Enhancement of the methodology of repository design and post-closure performance assessment for preliminary investigation stage, 3; Progress report on NUMO-JAEA collaborative research in FY2013 (Joint research)

Shibata, Masahiro; Sawada, Atsushi; Tachi, Yukio; Makino, Hitoshi; Wakasugi, Keiichiro; Mitsui, Seiichiro; Kitamura, Akira; Yoshikawa, Hideki; Oda, Chie; Ishidera, Takamitsu; et al.

JAEA-Research 2014-030, 457 Pages, 2015/03

JAEA-Research-2014-030.pdf:199.23MB

JAEA and NUMO have conducted a collaborative research work which is designed to enhance the methodology of repository design and post-closure performance assessment in preliminary investigation stage. With regard to (1) study on rock suitability in terms of hydrology, based on some examples of developing method of hydro-geological structure model, acquired knowledge are arranged using the tree diagram, and model uncertainty and its influence on the evaluation items were discussed. With regard to (2) study on scenario development, the developed approach for "defining conditions" has been reevaluated and improved from practical viewpoints. In addition, the uncertainty evaluation for the effect of use of cementitious material, as well as glass dissolution model, was conducted with analytical evaluation. With regard to (3) study on setting radionuclide migration parameters, based on survey of precedent procedures, multiple-approach for distribution coefficient of rocks was established, and the adequacy of the approach was confirmed though its application to sedimentary rock and granitic rock. Besides, an approach for solubility setting was developed including the procedure of selection of solubility limiting solid phase. The adequacy of the approach was confirmed though its application to key radionuclides.

Hydrothermal-method-grown ZnO single crystal as fast EUV scintillator for future lithography

Nakazato, Tomoharu*; Furukawa, Yusuke*; Tanaka, Momoko; Tatsumi, Toshihiro*; Nishikino, Masaharu; Yamatani, Hiroshi*; Nagashima, Keisuke; Kimura, Toyoaki*; Murakami, Hidetoshi*; Saito, Shigeki*; et al.

Journal of Crystal Growth, 311(3), p.875 - 877, 2009/01

https://doi.org/10.1016/j.jcrysgro.2008.09.106

The temperature dependence of scintillation properties of a hydrothermal-method-grown zinc oxide (ZnO) emission is investigated using a nickel-like silver laser emitting at 13.9 nm. A broad peak at 386 nm with a full-width at half-maximum (FWHM) of 15 nm at room temperature (298 K) is obtained. The peak position tends to be blue shifted while the FWHM becomes narrower when the crystal temperature is decreased to 25 K. Streak images fitted by a double exponential decay reveal that the measured emission decay at 105 K was = 0.88 ns and = 2.7 ns. This decay time of a few nanoseconds is suitable for lithographic applications and is sufficiently short for the characterization of laser plasma extreme ultraviolet (EUV) sources with nanosecond durations.

Temperature dependence of scintillation properties for a hydrothermal-method-grown zinc oxide crystal evaluated by nickel-like silver laser pulses

Furukawa, Yusuke*; Tanaka, Momoko; Nakazato, Tomoharu*; Tatsumi, Toshihiro*; Nishikino, Masaharu; Yamatani, Hiroshi; Nagashima, Keisuke; Kimura, Toyoaki; Murakami, Hidetoshi*; Saito, Shigeki*; et al.

Journal of the Optical Society of America B, 25(7), p.B118 - B121, 2008/07

https://doi.org/10.1364/JOSAB.25.00B118

Using EUV laser operated at 13.9 nm ZnO and GaN are shown to be excellent scintillators in this wavelength region. Especially ZnO has short response time of 3 ns and prominent peak fluorescence from excitation at 380 nm.

Evaluation of characteristics of race-track bellows

Watanabe, Masao; Ogiwara, Norio; Sawa, Soji*; Tanaka, Toshihiro*

JAEA-Technology 2008-004, 14 Pages, 2008/02

JAEA-Technology-2008-004.pdf:1.44MB

At the extraction part of J-PARC 3 GeV Rapid Cycling Synchrotron, a race-track bellows between the vacuum chamber of extraction septum magnet 1 and 2 is required, because there is no space to install a circular bellows. However, formed titanium bellows of race-track shape has never been fabricated. Smaller size race-track bellows than that of actual size were fabricated. Characteristics of them were and measured and evaluated. We performed measurements of spring force, expansion/contraction repetition life test, vacuum heating test and He-gas leak test. The characteristics of the race-track bellows are satisfied with our use conditions. It was judged from the above, we obtained prospect that using race-track bellows between the vacuum chamber of extraction septum magnet 1 and 2 is one of the solutions.

Soft X-ray absorption spectroscopy and magnetic circular dichroism study of electroless-deposited CoNiFe ternary alloy soft magnetic films

Tanaka, Masahito*; Nakamura, Naomichi*; Asahi, Toru*; Tsumori, Toshihiro*; Agui, Akane; Mizumaki, Masaichiro*; Osaka, Tetsuya*

Physica Status Solidi (C), 3(8), p.2783 - 2786, 2006/09

https://doi.org/10.1002/pssc.200669605

no abstracts in English

Soft X-ray absorption spectroscopy and magnetic circular dichroism study of electroless-deposited CoNiFe ternary alloy soft magnetic film

Tanaka, Masahito*; Nakamura, Naomichi*; Asahi, Toru*; Osaka, Tetsuya*; Tsumori, Toshihiro*; Agui, Akane; Mizumaki, Masaichiro*

no journal, , 

no abstracts in English

Hydro-formed Ti bellows with the same flexibility as the welded ones

Matsue, Masaki*; Arakawa, Satoru*; Tanaka, Toshihiro*; Sawa, Soji*; Ogiwara, Norio; Suganuma, Kazuaki

no journal, , 

At the 3 GeV-RCS in J-PARC project, pure Ti is adopted as a material for bellows. The space available for the bellows is so narrow that the requirements are hard. To make the hydro-formed bellows like the welded ones, it is essential to bend and press the Ti plates and to keep the 2 sides facing each other in close contact. The repetition of the combination of bending (pressing) with annealing enables us to realize the close contact of Ti plates. We produced the experimental bellows with the inner diameter of 50 mm. It shows suitable performance: (1) spring rates are 1.5 N/mm (axial) and 4.0 N/mm (lateral), respectively; (2) endurance test shows the fatigue life of over than 1 million cycles with the displacement of 20 mm. Thus we have succeeded in developing the hydro-formed bellows with the same flexibility as the welded ones. Now we have completed the performance tests about the prototype of the large bellows (400 mm in a diameter), and mass production has been performed.

2nd investigation and research on depth distribution in soil of radionuclides released by accident of Fukushima Dai-ichi Nuclear Power Station, TEPCO, 2; Depth distributions of radionuclides and its relationship with landform, soil, geology, and land use of investigation area

Niizato, Tadafumi; Abe, Hironobu; Sato, Haruo; Sakai, Toshihiro; Tanaka, Shingo; Aoki, Kazuhiro

no journal, , 

This paper presents preliminary results of depth distributions of radionuclides released by accident of Fukushima Dai-ichi Nuclear Power Station, TEPCO and its relationship with landform, soil, geology, and land use of investigation area.