Kawaguchi, Koichi; Segawa, Tomoomi; Yamamoto, Kazuya; Makino, Takayoshi; Iso, Hidetoshi; Ishii, Katsunori
Funtai Kogakkai-Shi, 57(9), p.478 - 484, 2020/09
A collision plate type jet mill is assumed to be a pulverizer that can control the particle size for nuclear fuel fabrication. The collision plate type jet mill consists of two modules, a classifier and a mill chamber. Coarse component of powder is cycled in the equipment and finally pulverized into objective particle size. In this report, simulated crushed powders were classified and pulverized step by step, and particle size distribution were compared. The collision plate type jet mil can produce objective size particles with low overgrinding.
Suzuki, Takayuki*; Yoshida, Hiroyuki; Horiguchi, Naoki; Yamamura, Sota*; Abe, Yutaka*
Proceedings of 2020 International Conference on Nuclear Engineering (ICONE 2020) (Internet), 7 Pages, 2020/08
Hamdani, A.; Abe, Satoshi; Ishigaki, Masahiro; Shibamoto, Yasuteru; Yonomoto, Taisuke
Proceedings of 18th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-18) (USB Flash Drive), p.5463 - 5479, 2019/08
Studer, E.*; Abe, Satoshi; Andreani, M.*; Bharj, J. S.*; Gera, B.*; Ishay, L.*; Kelm, S.*; Kim, J.*; Lu, Y.*; Paliwal, P.*; et al.
Proceedings of 12th International Topical Meeting on Nuclear Reactor Thermal-Hydraulics, Operation and Safety (NUTHOS-12) (USB Flash Drive), 16 Pages, 2018/10
Abe, Yuta; Nakagiri, Toshio; Watatani, Satoshi*; Maruyama, Shinichiro*
JAEA-Technology 2017-023, 46 Pages, 2017/10
This is a report on Abrasive Water Jet (AWJ) cutting work carried out on specimen, which was used for Simulated Fuel Assembly Heating Examination by Collaborative Laboratories for Advanced Decommissioning Science (CLADS) molten core behavior analysis group in February 2016. The simulated fuel assembly is composed of Zirconia for the outer crucible/simulated fuel, stainless steel for the control blade and Zircaloy (Zr) for the cladding tube/channel box. Therefore, it is necessary to cut at once substances having a wide range of fracture toughness and hardness. Moreover, it is a large specimen with an approximate size of 300 mm. In addition, epoxy resin has high stickiness, making it more difficult to cut. Considering these effects, AWJ cutting was selected. The following two points were devised, and this specimen could be cut with AWJ. If it was not possible to cut at one time like a molten portion of boride, it was repeatedly cut. By using Abrasive Suspension Jet (ASJ) system with higher cutting ability than Abrasive Injection Jet (AIJ, conventional method) system, cutting time was shortened. As a result of this work, the cutting method in Simulated Fuel Assembly Heating Examination was established. Incidentally, in the cutting operation, when the cutting ability was lost at the tip of the AWJ, a curved cut surface, which occurs when the jet flowed away from the feeding direction, could be confirmed at the center of the test body. From the next work, to improve the cutting efficiency, we propose adding a mechanism such as turning the cutting member itself for re-cutting from the exit side of the jet and appropriate traverse speed to protect cut surface.
Nakamura, Yasuyuki; Iwai, Hiroki; Tezuka, Masashi; Sano, Kazuya
JAEA-Technology 2015-055, 89 Pages, 2016/03
It was reported that Fukushima Daiichi Nuclear Power Station (1F) had lost the cooling function of the reactor by the Tohoku Earthquake. It is assumed that the core internals became narrow and complicated debris structure mixed with the molten fuel. In consideration of the above situations, the AWJ cutting method, which has features of the long work distance and little heat effect for a material, has been developed for the removal of the molten core internals through cutting tests for 3 years since FY 2012. And it was confirmed that AWJ cutting method is useful for the removal of the core internals etc. The results in FY 2012 were reported in "R&D of the fuel debris removal technologies by abrasive water jet cutting technology (JAEA-Technology 2013-041)" and this report summarizes the results of FY 2012, 2013 and 2014 in this report. It was confirmed the possibility to apply the removal work of the fuel debris and the core internals.
