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Koarai, Kazuma; Matsueda, Makoto; Aoki, Jo; Yanagisawa, Kayo*; Fujiwara, Kenso; Terashima, Motoki; Kino, Yasushi*; Oka, Toshitaka; Okutsu, Kenichi*; Yamashita, Takuma*; et al.
no journal, ,
We demonstrated a method of 
Sr measurement in small pieces of hard tissues with radioactivity measurement or ICP-MS measurement. Interference elements of the measurements were removed by chemical separation. We could determine Sr in 0.1 g of hard tissues by radioactivity measurement method and ICP-MS method. Limit of detection of the ICP-MS method was lower than that of the radioactivity measurement. The ICP-MS method is adequate method for distribution analysis of Sr in the hard tissues.
AtSegawa, Mariko; Maeda, Makoto; Toh, Yosuke; Nishinaka, Ichiro*; Watanabe, Shigeki*; Ishioka, Noriko*
no journal, ,
no abstracts in English
Cs/
Cs isotope ratio in environmental soil samplesShimada, Asako; Kim, M. S.*; Tsukahara, Takehiko*; Nomura, Masao*; Shimada, Taro; Takeda, Seiji; Yamaguchi, Tetsuji
no journal, ,
no abstracts in English
Tomita, Jumpei; Tomita, Ryohei; Suzuki, Daisuke; Yasuda, Kenichiro; Miyamoto, Yutaka
no journal, ,
no abstracts in English
Tomita, Ryohei; Esaka, Fumitaka; Yomogida, Takumi; Miyamoto, Yutaka
no journal, ,
Large Geometry Secondary Ion Mass Spectrometry (LG-SIMS) is one of the strongest tools for analyzing isotope ratios of micron sized uranium particle. LG-SIMS has high spatial resolution of less than 1 
m with microprobe mode. However, this capability is bit less under automated particle measurement (APM) condition. If two or more particles are located in a quite narrow area, APM may detect the cluster as one particle. This particle mixing effect shows analytical results including false isotope ratios. In order to investigate how often particle mixing happens and how to solve this problem, we implemented APM to mixed uranium particle standard (U010, U100, U350 and U850) and try to apply particle manipulation with APM. In our experiment, each area (350
350 m
) was scanned with an O
primary beam with a current of 1.5 nA for 9 sec. Then, secondary ion images were recorded for circular area with a radius of 8500 m on the center of a sample planchet. The APM detected 5976 particles, and 1943 particles (32%) in them showed false isotope ratios. In addition to particle mixing, U850 cluster was shifted down to around 75% enrichment. The sample showed too high hydride rate, so that 
UH interfered 
U. This interference caused false U abundance and lead to false U abundance. To solve these problems, 50
80 particles were manipulated randomly from another mixed standards planchet and analyzed them by APM.
Np isomer and its decay propertiesAsai, Masato; Suekawa, Yoshihide*; Higashi, Masato*; Kamada, Hiroki*; Tobe, Teruhisa*; Andreyev, A. N.; Hirose, Kentaro; Ito, Yuta; Makii, Hiroyuki; Nishio, Katsuhisa; et al.
no journal, ,
A new isomer 
Np with a half-life of 9 min has been discovered. It was produced in the reaction of 
U target with 
Li beam at JAEA tandem accelerator, and was identified through characteristic X-ray measurement and mass separation with an on-line isotope separator (ISOL). Gamma-ray singles, gamma-gamma coincidence, and internal-conversion electron measurements were performed. It was revealed that the Np decays mostly through an isomeric E4 transition followed by an M1 transition, and that the spin-parity of the Np should be 5
. The results are introduced in detail, and the nuclear structure of the Np are discussed.
Satou, Yukihiko; Igarashi, Yasuhito*; Martin, P.*; Alhaddad, O.*; Scott, T.*
no journal, ,
no abstracts in English
Kato, Akane*; Kaneko, Masashi; Nakashima, Satoru*
no journal, ,
Aiming to predict ruthenium spices in high-level radioactive liquid waste, we demonstrated to simulate the complexation reaction between nitrosylruthenium and nitrate ions. When comparing the thermodynamic stability of the twelve geometrical isomers of the nitrosylruthenium nitrate complexes, the complexes with nitrate ions at the equatrial position toward the Ru-NO axis were confirmed to be the most stable isomers. Moreover, the Gibbs free energies analysis of the stepwise complexation reactions indicated that the Gibbs energy difference was improved the dependency of the fraction of the ruthenium species on the nitrate ions concentration by considering the association energy between the complex and the substituting ligands.
