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Kitazawa, Sin-iti*; Wakai, Eiichi; Aoto, Kazumi
Radiation Physics and Chemistry, 127, p.264 - 268, 2016/10
Times Cited Count：4 Percentile：36.53(Chemistry, Physical)The effects of annealing and double ion irradiation on nuclear structural materials were investigated using a novel, non-destructive, non-contact diagnostic method. A laser-induced and laser-detected surface acoustic wave (SAW) was adopted as a diagnostic system. The SAWs propagation velocity and the SAWs vibration velocity along the normal direction of the surface were measured to investigate mechanical properties of the substrates. Change of the shear modulus was detected in the annealed substrates. Non-linear effect on amplitude of the excited SAW was observed on the double ion irradiated materials. The potential of the SAW diagnostic system for assessing nuclear structural materials was demonstrated.
Aoto, Kazumi; Dufour, P.*; Hongyi, Y.*; Glats, J. P.*; Kim, Y.-I.*; Ashurko, Y.*; Hill, R.*; Uto, Nariaki
Progress in Nuclear Energy, 77, p.247 - 265, 2014/11
Times Cited Count：113 Percentile：99.53(Nuclear Science & Technology)Much of the basic technology for the Sodium-cooled fast Reactor (SFR) has been established through long term development experience with former fast reactor programs, and is being confirmed by the Ph
nix end-of-life tests, the restart of Monju, the lifetime extension of BN-600 and the startup of CEFR. Planned startup in 2014 for BN-800 and PFBR will further enhance the confirmation of the SFR basic technology. Nowadays, the SFR development has advanced to aiming at establishment of the Generation-IV system which is dedicated to sustainable energy generation and actinide management, and several advanced SFR concepts are under development. Generation-IV International Forum is an international collaboration framework where various R&D activities are progressing for the Generation-IV SFR development, and will play a beneficial role of promoting them thorough providing an opportunity to share the past experience and the latest data of design and R&D among countries developing SFR.
Saha, P.*; Aksan, N.*; Andersen, J.*; Yan, J.*; Simoneau, J. P.*; Leung, L.*; Bertrand, F.*; Aoto, Kazumi; Kamide, Hideki
Nuclear Engineering and Design, 264, p.3 - 23, 2013/11
Times Cited Count：36 Percentile：93.31(Nuclear Science & Technology)The paper archives the proceedings of an expert panel discussion on the issues and future direction of thermal-hydraulic research and development in nuclear power reactors held at the NURETH-14 conference in September 2011. Advances in thermal hydraulics have significantly improved the performance of operating reactors and are continuing in both experimental and computational areas for reactors under construction or ready for near-term deployment, and advanced Generation-IV reactors. As the computing power increases, the fine-scale multi-physics computational models, coupled with the systems analysis code, are expected to provide answers to many challenging problems in both operating and advanced reactor designs.
Aoto, Kazumi; Chikazawa, Yoshitaka; Okubo, Tsutomu; Okada, Keizo*; Ito, Takaya*
Proceedings of International Conference on Fast Reactors and Related Fuel Cycles; Safe Technologies and Sustainable Scenarios (FR-13) (USB Flash Drive), 10 Pages, 2013/03
Overview of Japan Sodium-cooled Fast Reactor (JSFR) development status and reflection of lessons learned from the TEPCO's Fukushima Dai-ichi Nuclear Power Plant (1F) accident have been summarized. JSFR was recognized as a promising next generation nuclear reactor. Even though the JSFR safety design already took into account measures against severe accident situations and passive safety features such as passive shutdown system and natural convection decay heat removal systems in the 2010 design version, it is become aware of importance of design measures against severe accidents and extreme external events by the 1F accident. As recent activities, external hazard evaluations and design improvements reflecting lessons learned from 1F accident have been conducted. This paper also discusses importance of development of global safety design criteria and international Research and Development cooperation on safety design measures.
Chikazawa, Yoshitaka; Aoto, Kazumi; Hayafune, Hiroki; Kotake, Shoji; Ono, Yushi; Ito, Takaya*; Toda, Mikio*
Nuclear Technology, 179(3), p.360 - 373, 2012/09
Times Cited Count：11 Percentile：63.41(Nuclear Science & Technology)Key technologies for Japan Sodium-cooled Fast Reactor (JSFR) have been evaluated. The ten technologies: high burn-up fuel, safety enhancement, compact reactor vessel, two-loop cooling system using high chromium steel, integrated intermediate heat exchanger/pump component, reliable steam generator, natural circulation decay heat removal system, simplified fuel handling system, containment vessel made of steel plate reinforced concrete and advanced seismic isolation system have been confirmed to be feasible to be installed a conceptual design of demonstration JSFR to be ready for large scale demonstration experiments.