Shoji, Tsugio; Fukui, Yasutaka; Ueda, Takiho
JAEA-Technology 2015-035, 70 Pages, 2016/01
The plasma jet cutting technology (Max output current is 250A) is developed for the dismantling of nuclear facilities in Oarai Research and Development Center. The plasma jet cutting technology is applicable to take out the debris. The plasma jet torch (Max output current is 600A) was produced for this application. This torch is available for the cutting of thick core internal materials in water. The ability of taking out debris and core internal material has been confirmed.
Nakano, Tomohide; Shumack, A.*; Maggi, C. F.*; Reinke, M.*; Lawson, K.*; Coffey, I.*; Ptterich, T.*; Brezinsek, S.*; Lipschultz, B.*; Matthews, G. F.*; et al.
Journal of Physics B; Atomic, Molecular and Optical Physics, 48(14), p.144023_1 - 144023_11, 2015/07
The and 3p-4d inner shell excitation lines in addition to 2p-3s lines have been identified from the spectrum taken by an upgraded high-resolution X-ray spectrometer. It is found from analysis of the absolute intensities of the and lines that W and Mo concentrations are in the range of and , respectively, with a ratio of 5% for ELMy H-mode plasmas with a plasma current of 2.0- 2.5 MA, a toroidal magnetic field of 2.7 T and a neutral beam injection power of 14-18 MW. For the purpose of checking self-consistency, it is confirmed that the W concentration determined from the line is in agreement with that from the line within 20% and that the plasma effective charge determined from the continuum of the first order reflection spectrum is also in agreement with that from the second order within 50%. Further, the determined plasma effective charge is in agreement with that determined from a visible spectroscopy, confirming that the sensitivity of the X-ray spectrometer is valid and that probably the W and the Mo concentrations are also valid.
Ishii, Yasutomo; Matsunaga, Go
Purazuma, Kaku Yugo Gakkai-Shi, 90(10), p.641 - 643, 2014/10
Loading of the dust from JET (Joint European Torus) to DEMO R&D Building, holding of the joint research joint meeting regarding the BA prototype reactor design and safety, and the progress of the satellite tokamak (JT-60SA) plan are reported. The test sample, carbon and beryllium tiles coated tungsten on the surface, obtained in ITER simulated driving that performed in JET was brought into DEMO R&D building, Rokkasho Institute on August 18, 2014. Preparation of materials analysis has started. The joint research joint meeting of the BA prototype reactor design and safety was held in Rokkaho on July 30-31st. A lively discussion about the current situation and individual design task of Japan-EU prototype reactor design research has taken place. In addition to the JT-60SA tokamak body, the development of heating devices are also progressing well in Naka. To disseminate information to the domestic community a major event in the BA activities.
Garcia, J.*; Hayashi, Nobuhiko; Baiocchi, B.*; Giruzzi, G.*; Honda, Mitsuru; Ide, Shunsuke; Maget, P.*; Narita, Emi*; Schneider, M.*; Urano, Hajime; et al.
Nuclear Fusion, 54(9), p.093010_1 - 093010_13, 2014/09
Shimada, Hiroyuki*; Fukao, Taishi*; Minami, Hirotake*; Ukai, Masatoshi*; Fujii, Kentaro; Yokoya, Akinari; Fukuda, Yoshihiro*; Saito, Yuji
Journal of Chemical Physics, 141(5), p.055102_1 - 055102_8, 2014/08
Garcia, J.*; Hayashi, Nobuhiko; Giruzzi, G.*; Schneider, M.*; Joffrin, E.*; Ide, Shunsuke; Sakamoto, Yoshiteru; Suzuki, Takahiro; Urano, Hajime; JT-60 Team; et al.
Europhysics Conference Abstracts (Internet), 38F, p.P1.029_1 - P1.029_4, 2014/06
Moriyama, Kiyofumi; Nakamura, Hideo; Maruyama, Yu*
Nuclear Engineering and Design, 236(19-21), p.2010 - 2025, 2006/10
A computer code JASMINE-pre was developed for the prediction of premixing conditions of fuel-coolant interactions and the debris bed formation behavior relevant to severe accidents of light water reactors. JASMINE-pre consists of three melt component models: melt jet, melt particles and melt pool, coupled with a two-phase flow model derived from the ACE-3D code developed at JAERI. Simulations of the FARO corium quenching experiments with a saturated water pool and with a subcooled water pool were performed with JASMINE-pre and . JASMINE-pre reproduced the pressurization and fragmentation behaviors observed in the experiments with a reasonable accuracy. The results by pmjet showed qualitatively the same trend with JASMINE-pre in the fragmentation behavior.
