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Journal Articles

Measurements and evaluations of air dose rates around Fukushima, 5; Characteristics of air dose rate distribution in the environment around the Fukushima Nuclear Power Plant site

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.

Journal Articles

Evaluation of SCCVII tumor cell survival in clamped and non-clamped solid tumors exposed to carbon-ion beams in comparison to X-rays

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:19 Percentile:60.07(Biotechnology & Applied Microbiology)

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

972-MHz RF digital feedback control system for J-PARC linac

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 $$pm$$1% in amplitude and $$pm$$1$$^{circ}$$ 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.

Journal Articles

Digital feedback control for 972 MHz RF system of J-PARC linac

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 $$pm$$ 1% in amplitude and $$pm$$ 1$$^{circ}$$. 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.

Journal Articles

Development of digital low level rf system

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.

Journal Articles

Progress in R&D efforts on the energy recovery linac in Japan

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.

JAEA Reports

Investigation of transmutation target for long-lived fission products; Basic examinations of iodide candidates, 2

Donomae, Takako; Tachi, Yoshiaki; Matsumoto, Shinichiro

JAEA-Research 2006-033, 35 Pages, 2006/07


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

JAEA Reports

Rod displacement measurements by X-ray CT and its impact on thermal-hydraulics in tight-lattice rod bundle (Joint research)

Mitsutake, Toru*; Katsuyama, Kozo*; Misawa, Takeharu; Nagamine, Tsuyoshi*; Kureta, Masatoshi*; Matsumoto, Shinichiro*; Akimoto, Hajime

JAERI-Tech 2005-034, 55 Pages, 2005/06


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.

Journal Articles

Experiences of Remote Operated Dismantling of Glove-Box

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.

Journal Articles

Rod displacement effect on thermal-hydraulic behaviour in tight-lattice bundle based on X-ray CT measurement

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.

JAEA Reports

Observation of dummy assembly made of the tight-lattice core using the X-ray CT technique

Katsuyama, Kozo; Nagamine, Tsuyoshi; Matsumoto, Shinichiro

JNC TY9410 2004-001, 54 Pages, 2004/09


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.

JAEA Reports

Development of Eddy Current Testing Technique for Irradiated Fuel Pins; ECT results of irradiated fuel pins of PFC030

Miyaji, Noriko; Nagamine, Tsuyoshi; Katsuyama, Kozo; Kikuchi, Shin; Matsumoto, Shinichiro

JNC TN9410 2003-012, 45 Pages, 2004/03


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.

JAEA Reports

Measurement and Analysis of the Fuel Pin Deflection Irradiated in Fast Reactor using the X-Ray CT Image

Katsuyama, Kozo; Nagamine, Tsuyoshi; Matsumoto, Shinichiro

JNC TN9400 2004-016, 38 Pages, 2004/03


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.

JAEA Reports

Scattering Profiles of Sparks and Combustibility of Filter against Hot Sparks

Asazuma, Shinichiro; Okada, Takashi; Kashiro, Kashio; Matsumoto, Masaki; Nakata, Keiji*; Gonnokami, Kiyomi*; Toda, Rikiya*

JNC TN8430 2003-011, 56 Pages, 2004/01


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.

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.

JAEA Reports

Evaluation of fuel pin internal pressure by the 7 spectrum measurement

Katsuyama, Kozo; Fujishima, Tadatsune; Nagamine, Tsuyoshi; Matsumoto, Shinichiro

JNC TN9410 2003-006, 40 Pages, 2003/08


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.

Journal Articles

Inside observation of the irradiated fuel subassembly by high energy X-Ray CT

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.

Journal Articles

Observation of deflection and displacement of fuel pin in irradiated FBR assembly using X-ray computer tomography

Katsuyama, Kozo; Nagamine, Tsuyoshi; Matsumoto, Shinichiro;

Journal of Nuclear Science and Technology, 40(4), p.220 - 223, 2003/00

 Times Cited Count:18 Percentile:76.42(Nuclear Science & Technology)


43 (Records 1-20 displayed on this page)