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Ariga, Hirotake*; Katori, Taku*; Yoshihara, Ryohei*; Hase, Yoshihiro; Nozawa, Shigeki; Narumi, Issei; Iuchi, Satoshi*; Kobayashi, Masatomo*; Tezuka, Kenji*; Sakata, Yoichi*; et al.
Plant Signaling & Behavior (Internet), 8(7), p.e24779_1 - e24779_5, 2013/07
Based on analysis of the salinity tolerance among 354 accessions, some accessions showed greater salt shock tolerance compared with a reference accession, Col-0 on a typical assay with drastic change in NaCl concentration from 0 mM to 225 mM. On the other hand, several accessions including Zu-0 exhibited marked acquired salt tolerance, which is induced after exposure to moderate salt stress (salt acclimation ability). It is likely that Arabidopsis plants have at least two types of tolerance abilities, salt shock tolerance and salt acclimation. To dissect the salt tolerance mechanisms of the salt tolerant accessions, we isolated a salt-sensitive mutant from ion beam-mutagenized Zu-0 seedlings. The mutant showed severe growth inhibition under salt shock stress due to a single base deletion in SOS1 gene as well-known salt shock tolerance gene, even more salt sensitive than Col-0. Nevertheless, the mutant was able to survive on the salt acclimation with 100 mM NaCl for 7 days followed with 750 mM sorbitol for 20 days (salt acclimation assay) as well as the Zu-0 wild type, whereas Col-0 showed apparent chlorosis under the condition. We propose that a gene for salt acclimation ability is different from a gene for salt shock tolerance and plays an important role in acquisition for marked salt- or osmotic tolerance.
Tagawa, Akihiro; Tezuka, Masashi; Terakura, Yoshihiro*; Naito, Masayuki*; Miyajima, Kenji*
Proceedings of 21st International Conference on Nuclear Engineering (ICONE-21) (DVD-ROM), 6 Pages, 2013/07
It is one of the most urgent issues to remediate the nuclear power plants contaminated by radioactive materials discharged following the accident at the TEPCO's Fukushima Daiichi NPS. Concrete walls of nuclear power plants in Japan are coated an epoxy resin coating for easily performing decontamination. We experimented a cutting test in Fugen Decommissioning Engineering Center using maximum 280 MPa pressure and 30 L/min water quantity, ultra-high pressure water jet system and 40 m/min air quantity vacuum system. We are conducting a study of decontamination technology in environmental pollution using this decontamination system. This decontamination system has achieved a decontamination factor 10 to 100. Thus, we have confirmed the change in a cutting ability by changing parameters. Parameters are the water pressure, the water quantity and air quantity. The impact force for water jet is a function that contains the test parameters. We have considered it using this function. The results of the test showed that there is a correlation between the impact force for water jet and a cutting capability. This decontamination technology can decontaminate radioactive material of the surface adhesion contamination and reduce the amount of waste generated for a thin cutting. In addition, we have experimented that the water can be recycled by chemical precipitation. After we experimented flocculation test using aluminum sulfate and zeolite flocculant, we have confirmed that it can clean water up to the level of suspended solids 5 mg/L, in turbid water using zeolite flocculant. This suspended solids concentration can be passed to the water processing system in nuclear power plant. From the test results, we found that ultra-high pressure water jet decontamination technology has a possibility that it can be used for decontamination of Fukushima Daiichi Nuclear Power Plant.
Saito, Shigeru; Kikuchi, Kenji*; Hamaguchi, Dai; Tezuka, Masao*; Miyagi, Masanori*; Kokawa, Hiroyuki*; Watanabe, Seiichi*
Journal of Nuclear Materials, 431(1-3), p.91 - 96, 2012/12
Times Cited Count:13 Percentile:71.39(Materials Science, Multidisciplinary)To evaluate lifetime of structural materials for ADS, corrosion tests in LBE have been done at JAEA. The corrosion test was performed by using JAEA lead-bismuth flowing loop (JLBL-1). Experimental condition was as follows; The temperature of high and low temperature parts of the loop were 450C and 350C, respectively. Flowing velocity at the test specimens was about 1m/s. Plate type SS316L-BM and SS316L-GBEM were used as a specimens. After the 3,000 hours operation, the test specimens were cut and macroscopic observation was carried out. The result showed that both materials were intensively eroded. Corrosion depth and LBE penetration through grain boundaries of GBEM were smaller than these of 316SS-BM.
