Refine your search:     
Report No.
 - 
Search Results: Records 1-20 displayed on this page of 113

Presentation/Publication Type

Initialising ...

Refine

Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...

Keyword

Initialising ...

Language

Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

Journal Articles

Development of an integrated active neutron non-destructive analysis system; Active-N

Toh, Yosuke; Ozu, Akira; Tsuchiya, Harufumi; Furutaka, Kazuyoshi; Kitatani, Fumito; Komeda, Masao; Maeda, Makoto; Koizumi, Mitsuo

Proceedings of INMM & ESARDA Joint Virtual Annual Meeting (Internet), 8 Pages, 2021/08

Journal Articles

Two-step-pressurization method in pulsed electric current sintering of MoO$$_{3}$$ for production of $$^{99m}$$Tc radioactive isotope

Suematsu, Hisayuki*; Sato, Soma*; Nakayama, Tadachika*; Suzuki, Tatsuya*; Niihara, Koichi*; Nanko, Makoto*; Tsuchiya, Kunihiko

Journal of Asian Ceramic Societies (Internet), 8(4), p.1154 - 1161, 2020/12

 Times Cited Count:0 Percentile:0.01(Materials Science, Ceramics)

Pulsed electric current sintering of molybdenum trioxide (MoO$$_{3}$$) was carried out by one- and two-step pressuring methods for fabrication of irradiation target using production of $$^{99}$$Mo and $$^{rm 99m}$$Tc nuclear medicine. At 550$$^{circ}$$C by the two-step pressurizing method, a relative density of 93.1% was obtained while, by the one-step pressurization method, the relative density was 76.9%. Direct sample temperature measurements were conducted by inserting a thermocouple in a punch. By the two-step pressurizing method, the sample temperature was higher than that by the one-step pressurizing method even almost the same die temperature. From voltage and current waveforms, it was thought that the conductivity of the sample increased by the two-step pressurizing method to increase the sample temperature and the relative density. The two-step pressurization method enables us to prepare dense targets at a low temperature from recycled and coarse-grained $$^{98}$$Mo enriched MoO$$_{3}$$ powder.

Journal Articles

Development of active neutron NDA system for radioactive nuclear materials

Toh, Yosuke; Ozu, Akira; Tsuchiya, Harufumi; Furutaka, Kazuyoshi; Kitatani, Fumito; Komeda, Masao; Maeda, Makoto; Koizumi, Mitsuo

Proceedings of INMM 60th Annual Meeting (Internet), 7 Pages, 2019/07

Journal Articles

Development of active neutron NDA system for nuclear materials

Toh, Yosuke; Ozu, Akira; Tsuchiya, Harufumi; Furutaka, Kazuyoshi; Kitatani, Fumito; Komeda, Masao; Maeda, Makoto; Koizumi, Mitsuo; Heyse, J.*; Paradela, C.*; et al.

Proceedings of INMM 59th Annual Meeting (Internet), 9 Pages, 2018/07

Journal Articles

Development of neutron resonance transmission analysis as a non-destructive assay technique for nuclear nonproliferation

Tsuchiya, Harufumi; Kitatani, Fumito; Maeda, Makoto; Toh, Yosuke; Kureta, Masatoshi

Plasma and Fusion Research (Internet), 13(Sp.1), p.2406004_1 - 2406004_4, 2018/02

Recently, it has become important in the field of nuclear nonproliferation and nuclear security to quantify nuclear materials (NMs) of uranium and plutonium in nuclear fuel using a non-destructive assay (NDA) technique. Currently, there is no reliable NDA system to apply to nuclear fuels such as spent fuel, fuel debris and next generation fuel for nuclear transmutation. Accordingly, development of NDA techniques for quantification of NMs in those fuels is an urgent issue. Neutron resonance transmission analysis (NRTA) is one candidate that is applicable to the quantification of NMs. Utilizing pulsed neutron beams, NRTA analyzes the content of a sample by measuring neutron beams that are transmitted from the sample. It is one of the reliable NDA methods that are based on a neutron time-of-flight technique for accurately evaluating nuclear data such as total cross sections and resonance parameters. A present NRTA system generally requires a large electron linear accelerator to produce intense neutron beams. Therefore this is not so easy to apply to various facilities that are used to measure NMs. Given this situation, a compact NRTA system would be required for practical applications of a method to quantify NMs in various samples. In order to realize a compact NRTA system, we consider two types of system: one uses a D-T neutron generator with pulse width of 10 $$mu$$sec and the other a small electron linac with pulse width of 1 $$mu$$sec Assuming each system is applied to measurements of NMs in spent fuel, numerical calculations were carried out and the results showed that the pulse widths of neutron beam largely affect the NRTA measurements. In this presentation, we will talk about the NRTA technique and give a schematic design of a compact NRTA system. Then, comparing calculation results for a D-T tube with those for a small electron linac, we especially discuss how the pulse widths of neutron beams to be used for NRTA affect the measurement of NMs in nuclear fuel.

