoidable with the proposed technique.
Iguchi, Kazunari
Nihon Shashin Gakkai-Shi, 68(1), p.56 - 59, 2005/02
In order to detect undeclared activities of nuclear facilities, Japan Atomic Energy Research Institute (JAERI) has developed analytical methods for safeguards environmental samples. As for particle analysis of safeguards environmental sample analysis which can determine isotope ratios of nuclear materials for individual particles, secondary ion mass spectrometry (SIMS) is known as a powerful method. However, it is difficult to analyze particles having diameter below 1 
m due to its detection limit. To overcome the problem, JAERI is developing an analytical method using fission track (FT) technique. The outline of the method is described in this report.
Lee, C. G.; Iguchi, Kazunari; Inagawa, Jun; Suzuki, Daisuke; Esaka, Fumitaka; Magara, Masaaki; Sakurai, Satoshi; Watanabe, Kazuo; Usuda, Shigekazu
Dai-26-Kai Kaku Busshitsu Kanri Gakkai (INMM) Nihon Shibu Nenji Taikai Rombunshu, p.171 - 178, 2005/00
Particle analysis by FT-TIMS method is effective for safeguards environmental samples because the isotope ratios of sub-micrometer particles can be determined. The FT-TIMS method developed by the authors, in which the particles are confined in the detector, has merits such as high detection efficiency and the possibility as a screening method for uranium particles according to their enrichment by controlling the etching time. However, it was found that a part of uranium particles contained in a detector may dissolve during the etching process of the detector. In order to overcome the problem, we are developing a novel sample preparing method in which the FT detector and the particle layer are separated. In the conventional FT sample of separated type, the detection process of particles of interest is time-consuming and complicated due to the discrepancy in position between tracks and particles. In contrast, the discrepancy was solved by fixing a part of a detector and a particle layer in our method, which improved the detection efficiency of particles containing fissile materials.
Magara, Masaaki; Usuda, Shigekazu; Sakurai, Satoshi; Watanabe, Kazuo; Esaka, Fumitaka; Hirayama, Fumio; Lee, C. G.; Yasuda, Kenichiro; Kono, Nobuaki; Inagawa, Jun; et al.
Proceedings of INMM 46th Annual Meeting (CD-ROM), 8 Pages, 2005/00
JAERI has been developing analytical techniques for ultra-trace amounts of nuclear materials in the environmental samples in order to contribute to the strengthened safeguards system. Development of essential techniques for bulk and particle analysis of the environmental swipe sample has been established as an ultra-trace analytical method of uranium and plutonium. In January 2003, JAERI was qualified as a member of the IAEA network analytical laboratories for environmental samples. Since then, JAERI has conducted the analysis of domestic and the IAEA samples. From Japanese fiscal year 2003, the second phase of the project was started for the development of advanced techniques, such as analyzing minor actinides and fission products as well as uranium and plutonium, particle analysis using fission-track technique, more efficient particle analysis using ICP-TOFMS and screening by X-ray fluorescent analysis. This paper deals with the progress in the development of the new techniques, applications and future perspective.
Esaka, Fumitaka; Watanabe, Kazuo; Fukuyama, Hiroyasu; Onodera, Takashi; Esaka, Konomi; Inagawa, Jun; Iguchi, Kazunari; Suzuki, Daisuke; Lee, C. G.; Magara, Masaaki; et al.
Dai-25-Kai Kaku Busshitsu Kanri Gakkai Nihon Shibu Nenji Taikai Rombunshu, p.128 - 135, 2004/00
Japan Atomic Energy Research Institute (JAERI) was qualified as a member of the IAEA network analytical laboratories (NWALs) for particle and bulk analyses of safeguards environmental samples in January 2003. The particle analysis gives more detailed information on nuclear facility operation than the bulk analysis because the isotope ratios of nuclear materials in the samples collected inside nuclear facilities (swipe samples) can be determined for individual particles. We applied, as a method for uranium isotope ratio measurement, secondary ion mass spectrometry (SIMS) to particle analysis. Prior to the SIMS analysis, the particles in a swipe sample are recovered onto a carrier by impaction. The carriers with the recovered particles are then screened by total reflection X-ray fluorescence spectrometry. We integrated these techniques into a standard procedure, which is applied to domestic and IAEA swipe samples routinely.
Usuda, Shigekazu; Umezawa, Hirokazu
Hoshasen, 16(1), p.73 - 81, 1989/00
no abstracts in English
Yasuda, Kenichiro; Suzuki, Daisuke; Miyamoto, Yutaka; Usami, Hidehiko*
no journal, ,
In safeguards environmental sample analysis, isotopic composition analysis of particles containing nuclear materials is an important technique for detecting undeclared activities at nuclear facilities. The alpha track and the fission track method are often used to detect the position of particles containing nuclear materials, but it has been difficult to use both methods on a sample because the track detector was deformed by the chemical etching. In this study, the alpha track and fission track methods were successfully applied to individual particles by correcting their positions by marking the track detector with a laser. Therefore, it was possible to classify differences in the amount and composition of nuclear material contained in the particles, and it is expected that the particles will be recovered efficiently.
Yasuda, Kenichiro; Suzuki, Daisuke; Tomita, Jumpei; Tomita, Ryohei; Miyamoto, Yutaka
no journal, ,
The safeguards environmental sample analysis by the IAEA requires the development of efficient methods for measuring isotope ratios of ultra-trace amounts of plutonium and uranium particles. We have applied fission track and alpha track techniques to identify of discrimination between plutonium and uranium particles and have successfully measured isotope ratios of the particles using a continuous heating method with a thermal ionization mass spectrometer (TIMS). This method made it possible to find particles containing plutonium and uranium and measure them simultaneously by the TIMS without a chemical separation.