Rivai, A. K.*; Saito, Shigeru; Tezuka, Masao*; Kato, Chiaki; Kikuchi, Kenji*
Journal of Nuclear Materials, 431(1-3), p.97 - 104, 2012/12
Times Cited Count:10 Percentile:60.5(Materials Science, Multidisciplinary)In the present study, we applied 20% cold work (CW) treatment to JPCA austenitic stainless steel and investigated it from the corrosion behavior viewpoint. The corrosion test of 20% CW JPCA has been carried in the JLBL-1 (JAEA Lead-Bismuth Loop-1) apparatus. The maximum temperature and the exposure time of LBE were 450C and 1000 h, respectively. The results showed a different corrosion behavior between the JPCA without and with CW. As for the JPCA without CW, LBE penetrated into the matrix through a ferrite layer which was formed because of constituent metals dissolution from the matrix into LBE. As for the 20% CW JPCA, dissolution attack occurred only partially and formed localized superficial pitting corrosion. It was found that the different corrosion behavior occurred because the CW induced a structure transformation from -austenite to '-martensite and affected the corrosion resistance of the JPCA in flowing LBE at 450C.
Tsujimoto, Kazufumi; Nishihara, Kenji; Takei, Hayanori; Sugawara, Takanori; Kurata, Yuji; Saito, Shigeru; Obayashi, Hironari; Sasa, Toshinobu; Kikuchi, Kenji*; Tezuka, Masao; et al.
JAEA-Research 2010-012, 59 Pages, 2010/07
The design of an accelerator-driven system was modified and its feasibility was investigated on the basis of new data and knowledge for corrosion by lead-bismuth eutectic and irradiation behavior of candidate materials. The neutronics and thermal design was carried out and a modified core concept was established. As a result of evaluation for the integrity of fuel cladding tubes and a beam window, it was confirmed that their structural strength was sufficient under the conditions of design temperature and corrosion environment without irradiation. Though irradiation effects on material properties were considered not to be so serious under the practical conditions of the ADS according to existing irradiation data, it was needed to accumulate further experimental data for more detailed evaluation. According to level-1 PSA and dynamic analysis of beyond-design-basis accidents, it was shown that there was little possibility of core disruption and re-criticality accidents for ADS.
Kikuchi, Kenji; Saito, Shigeru; Hamaguchi, Dai; Tezuka, Masao; Obayashi, Hironari
Proceedings of 10th OECD/NEA Information Exchange Meeting on Actinide and Fission Product Partitioning and Transmutation (CD-ROM), p.315 - 320, 2010/00
R&Ds to know materials performance and its limit for usage applying to the beam window of ADS are conducted by irradiation material test and lead bismuth flowing loop tests. Proton irradiation experiment showed ductility reduction and off-set stress increase in austenitic steels. Fracture mode change in ferritic-martensitic steels, 8-9 Cr steels. Fatigue test is under way in the hot cell. Microstructure analyses found that many bubbles exist in the materials. The relation between mechanical strength and nano-scale observation results is studied now. Corrosion of the materials under the lead bismuth flows showed local erosion-corrosion. A visualization technique has developed by using ultrasonic Doppler method and surface vitalizing techniques to inspect a local flow condition. Thermal fluid experiment was conducted to know heat transfer performance at the beam window, which will affect thermal loading magnitude. Experimental formula was established for design work.
Takei, Hayanori; Ouchi, Nobuo; Sasa, Toshinobu; Hamaguchi, Dai; Kikuchi, Kenji*; Kurata, Yuji; Nishihara, Kenji; Obayashi, Hironari; Saito, Shigeru; Sugawara, Takanori; et al.
Proceedings of International Topical Meeting on Nuclear Research Applications and Utilization of Accelerators (CD-ROM), 11 Pages, 2009/05
JAEA has been promoting the research and development (R&D) on accelerator-driven subcritical system (ADS) as a dedicated system for the transmutation of long-lived radioactive nuclides. The ADS proposed by JAEA is a lead-bismuth eutectic (LBE) cooled, tank-type subcritical reactor with a thermal power of 800 MW driven by a superconducting linac. The R&D activities can be divided into two categories: one is the design study and technical development for a future large-scale ADS, and the other is the experimental programme at the Transmutation Experimental Facility (TEF) under the J-PARC (Japan Proton Accelerator Research Complex) project. As for the design study of the future ADS, the reliability of the accelerator is being investigated based on the data analysis of existing linac facilities. As for the technical development of the superconducting linac, fabrication and tests of prototype cryomodule were carried out, and its good performance was demonstrated. As for the TEF development, design study including experimental device to handle minor actinide fuels is being conducted.
