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Mikami, Satoshi; Matsuda, Norihiro; Ando, Masaki; Kinase, Sakae; Kitano, Mitsuaki; Kawase, Keiichi; Matsumoto, Shinichiro; Yamamoto, Hideaki; Saito, Kimiaki
Radioisotopes, 64(9), p.589 - 607, 2015/09
This article presents the features of regional distributions and temporal changes in air dose rate and radionuclide deposition densities in Fukushima on the basis of analyses on large-scale environmental monitoring results using diverse methods. The continuity of decontamination effects is discussed according to repeated monitoring data after the decontamination model project. Further, some examples are shown on the projection of air dose rates together with the ecological half lives for different land uses.
Hirayama, Ryoichi*; Uzawa, Akiko*; Takase, Nobuhiro*; Matsumoto, Yoshitaka*; Noguchi, Miho; Koda, Kana*; Ozaki, Masakuni*; Yamashita, Kei*; Li, H.*; Kase, Yuki*; et al.
Mutation Research; Genetic Toxicology And Environmental Mutagenesis, 756(1-2), p.146 - 151, 2013/08
Times Cited Count：26 Percentile：62.50(Biotechnology & Applied Microbiology)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.
Kobayashi, Tetsuya; Michizono, Shinichiro*; Fang, Z.*; Matsumoto, Toshihiro*; Suzuki, Hiroyuki; Yamaguchi, Seiya*; Okada, Yoshihito*
Proceedings of 6th Annual Meeting of Particle Accelerator Society of Japan (CD-ROM), p.1068 - 1070, 2010/03
A 972-MHz RF system is being developed for 400-MeV upgrade of the J-PARC linac. The accelerating field stabilities should be less than 
1% in amplitude and 1
in phase. The basic digital LLRF (Low-Level RF) concept is the same as that of the present 324-MHz system with a compact-PCI crate. The main alterations are RF and clock generator (RF&CLK), mixer and I/Q modulator (IQ&Mixer) and digital LLRF algorithm. Since the typical decay time of the new system is faster (because its operational frequency is higher than that of the present 324-MHz cavity), chopped beam compensation is essential. The performance study of the digital feedback system with a cavity simulator is summarized.
Michizono, Shinichiro*; Fang, Z.*; Matsumoto, Toshihiro*; Yamaguchi, Seiya*; Kobayashi, Tetsuya; Okada, Yoshihito*
Proceedings of 2009 Particle Accelerator Conference (PAC '09) (DVD-ROM), p.2201 - 2203, 2009/05
Upgrade of J-PARC linac has been planed using 972 MHz rf system. The rf eld regulation is required to be less than 1% in amplitude and 1. in phase. The basic digital llrf concept is same as the present 324 MHz llrf system using a compact PCI crate. The main alterations are rf and clock generator (RF&LK), mixer and IQ modulator (IQ&Mixer) and digital llrf algorithm. Since the typical decay time is faster (due to higher operational frequency than present 324 MHz cavity), chopped beam compensation is one of the main concerns. Performance of the digital feedback system using a cavity simulator is summarized.
Michizono, Shinichiro*; Anami, Shozo*; Katagiri, Hiroaki*; Fang, Z.*; Matsumoto, Toshihiro*; Miura, Takako*; Yano, Yoshiharu*; Yamaguchi, Seiya*; Kobayashi, Tetsuya
Kasokuki, 5(2), p.127 - 136, 2008/07
One of the biggest advantages of the digital low level rf (LLRF) system is its flexibility. Owing to the recent rapid progress in digital devices (such as ADCs and DACs) and telecommunication devices (mixers and IQ modulators), digital LLRF system for accelerators becomes popular in these 10 years. The J-PARC linac LLRF system adopted cPCI crates and FPGA based digital feedback system. After the successful operation of J-PARC linac LLRF system, we developed the STF (ILC test facility in KEK) LLRF system. The future R&D projects (ILC and ERL) are also described from the viewpoints of LLRF.
Sakanaka, Shogo*; Ago, Tomonori*; Enomoto, Atsushi*; Fukuda, Shigeki*; Furukawa, Kazuro*; Furuya, Takaaki*; Haga, Kaiichi*; Harada, Kentaro*; Hiramatsu, Shigenori*; Honda, Toru*; et al.
Proceedings of 11th European Particle Accelerator Conference (EPAC '08) (CD-ROM), p.205 - 207, 2008/06
Future synchrotron light sources based on the energy-recovery linacs (ERLs) are expected to be capable of producing super-brilliant and/or ultra-short pulses of synchrotron radiation. Our Japanese collaboration team is making efforts for realizing an ERL-based hard X-ray source. We report recent progress in our R&D efforts.
