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Journal Articles

Irradiation performance of sodium-bonded control rod for the fast breeder reactor

Sasaki, Shinji; Maeda, Koji; Furuya, Hirotaka*

Journal of Nuclear Science and Technology, 55(3), p.276 - 282, 2018/03

 Times Cited Count:1 Percentile:70.85(Nuclear Science & Technology)

Journal Articles

Distributions of density and fission products in the reaction product between irradiated MOX fuel and molten zircaloy-2

Ishimi, Akihiro; Katsuyama, Kozo; Maeda, Koji; Furuya, Hirotaka*

Journal of Nuclear Science and Technology, 54(11), p.1274 - 1276, 2017/11

 Times Cited Count:0 Percentile:100(Nuclear Science & Technology)

Two- and three-dimensional images were obtained in the reaction product between zircaloy and MOX fuel by X-ray CT. In addition, the $$gamma$$-ray intensity distributions of two fission products (Cs-137 and Eu-154) and one neutron-activated nuclide (Co-60) were obtained in this specimen by $$gamma$$-ray measurements. The average values of the fuel density (about 10.5 g/cm$$^{3}$$) and the cladding density (about 6.55 g/cm$$^{3}$$) were obtained in the metallic phase region by evaluation of the density distributions on two-dimensional X-ray CT images. In addition, the distributions of the roughly crushed fuel pellet and the pores in the specimen could be clearly observed on the three-dimensional X-ray CT images. From the $$gamma$$-ray measurement, Cs-137 was observed on the unreacted fuel region and the region where pores exist in the metallic phase, and Eu-154 was widely distributed to all regions. On the other hand, Co-60 was confirmed only in the metallic phase region.

Journal Articles

Radial density distribution in irradiated FBR MOX fuel pellets

Ishimi, Akihiro; Katsuyama, Kozo; Nakamura, Hirofumi; Asaka, Takeo; Furuya, Hirotaka

Nuclear Technology, 189(3), p.312 - 317, 2015/03

 Times Cited Count:3 Percentile:61.74(Nuclear Science & Technology)

A high resolution X-ray CT technique was developed, which made it possible to obtain fine X-ray CT images of an irradiated fuel assembly. In addition, the density distributions in the irradiated MOX fuel pellet could be continually measured, using the relationship between the densities and CT values. These results were compared to the one obtained by metallographical method. As results, it was found that the relative change of radial density distributions in the irradiated fuel pellet can be measured more accurately by the X-ray CT technique than by the metallographical examination.

Journal Articles

Upgrading of X-ray CT technology for analyses of irradiated FBR MOX fuel

Ishimi, Akihiro; Katsuyama, Kozo; Maeda, Koji; Nagamine, Tsuyoshi; Asaka, Takeo; Furuya, Hirotaka

Journal of Nuclear Science and Technology, 49(12), p.1144 - 1155, 2012/12

 Times Cited Count:6 Percentile:47.47(Nuclear Science & Technology)

no abstracts in English

Journal Articles

Application of X-ray computer tomography for observing the central void formations and the fuel pin deformations of irradiated FBR fuel assemblies

Katsuyama, Kozo; Nagamine, Tsuyoshi; Furuya, Hirotaka

IEEE Transactions on Instrumentation and Measurement, 57(5), p.2714 - 2718, 2010/10

In order to observe the structural change in the interior of irradiated fuel assembly, the non-destructive post irradiation examination technique using X-ray computer tomography (X-ray CT) was developed. In this X-ray CT system, the 12 MeV X-ray pulses was used in synchronization with the switch-in of the detector to minimize the effects of the $$gamma$$ ray emissions from the irradiated fuel assembly, and then clear cross section CT image could be successfully obtained.

