Characterization of precipitated phase in Cu-Ni-Si alloy by small angle X-ray scattering, small angle neutron scattering and atom probe tomography

Sasaki, Hirokazu*; Akiya, Shunta*; Oba, Yojiro; Onuma, Masato*; Giddings, A. D.*; Okubo, Tadakatsu*

Do To Dogokin, 60(1), p.309 - 314, 2021/08

https://doi.org/10.34562/jic.60.1_309

no abstracts in English

Characterization of BaZrO nanocolumns in Zr-added (Gd,Y)BaCuOx superconductor tape by anomalous small-angle X-ray scattering

Oba, Yojiro; Sasaki, Hirokazu*; Yamazaki, Satoshi*; Nakasaki, Ryusuke*; Onuma, Masato*

Superconductor Science and Technology, 32(5), p.055011_1 - 055011_5, 2019/05

https://doi.org/10.1088/1361-6668/ab0f55

Development of safety assessment method for human intrusion scenario in Japan, 2; Development of a human intrusion scenario evaluation code in radioactive waste disposal (Contract research)

Takeda, Seiji; Sasaki, Toshihisa*; Nagasawa, Hirokazu; Kimura, Hideo

JAEA-Data/Code 2010-019, 61 Pages, 2010/11

JAEA-Data-Code-2010-019.pdf:1.47MB

In deep geological disposal or intermediate depth disposal, human intrusion, i.e. accidental excavation or drilling into the disposal site, may make a direct or indirect effect on the disposal system. Assessment of the human intrusion would need the examination of institutional control to reduce the probability of the intrusion occurring, the estimation of its probability, and the development of method to estimate its associated exposure of persons, as well as some foreign countries. Assuming that drilling action into the disposal site especially leads to the human proximity to the radioactive waste or the damage to the barrier system (drilling scenario), we have developed the evaluation code of radiological effect from the human intrusion into radioactive waste disposal system (HUINT). The evaluation code of human intrusion scenario, HUINT, can calculate the radiation exposure dose for the workers of a series of actions accompanied with drilling and for the workers and public people concerned with the reuse of drilling cores, identified with the actual information on drilling action in Japan. This report provides the descriptions of mathematical models on the drilling scenario, input specification and user information for execution of HUINT (user manual), and the result of verification for calculation with the models in HUINT.

Assessment on long-term safety for geological disposal of high level radioactive waste; Application of probabilistic safety assessment methodology to uncertainties in hypothetical geological disposal system (Contract research)

Takeda, Seiji; Yamaguchi, Tetsuji; Nagasawa, Hirokazu; Watanabe, Masatoshi; Sekioka, Yasushi; Kanzaki, Yutaka; Sasaki, Toshihisa; Ochiai, Toru; Munakata, Masahiro; Tanaka, Tadao; et al.

JAEA-Research 2009-034, 239 Pages, 2009/11

JAEA-Research-2009-034.pdf:33.52MB

In safety assessment for geological disposal of high level radioactive waste, it is of consequence to estimate the uncertainties due to the long-term frame associated with long-lived radionuclides and the expanded geological environment. The uncertainties result from heterogeneity intrinsic to engineered and natural barrier materials, insufficient understanding of phenomena occurring in the disposal system, erroneous method of measurement, and incomplete construction. It is possible to quantify or to reduce the uncertainties according to scientific and technological progress. We applied a deterministic and a Monte Carlo-based probabilistic method simulation techniques to the uncertainty analysis for performance of hypothetical geological disposal system for high level radioactive waste. This study provides the method to evaluate the effects of the uncertainties with respect to scenarios, models and parameters in engineering barrier system on radiological consequence. The results also help us to specify prioritized models and parameters to be further studied for long-term safety assessment.

Development of database on human intrusion in Japan

Nagasawa, Hirokazu; Takeda, Seiji; Kimura, Hideo; Sasaki, Toshihisa

no journal, , 

no abstracts in English

Characterization of pinning site in high-temperature superconducting wire using anomalous small-angle X-ray scattering

Sasaki, Hirokazu*; Yamazaki, Satoshi*; Nakasaki, Ryusuke*; Oba, Yojiro; Onuma, Masato*; Sugiyama, Masaaki*

no journal, , 

no abstracts in English

Characterization of pinning center in Zr-doped (Gd,Y)BaCuO superconductor tape by anomalous small-angle X-ray scattering

Oba, Yojiro; Sasaki, Hirokazu*; Yamazaki, Satoshi*; Nakasaki, Ryusuke*; Onuma, Masato*

no journal, , 

Since pinning centers are closely related to the physical properties in Zr-doped (Gd,Y)BaCuO superconductor tapes, the accurate characterization of the pinning centers is required. Although small-angle X-ray scattering (SAXS) is suitable for this purpose, weak scattering contrast between (Gd,Y)BaCuO matrix and BaZrO pinning center is a problem. Therefore, anomalous small-angle X-ray scattering (ASAXS) at Zr K absorption edge was performed. Since Zr is concentrated in only the pinning center, the scattering of the pinning center is enhanced. As the result, we successfully observed the scattering of the pinning centers in the Zr-doped (Gd,Y)BaCuO tapes. The detail of the nanostructures of the pinning centers is discussed.

Characterization of secondary phase in Cu alloy by small-angle scattering and TEM

Sasaki, Hirokazu*; Isomatsu, Takemi*; Higuchi, Masaru*; Oba, Yojiro; Onuma, Masato*

no journal, , 

no abstracts in English

Nano-scale precipitates in Corson alloy during aging process characterized by in-situ small-angle X-ray scattering

Yamazaki, Satoshi*; Hirose, Kiyoshige*; Sasaki, Hirokazu*; Oba, Yojiro; Miyazawa, Tomotaka*; Onuma, Masato*

no journal, , 

no abstracts in English