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Oyama, Koichi; Inose, Takehiko*; Miyauchi, Atsushi; Nishizawa, Daiji*; Nagai, Takayuki
no journal, ,
no abstracts in English
Inose, Takehiko*; Oyama, Koichi; Miyauchi, Atsushi; Nishizawa, Daiji*; Nagai, Takayuki
no journal, ,
no abstracts in English
Esaka, Fumitaka; Suzuki, Daisuke; Yomogida, Takumi; Magara, Masaaki
no journal, ,
Analysis of individual uranium particles in environmental samples taken at nuclear facilities enables to clarify nuclear activities in the facilities. In particular, the detection of high enriched uranium particles is important to unveil nuclear activities related to the production of nuclear weapons. In this study, we developed analytical techniques by the combination of secondary ion mass spectrometry (SIMS) or thermal ionization mass spectrometry with automated particle measurement. The results indicated that these techniques are efficient to detect high enriched uranium particles.
Okamura, Hiroyuki; Mizuno, Masayoshi*; Hirayama, Naoki*; Shimojo, Kojiro; Naganawa, Hirochika; Imura, Hisanori*
no journal, ,
Solvent extraction technique is widely investigated to separate lanthanoids (Ln). The development of a more effective separation system is an important issue in the field of atomic energy. Recently, the synergistic ionic-liquid (IL) extraction of Ln(III) with several 
-diketones and trioctylphosphine oxide (TOPO) in 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide was studied, and it was found that the separability of Ln(III) was remarkably enhanced by the selective synergism for heavier rate earth. In this study, the method of extraction equilibrium analysis for Ln(III) in the synergistic ionic-liquid extraction system with 2-thenoyltrifluoroacetone (Htta) and TOPO was investigated. To determine the extraction constants of the respective Ln(III) complexes, a three-dimensional non-linear analysis of log 
-log [tta
]
-log [TOPO]
was applied. The formation constants of various ternary complexes formed in IL were calculated, and the order of the formation constants of the Ln(tta)
(TOPO)
complexes was found to be Eu(III) 
Nd(III). Consequently, it was suggested that the formation of hydrophobic charged complexes is a factor for the selective synergism.
Yomogida, Takumi; Esaka, Fumitaka; Magara, Masaaki
no journal, ,
Chemical forms of particles in environmental samples give important information on the history of particles. In particular, we can detect the nuclear activities such as refining, conversion and enrichment process by determination of the chemical form of uranium particles. In this study, we developed a micro-Raman spectroscopy technique combined with particle detection by scanning electron microscope (SEM) and micro manipulation to identify chemical forms of standard uranium particles. The characteristic Raman bands which derive from UO
structures were observed in the Raman spectra of a standard uranium particle with a diameter of 2 
m.
Shimojo, Kojiro; Fujiwara, Iori*; Okamura, Hiroyuki; Oshima, Tatsuya*; Baba, Yoshinari*; Naganawa, Hirochika
no journal, ,
The extractant plays a key role in the extraction efficiency and the separation operation. Thus, the development of novel extractants, which perform better than conventional commercial extractants, is required for effective separation of metal ions. In this study, we have developed diglycolamic acid (DGAA) ligand as a new extractant. Extraction behavior of 56 metal ions using DGAA extractants was comprehensively investigated, and basic data on the extraction performance and selectivity of DGAA extractants was collected. In addition, we demonstrated the relationship between substituent group and extraction separation performance of DGAA extractants by the difference in performance of tertiary amide and secondary amide.
Maeda, Satoshi; Yoda, Tomoyuki; Okazaki, Tsutomu; Saegusa, Jun
no journal, ,
no abstracts in English
Pd in radioactive wastes with mass spectrometryYomogida, Takumi; Asai, Shiho; Saeki, Morihisa; Hanzawa, Yukiko; Esaka, Fumitaka; Oba, Hironori; Kitatsuji, Yoshihiro
no journal, ,
Palladium-107, which is one of the long-lived fission products in high-level radioactive waste (HLW), is a pure beta emitter with a half-life of 6.5
10
y. The inventory estimation of Pd is demanded for the long-term safety assessment of geological repository. ICP-MS is suitable for the determination of Pd because radiometry with a low beta energy of 33 keV is practically inapplicable. However, cumbersome chemical separation accompanied with highly radioactive sample treatment is still necessary prior to the measurement with ICP-MS. To minimize radioactive contamination and radiation exposure, simplified procedure is desirable. In this study, a simple separation technique based on laser-induced microparticle formation has been applied to Pd separation in a simulated HLW solution. Sufficiently high decontamination factors of coexisting elements ( 1000) were observed, indicating that the proposed method achieved highly-selective separation of Pd.
Harjo, S.; Aizawa, Kazuya; Kawasaki, Takuro
no journal, ,
no abstracts in English