Journal Articles

Development of active neutron NDA techniques for nuclear nonproliferation and nuclear security

Toh, Yosuke; Ozu, Akira; Tsuchiya, Harufumi; Furutaka, Kazuyoshi; Kitatani, Fumito; Komeda, Masao; Maeda, Makoto; Kureta, Masatoshi; Koizumi, Mitsuo; Seya, Michio; et al.

EUR-28795-EN (Internet), p.684 - 693, 2017/00

Journal Articles

Development of active neutron NDA techniques for nonproliferation and nuclear security, 2; Study on a compact NRTA system

Tsuchiya, Harufumi; Kitatani, Fumito; Maeda, Makoto; Kureta, Masatoshi

Proceedings of INMM 57th Annual Meeting (Internet), 6 Pages, 2016/07

From a viewpoint of nuclear safeguards and nuclear security, it has recently become important to develop a non-destructive assay (NDA) system that accurately determines the amount of special nuclear materials (SNMs) in various samples such as spent fuels, next generation MA-Pu fuels and fuel debris. One candidate of those NDA techniques is neutron resonance transmission analysis (NRTA). It relies on a neutron time-of-flight measurement and is a well-established method to apply for the accurate evaluations of nuclear data, including total cross sections and resonance parameters. The potential of NRTA to quantify SNM in complex materials has been already demonstrated by performing NRTA measurement at IRMM/GELINA under collaboration of JAEA and JRC. However, a present NRTA system usually has a large electron accelerator facility to generate intense neutrons, whereas this is very difficult to apply to various facilities that need to measure SNM. Therefore a compact NRTA system would be required for practical applications of quantifying SNM in a variety of samples. In order to realize a compact NRTA system, we are developing a prototype with a D-T neutron generator that has a pulse width of 10 $$mu$$s and an average maximum neutron yield ranging from $$10^{8}$$ n/s to $$2times10^{9}$$ n/s. Numerical calculations were used to optimize the system performance to quantify SNM and MA in spent and MA-Pu fuels. In this presentation, those numerical calculation results, together with a brief description of the prototype, are presented. In addition, we discuss a future prospect of a compact NRTA system equipped with a neutron source with a shorter pulse width (ex. 100 ns) and a more intense neutron yield.

Journal Articles

Neutron irradiation effect of high-density MoO$$_{3}$$ pellets for Mo-99 production, 2

Nishikata, Kaori; Ishida, Takuya; Yonekawa, Minoru; Kato, Yoshiaki; Kurosawa, Makoto; Kimura, Akihiro; Matsui, Yoshinori; Tsuchiya, Kunihiko; Sano, Tadafumi*; Fujihara, Yasuyuki*; et al.

KURRI Progress Report 2014, P. 109, 2015/07

As one of effective applications of the Japan Materials Testing Reactor (JMTR), JAEA has a plan to produce $$^{99}$$Mo by (n,$$gamma$$) method ((n,$$gamma$$)$$^{99}$$Mo production), a parent nuclide of $$^{99m}$$Tc. In this study, preliminary irradiation test was carried out with the high-density molybdenum trioxide (MoO$$_{3}$$) pellets in the hydraulic conveyer (HYD) of the Kyoto University Research Reactor (KUR) and the $$^{99m}$$Tc solution extracted from $$^{99}$$Mo was evaluated. After the irradiation test of the high-density MoO$$_{3}$$ pellets in the KUR, $$^{99m}$$Tc was extracted from the Mo solution and the recovery rate of $$^{99m}$$Tc achieved the target values. The $$^{99m}$$Tc solution also got the value that satisfied the standard value for $$^{99m}$$Tc radiopharmaceutical products by the solvent extraction method.