Journal Articles

Development of a prototype module for the ERL superconducting main linac at KEK

Furuya, Takaaki*; Hara, Kazufumi*; Hosoyama, Kenji*; Kojima, Yuji*; Nakai, Hirotaka*; Nakanishi, Kota*; Sakai, Hiroshi*; Umemori, Kensei*; Sawamura, Masaru; Shinoe, Kenji*

Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.2923 - 2925, 2010/05

A prototype module including a couple of 1.3 GHz superconducting 9-cell cavities has been designed as the main linac of cERL which is the test facility to establish the basic ERL technology at KEK. The shape of 9-cell Nb structure is optimized to accelerate a CW beam of 100 mA with sufficiently damped higher order modes (HOM) which is achieved by adopting an eccentric fluted beam pipe and a cylindrical beam pipe of a large diameter of 120 mm. Extracted HOMs are absorbed by the ferrite cylinders bonded on the copper beam pipes by HIP process. A power coupler with double disk-ceramics has been developed to transfer an RF of 20 kW CW to the cavity in full reflection. The test results of fabrication, cooling and RF performance for these components are integrated as the prototype module of the main linac for cERL facility.

Journal Articles

Recent progress in the energy recovery linac project in Japan

Sakanaka, Shogo*; Akemoto, Mitsuo*; Aoto, Tomohiro*; Arakawa, Dai*; Asaoka, Seiji*; Enomoto, Atsushi*; Fukuda, Shigeki*; Furukawa, Kazuro*; Furuya, Takaaki*; Haga, Kaiichi*; et al.

Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.2338 - 2340, 2010/05

Future synchrotron light source using a 5-GeV energy recovery linac (ERL) is under proposal by our Japanese collaboration team, and we are conducting R&D efforts for that. We are developing high-brightness DC photocathode guns, two types of cryomodules for both injector and main superconducting (SC) linacs, and 1.3 GHz high CW-power RF sources. We are also constructing the Compact ERL (cERL) for demonstrating the recirculation of low-emittance, high-current beams using above-mentioned critical technologies.

Journal Articles

Three-dimensional X-ray CT image of an irradiated FBR fuel assembly

Katsuyama, Kozo; Maeda, Koji; Nagamine, Tsuyoshi; Furuya, Hirotaka

Nuclear Technology, 169(1), p.73 - 80, 2010/01

 Times Cited Count:3 Percentile:71.83(Nuclear Science & Technology)

Three-dimensional X-ray CT (computer tomography) images were successfully taken of a fast breeder reactor fuel assembly which had been irradiated to high burn-up. The interior and outside of the fuel assembly can be clearly observed on any cross section from any angle. Using these images, it is possible to analyze the deformation of fuel pins, abnormalities in the fuel assembly, and microstructural change in the fuel pins. 127 central void sizes were tentatively analyzed as a function of linear heat rating. Compared with conventional non-destructive and destructive post irradiation examination (PIEs), this X-ray CT technique has great advantages including the number of PIE data acquisitions in a short time, reduced PIE costs, reduced radioactive waste generation, and physical protection of nuclear materials.

Journal Articles

Characteristics and sinterability of MOX powder prepared by the microwave heating denitration method

Asakura, Koichi; Kato, Yoshiyuki; Furuya, Hirotaka

Nuclear Technology, 162(3), p.265 - 275, 2008/06

 Times Cited Count:6 Percentile:54.69(Nuclear Science & Technology)

UO$$_{2}$$, PuO$$_{2}$$ and MOX (mixed oxide of U and Pu) powders were prepared by the MH (microwave heating de-nitration), ADU (Ammonia diuranate) and OX (oxalate) methods. The BET specific surface area, avarage particle size by air permiation method, bulk density, tap density, angle of repose, angle of spatula and cohesiveness of these powders were measured. The degree of surface roughness was evaluated from the ratio of BET surface area to the one calculated from average particle size and then flowability was evaluated on the basis of Carr's theory. These results were compared for the different powders and preperation methods as a parameter of calcination temperature. The degree of surface roughness in MH-MOX powder was larger than in ADU-UO$$_{2}$$ powder and smaller in OX-PuO$$_{2}$$ powder. These results could be understood using the concpt of H$"u$ttig and Tamman temperatures commonly cited in ceramics materials. As already reported for the general papers, the flowabilities of MH-MOX and ADU-UO$$_{2}$$ powders also decreased with increase of compressibility, and their absolute values were below 50 points. According to Carr's theory, the brderline between free-flowing and non-free-flowing powders is from 60 to 69 points. It is, therefore, necessary for the mixed powder of MH-MOX powder, ADU-UO$$_{2}$$ powder and dry recycled MOX scrap powder to be granulated to provide a free flowing feed to the pelletizing press in the MOX pellet fabrication process.