Aoto, Kazumi; Uto, Nariaki; Sakamoto, Yoshihiko; Ito, Takaya*; Toda, Mikio*; Kotake, Shoji*
Proceedings of International Conference on Fast Reactors and Related Fuel Cycles (FR 2009) (CD-ROM), 11 Pages, 2012/00
In the FaCT project, SFR with 1,500 MWe is a target for the commercialization. R&D on innovative technologies to achieve the economic competitiveness and enhance the reliability and safety is carried out. A compact RV without wall-cooling layer is pursued in consideration of seismic reliability. For a two-loop cooling system with shortened high chromium steel piping, studies on the hydraulics in the pipe elbow and the fabrication capability of the pipes are being performed. A double-walled straight tube SG is investigated to enhance the reliability against sodium/water reaction, and developmental works are progressing including the thermal-hydraulic design and trial manufacturing for components. SASS is being developed with safety analysis of the applicability for JSFR and experimental demonstration in JOYO. An advanced fuel handling system is also pursued. Discussion on whether the innovative technologies can be adopted for JSFR is in progress to be finalized in 2010.
Nagae, Yuji; Takaya, Shigeru; Wakai, Eiichi; Aoto, Kazumi
Journal of Nuclear Materials, 414(2), p.205 - 210, 2011/07
Times Cited Count：3 Percentile：26.02(Materials Science, Multidisciplinary)Chikazawa, Yoshitaka; Aoto, Kazumi; Hayafune, Hiroki; Ono, Yushi; Kotake, Shoji; Toda, Mikio*; Ito, Takaya*
Proceedings of 2011 International Congress on Advances in Nuclear Power Plants (ICAPP '11) (CD-ROM), p.426 - 435, 2011/05
Key technologies for Japan Sodium-cooled Fast Reactor (JSFR) has been evaluated. The hot vessel, two-loop cooling system using high chromium steel, integrated intermediate heat exchanger/pump component, highly reliable steam generator, natural circulation decay heat removal system and improved in-service inspection and repair capability have been confirmed to be feasible as development items for the next stage.
Aoto, Kazumi; Uto, Nariaki; Sakamoto, Yoshihiko; Ito, Takaya*; Toda, Mikio*; Kotake, Shoji*
Journal of Nuclear Science and Technology, 48(4), p.463 - 471, 2011/04
In the FaCT project, SFR with 1,500 MWe is a target for the commercialization. R&D on innovative technologies to achieve the economic competitiveness and enhance the reliability and safety is carried out. A compact RV without wall-cooling layer is pursued in consideration of seismic reliability. For a two-loop cooling system with shortened high chromium steel piping, studies on the hydraulics in the pipe elbow and the fabrication capability of the pipes are being performed. A double-walled straight tube SG is investigated to enhance the reliability against sodium/water reaction, and developmental works are progressing including the thermal-hydraulic design and trial manufacturing for components. SASS is being developed with safety analysis of the applicability for JSFR and experimental demonstration in JOYO. An advanced fuel handling system is also pursued. Discussion on whether the innovative technologies can be adopted for JSFR is in progress to be finalized in 2010.
Takaya, Shigeru; Yamagata, Ichiro; Ichikawa, Shoichi; Nagae, Yuji; Aoto, Kazumi
International Journal of Applied Electromagnetics and Mechanics, 33(3-4), p.1335 - 1342, 2010/10
Times Cited Count：8 Percentile：45.71(Engineering, Electrical & Electronic)We newly developed a vibrating sample magnetometer (VSM) for neutron irradiated materials to investigate the relationship between neutron irradiation damage and magnetic property. The magnetization curves of type 316 stainless steels irradiated in a fast reactor JOYO, a light water reactor JRR-3M or both of them were measured. The ranges of dose and He content were about 0.1-1.8 dpa and 0.5-35 appm, respectively. As the result, it was revealed that the magnetization at 5 kOe increases monotonously with dose regardless of He content. This result shows the possibility of nondestructive evaluation of dose of structural materials by VSM measurement of surveillance samples.