Journal Articles

Neutron irradiation effect of high-density MoO$$_{3}$$ pellets for Mo-99 production

Nishikata, Kaori; Ishida, Takuya; Yonekawa, Minoru; Kato, Yoshiaki; Kurosawa, Makoto; Kimura, Akihiro; Matsui, Yoshinori; Tsuchiya, Kunihiko; Sano, Tadafumi*; Fujihara, Yasuyuki*; et al.

KURRI Progress Report 2013, P. 242, 2014/10

As one of effective applications of the Japan Materials Testing Reactor (JMTR), JAEA has a plan to produce Mo-99 ($$^{99}$$Mo) by (n,$$gamma$$) method ((n,$$gamma$$)$$^{99}$$Mo production), a parent nuclide of $$^{99m}$$Tc. In this study, preliminary irradiation tests were carried out with the high-density MoO$$_{3}$$ pellets in the KUR and the $$^{99}$$Mo production amount was evaluated between the calculation results and measurement results.

JAEA Reports

Study to improve recriticality evaluation methodology after severe accident (Joint research)

Kugo, Teruhiko; Ishikawa, Makoto; Nagaya, Yasunobu; Yokoyama, Kenji; Fukaya, Yuji; Maruyama, Hiromi*; Ishii, Yoshihiko*; Fujimura, Koji*; Kondo, Takao*; Minato, Hirokazu*; et al.

JAEA-Research 2013-046, 53 Pages, 2014/03

JAEA-Research-2013-046.pdf:4.42MB

The present report summarizes the results of a 2-year cooperative study between JAEA and Hitachi-GE in order to contribute to the settlement of the Fukushima-Daiichi Nuclear Power Plants which suffered from the severe accident on March 2011. In the present study, the possible scenarios to reach the recriticality events in Fukushima-Daiichi were investigated first. Then, the analytical methodology to evaluate the time-dependent recriticality events has been developed by modelling the reactivity insertion rate and the possible feedback according to the recriticality scenarios identified in the first step. The methodology developed here has been equipped as a transient simulation tool, PORCAS, which is operated on a multi-purpose platform for reactor analysis, MARBLE. Finally, the radiation exposure rates by the postulated recriticality events in Fukushima-Daiichi were approximately evaluated to estimate the impact to the public environment.

Journal Articles

Mo recycling property from generator materials with irradiated molybdenum

Kakei, Sadanori*; Kimura, Akihiro; Niizeki, Tomotake*; Ishida, Takuya; Nishikata, Kaori; Kurosawa, Makoto; Yoshinaga, Hideo*; Hasegawa, Yoshio*; Tsuchiya, Kunihiko

Proceedings of 6th International Symposium on Material Testing Reactors (ISMTR-6) (Internet), 7 Pages, 2013/10

The Japan Materials Testing Reactor (JMTR) is expected to contribute to the expansion of industrial utilization, such as the domestic production of $$^{99}$$Mo for the medical diagnosis medicine $$^{rm 99m}$$Tc. Production by the (n, $$gamma$$) method is proposed as domestic $$^{99}$$Mo production in JMTR because of the low amount of radioactive wastes and the easy $$^{99}$$Mo/$$^{rm 99m}$$Tc production process. Molybdenum oxide (MoO$$_{3}$$) pellets, poly zirconium compounds (PZC) and poly titanium compounds (PTC) are used as the irradiation target and generator for the production of $$^{99}$$Mo/$$^{rm 99m}$$Tc by the (n, $$gamma$$) method. However, it is necessary to use the enriched $$^{98}$$MoO$$_{3}$$, which is very expensive, to increase the specific activity of $$^{99}$$Mo. Additionally, a large amount of used PZC and PTC is generated after the decay of $$^{99}$$Mo. Therefore, this recycling technology of used PZC/PTC has been developed to recover molybdenum (Mo) as an effective use of resources and a reduction of radioactive wastes. The total Mo recovery rate of this process was 95.8%. From the results of the hot experiments, we could demonstrate that the recovery of MoO$$_{3}$$ and the recycling of PZC are possible. In the future, the equipment of recovering Mo will be installed in JMTR-Hot Cell, and this recycling process will be able to contribute to the reduction of production costs of $$^{rm 99m}$$Tc and the reduction of radioactive wastes.