Donomae, Takako; Tachi, Yoshiaki; Matsumoto, Shinichiro
JAEA-Research 2006-033, 35 Pages, 2006/07
JAEA-Research-2006-033.pdf:8.59MB
no abstracts in English
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
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.
Okada, Takashi; Asazuma, Shinichiro; Kashiro, Kashio; Matsumoto, Masaki
CD-ROM, WM-5214, p.8, 8 Pages, 2005/00
The dismantling activities, which consist of removal of the glove panel, dismantling of the interior equipment and dismantling of the GB body and made up about 45% of the dismantling of the GB in GBDF, could be performed by remote control.
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.
Miyaji, Noriko; Nagamine, Tsuyoshi; Katsuyama, Kozo; Kikuchi, Shin; Matsumoto, Shinichiro
JNC TN9410 2003-012, 45 Pages, 2004/03
JNC-TN9410-2003-012.pdf:1.84MB
Post irraiated fuel pins which irradiated in JOYO PFC030 by eddy current test (ECT) were carried out. The results of the tests, we have some possibility to find FCCI points using gamma scanning result Cs137. And thecorrelation between FCCI quantity and eddy current signal was within that of trial FCCI.
Katsuyama, Kozo; Nagamine, Tsuyoshi; Matsumoto, Shinichiro
JNC TN9400 2004-016, 38 Pages, 2004/03
JNC-TN9400-2004-016.pdf:1.34MB
In order to evaluate the irradiation behavior of fuel pin, X-ray CT test was carried out for the fuel assembly irradiated in the experimental fast reactor Joyo and fuel pin deflection were measured based on the analysis of CT image. It was observed that the deflection of the fuel pins loaded in the outermost array of the fuel assembly were large as compared with the fuel pins loaded in the inner region and the fuel pins fuel situated fronting on wrapper tube were markedly displaced in the direction of wrapper tube.
Asazuma, Shinichiro; Okada, Takashi; Kashiro, Kashio; Matsumoto, Masaki; Nakata, Keiji*; Gonnokami, Kiyomi*; Toda, Rikiya*
JNC TN8430 2003-011, 56 Pages, 2004/01
JNC-TN8430-2003-011.pdf:2.07MB
The glove-box dismantling facility in the Plutonium Fuel Production Facility is developed to dismantle after-service glove-boxes with remote-controlled devices such as an arm-type manipulator. An abrasive wheel cutter, which is used to size reduce the gloveboxes, generates sparks during operation. This dispersing spark was a problem from the fire prevention point of view. A suitable spark control measures for this operation were required. We developed panels to minimize spark dispersion, shields to prevent the income of sparks to the pre-filter, and incombustible pre-filters. The equipment was tested and effectiveness was confirmed. This report provides the results of these tests.
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.
Katsuyama, Kozo; Fujishima, Tadatsune; Nagamine, Tsuyoshi; Matsumoto, Shinichiro
JNC TN9410 2003-006, 40 Pages, 2003/08
JNC-TN9410-2003-006.pdf:1.04MB
85Kr, which is one of gaseous nuclides generated in nuclear fissions, can be detected by gamma spectrum measurement. It is possible to calculate the fission gas amount discharged into the gas plenum of fuel pin and the inner pressure, based on the measurement data. In this study, the measurement and calculation were applied to the fuel pins irradiated in the experimental fast reactor JOY0. Then puncture testing was carried out for the applied fuel pins to measure fission gas amount and real inner pressure. As a result, it was confirmed that that calculated data were appropriate in general, compared with those gained by puncture testing. (1)The error of inner pressure calculated on the basis of gamma spectrum measurement is less than 25%, compared with the puncture test results. (2)As the result of this method applied to the fuels irradiation test rig (No.PFB090), the highest pressure was calculated in one of fuel pins loaded into N0.5 compartment, which burn-up was over 110 GWd/t. The pressure was about 50 Kg/cm2. This value was sufficiently less than that used in the fuel design.
Katsuyama, Kozo; Nagamine, Tsuyoshi; Matsumoto, Shinichiro
Genshiryoku eye, 49(12), p.58 - 61, 2003/00
Focusing on the cover layer materials (as the Radon Barrier Materials), which could have the effect to restrain the radon from scattering into the air and the effect of the radiation shielding, we produced the radon barrier materials with crude bentonite on an experimental basis, using the rotary type comprehensive unit for grinding and mixing, through which we carried out the evaluation of the characteristics thereof.
Katsuyama, Kozo; Nagamine, Tsuyoshi; Matsumoto, Shinichiro;
Journal of Nuclear Science and Technology, 40(4), p.220 - 223, 2003/00
Times Cited Count：18 Percentile：73.82(Nuclear Science & Technology)None