Journal Articles

Three-dimensional X-ray CT image of irradiated FBR fuel assembly

Katsuyama, Kozo; Nagamine, Tsuyoshi; Nakamura, Yasuo; Asaka, Takeo; Furuya, Hirotaka

Transactions of the American Nuclear Society, 97(1), p.620 - 621, 2007/11

no abstracts in English

Journal Articles

Measurement of the fuel pin deflection in an assembly irradiated in FBR "JOYO"

Katsuyama, Kozo; Nagamine, Tsuyoshi; Nakamura, Yasuo; Matsumoto, Shinichiro; Asaka, Takeo; Furuya, Hirotaka

Transactions of the American Nuclear Society, 94(1), p.771 - 772, 2006/06

no abstracts in English

Journal Articles

Measurement of the radioactive concentration in consumer's goods containing natural uranium and thorium and evaluation of the exposure by their utilization

Yoshida, Masahiro*; Endo, Akira; Sato, Shigero*; Ohata, Tsutomu*; Watanabe, Masatoshi*; Oyama, Ryutaro*; Furuya, Hirotaka*

Nippon Genshiryoku Gakkai Wabun Rombunshi, 4(3), p.213 - 218, 2005/09

no abstracts in English

Journal Articles

Development of Non-destructive Post-Irradiation Examination Technique using High-energy X-ray Computer Tomography

Katsuyama, Kozo; Nagamine, Tsuyoshi; Matsumoto, Shinichiro; Asaka, Takeo; Ito, Masahiko; Furuya, Hirotaka

2004 ANS Winter Meeting, 91, 0 Pages, 2004/00

Non-destructive X-ray computed tomography (X-ray CT scanning) is a powerful technique for characterizing the morphology in structural materials as used in medical field. This X-ray CT scanning technique was developed for the purpose of post irradiation examinations (PIE), and applied to the fuel assemblies irradiated in the experimental fast reactor Joyo.

Journal Articles

Axial Distribution of Cesium in the Heterogeneous FBR Fuel Pins

Furuya, Hirotaka*; Ukai, S.; Shikakura, Sakae; Tsuchiuchi, Y.*; Idemitsu, Kazuya*

Journal of Nuclear Materials, 201, p.46 - 53, 1993/05

 Times Cited Count:7 Percentile:38

None

Journal Articles

Effect of Temperature and Deformation Rate on Fracture Strength of Sintered Uranium Dioxide

Tachibana, Toshimichi; Furuya, Hirotaka*; Koizumi, Masumichi*

Journal of Nuclear Science and Technology, 16(4), p.266 - 277, 1979/00

JAEA Reports

None

Tsunoda, Naomi; *; *; *; Tachibana, Toshimichi; Furuya, Hirotaka; Koizumi, Masumichi

PNC-TN841 77-64, 48 Pages, 1977/12

PNC-TN841-77-64.pdf:2.87MB

no abstracts in English

JAEA Reports

None

Koizumi, Masumichi; *; *; *; Furuya, Hirotaka

PNC-TN841 76-33, 72 Pages, 1976/10

PNC-TN841-76-33.pdf:4.07MB

no abstracts in English

JAEA Reports

Physical and chemical properties of nuclear fuels(April ; 1973 $$sim$$ May ; 1976)

Koizumi, Masumichi; Furuya, Hirotaka; *; Nagai, Shuichiro; Tachibana, Toshimichi; *

PNC-TN843 76-04, 40 Pages, 1976/08

PNC-TN843-76-04.pdf:1.14MB

None

JAEA Reports

None

Koizumi, Masumichi; *; *; Nagai, Shuichiro; Furuya, Hirotaka

PNC-TN841 76-23, 27 Pages, 1976/06

PNC-TN841-76-23.pdf:2.19MB

no abstracts in English

JAEA Reports

None

*; Koizumi, Masumichi; Nagai, Shuichiro; Fukuda, Shoji*; *; *; Furuya, Hirotaka

PNC-TN841 76-16, , 1976/04

PNC-TN841-76-16.pdf:1.63MB

no abstracts in English

43 (Records 1-20 displayed on this page)