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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：8 Percentile：52.49(Nuclear Science & Technology)no abstracts in English
Ichikawa, Shoichi; Haga, Hiroyuki; Kikukawa, Kiyohide*; Fukasaku, Hironobu*; Kurosawa, Yoichi*; Katsuyama, Kozo; Maeda, Koji; Nagamine, Tsuyoshi
JAEA-Technology 2011-020, 32 Pages, 2011/07
JAEA-Technology-2011-020.pdf:6.56MB
Disassembling technique of the driver fuel assembly irradiated in the experimental fast reactor JOYO has been established at Fuel Monitoring Facility in JAEA. This technique made it possible to remove the fuel pins from the driver fuel assembly without the fuel pin sectioning. After disassembling the fuel assembly, some selected fuel pins can be reassembled into the new irradiation vehicle for the continuous irradiation at JOYO. This technique enables us to obtain the irradiation data of high burn-up fuel and high neutron dose material.
Katsuyama, Kozo; Ishimi, Akihiro; Nagamine, Tsuyoshi; Asaka, Takeo
Kensa Gijutsu, 16(2), p.12 - 18, 2011/02
no abstracts in English
Katsuyama, Kozo; Nagamine, Tsuyoshi; Furuya, Hirotaka
IEEE Transactions on Nuclear Science, 57(5), p.2714 - 2718, 2010/10
Times Cited Count：1 Percentile：12.12(Engineering, Electrical & Electronic)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 
ray emissions from the irradiated fuel assembly, and then clear cross section CT image could be successfully obtained.
Katsuyama, Kozo; Ishimi, Akihiro; Nagamine, Tsuyoshi; Asaka, Takeo
Proceedings of 47th Annual Meeting of the Working Group "Hot Laboratories and Remote Handling" (HOTLAB 2010) (CD-ROM), 4 Pages, 2010/09
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 pulse was used in synchronization with the switch-in of the detector to minimize the effects of the ray emissions from the irradiated fuel assembly. In this study, this X-ray CT technique was upgraded for observing the inner condition of the fuel pellet using the high resolution X-ray CT image. In this paper, we describe following two items; (1) Development of high resolution X-ray CT technique, and (2) Result of high resolution X-ray CT image of an irradiated fuel pellet.
Katsuyama, Kozo; Ishimi, Akihiro; Maeda, Koji; Nagamine, Tsuyoshi; Asaka, Takeo
Journal of Nuclear Materials, 401(1-3), p.86 - 90, 2010/06
Times Cited Count：4 Percentile：30.63(Materials Science, Multidisciplinary)The helium releases were investigated in FBR fuel pins irradiated to high burn-up. The released amounts of helium gas increased with the increase of burn-up, but their data were scattered in the region of high burn-up region. This was understood to be caused by the differences of 
Am contents among fuel pellets, because this nuclide generates 
Cm which undergoes alpha decay at a short half life.
Katsuyama, Kozo; Maeda, Koji; Nagamine, Tsuyoshi; Furuya, Hirotaka
Nuclear Technology, 169(1), p.73 - 80, 2010/01
Times Cited Count：3 Percentile：24.08(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.
Miyaji, Noriko; Katsuyama, Kozo; Nagamine, Tsuyoshi
Proceedings of 46th Annual Meeting of "Hot Laboratories and Remote Handling" Working Group (HOTLAB 2009) (CD-ROM), 5 Pages, 2009/09
An eddy current testing (ECT) technique was developed to check the soundness of irradiated fuel pins non-destructively. Here, the technique was applied to detect the decrease in wall thickness of the fuel pin cladding due to corrosion occurrence which had been irradiated in the experimental fast reactor Joyo. Dummy cladding provided with simulated inner corrosion was used to ascertain the technique applicability. This test confirmed that the decrease in wall thickness with simulated inner corrosion exceeding 30 
m in depth could be detected. In the case of irradiated fuel pins, the decrease in wall thickness due to corrosion occurrence was not detected because the depth was too small; the maximum depth of the inner corrosion was 14 m. In addition, it should be noted that the physical changes on the cladding due to irradiation might have an influence on the signal.
