Enhancement of the methodology of repository design and post-closure performance assessment for preliminary investigation stage, 2; Progress report on NUMO-JAEA collaborative research in FY2012 (Joint research)

Shibata, Masahiro; Sawada, Atsushi; Tachi, Yukio; Hayano, Akira; Makino, Hitoshi; Wakasugi, Keiichiro; Mitsui, Seiichiro; Oda, Chie; Kitamura, Akira; Osawa, Hideaki; et al.

JAEA-Research 2013-037, 455 Pages, 2013/12

JAEA-Research-2013-037.pdf:42.0MB

Following FY2011, JAEA and NUMO have conducted a collaborative research work which is designed to enhance the methodology of repository design and performance assessment in preliminary investigation stage. With regard to (1) study on rock suitability in terms of hydrology, the tree diagram of methodology of groundwater travel time has been extended for crystalline rock, in addition, tree diagram for sedimentary rock newly has been organized. With regard to (2) study on scenario development, the existing approach has been improved in terms of a practical task, and applied and tested for near field focusing on the buffer. In addition, the uncertainty of some important processes and its impact on safety functions are discussed though analysis. With regard to (3) study on setting radionuclide migration parameters, the approaches for parameter setting have been developed for sorption for rocks and solubility, and applied and tested through parameter setting exercises for key radionuclides.

Recovery of acceleration field gradients of superconducting booster resonators by high pressure water jet rinsing

Kabumoto, Hiroshi; Takeuchi, Suehiro; Ishizaki, Nobuhiro; Yoshida, Takahiro*; Ishiguro, Takayuki*; Yamaguchi, Kazushi*

Proceedings of 6th Annual Meeting of Particle Accelerator Society of Japan (CD-ROM), p.1120 - 1122, 2010/03

http://www.pasj.jp/web_publish/pasj6/papers/fpaca65.pdf

The JAEA-Tokai tandem accelerator was built for basic science researches with heavy ions. Its superconducting booster was completed in 1994 for increasing the acceleration energy of ions. The booster consists of 40 superconducting acceleration resonators and 10 cryostats. Every resonator is a coaxial quarter wave resonator (QWR) of which frequency is 129.8MHz, and optimum beam velocity is 10% of the light velocity. When it was built, the acceleration field gradients of superconducting resonators were 5.0MV/m at RF power input of 4W on their average. The performance decrease little by little, and it become 4.0MV/m now. Some of the resonators generate X-rays from a low electric field. A field emission will be occurred from small contaminations accumulated on the surfaces of niobium. We examined the high pressure water jet rinsing (HPWR) to re-recondition the superconducting booster. The HPWR is the technology of removing small contaminations on resonator surfaces, and very effective for the improvement of acceleration field gradients. The acceleration field gradients of 20 on-line resonators were improved from 4.4MV to 5.7MV on their average.

CARS study of deuterium clusters stabilized in solid helium

Gordon, E. B.*; Kumada, Takayuki; Ishiguro, Masazumi; Aratono, Yasuyuki

Journal of Experimental and Theoretical Physics, 99(4), p.776 - 783, 2004/10

The solid Deuterium clusters for the first time isolated in a matrix of solid Helium have been investigated at T = 1.3K and P = 3 MPa by CARS (Coherent anti-Stokes Raman spectroscopy) technique. The Q1(J=0) and Q1(J=1) lines intensity, shape and positions have been studied as the functions of ortho- para content in the solid, as well as of clusters size. The strong effect of Raman scattering cross section sensitivity to the molecular environment nuclear spin state has been found in CARS; the ratio of probabilities for the scattering by para (J=1) and ortho (J=0) deuterium being equal to 1 in a gas is as high as 10,000 in nearly pure o-D2, whereas it is about 50 in spontaneous Raman scattering. This effect has been shown to give rise starting from cluster size corresponding to the phonon band onset.

DMFC performance of crosslinked-polytetrafluoroethylene electrolyte membranes

Yamaki, Tetsuya; Kawahito, Shimpei; Sawada, Shinichi; Asano, Masaharu; Ishiguro, Hironori*; Mohammad Ali, A.*; Nakagawa, Nobuyoshi*; Suzuki, Akihiro*; Terai, Takayuki*

no journal, , 

no abstracts in English