Sakai, Takaaki; Kotake, Shoji; Aoto, Kazumi; Ito, Takaya*; Kamishima, Yoshio*; Oshima, Jun*
Proceedings of 2010 International Congress on Advances in Nuclear Power Plants (ICAPP '10) (CD-ROM), p.521 - 530, 2010/06
JAEA is now conducting "Fast Reactor Cycle Technology Development (FaCT)" project for the commercialization before 2050s. A demonstration reactor of Japan Sodium-cooled Fast Reactor (JSFR) is planned to start operation around 2025. In the FaCT project, conceptual design study on the demonstration reactor has been performed since 2007 to determine the referential reactor specifications for the next stage design work from 2011 for the licensing and construction. Plant performance as a demonstration reactor for the 1.5 GWe commercial reactor JSFR is being compared between 750 MWe and 500 MWe plant designs. By using the results of conceptual design study, output power will be determined during year of 2010. In this paper, current status of the conceptual design study will be summarized with related research and developments on plant technologies.
Sakamoto, Yoshihiko; Kotake, Shoji; Aoto, Kazumi; Toda, Mikio*
Proceedings of 18th International Conference on Nuclear Engineering (ICONE-18) (CD-ROM), 9 Pages, 2010/05
JAEA is now performing a FaCT project. The first milestone is in 2010; decisions about whether or not to adopt innovative technologies in the JSFR design will be made in the year. Preliminary assessment is underway to produce recommendations for final discussion. This paper describes some important progress in the preliminary assessment. As for the reactor system design, structural integrity against both thermal stress and seismic force was investigated. Then, the specification of the reactor system was established. Also, investigation of design options to extend a design margin against seismic force has been suggested. Regarding thermal hydraulics issues, design measures have been introduced to restrain cover gas entrainment and vortex cavitations. Further investigation is now in progress for design optimization or improvement of preventive effect. Concerning the piping design of primary cooling circuit, the creep strength reduction by Type-IV damage was taken into account.
Sakai, Takaaki; Kotake, Shoji; Aoto, Kazumi; Ito, Takaya*; Kamishima, Yoshio*; Oshima, Jun*
Proceedings of 18th International Conference on Nuclear Engineering (ICONE-18) (CD-ROM), 8 Pages, 2010/05
JAEA is now conducting "Fast Reactor Cycle Technology Development (FaCT)" project for commercialization before 2050s. A demonstration reactor for Japan Sodium-cooled Fast Reactor (JSFR) is planned to start operation around 2025. In the FaCT project, conceptual design study on the demonstration reactor has been performed since FY2007 to determine referential reactor specifications for the next stage of design work of licensing and construction study. Plant performance as a demonstration reactor for the 1.5 GWe commercial reactor JSFR is being compared between 750 MWe and 500 MWe plant designs. In this paper, the current status of the conceptual design study for the demonstration reactor plant is summarized.
Takaya, Shigeru; Yamagata, Ichiro; Ichikawa, Shoichi; Nagae, Yuji; Wakai, Eiichi; Aoto, Kazumi
Hozengaku, 9(1), p.51 - 56, 2010/04
The remote operated vibrating sample magnetometer (VSM) for neutron irradiated samples has been developed. The maximum range of applied magnetic field is more than 
0.5/
A/m, and the resolution of magnetization is higher than 5
10
A
m
. The hysteresis loops of neutron irradiated samples were measured by this VSM, and the relationships between dose, which is one of representative irradiation parameter, and magnetic properties such as magnetic coercive force were examined. As result, it was revealed that there are good correlations between them. This fact shows the possibility of nondestructive evaluation of irradiation damage by using VSM.
Kotake, Shoji; Sakamoto, Yoshihiko; Mihara, Takatsugu; Kubo, Shigenobu*; Uto, Nariaki; Kamishima, Yoshio*; Aoto, Kazumi; Toda, Mikio*
Nuclear Technology, 170(1), p.133 - 147, 2010/04
Times Cited Count：36 Percentile：91.14(Nuclear Science & Technology)Japan Atomic Energy Agency (JAEA) is now executing "Fast Reactor Cycle Technology Development (FaCT)" project in cooperation with the Japanese electric utilities. In the FaCT project, both the conceptual design study for Japan Sodium-cooled Fast Reactor (JSFR) and the developments of innovative technologies to be adopted to JSFR are now implemented with paying attention to the consistency between the design and the innovative technologies. The current target is that the development will be accomplished around 2015, after that a licensing procedure for the demonstration JSFR will be launched. This paper describes design requirements, design characteristics of JSFR and evaluation on the performances for economic competitiveness. Furthermore, the current status of the key technology development for JSFR is briefly introduced.
