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Natsume, Kyohei; Murakami, Haruyuki; Kizu, Kaname; Yoshida, Kiyoshi; Koide, Yoshihiko
IOP Conference Series; Materials Science and Engineering, 101(1), p.012113_1 - 012113_8, 2015/12
Times Cited Count：2 Percentile：65.53(Thermodynamics)Tatsumoto, Hideki; Shirai, Yasuyuki*; Shiotsu, Masahiro*; Naruo, Yoshihiro*; Kobayashi, Hiroaki*; Nonaka, Satoshi*; Inatani, Yoshifumi*
IOP Conference Series; Materials Science and Engineering, 101, p.012177_1 - 012177_8, 2015/12
Times Cited Count：0 Percentile：0.05(Thermodynamics)Transient heat transfers from PtCo wire heaters inserted into vertically-mounted pipes, through which forced flow subcooled liquid hydrogen was passed, were measured by increasing the exponential heat input with various time periods at a pressure of 0.7 MPa and inlet temperature of 21 K. The flow velocities ranged from 0.3 to 7 m/s. The PtCo wire heaters had a diameter of 1.2 mm and lengths of 60 mm, 120 mm and 200 mm and were inserted into the pipes with diameters of 5.7mm, 8.0 mm, and 5.0 mm, respectively. With increase in the heat flux to the onset of nucleate boiling, surface temperature increased along the curve predicted by the Dittus-Boelter correlation for longer period, where it can be almost regarded as steady-state. For shorter period, the heat transfer became higher than the Dittus-Boelter correlation. In nucleate boiling regime, the heat flux steeply increased to the transient critical heat flux (CHF), which became higher for shorter period. Effect of flow velocity, period, and heated geometry on the transient CHF was clarified.
Tatsumoto, Hideki; Aso, Tomokazu; Otsu, Kiichi; Kawakami, Yoshihiko; Aoyagi, Katsuhiro; Muto, Hideki
IOP Conference Series; Materials Science and Engineering, 101, p.012107_1 - 012107_8, 2015/12
Times Cited Count：0 Percentile：0.05(Thermodynamics)The Japan Proton Accelerator Research Complex (J-PARC) cryogenic hydrogen system was completed in April 2008. The proton beam power was gradually increased to 500 kW. A trial 600-kW proton beam operation was successfully completed in April 2015. We achieved long-lasting operation for more than three months. However, thus far, we encountered several problems such as unstable operation of the helium refrigerator because of some impurities, failure of a welded bellows of an accumulator, and hydrogen pump issues. Furthermore, the Great East Japan Earthquake was experienced during the cryogenic hydrogen system operation in March 2011. In this study, we describe the operation characteristics and our experiences with the J-PARC cryogenic hydrogen system.
Tatsumoto, Hideki; Otsu, Kiichi; Aso, Tomokazu; Kawakami, Yoshihiko
IOP Conference Series; Materials Science and Engineering, 101, p.012109_1 - 012109_8, 2015/12
Times Cited Count：1 Percentile：0.05(Thermodynamics)The J-PARC cryogenic hydrogen system provides supercritical cryogenic hydrogen to the moderators at a pressure of 1.5 MPa and temperature of 18 K and removes 3.8 kW of nuclear heat from the 1 MW proton beam operation. We prepared a heater for thermal compensation and an accumulator, with a bellows structure for volume control, to mitigate the pressure fluctuation caused by switching the proton beam on and off. In this study, a 1-D simulation code named DiSC-SH2 was developed to understand the propagation of pressure and temperature propagations through the hydrogen loop due to on and off switching of the proton beam. We confirmed that the simulated dynamic behaviors in the hydrogen loop for 300-kW and 500-kW proton beam operations agree well with the experimental data under the same conditions.
