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Hirose, Takanori; Nozawa, Takashi; Stoller, R. E.*; Hamaguchi, Dai; Sakasegawa, Hideo; Tanigawa, Hisashi; Tanigawa, Hiroyasu; Enoeda, Mikio; Kato, Yutai*; Snead, L. L.*
Fusion Engineering and Design, 89(7-8), p.1595 - 1599, 2014/10
Times Cited Count：50 Percentile：96.16(Nuclear Science & Technology)The material properties, focusing on the properties used for design analysis were re-assessed and newly investigated for various heats including F82H-IEA. Moreover, irradiation effects on those properties were studied in this work. As for thermal properties, thermal conductivity that has significant impacts on the thermo-hydraulic properties of the blanket was investigated on several heats of F82H including F82H-IEA. According to the measurements, the thermal conductivity falls in the range 28.3
1.1 W/m/K at 293 K. Although this is comparable with that of the other ferritic/martensitic steels, it is 20% lower than the published value for F82H-IEA. The re-assessment on the published value revealed that the thermal diffusivity was over-estimated. As for irradiation effects on the physical properties, electric resistivity was measured after irradiation up to 6 dpa at 573 K and 673 K. The reduction of resistivity in F82H and its welds were 3% and 6%, respectively.
Saito, Shigeru; Kikuchi, Kenji*; Hamaguchi, Dai; Endo, Shinya; Sakuraba, Naotoshi; Miyai, Hiromitsu; Kawai, Masayoshi*; Dai, Y.*
Journal of Nuclear Materials, 450(1-3), p.27 - 31, 2014/07
Times Cited Count：1 Percentile：8.00(Materials Science, Multidisciplinary)no abstracts in English
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：16 Percentile：72.91(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 450
C 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.
Saito, Shigeru; Kikuchi, Kenji*; Hamaguchi, Dai; Usami, Koji; Endo, Shinya; Ono, Katsuto; Matsui, Hiroki; Kawai, Masayoshi*; Dai, Y.*
Journal of Nuclear Materials, 431(1-3), p.44 - 51, 2012/12
Times Cited Count：3 Percentile：23.63(Materials Science, Multidisciplinary)To evaluate the lifetime of the beam window of an accelerator-driven transmutation system (ADS), post irradiation examination (PIE) of the STIP (SINQ target irradiation program, SINQ; Swiss spallation neutron source) specimens was carried out. The specimens tested in this study were made from the austenitic steel JPCA (Japan primary candidate alloy). The specimens were irradiated at SINQ Target 4 (STIP-II) with high-energy protons and spallation neutrons. The irradiation conditions were as follows: the proton energy was 580 MeV, irradiation temperatures ranged from 100 to 430C, and displacement damage levels ranged from 7.1 to 19.5 dpa. Tensile tests were performed in air at room temperature (R.T.), 250C and 350C. Fracture surface observation after the tests was done by SEM (Scanning electron microscope). Results of the tensile tests performed at R.T. showed the extra hardening of JPCA at higher dose compared to the fission neutron irradiated data. At the higher temperatures, 250C and 350C, the extra hardening was not observed. Degradation of ductility bottomed around 10 dpa, and specimens kept their ductility until 19.5 dpa. All specimens fractured in ductile manner. The result from a microstructure observation on a specimen irradiated to 19.3 dpa at 420C indicates that some agglomeration of bubbles on grain boundaries was observed in the specimen irradiated to 19.3 dpa at 420C. However the tensile specimen irradiated up to 18.4 dpa at 425C still exhibited little loss of ductility. Since He/dpa was very high on SINQ target irradiations, the formation of highly dense small bubbles in the matrix consequently avoided the accumulation of He on grain boundaries, which might have resulted in avoiding grain boundary embrittlement.
Saito, Shigeru; Kikuchi, Kenji*; Hamaguchi, Dai; Usami, Koji; Ishikawa, Akiyoshi; Nishino, Yasuharu; Endo, Shinya; Kawai, Masayoshi*; Dai, Y.*
Journal of Nuclear Materials, 398(1-3), p.49 - 58, 2010/03
Times Cited Count：6 Percentile：39.00(Materials Science, Multidisciplinary)In several institutes, R&D for an ADS have been progressed. Ferritic / martensitic (F/M) steels are the candidate material for the beam window. To obtain the irradiation data, the PIE work of the SINQ target irradiation program (STIP) specimens was carried out at JAEA. In this study, the results of PIE on F/M steel F82H and its welded joint will be reported. The results of tensile tests indicate that the irradiation hardening occurred with increasing dpa up to 10.1 dpa below 320C irradiation. At higher dose (- 11.8 dpa) and higher temperature (- 380C), irradiation hardening and degradation of ductility relaxed. In this study, all specimens kept its ductility after irradiation and fractured in ductile manner. The fatigue life of F82H base metal is almost the same as that of unirradiated specimens. Though the number of specimen is limited, the fatigue life of F82H EB welded joints seems to increase after irradiation. The fracture surfaces of the specimens showed transgranular morphology. While F82H TIG welded specimens were not fractured by 10
cycles.