Sakamoto, Naoki; Yoshikawa, Katsunori; Kushida, Naoya; Katsuyama, Kozo; Nagamine, Tsuyoshi
Proceedings of 46th Annual Meeting of "Hot Laboratories and Remote Handling" Working Group (HOTLAB 2009) (CD-ROM), 5 Pages, 2009/09
The large-scale post irradiation examination facility for fast breeder reactor fuel assemblies has been operated since 1978 in JAEAs Oarai Research and Development Center. The facility has several hot cells and irradiated fuel assemblies are dismantled in the examination cell which is 6 m in length, 19.5 m in width and 7 m in height. Remote maintenance technology for use in the hot laboratory was established using electromechanical manipulators, in-cell cranes and a repair hoist system installed in the examination cell. The test equipment which is used for post irradiation examinations can be repaired using the electromechanical manipulators and in-cell cranes by remote handling. In addition, the electromechanical manipulators and in-cell cranes are designed to permit self-repair using the repair hoist system in the cell by remote handling.
Ishimi, Akihiro; Katsuyama, Kozo; Abe, Kazuyuki; Nagamine, Tsuyoshi; Nakamura, Yasuo
JAEA-Technology 2009-003, 58 Pages, 2009/05
JAEA-Technology-2009-003.pdf:8.95MB
Japan Atomic Energy Agency executed the irradiation examination of the MA content mixed oxide fuel by Experimental Fast Reactor "JOYO". This examination was used that the mixed oxide fuel that contained Americium by 3% and 5%, and the mixed oxide fuel of Americium and Neptunium that contained 2% for each. The irradiation examination executed a short term irradiation (For ten minutes and 24 hours) by the high linear heat, and achieved maximum linear heat about 430 W/cm in "JOYO". After it had irradiated it, the post irradiation examination of the fuel pin was executed in the Fuels Monitoring facilities. On the results of X ray CT examination, the result that the density decrease is forecast to the vicinity of the center of the fuel was obtained for ten minutes in the irradiation. The formation of the central void was confirmed to the center of the fuel in 24 hour irradiation.
Sasaki, Shinji; Abe, Kazuyuki; Nagamine, Tsuyoshi
JAEA-Conf 2008-010, p.362 - 371, 2008/12
An innovative technique to measure the deformation of irradiated wrapper tube of FBR fuel assembly was developed, and installed in the hot cell of the Fuels Monitoring Facility in JAEA. In order to confirm the performance of this instrument, a number of measurements were carried out in the wrapper tubes irradiated to high burnup in the experimental fast reactor Joyo. In the instrument used until now, only three face to face distances in the hexagonal wrapper tube have been measured along the axial direction. On the other hand, in the instrument developed in this technique the face to face distances could be continuously measured along the lateral direction in the outer surfaces of wrapper tube. Using data obtained by this technique, the detailed analyses of deformation can be done throughout a whole wrapper tube.
Abe, Kazuyuki; Kobayashi, Takashi*; Kajima, Hisashi*; Yoshikawa, Katsunori; Nagamine, Tsuyoshi; Nakamura, Yasuo
JAEA-Technology 2008-008, 53 Pages, 2008/03
JAEA-Technology-2008-008.pdf:19.28MB
MARICO-2 is a Testing Rig for the continuous irradiation examination of ODS ferrite steel etc.. It was necessary to re-assemble of MARICO-2 in Fuel Monitoring Facility (FMF). However, MARICO-2 is not applicable a past technology of re-assembly because it is a Rig of the total length about 11 m and its hex-tube must be welded by remote control. Then, MARICO-2 re-assembly technology development was executed, the device was designed, it produced, and the procedure of re-assembly by remote control was established.