Tatsumoto, Hideki; Aso, Tomokazu; Otsu, Kiichi; Kawakami, Yoshihiko
IOP Conference Series; Materials Science and Engineering, 101, p.012108_1 - 012108_8, 2015/12
Times Cited Count：0 Percentile：0.05(Thermodynamics)Supercritical hydrogen with a temperature of less than 20 K and a pressure of 1.5 MPa is used as moderator material at J-PARC. Total nuclear heating of 3.75 kW is generated by three moderators for a 1-MW proton beam operation. We have developed an orifice-type high-power heater for thermal compensation to mitigate hydrogen pressure fluctuation caused by the abrupt huge heat load and to reduce the fluctuation in the temperature of the supply hydrogen to less than 0.25 K. Through a performance test, we confirmed that the developed orifice-type heater could be heated uniformly and showed fast response, as expected. Furthermore, a simulation model that can describe heater behaviors has been established on the basis of the experimental data. The heater control approach was studied using the aforementioned heater simulation model and a dynamic simulation code developed by the authors.
Ozeki, Hidemasa; Saito, Toru; Kawano, Katsumi; Takahashi, Yoshikazu; Nunoya, Yoshihiko; Yamazaki, Toru; Isono, Takaaki
Physics Procedia, 67, p.1010 - 1015, 2015/07
Times Cited Count：3 Percentile：73.17(Physics, Applied)Saito, Toru; Kawano, Katsumi; Yamazaki, Toru; Ozeki, Hidemasa; Isono, Takaaki; Hamada, Kazuya*; Devred, A.*; Vostner, A.*
Physics Procedia, 67, p.1016 - 1021, 2015/07
Times Cited Count：6 Percentile：87.17(Physics, Applied)Sakurai, Takeru; Iguchi, Masahide; Nakahira, Masataka; Saito, Toru*; Morimoto, Masaaki*; Inagaki, Takashi*; Hong, Y.-S.*; Matsui, Kunihiro; Hemmi, Tsutomu; Kajitani, Hideki; et al.
Physics Procedia, 67, p.536 - 542, 2015/07
Times Cited Count：3 Percentile：73.17(Physics, Applied)Japan Atomic Energy Agency (JAEA) has developed the tensile strength prediction method at liquid helium temperature (4K) using the quadratic curve as a function of the content of carbon and nitrogen in order to establish the rationalized quality control of the austenitic stainless steel used in the ITER superconducting coil operating at 4K. ITER is under construction aiming to verify technical demonstration of a nuclear fusion generation. Toroidal Field Coil (TFC), one of superconducting system in ITER, have been started procurement of materials in 2012. JAEA is producing materials for actual product which are the forged materials with shape of rectangle, round bar, asymmetry and etc. JAEA has responsibility to procure all ITER TFC Structures. In this process, JAEA obtained many tensile strength of both room temperature and 4K about these structural materials, for example, JJ1: High manganese stainless steel for structure (0.03C-12Cr-12Ni-10Mn-5Mo- 0.24N) and 316LN: High nitrogen containing stainless steel (0.2Nitrogen). Based on these data, accuracy of 4K strength prediction method for actual TFC Structure materials was evaluated and reported in this study.
Tatsumoto, Hideki; Otsu, Kiichi; Aso, Tomokazu; Kawakami, Yoshihiko; Teshigawara, Makoto
AIP Conference Proceedings 1573, p.66 - 73, 2014/01
Times Cited Count：6 Percentile：92.61(Thermodynamics)The J-PARC cryogenic hydrogen system provides supercritical hydrogen provides to three moderators. A heater for the thermal compensation and a cryogenic accumulator are prepared to mitigate a pressure fluctuation. A feed temperature should be lower than 20 K and its fluctuation should be within 0.25 K to provide cold pulsed neutron beams of a higher neutronic performance. An ortho-para hydrogen convertor is installed to maintain the para-hydrogen concentration of more than 99.0%. In this study, it is confirmed that para-hydrogen always exists in the equilibrium concentration during the cool-down process. Propagation characteristics of temperature fluctuation caused by sudden heater power variations were studied. An allowable temperature fluctuation caused by the heater control approach is determined to be 1.05 K. It is found that the heater control would be applicable for the 1-MW proton beam operation by extrapolating from the experimental data for on-beam commissioning.