Saito, Shigeru; Hamaguchi, Dai; Usami, Koji; Endo, Shinya; Ono, Katsuto; Matsui, Hiroki; Kikuchi, Kenji*; Kawai, Masayoshi*; Yong, D.*
Proceedings of 1st International Workshop on Technology and Components of Accelerator-driven Systems (TCADS-1) (Internet), 9 Pages, 2010/03
The research and development for an accelerator-driven system (ADS) to transmute minor actinide (MA) have been progressed. The target beam window of ADS submerged in the reactor will be subjected to high-energy proton and spallation neutron irradiation. To evaluate mechanical properties of irradiated materials, post irradiation examination (PIE) of the STIP (SINQ target irradiation program) specimens was carried out at JAEA. In the present study, PIE on austenitic steels JPCA and Alloy800H irradiated at SINQ target 4 (STIP-II) was conducted. Austenitic steels are preferable as the material for the target beam window of ADS from the view point of DBTT shift, which should be taken into consideration for ferritic / martensitic steels. The irradiation conditions were as follows: proton energy was 580 MeV, irradiation temperatures were ranged from 100 to 450C, and displacement damage levels were ranged from 6.5 to 19.5 dpa. Tensile tests were performed in air at R.T. to 350C. Results of the tensile tests performed at R.T. indicate that irradiation hardening occurred with increasing displacement damage level up to 10 dpa. At higher doses, irradiation hardening seemed to tend to saturate. Degradation of ductility was bottomed around 10 dpa and specimens kept its ductility until 19.5 dpa. All the specimens fractured in ductile manner.
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.
Kikuchi, Kenji; Hamaguchi, Dai; Saito, Shigeru
Materia, 47(12), P. 635, 2008/12
TEM observation on austenitic stainless steel irradiated by proton beam was reported. Two cases were studied; those are 10 dpa, 623 K and 800 appm, and 20 dpa. 693 K and 1800 appm in irradiation damage, irradiated temperature and Helium gas production, respectively. The results showed that bubbles are formed homogeneously in the matrix and the bubble size is averagely 2.5 nm. Swelling volume is calculated to be less than 0.1% by the bubbles size and the bubble density.
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.
Oigawa, Hiroyuki; Nishihara, Kenji; Tsujimoto, Kazufumi; Takei, Hayanori; Kikuchi, Kenji; Kurata, Yuji; Saito, Shigeru; Mizumoto, Motoharu; Sasa, Toshinobu; Sugawara, Takanori; et al.
Proceedings of 9th OECD/NEA Information Exchange Meeting on Actinide and Fission Product Partitioning and Transmutation, p.371 - 382, 2007/00
JAEA has been conducting the R&D on accelerator-driven subcritical system (ADS) as a dedicated system for the transmutation of long-lived radioactive nuclides. The ADS can co-exist with FBR symbiotically and complementarily to enhance the reliability and the safety of the commercial FBR cycle. The R&D activities in JAEA include neutronics, thermal-hydraulic and structural design, transient analysis in case of beam trips, development of spallation target using Pb-Bi, research on the materials, and cost estimation. In addition, the high-intensity proton accelerator project J-PARC is under construction. One of the main experimental facilities of the J-PARC is the Transmutation Experimental Facility (TEF), which is assigned as Phase-II of the project.
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.