Oigawa, Hiroyuki; Nishihara, Kenji; Sasa, Toshinobu; Tsujimoto, Kazufumi; Sugawara, Takanori; Iwanaga, Kohei; Kikuchi, Kenji; Kurata, Yuji; Takei, Hayanori; Saito, Shigeru; et al.
Proceedings of 5th International Workshop on the Utilisation and Reliability of High Power Proton Accelerators (HPPA-5), p.387 - 399, 2008/04
JAEA has been promoting the research and development on accelerator-driven subcritical system (ADS) as a dedicated system for the transmutation of long-lived radioactive nuclides. The ADS proposed by JAEA is a lead-bismuth eutectic cooled, tank-type subcritical reactor with the thermal power of 800 MWth driven by a 30 MW superconducting linac. As for the design study of the future ADS, reduction of the maximum temperature of fuel claddings and verification of the feasibility of the beam window are under way. As for the Transmutation Experimental Facility (TEF) of the J-PARC project, design study including experimental device to deal with minor actinide fuels is being conducted. To facilitate the research and development on ADS, a common road map is necessary to be shared by international communities. The TEF program can play an important role in such an international context as an experimental platform to conduct basic and flexible experiments.
Takahashi, Kenji*; Sakai, Shingo*; Tezuka, Hiroaki*; Hiejima, Yusuke*; Katsumura, Yosuke; Watanabe, Masayoshi*
Journal of Physical Chemistry B, 111(18), p.4807 - 4811, 2007/05
Times Cited Count:41 Percentile:69.06(Chemistry, Physical)Kikuchi, Kenji; Takeda, Yasushi*; Obayashi, Hiroo*; Tezuka, Masao*; Sato, Hiroshi
Journal of Nuclear Materials, 356(1-3), p.273 - 279, 2006/09
Times Cited Count:9 Percentile:57.07(Materials Science, Multidisciplinary)Measurements of LBE flow velocity profile were realized in the spallation target model by the ultrasonic Doppler velocity profile technique. Hitherto, it has not yet been done well because both of poor wetting property of LBE with stainless steels and poor performance of supersonic probes at high temperatures. Measurement was made for a return flow in the target model, which has coaxially arranged annular and tube channels. The electromagnetic pump generates LBE flow and the flow rate was measured by the electromagnetic flow meter. Measurement results show that re-circulation occurred near the surface of beam window, which might affect a heat transfer of target container.
Kikuchi, Kenji; Tezuka, Masao*; Saito, Shigeru; Oigawa, Hiroyuki; Takeda, Yasushi*
Proceedings of 4th International Symposium on Ultrasonic Doppler Method for Fluid Mechanics and Fluid Engineering (ISUD-4), p.107 - 110, 2004/09
When the steel is submerged into LBE, LBE will contact with the steel except for the interface among LBE, gas and metal where the surface energy controls the shape of the free surface in LBE. It is supposed that LBE will transmit ultrasonic wave into LBE through the contacting area. However, the ultrasonic echo was too low to detect from the steel container filled with LBE. The measurement was improved by coating the interface between the steel and LBE with the SnPb solder. After an immersion test the steel surface was covered with thin LBE layer. The thickness of the layer is only 10 to 20 micron m. So it will not disturb the flow pattern where UVP is applied. Sn was not detected by X ray analyses. This is an evidence how the steel was wetted in LBE and how the ultrasonic wave transmitted though the interface of LBE and the steel.
Kikuchi, Kenji; Saito, Shigeru; Hamaguchi, Dai; Tezuka, Masao*
no journal, ,
In order to establish LBE handling technology, which will be utilized as target of high energy incident protons, a change of chemical composition of circulated LBE in the loop, especially focused on the Fe Cr and Ni, was analyzed by ICP mass spectrometer. Portions of solidified LBE were sampled from the tube, specimens, filter, electromagnetic pump and so on. Consequently it is concluded that dissolved Fe and Cr were saturated in the LBE but not Ni done. Precipitation of Fe-Cr alloy resulted from the differential solubility at temperatures.