Tatsumoto, Hideki; Shirai, Yasuyuki*; Shiotsu, Masahiro*; Hata, Koichi*; Naruo, Yoshihiro*; Kobayashi, Hiroaki*; Inatani, Yoshifumi*
AIP Conference Proceedings 1573, p.44 - 51, 2014/01
Times Cited Count：13 Percentile：97.93(Thermodynamics)Heat transfers from the inner side of vertically-mounted heated pipes to forced flow of saturated liquid hydrogen were measured with a quasi-steady increase of a heat generation rate for wide ranges of flow rate and saturated pressure. The tube heaters have lengths L of 100 mm and 167 mm with the diameter D of 4 mm and lengths of 150 mm and 250 mm with the diameter of 6 mm. The heat fluxes at departure from nucleate boiling (DNB) were higher for higher flow velocity, lower pressures and shorter L/D. The effect of L/D on the DNB heat flux was clarified. It is confirmed that our DNB correlation can describe the experimental data.
Kamiya, Koji; Furukawa, Masato; Hatakenaka, Ryuta*; Miyakita, Takeshi*; Murakami, Haruyuki; Kizu, Kaname; Tsuchiya, Katsuhiko; Koide, Yoshihiko; Yoshida, Kiyoshi
AIP Conference Proceedings 1573, p.455 - 462, 2014/01
Times Cited Count：5 Percentile：90.51(Thermodynamics)The thermal shield of JT-60SA is kept at 80 K and will use the Multi Layered Insulator (MLI) to reduce radiation heat load to the superconducting coils at 4.4 K from the cryostat at 300 K. Due to plasma pulse operation, the MLI is affected by eddy current in toroidal direction. The MLI is designed to suppress the current by electrically insulating every 20 degree in the toroidal direction by covering the MLI with polyimide films. In this paper, two kinds of designs for insulated MLI are proposed focusing on a way to overlap MLI. A boil-off calorimeter method and temperature measurement has been performed to determine the thermal performance of MLI. The design of electrical insulated thermal anchor between the toroidal field (TF) coil and the thermal shield is also explained.
Hemmi, Tsutomu; Nishimura, Arata*; Matsui, Kunihiro; Koizumi, Norikiyo; Nishijima, Shigehiro*; Shikama, Tatsuo*
AIP Conference Proceedings 1574, p.154 - 161, 2014/01
Times Cited Count：6 Percentile：92.61(Thermodynamics)Japan Atomic Energy Agency (JAEA), as Japan Domestic Agency, has responsibility to procure 9 ITER Toroidal Field (TF) coils. The insulation system of the ITER TF coils consists of 3 layers of insulations, which are a conductor insulation, a double-pancake (DP) insulation and a ground insulation, composed of multi-layer glass/polyimide tapes impregnated a resin. The ITER TF coils are required to withstand an irradiation of 10 MGy from 
-ray and neutrons since the ITER TF coils is exposed by first neutron (
0.1 MeV) of 10
n/m
during the operation of 20 years in the ITER. Cyanate-ester/epoxy blended resins and bonded glass/polyimide tapes are developed as insulation materials to realize the required radiation-hardness for the insulation of the ITER TF coils. To evaluate the radiation-hardness of the developed insulation materials, the inter-laminar shear strength of glass-fiber reinforced plastics (GFRP) fabricated using developed insulation materials is measured as one of most important mechanical properties before/after the irradiation in a fission reactor of JRR-3. As a result, it is demonstrated that the GFRPs using the developed insulation materials have a sufficient performance to apply the ITER TF coil insulation.
Hamada, Kazuya; Kawano, Katsumi; Saito, Toru; Iguchi, Masahide; Nakajima, Hideo; Teshima, Osamu*; Matsuda, Hidemitsu*
AIP Conference Proceedings 1435, p.55 - 62, 2012/06
Times Cited Count：3 Percentile：73.59(Physics, Applied)The TF coil conductor was composed of 900 Nb
Sn superconducting strands and 522 Cu strands protected by circular sheath tube (jacket) with the outer diameter of 43.7 mm. The jacket section is a seamless tube made of modified 316LN. JAEA tested different types of tensile specimen (Japanese Industrial Standards (JIS) type and ASTM type) cut from jacket. ASTM type specimen has longer and wider reduced section than those of JIS type specimen. Elongation of as received condition is not dependent on specimen shape. But after cold work and aging, the elongation is deteriorated due to a sensitization and scattering of elongation is larger than that of as received condition. Fracture mode of aged jacket is "cup and cone fracture", which have a mixture of inter granular at center area and trans-granular factures in circumference area. It is considered that initiation of fracture is more sensitive on test specimen shape with low ductility.