Journal Articles

Resonance characteristics and maximum turn voltage of JT-60SA EF coil

Murakami, Haruyuki; Kizu, Kaname; Tsuchiya, Katsuhiko; Yoshida, Kiyoshi; Yamauchi, Kunihito; Shimada, Katsuhiro; Terakado, Tsunehisa; Matsukawa, Makoto; Hasegawa, Mitsuru*; Minato, Tsuneaki*; et al.

IEEE Transactions on Applied Superconductivity, 22(3), p.9501405_1 - 9501405_5, 2012/06

 Times Cited Count:4 Percentile:30.57(Engineering, Electrical & Electronic)

The withstand voltage of turn insulation is essential issues for the superconducting magnet. The actual turn voltage is larger than the turn voltage under the ideal condition because of the voltage fluctuations of the power supply and the resonance phenomenon in the magnet. In this paper, the voltage measurement of the JT-60U power supply and the resonance characteristics of the EF4 are described. The actual maximum turn voltage is almost same as the voltage under the ideal condition.

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

Critical current measurement of prototype NbTi cable-in-conduit conductor for JT-60SA

Kizu, Kaname; Tsuchiya, Katsuhiko; Obana, Tetsuhiro*; Takahata, Kazuya*; Hoshi, Ryo; Hamaguchi, Shinji*; Nunoya, Yoshihiko; Yoshida, Kiyoshi; Matsukawa, Makoto; Yanagi, Nagato*; et al.

Fusion Engineering and Design, 84(2-6), p.1058 - 1062, 2009/06

 Times Cited Count:12 Percentile:64.43(Nuclear Science & Technology)

The maximum magnetic field and maximum current of EF coils for JT-60SA is 6.2T, 20 kA, respectively. The EF coil conductors are NbTi cable-in-conduit (CIC) conductor with SS316L conduit. In order to confirm the performance of current sharing temperature ($$T$$$$_{rm cs}$$) tests under coil operational condition was performed. As a results, the degradation of $$T$$$$_{rm cs}$$ was 0.01-0.08 K indicating that the conductor design and its fabrication method is appropriate. Experimental results were compared with the $$I$$ and $$T$$ by standard plasma operation scenario. It was confirmed that the conductor has $$T$$$$_{rm cs}$$ margin of $$>$$ 1K.

Journal Articles

Status of JT-60SA tokamak under the EU-JA broader approach agreement

Matsukawa, Makoto; Kikuchi, Mitsuru; Fujii, Tsuneyuki; Fujita, Takaaki; Hayashi, Takao; Higashijima, Satoru; Hosogane, Nobuyuki; Ikeda, Yoshitaka; Ide, Shunsuke; Ishida, Shinichi; et al.

Fusion Engineering and Design, 83(7-9), p.795 - 803, 2008/12

 Times Cited Count:16 Percentile:73.03(Nuclear Science & Technology)

no abstracts in English

Journal Articles

Conductor design of CS and EF coils for JT-60SA

Kizu, Kaname; Tsuchiya, Katsuhiko; Yoshida, Kiyoshi; Edaya, Masahiro; Ichige, Toshikatsu*; Tamai, Hiroshi; Matsukawa, Makoto; della Corte, A.*; Di Zenobio, A.*; Muzzi, L.*; et al.

IEEE Transactions on Applied Superconductivity, 18(2), p.212 - 215, 2008/06

 Times Cited Count:18 Percentile:67.05(Engineering, Electrical & Electronic)

The maximum magnetic field and maximum current of CS and EF coils is 9 T, 20 kA and 6.2 T, 21 kA, respectively. The conductor for CS is Nb$$_{3}$$Sn CIC conductor with JK2LB conduit. On the other hand, EF coil conductors are NbTi CIC conductor with SS316LN conduit. In order to reduce the pressure drop and to raise the temperature margin against large AC loss and nuclear heating, central spiral is introduced inside cable. The Tcs margin and stability analyses of the CS and EF coils are performed by using the one-dimensional fluid analysis code with transient heat loads. These coils have enough high Tcs and stability margin against the operational scenario.