Katakabe, Yoichi*; Sugano, Ryuichiro*; Iwakiri, Hirotomo*; Hamaguchi, Dai; Iwai, Takeo*; Yoshida, Naoaki*
no journal, ,
no abstracts in English
Hamaguchi, Dai; Kikuchi, Kenji; Saito, Shigeru; Endo, Shinya; Yong, D.*
no journal, ,
The microstructural evolutions on austenitic stainless steel JPCA irradiated in SINQ target was investigated. JPCA is Ti-modified type-316 base austenitic stainless steel for reduced swelling, and is one of the candidate materials for the structural material on Japanese ADS. Specimens were irradiated in STIP-I and STIP-II with 580MeV proton. For the sample irradiated to 5.7dpa at 150C on STIP-I, only high density of small loops and black dot defects were observed. The density of the loops did not increase significantly with doses and temperatures, which was around 7
10
m
, but the size increased from around 15nm at 5.7dpa to 25nm at 19.5dpa on STIP-II irradiated sample. On the other hand, formation of high density small He bubbles with a size of about 2 to 3nm and a density around 1 to 410
m were observed for the samples irradiated more than 7.9dpa at above 200C. The densities of the bubbles did not significantly change with doses but the sizes slightly decreased. The helium concentration for the sample with the dose of 7.9dpa was about 600appm, and for the highest dose sample with 19.5dpa was about 1600appm. The formation of bubbles on JPCA was observed at lower temperature compared to EC316LN on STIP-I irradiated samples. This might due to the Ti modification, since Ti in steel is known to be an over-size element and prefer to combine with vacancies, which leads to shorten the incubation period for cavity formation.
Saito, Shigeru; Kikuchi, Kenji; Hamaguchi, Dai; Usami, Koji; Ishikawa, Akiyoshi; Nishino, Yasuharu; Endo, Shinya; Kawai, Masayoshi*; Yong, D.*
no journal, ,
In several institutes, research and development for an accelerator-driven transmutation system have been progressed. Ferritic/martensitic steels are the candidate material for the beam window. To obtain the irradiation data, the PIE work of the SINQ target irradiation program (STIP) specimens was carried out at JAEA. In this study, the results of PIE on F82H and its welded joint will be reported. The tensile tests were performed for F82H EB and TIG welded specimens. The results indicate that all specimens kept its ductility after 10 dpa irradiation and fractured in ductile manner. The fatigue life of F82H base metal is almost the same as that of unirradiated specimens. Though the number of specimen is limited, the fatigue life of F82H EB (15mm and 3.3mm) welded joints seems to increase after irradiation. The fracture surfaces of the specimens showed transgranular morphology. While F82H TIG welded specimens were not fractured by 10 cycles.
Katakabe, Yoichi*; Sugano, Ryuichiro*; Iwakiri, Hirotomo*; Hamaguchi, Dai; Iwai, Takeo*; Yoshida, Naoaki*
no journal, ,
no abstracts in English
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; Saito, Shigeru; Hamaguchi, Dai; Endo, Shinya; Usami, Koji
no journal, ,
Spallation materials research was started in the mid of 1990s in order to have design data for constructing MW grade spallation neutron source facilities. Irradiation materials experiments were conducted by using the existing high-energy accelerator facility at PSI, under the worldwide cooperation. As a result spallation material showed less ductility and larger DBTT shift than neutron irradiation materials. Spallation materials are characterized by the higher concentration of residual He gas in the materials. Bubbles are also observed in the irradiated samples. It is essential to have an accurate evaluation of He gas production rate both numerically and experimentally.
Tanigawa, Hiroyasu; Hamaguchi, Dai; Sakasegawa, Hideo; Shiba, Kiyoyuki; Ando, Masami; Jitsukawa, Shiro
no journal, ,
The structural material development for DEMO breeding blanket is one of the important factors on the path to fusion power. Reduced activation ferritic/martensitic (RAFM) steels, such as F82H (Fe-8Cr-2W-V,Ta), are now being considered as the first candidate materials in the DEMO reactor, and it is expected to have sound engineering bases, such as fabrication technology and materials database including irradiation data base. It is also important to develop design methodology of fusion neutron irradiated structure These issues have recently been identified as the key R&D issues on materials engineering for DEMO blanket under the International Fusion Energy Research Centre (IFERC) project in the Broader Approach (BA) activities between EU and Japan. This paper presents issues and current status of Japanese activities of the R&D on RAFM steels in the first phase (2007-2009).
Kikuchi, Kenji; Hamaguchi, Dai; Saito, Shigeru; Endo, Shinya; Yong, D.*
no journal, ,
Residual hydrogen and helium gases in the materials irradiated in SINQ were measured by two different methods. The results showed that the amount of residual helium gas was within a factor two. For the case of TEM specimens the residual helium gas was scattered within a couple of tens percent in comparison with published data. Residual hydrogen could not be quantified because of measuring accuracy.
