Development of a hybrid evaluation method for long-term structural soundness of nuclear reactor buildings using monitoring and damage imaging technologies; Nuclear energy science & technology and human resource development project

Maeda, Masaki*; Tanabe, Tadao*; Nishiwaki, Tomoya*; Aoki, Takayuki*; Dozaki, Koji*; Nishimura, Koshiro*; Fujii, Sho*; Ueno, Fumiyoshi; Tanaka, Akio*; Suzuki, Yusuke*; et al.

Transactions of the 27th International Conference on Structural Mechanics in Reactor Technology (SMiRT 27) (Internet), 10 Pages, 2024/03

Hydrogen adsorption on single-walled carbon nanotubes studied by core-level photoelectron spectroscopy and Raman spectroscopy

Tokura, Akio*; Maeda, Fumihiko*; Teraoka, Yuden; Yoshigoe, Akitaka; Takagi, Daisuke*; Homma, Yoshikazu*; Watanabe, Yoshio*; Kobayashi, Yoshihiro*

Carbon, 46(14), p.1903 - 1908, 2008/11

https://doi.org/10.1016/j.carbon.2008.07.041

We have investigated the adsorption of atomic hydrogen on vertically aligned carbon nanotube using synchrotron-radiation-based core-level photoelectron spectroscopy and Raman spectroscopy. From C1s spectra, we identified a peak component due to CH bonds of carbon atoms in single-walled carbon nanotubes. We also found the suppression of -plasmon excitation, indicating that the hydrogen adsorption deforms the bonding structure. Raman spectra of the single-walled carbon nanotubes indicated that the radial-breathing-mode intensities decreased due to the adsorption-induced bonding-structure deformation. Moreover, the decrease for single-walled carbon nanotubes with small-diameter was more severe than that for large-diameter. Our results strongly suggest that the hydrogen adsorption, which induces the structure deformation from sp to sp bonding, depends on the diameter of SWCNTs.

Evaluation of core characteristics with two-dimensional lattice calculations

Sato, Osamu*; Maeda, Akio*

JNC TJ9400 2003-008, 139 Pages, 2003/03

JNC-TJ9400-2003-008.pdf:3.49MB

Two-dimensional cell calculation is necessary to exactly treat the major heterogeneous structure of fuel pins and a wrapper tube in fast reactor fuel assemblies. JNC has been developing the new SLAROM, which includes a two-dimensional cell calculation routine. In this report, validity and effect of two-dimensional calculation were investigated. The validity was checked by comparing neutron flux in fuel assemblies and assembly averaged cross sections with those calculated by Monte Carlo code GMVP. The comparisons were made for the calculation model called "concentric layers of hexagon with equi-distance pin-rod array"(IGT=13) with a fuel assembly of JOYO and were also made for the model of a two-dimensional slab called "Quadrant of an octant symmetric assembly" (IGT=8) with SCF and DCF fuel cells in ZPPR=9. The calculated results with the new SLAROM and GMVP were agreed within statistical errors for the JOYO fuel assembly and the adequacy of the collision probability calculations in the new SLAROM was proved for a hexagonal fuel assembly. For a two-dimensional slab geometry, the assembly averaged absorption cross sections and total cross sections were 20% higher than those with Monte Carlo calculations below 24keV at which the large resonance of sodium exist. Further investigations are required to explain the differences. The results of core calculations with CITATION were performed and compared with the assembly-averaged cross sections using one-dimensional cell model and with the cross sections using two-dimentional cell model. THe differences caused by the cell calculation model were larger for radial blanket regions than for fuel regions. It revealed that the fewer numbers of fuel pins in radial blanket bring out the larger error of one-dimensional cell model.

Research activities on advanced nuclear fuel cycle in NUCEF

Suzuki, Yasufumi; Dojiri, Shigeru; Ono, Akio; Maeda, Atsushi; Sugikawa, Susumu

Proceedings of International Conference on Back-End of the Fuel Cycle: From Research to Solutions (GLOBAL 2001) (CD-ROM), 7 Pages, 2001/09

no abstracts in English

Creep failure of reactor cooling system piping of nuclear power plant under severe accident conditions

Chino, Eiichi; Maruyama, Yu; Maeda, Akio*; Harada, Yuhei*; Nakamura, Hideo; Hidaka, Akihide; Shibazaki, Hiroaki*; Yuchi, Yoko; Kudo, Tamotsu; Hashimoto, Kazuichiro*

Proceedings of the 7th International Conference on Creep and Fatigue at Elevated Temperatures (CREEP7), p.107 - 115, 2001/06

no abstracts in English

Reduction technique of welding defect in the welded joint of aluminum alloys base on GTAW

Maeda, Akio; Oba, Toshihiro; Kikuchi, Hiroyuki; Shibata, Katsuyuki

JAERI-Tech 2001-003, 48 Pages, 2001/02

JAERI-Tech-2001-003.pdf:5.95MB

no abstracts in English

Post-test creep analysis of piping failure tests in WIND project

Chino, Eiichi; Maruyama, Yu; Yuchi, Yoko; Shibazaki, Hiroaki*; Nakamura, Hideo; Hidaka, Akihide; Kudo, Tamotsu; Hashimoto, Kazuichiro; Maeda, Akio*

JAERI-Conf 2000-015, p.303 - 308, 2000/11

https://doi.org/10.11484/jaeri-conf-2000-015

no abstracts in English

Effect of microstructure on failure behavior of light water reactor coolant piping under severe accident conditions

Harada, Yuhei; Maruyama, Yu; Maeda, Akio; Shibazaki, Hiroaki*; Kudo, Tamotsu; Hidaka, Akihide; Hashimoto, Kazuichiro; Sugimoto, Jun

Journal of Nuclear Science and Technology, 36(10), p.923 - 933, 1999/10

https://doi.org/10.3327/jnst.36.923

no abstracts in English

Current status of criticality safety experiment in NUCEF and its enhancement of facility function toward Pu experiment

Takeshita, Isao; Ono, Akio; Izawa, Naoki*; Miyoshi, Yoshinori; Maeda, Atsushi; Sugikawa, Susumu; Miyauchi, Masakatsu

Proceedings of 6th International Conference on Nuclear Criticality Safety (ICNC '99), p.1512 - 1576, 1999/09

no abstracts in English

Analyses of CsI aerosol deposition in aerosol behavior tests in WIND project

Kudo, Tamotsu; Shibazaki, Hiroaki*; Hidaka, Akihide; Maruyama, Yu; Maeda, Akio; Harada, Yuhei; Hashimoto, Kazuichiro; Sugimoto, Jun; Yoshino, T.*; Suzuki, K.*

JAERI-Conf 99-005, p.197 - 201, 1999/07

https://doi.org/10.11484/jaeri-conf-99-005

no abstracts in English