Journal Articles

Mechanical design of JT-60SA magnet system

Tsuchiya, Katsuhiko; Suzuki, Yutaka; Kizu, Kaname; Yoshida, Kiyoshi; Tamai, Hiroshi; Matsukawa, Makoto; Dolgetta, N.*; Portafaix, C.*; Zani, L.*; Pizzuto, A.*

IEEE Transactions on Applied Superconductivity, 18(2), p.208 - 211, 2008/06

 Times Cited Count:7 Percentile:43.48(Engineering, Electrical & Electronic)

Magnet system in JT-60SA consists of 18 toroidal field coils, 7 plasma equilibrium field (EF) coils, and central solenoid (CS) that has 4 modules of solenoids. Mechanical design of EF coils and CS is optimized in order to obtain the broad operational space of plasmas that are double-null plasma with high plasma current for high performance operation and ITER-like configuration with IP=3.5MA for ITER-relevant experiment. In the former design, called NCT, divertor coil (EF4) is made of Nb$$_{3}$$Sn conductor, as well as CS conductor. However, it is clear that 6.2T of Bmax is significant to operate ITER-like plasma. Therefore, material of cable for EF4 conductor is changed into NbTi, so that this contributes to cost reduction. Regarding CS design, material of conduit is changed into JK2LB in order to simplify the structure of pre-compression. Stress analysis for support structure and winding pack of EF coils and CS is currently carried out. In the case where the vertical unbalance force of CS is largest in the designed plasma operation, peak stress of conduit is less than fatigue limit in 18,000 cycles that is designed number of plasma shot in JT-60SA. This result shows the recent design of CS conductor has significant mechanical strength.

Journal Articles

Conceptual design of superconducting magnet system for JT-60SA

Yoshida, Kiyoshi; Kizu, Kaname; Tsuchiya, Katsuhiko; Tamai, Hiroshi; Matsukawa, Makoto; Kikuchi, Mitsuru; della Corte, A.*; Muzzi, L.*; Turt$`u$, S.*; Di Zenobio, A.*; et al.

IEEE Transactions on Applied Superconductivity, 18(2), p.441 - 446, 2008/06

 Times Cited Count:21 Percentile:70.86(Engineering, Electrical & Electronic)

The upgrade of JT-60U magnet system to superconducting coils (JT-60SA) has been decided by both parties of Japan and EU in the framework of the Broader Approach agreement. The magnet system for JT-60SA consists of 18 toroidal field (TF) coils, a central solenoid (CS) with four modules, seven equilibrium field (EF) coils. TF case encloses the winding pack and is the main structural component. CS consists of four winding pack modules with its pre-load structure. Seven EF coils are attached to the TF coil cases through supports which include flexible plates. Since CS modules are operated at high magnetic field, Nb$$_{3}$$Sn superconductor is used. While NbTi superconductor is used in TF coils and EF coils. The magnet system has large heat load from nuclear heating by DD fusion and large AC loss from control actions. This paper descries the technical requirements, the operational interface and the conceptual design of the superconducting magnet system for JT-60SA.

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.

Journal Articles

Isotope effects in thermal neutron transmission and backscattering processes for $$varepsilon$$-phase zirconium hydrides and deuterides

Tsuchiya, Bun*; Yasuda, Ryo; Teshigawara, Makoto; Konashi, Kenji*; Nagata, Shinji*; Shikama, Tatsuo*; Yamawaki, Michio*

Journal of Nuclear Materials, 376(1), p.60 - 65, 2008/05

 Times Cited Count:2 Percentile:18.1(Materials Science, Multidisciplinary)

Distributions of hydrogen isotope concentrations in e-phase zirconium hydrides and deuterides ($$varepsilon$$-ZrHx and $$varepsilon$$-ZrDx: 1.8 $$<$$ x $$<$$ 2.0) were investigated by neutron radiography (NRG). The NRG images of the thermal neutron transmission and backscattering revealed hydrogen concentration dependence and isotope differences. The thermal neutron mass attenuation coefficients in relation to the hydrogen isotope concentrations were determined from the transmission NRG images. The results showed the isotope effects of the thermal neutron mass attenuation coefficients for $$varepsilon$$-ZrHx to be about 6-9 times higher than those for $$varepsilon$$-ZrDx. The neutron scattering processes for transmission and backscattering NRG images of $$varepsilon$$-ZrHx and $$varepsilon$$-ZrDx were also analyzed using a general Monte Carlo neutron-particle transport (MCNP) code.

113 (Records 1-20 displayed on this page)