Iguchi, Masahide; Saito, Toru; Kawano, Katsumi; Takano, Katsutoshi; Tsutsumi, Fumiaki; Chida, Yutaka; Nakajima, Hideo
AIP Conference Proceedings 1435, p.70 - 77, 2012/06
Times Cited Count：2 Percentile：63.55(Physics, Applied)A prediction method for tensile strengths at liquid helium temperature (4K) has been developed in order to rationalize qualification tests of cryogenic structural materials used in large superconducting magnet for a fusion device. This method is to use quadratic curves which are expressed as a function of carbon and nitrogen contents and strengths at room temperature. This study shows results of tensile tests at 4K and confirmation of accuracy of prediction method for tensile strengths at 4K for large forgings and thick hot rolled plates of austenitic stainless steels, which can be used in the actual coil case and radial plates of the ITER toroidal field coils. These products are 316LN having high nitrogen from 0.09 to 0.24% and maximum thickness is 600mm. As the results, it was confirmed that the tensile strengths of these products at 4K can be predicted by using appropriate quadratic curves. And distribution of strengths for each product was estimated.
Hamada, Kazuya; Kawano, Katsumi; Ebisawa, Noboru; Nakajima, Hideo; Yano, Yoshitaka*; Yamaguchi, Takanori*
Proceedings of 24th International Cryogenic Engineering Conference (ICEC 24) and International Cryogenic Materials Conference 2012 (ICMC 2012) (CD-ROM), p.559 - 562, 2012/05
The Japan Atomic Energy Agency (JAEA) has the responsibility to procure 25% of the ITER Toroidal Field Coil conductors and 100% of Central Solenoid Conductor as the Japanese Domestic Agency (JADA) in the ITER project. The TF conductor is composed of 900 NbSn superconducting strands and 522 Cu strands protected by a circular sheath tube (jacket) with an outer diameter of 43.7 mm. The TF conductor has a central spiral cooling tube and a coolant flows into the cable space and the central channel in parallel. JAEA has measured a pressure drop characteristic of more than 20 TF conductors having different length using nitrogen gas at room temperature as a part of acceptance test. The measurement results are normalized to friction factor as a function of Reynolds number to check the difference of each other. The results show the normalized pressure drop characteristic is same among conductors. This is one of evidences that TF conductor is manufactured uniformly.
Kamiya, Koji; Onishi, Yoshihiro; Ichige, Toshikatsu; Furukawa, Masato; Murakami, Haruyuki; Kizu, Kaname; Tsuchiya, Katsuhiko; Yoshida, Kiyoshi; Mizumaki, Shoichi*
Proceedings of 24th International Cryogenic Engineering Conference (ICEC 24) and International Cryogenic Materials Conference 2012 (ICMC 2012) (CD-ROM), p.587 - 590, 2012/05
The JT-60 plans to be upgraded to a full-superconducting tokamak referred as the JT-60 Super Advance (JT-60SA) as one of the JA-EU broader approach projects. In the JT-60SA, the superconducting magnets are surrounded by thermal shield cooled at 80 K, which is categorized into 3 groups; the vacuum vessel thermal shield (VVTS), the port thermal shield (PTS) and the cryostat thermal shield (CTS). In this study, seismic analysis was conducted for the thermal shield to confirm the soundness of the latest design, taking the dynamical analysis into account. Trial manufacturing of a 10 degree outer VVTS was also conducted. The outer VVTS was subsequently assembled with already existing inner VVTS to measure the total tolerance (manufacturing plus assembly). It was found that the total tolerance was 5.2 mm which is less than the target tolerance of 10 mm. Finally, concept and the current status of the JT-60SA cryodistribution design are reported.
Murakami, Haruyuki; Kizu, Kaname; Ichige, Toshikatsu; Kamiya, Koji; Tsuchiya, Katsuhiko; Yoshida, Kiyoshi; Obana, Tetsuhiro*; Hamaguchi, Shinji*; Takahata, Kazuya*; Yanagi, Nagato*; et al.