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
Misawa, Takeharu; Onuki, Akira; Mitsutake, Toru*; Katsuyama, Kozo; Misawa, Susumu*; Nagamine, Tsuyoshi; Nakamura, Yasuo; Akimoto, Hajime
Proceedings of 15th International Conference on Nuclear Engineering (ICONE-15) (CD-ROM), 8 Pages, 2007/04
Miyaji, Noriko; Nagamine, Tsuyoshi; Katsuyama, Kozo
JAEA-Technology 2006-036, 41 Pages, 2006/06
JAEA-Technology-2006-036.pdf:3.91MB
Eddy current testing (ECT) technique has been developed in order to check the soundness of irradiated fuel pins non-destructively. This paper describes the results that it was examined if corrosions were detected using an imitation fuel pin, made of 15Ni-15Cr-Ti and same type of the fuel pins irradiated in JOYO. As the results of experimental for an imitation pin, ECT detected the corrosions using frecquency 32kHz. And, the signal of eddy current became larger as the thickness of the cladding became smaller, because there was some correlation between the signal and thickness. As for the irradiated fuel pins, inner corrosions were not recognized from the signal because their sizes were too small. However, outside corrosions by sodium as coolant might have an influence on the signal. And, as well as a change of the electromagnetic characteristics of cladding by irradiation, inner pressure by FP gas and PCMI might have an influence on the signal.
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
Katsuyama, Kozo; Toyoda, Hiromasa*; Nagamine, Tsuyoshi
JAEA-Technology 2006-004, 30 Pages, 2006/02
JAEA-Technology-2006-004.pdf:2.44MB
no abstracts in English
Mitsutake, Toru*; Katsuyama, Kozo*; Misawa, Takeharu; Nagamine, Tsuyoshi*; Kureta, Masatoshi*; Matsumoto, Shinichiro*; Akimoto, Hajime
JAERI-Tech 2005-034, 55 Pages, 2005/06
JAERI-Tech-2005-034.pdf:7.76MB
In tight-lattice bundles with about 1mm gap between rods, a rod displacement might affect thermal-hydraulic characteristics. The inside-structure observation of the simulated seven-rod bundle of RMWR was made with the high-energy X-ray CT of JNC. The CT view assured that the rod position was almost the same as expected by design. In the heat transfer experiments, all thermocouples on the center rod showed almost simultaneous BT-induced temperature increase and on the same axial heights showed quite similar time-variation behaviors in the vapor cooling heat transfer regime. It showed that the effect of the geometrical asymmetry was small on the BT characteristics. The calculated critical power by subchannel analysis with the input of the CT measured rod position was smaller by about 5% than that with the designed rod position. It concluded that the error in the calculated critical power was attributable not to the asymmetry in the rod position, but to the models in the subchannel analysis code.
Mitsutake, Toru*; Akimoto, Hajime; Misawa, Takeharu; Kureta, Masatoshi*; Katsuyama, Kozo*; Nagamine, Tsuyoshi*; Matsumoto, Shinichiro*
Proceedings of 4th World Congress on Industrial Process Tomography, Vol.1, p.348 - 353, 2005/00
An inside-structure observation of a tight-lattice 7-rod bundle was made, using the high-energy X-ray computer tomography(CT) apparatus. The two-dimensional configurations of all rods were obtained at seventy-six axial height positions over the whole length of the bundle. The measured results of the rod positions showed small rod position displacements, about 0.5 millimeters at maximum, from the lattice positions. Based on these measured rod position displacement results, the flow area, equivalent hydraulic diameter, rod-rod clearance, and rod-shroud clearance were calculated. The effect of rod position displacement on critical power was estimated by a sub-channel analysis. The result showed that the rod position displacement effect has only a small effect on critical power calculations. The calculated critical power still overestimated the measured value.
Katsuyama, Kozo; Nagamine, Tsuyoshi; Matsumoto, Shinichiro
JNC TY9410 2004-001, 54 Pages, 2004/09
JNC-TY9410-2004-001.pdf:14.44MB
In order to contribute to the development of cooling technique for the Tight-Lattice Core used in Reduced-Moderation Water Reactor, which was mainly studied in Japan Atomic Energy Research Institute, the inner condition of Dummy Assembly made of the Tight-Lattice Core was observed with X-ray Computer Tomography (CT) technique. In the observation using X-ray CT, the non-destructive examination technique for the un-irradiated specimens was also established. The results obtained from this study are following.