La Haye, R. J.*; Prater, R.*; Buttery, R. J.*; Hayashi, Nobuhiko; Isayama, Akihiko; Maraschek, M. E.*; Urso, L.*; Zohm, H.*
Nuclear Fusion, 46(4), p.451 - 461, 2006/04
no abstracts in English
Nakamura, Hirofumi; Higashijima, Satoru
Shinku, 49(2), p.62 - 68, 2006/02
no abstracts in English
Stober, J.*; Lomas, P. J.*; Saibene, G.*; Andrew, Y.*; Belo, P.*; Conway, G. D.*; Herrmann, A.*; Horton, L. D.*; Kempenaars, M.*; Koslowski, H.-R.*; et al.
Nuclear Fusion, 45(11), p.1213 - 1223, 2005/11
no abstracts in English
Futakawa, Masatoshi; Naoe, Takashi*; Kogawa, Hiroyuki; Date, Hidefumi*; Ikeda, Yujiro
JSME International Journal, Series A, 48(4), p.234 - 239, 2005/10
Mercury target will be installed at the material science and life facility in J-PARC, which will promote innovative science. The mercury target will be subjected to the pressure wave caused by proton bombarding in the mercury. The pressure wave propagation induces the cavitation in mercury that imposes localized impact damage on the target vessel. The impact erosion is a critical issue to decide the lifetime of target. An electromagnetic impact testing machine, MIMTM, was developed to reproduce the localized impact erosion damage and evaluate the damage formation. Additionally, droplet impact analyses were carried out to investigate the correlation between isolate pit profile and micro-jet velocity. We confirmed that the value of depth/radius was applicable to estimate micro-jet velocity, and the velocity at 560 W in MIMTM equivalent to 1MW proton beam injection was 300 m/s approximately.
Tanabe, Tetsuo*; Sugiyama, Kazuyoshi*; Coad, P.*; Bekris, N.*; Glugla, M.*; Miya, Naoyuki
Journal of Nuclear Materials, 345(2-3), p.89 - 95, 2005/10
no abstracts in English
Asai, Masato; Tsukada, Kazuaki; Sakama, Minoru*; Ichikawa, Shinichi; Ishii, Tetsuro; Nagame, Yuichiro; Nishinaka, Ichiro; Akiyama, Kazuhiko; Osa, Akihiko; Oura, Yasuji*; et al.
Physical Review Letters, 95(10), p.102502_1 - 102502_4, 2005/09
Excited states in Fm fed by the decay of No have been established through - and -electron coincidence spectroscopy using a gas-jet transport system and an on-line isotope separator. The spin-parity of the 124.1 keV level in Fm has been identified on the basis of the measured internal conversion coefficients. The configuration has been assigned to the ground state of No as well as to the 124.1 keV level. It was found that the ground state configuration of No is different from that of lighter isotones.
Moriyama, Kiyofumi; Maruyama, Yu; Usami, Tsutomu*; Nakamura, Hideo
JAERI-Research 2005-017, 173 Pages, 2005/08
A series of experiments on the break-up of high temperature oxide and steel melt jets in a water pool was conducted. The objective was to obtain data for the jet break-up length and size distribution of the droplets produced by the jet break-up, and information on the influence of material properties. Also, we tried to obtain additional information giving a clue to the mechanism governing the melt jet break-up, such as flow intensity of the steam column surrounding the melt jet, and its relation with the droplet size. In the experiments, zirconia-alumina mixture and stainless steel melt jets with diameter 17mm and velocity 7.8m/s at the water surface were dropped into a deep (2.1m) or shallow (0.6m) water pool with various subcool. From the results of the present experiments and also by referring other experimental data from literature, we obtained empirical correlation equations for the jet break-up length, the fraction of jet broken-up in a shallow pool where the jet was not completely broken-up, and the droplet size.