Proceedings of 24th International Cryogenic Engineering Conference (ICEC 24) and International Cryogenic Materials Conference 2012 (ICMC 2012) (CD-ROM), p.575 - 578, 2012/05
The JT-60U magnet system will be upgraded to the superconducting coils (JT-60SA) in the Broader Approach (BA) project. The JT-60SA magnet system has 18 Toroidal Field (TF) coils, a Central Solenoid (CS) with 4 modules and 6 Equilibrium Field (EF) coils. The CS conductors are designed with NbSn cable in conduit (CIC) conductor because the magnetic field of CS is up to 8.9 T. The short CS conductor was manufactured and processed into the performance verification test sample. The Tcs test results indicate that the initial Tcs of the CS conductor is about 2 K higher than the minimum requirement of the conductor design. In addition the Tcs after the repetition excitation is more important issues for the CS conductor because the CS conductor is made of NbSn strand. The Tcs changes with the repetition excitation and the influence of the warm up and cool down process on the Tcs were measured. The test results show that there is no degradation while the repetition excitation tests. The AC loss test of the CS conductor was also performed for precise estimation of the conductor heat loads. The Tcs margin analysis of the CS conductor was conducted based on the latest conductor heat loads. The analysis results show that the CS conductor has enough Tcs margin during the JT-60SA operation. These results show that the design and the manufacturing process of the CS conductor satisfy its requirements. Thus CS conductors for the CS1 module have been manufactured on the mass production process. In this paper, the Tcs test, the repetition excitation test, the AC loss test and the Tcs margin analysis of the CS conductor are described.
Sugimoto, Masahiro*; Kosugi, Keizo*; Katayama, Kota*; Ii, Hideki*; Takagi, Akira*; Endo, Sakaru*; Shimizu, Hitoshi*; Tsubouchi, Hirokazu*; Kizu, Kaname; Yoshida, Kiyoshi
Proceedings of 24th International Cryogenic Engineering Conference (ICEC 24) and International Cryogenic Materials Conference 2012 (ICMC 2012) (CD-ROM), p.799 - 802, 2012/05
We have successfully manufactured all superconducting cables for CS and EF coils of JT-60SA. The low temperature performance of superconducting wires satisfied the specifications under sufficiently low deviations and high production yields. Ni-plated strands of EF cables having the larger sliding friction between strands than that of Cr-plated strands of CS cable caused difficulties on the cabling without any defects. Consequently, the newly developed cabling techniques with the original inspection apparatus significantly enhanced the manufacturability and were effective for guarantee of the quality.
Tatsumoto, Hideki; Shirai, Yasuyuki*; Shiotsu, Masahiro*; Hata, Koichi*; Naruo, Yoshihiro*; Kobayashi, Hiroaki*; Inatani, Yoshifumi*; Narita, Norihiko*
Proceedings of 24th International Cryogenic Engineering Conference (ICEC 24) and International Cryogenic Materials Conference 2012 (ICMC 2012) (CD-ROM), p.157 - 160, 2012/05
The heat transfer in a forced flow of saturated liquid hydrogen was measured using vertically-mounted heated pipes with an inner diameter d of 6.0 mm and lengths L of 50, 100, 200 and 250 mm for wide ranges of flow velocity and pressure. The heat fluxes at departure from nucleate boiling were higher for higher flow velocities, lower pressures and shorter L. The effect of L on the DNB heat flux was clarified and could be described by the modified authors' DNB correlation.
Hasegawa, Mitsuru*; Horii, Hiroyuki*; Nomoto, Kazuhiro*; Imai, Yoshio*; Murai, Takashi*; Minato, Tsuneaki*; Kuno, Kazuo*; Tsuchiya, Katsuhiko; Murakami, Haruyuki; Kizu, Kaname; et al.
Proceedings of 24th International Cryogenic Engineering Conference (ICEC 24) and International Cryogenic Materials Conference 2012 (ICMC 2012) (CD-ROM), p.571 - 574, 2012/05
JT-60U magnet system will be upgraded to the superconducting coils (JT-60SA) in the Broader Approach project. JT-60SA magnet system has 18 Toroidal Field coils, a Central Solenoid with 4 modules and 6 Equilibrium Field (EF) coils. This paper describes the manufacturing procedure of EF4 coil, that is the first manufactured EF coil of JT-60SA. The winding pack of EF4 coil was successfully manufactured within geometrical tolerance requirements.