Kikuchi, Kenji; Saito, Shigeru; Hamaguchi, Dai; Tezuka, Masao
no journal, ,
JLBL-1 is a circulation loop of Pb-Bi. The loop was operated more than 9000 hrs. During an operation pieces of Pb-Bi are sampled from loop tube, test pieces, filter, electro-magnetic pump and valve. We observed Fe-Cr precipitation at lower temperature part. These materials are dissolved at high temperature part of test loop and transported to the lower temperature part. Interesting matter is how much materials are exited in the Pb-Bi. We analysed Fe, Cr and Ni in the portion of sampled Pb-Bi by ICP mass spectrometer and found that Cr and Fe was over the saturated valuesin LBE.
Kikuchi, Kenji; Tezuka, Masao; Yamamura, Tsutomu*
no journal, ,
Wetting experiment of Pb-Bi was done in the gold image furnace by changing temperatures up to 500 degree C. A piece of solid Pb-Bi was put on the plate made of aluminum, SS316L and cast iron. Shapes are observed by microscope and data was recorded by video system. Contacting angles between Pb-Bi and metal plate are meadured. Bad wetting was described by the order of Aluminum, SS316 and Cast iron. Bad wetting makes good corrosion resistenace but bad heat transfer. Wetting property is seemed to be a parameter to be compatible with Pb-Bi.
Hamaguchi, Dai; Kikuchi, Kenji; Saito, Shigeru; Oigawa, Hiroyuki; Tezuka, Masao*
no journal, ,
no abstracts in English
Obayashi, Hironari; Kikuchi, Kenji; Tezuka, Masao
no journal, ,
UVP is a powerful tool to measure an instantaneous space-time velocity profile especially on a velocity measurement of an opaque liquid flow, such as liquid metal. However, velocity measurement of high temperature liquid metal flow has not yet been done well because development of high-sensitive ultrasonic transducer used under the high temperature conditions more than 500 degrees centigrade is not enough. In this study, we proposed the transducer system that has the acoustic wave guide a measure devised to deal with this problem and evaluated materials to use for a wave guide by numerical calculation.
Kikuchi, Kenji; Tezuka, Masao*; Saito, Shigeru; Onizawa, Tatsuya*; Abe, Yuji*; Miura, Kuniaki*
no journal, ,
Solid-electrolyte oxygen-probe was developed for measurement of oxygen concentration in lead bismuth eutectic. The difference of the probe from conventional ones is that first reference electrolyte is iron oxide, secondly it is a cassette type model that can be a part of circulating pipe, and thirdly measuring temperature is below 400 C. Proto type probe was attached in the circulating PbBi loop of JAEA and measurement rest was done during about 8000 hrs. Oxygen concentration of the loop, with non-active oxygen control but PbBi was shielded from the air by high purity argon gas, was evaluated to be 1E-5 to 1E-2 wppm.
Saito, Shigeru; Kikuchi, Kenji; Hamaguchi, Dai; Tezuka, Masao; Miyagi, Masanori*; Kokawa, Hiroyuki*
no journal, ,
no abstracts in English
Kikuchi, Kenji; Saito, Shigeru; Hamaguchi, Dai; Tezuka, Masao
no journal, ,
JLBL-1 operation has been done over 18000 hrs to get design data for LBE spallation target in J-PARC facility. Interested materials are austenitic steel because electro-magnetic pump needed non-magnetized materials. The loop was made mainly by SS316 in order to know mass traveling in the closed system. The temperature difference was 50-100 C and flow rate was 1 m/s at the test section. Active control of oxygen concentration in the system was not done but inert gas was used to separate LBE from oxygen environment. Oxygen sensor was set up in the loop later. We experienced blockade of pass in the pump, mass transfer from hot parts to cold parts, precipitations of dissolved components from materials. Lead bismuth was sampled from the loop and replaced by new one. Electro-magnetic flow meter was inspected to take output change into consideration. Most important thing experienced hitherto was a find of erosion-corrosion in the narrow path at the high temperature test section.
Saito, Shigeru; Hamaguchi, Dai; Tezuka, Masao; Yamaki, Eriko*; Kikuchi, Kenji*
no journal, ,
no abstracts in English