Oka, Toshitaka; Mitsuyasu, Yusuke*; Takahashi, Atsushi*; Koarai, Kazuma; Kino, Yasushi*; Sekine, Tsutomu*; Okutsu, Kenichi*; Yamashita, Takuma*; Shimizu, Yoshinaka*; Chiba, Mirei*; et al.
no journal, ,
Releases of the radioactive materials from the Fukushima Daiichi Nuclear Power Plant accident result in a low dose exposure to wild animals. The external dose of wild animals is commonly estimated by the external dose rate of the captured point, but the estimated exposure dose has huge uncertainties because the size of the habitat and/or the movement of the wild animals are not included in the estimation. To estimate the external dose precisely, we utilize electron spin resonance (ESR) dosimetry. In this work, we investigated the sample preparation procedure of wild animals. The ESR spectrum of enamel of racoon captured in Namie-town, Fukushima has a broad ESR signal due to metal components. The linear relationship between the Co
intensity and the absorbed dose that we can apply ESR dosimetry for racoon teeth. Using this relationship, the external exposure dose was estimated.
solutionKato, Mizuho*; Adachi, Sadia*; Toyoshima, Atsushi*; Tsukada, Kazuaki; Asai, Masato; Haba, Hiromitsu*; Yokokita, Takuya*; Komori, Yukiko*; Shigekawa, Yudai*; Sueki, Keisuke*
no journal, ,
A few studies have been so far performed on aqueous chemistry of Db, the group-5 superheavy element, by anion-exchange experiments in HF and HF/HNO mixture solutions. Although the distribution coefficient (Kd) of Db was shown to trend to Ta 
Nb Db Pa in the group-5 homologs and pseudo-homolog elements, its chemical species has not been clarified. In this work, for identification of fluoride species of Db, we performed anion-exchange experiments of Nb, Ta, and Db in HF/1.0 M HNO mixture solutions by using an automated rapid chemistry apparatus, ARCA.
Kitada, Naoya*; Oka, Toshitaka; Okutsu, Kenichi*; Yamashita, Takuma*; Kino, Yasushi*; Sekine, Tsutomu*
no journal, ,
Polyethylene (PE) is widely used for insulators in nuclear power plants and accelerators. During long-term usage, since PE is subjected to radiation environments, and is degraded by oxidation. To evaluate the degradation of PE, destructive measurement such as gel fraction measurement and tensite test, are usually utilized. In this work, we attempted to evaluate the degradation undestructively by using positron annihilation lifetime spectroscopy. We found out the relationship between the ratio of the positrons annihilation in the free volume hole and the gel fraction (corresponds with the cross-linking of the polymer matrix).
-X-ray absorption near edge structure spectraYomogida, Takumi; Ouchi, Kazuki; Kitatsuji, Yoshihiro; Takahashi, Yoshio*
no journal, ,
During the decommissioning of the Fukushima Daiichi Nuclear Power Plant, there is concern about the release of fine fuel debris containing nuclear fuel materials into the environment. Solubility of uranium in water differs greatly depending on the chemical species. To estimate the migration behavior of uranium in the environment, it is necessary to understand the chemical species of uranium particles. In this study, we analyzed uranium particles using microbeam X-ray absorption spectroscopy. Uranium particles with a diameter of about 3 m were detected by X-ray fluorescence mapping analysis using a focused X-ray microbeam at about 500 nm. The X-ray absorption near edge structure spectra of the detected particles showed good signal-to-noise ratio and consistent spectra with the UO standard. It is suggested that the proposed method was able to correctly identify the species of UO particles with a diameter of 3 m.
Yamaguchi, Akiko; Kuribara, Yuichi; Higaki, Shogo*; Okumura, Masahiko; Takahashi, Yoshio*
no journal, ,
no abstracts in English
Sato, Tetsuya; Chiera, N. M.*; Tomitsuka, Tomohiro; Tokoi, Katsuyuki*; Suzuki, Hayato*; Ito, Yuta; Asai, Masato; Shirai, Kaori*; Inoue, Hiroki*; Adachi, Sadia*; et al.
no journal, ,
The influence of strong relativistic effects on chemical properties has been interesting in the superheavy element region. Their chemical properties, however, have not been investigated sufficiently because of experimental difficulties owing to their low production rates and short half-lives. In order to elucidate the chemical properties of dubnium (Db, Z = 105), we have conducted on-line isothermal gas chromatographic experiments of oxychloride of group-5 elements. We confirmed the formation of volatile oxychlorides of Db and its lighter homologs Nb and Ta by using 
Db (half-life, 
= 33.8 s), 
Nb ( = 14.5 min.), and 
Ta ( = 6.76 min.), respectively. We successfully determined the adsorption enthalpies of the oxychlorides of each element on the quartz surface from their isothermal gas chromatographic behavior. The obtained volatility sequence of the group-5 elements is found to be Nb Ta 
Db.
Konno, Yuta*; Maeyama, Takeshi*; Saegusa, Jun; Shinohara, Hirofumi*; Ota, Hiroshi*; Isogai, Keisuke*
no journal, ,
no abstracts in English