Matsui, Yoshinori; Takahashi, Hiroyuki; Yamamoto, Masaya; Nakata, Masahito; Yoshitake, Tsunemitsu; Abe, Kazuyuki; Yoshikawa, Katsunori; Iwamatsu, Shigemi; Ishikawa, Kazuyoshi; Kikuchi, Taiji; et al.
JAEA-Technology 2009-072, 144 Pages, 2010/03
JAEA-Technology-2009-072.pdf:45.01MB
"R&D Project on Irradiation Damage Management Technology for Structural Materials of Long-life Nuclear Plant" was carried out from FY2006 in a fund of a trust enterprise of the Ministry of Education, Culture, Sports, Science and Technology. The coupled irradiations or single irradiation by JOYO fast reactor and JRR-3 thermal reactor were performed for about two years. The irradiation specimens are very important materials to establish of "Evaluation of Irradiation Damage Indicator" in this research. For the acquisition of the examination specimens irradiated by the JOYO and JRR-3, we summarized about the overall plan, the work process and the results for the study to utilize these reactors and some facilities of hot laboratory (WASTEF, JMTR-HL, MMF and FMF) of the Oarai Research-and-Development Center and the Nuclear Science Research Institute in the Japan Atomic Energy Agency.
C in oxygen-containing flowing lead-bismuth eutecticSchroer, C.*; Konys, J.*; Furukawa, Tomohiro; Aoto, Kazumi
Journal of Nuclear Materials, 398(1-3), p.109 - 115, 2010/03
Times Cited Count：53 Percentile：95.31(Materials Science, Multidisciplinary)The long-term performance of P122 and ODS steel was tested in oxygen-containing flowing lead-bismuth eutectic at 550 C and a flow velocity of 2 m/s by means of exposure experiments in the CORRIDA loop of FZK. The target for the enrichment of dissolved oxygen was a concentration, c
, of 10
mass%. Owing to initial problems in controlling c, some of the exposed specimens experienced varying conditions, which allowed for investigating the influence of temporarily low c (down to 10
mass%), in addition to constantly high c (averaging 1.610mass%). Maximum exposure times at constantly high c were 10,000 and 20,000 h for P122 and the ODS steel, respectively. Under the testing conditions, both steels were affected by moderate oxidation resulting in the formation of a compact layer of a spinel-type oxide on the surface and a more or less pronounced internal oxidation zone. The thickness of the oxide scale was quantified and used for determining the material loss. For c = 10mass%, logarithmic and power rate laws were fitted to the obtained data as a basis for predicting the metal recession at times exceeding the experimental exposure times.
Takaya, Shigeru; Nagae, Yuji; Yoshitake, Tsunemitsu; Nemoto, Yoshiyuki; Nakano, Junichi; Ueno, Fumiyoshi; Aoto, Kazumi; Tsukada, Takashi
E-Journal of Advanced Maintenance (Internet), 1(1), p.44 - 51, 2009/05
As the result of comparing the magnetic flux density and the IASCC susceptibility evaluated by SSRT test on neutron irradiated model alloys, it was shown that there is the relation without depending on dose level and chemical compositions as long as the contribution of neutron irradiation to SCC was seen. Furthermore, measuring the magnetic flux density of unirradiated simulated degraded materials indicates that not only change in chemical compositions but also some defects are needed for the magnetic flux density to increase. These results show the possibility of non-destructive estimation of susceptibility to IASCC by measuring magnetic flux density.
Uto, Nariaki; Sakai, Takaaki; Mihara, Takatsugu; Toda, Mikio*; Kotake, Shoji; Aoto, Kazumi
Proceedings of 2009 International Congress on Advances in Nuclear Power Plants (ICAPP '09) (CD-ROM), p.9298_1 - 9298_11, 2009/05
A conceptual design for JSFR and developments of innovative technologies are implemented. A compact RV has been designed to enhance the economy. The regarding development results have been reflected to the RV design. An innovative CV design has been implemented with elemental tests to reduce the construction cost. SASS and the NC DHRS have been designed to enhance the safety, with the irradiation data acquired in Joyo and the development of a 3-dimensional thermal-hydraulic evaluation method. An approach for ISI/R has been provided to be applicable for FR characteristics, and the developmental studies on innovative inspection technologies have been progressed. Other technologies including double-walled pipes with short elbows, a pump-integrated IHX are also being developed. These results, together with a preliminary conceptual design study on a demonstrative reactor for JSFR, will be utilized as resources in 2010 to determine which innovative technologies should be adopted.
Takaya, Shigeru; Furukawa, Tomohiro; Aoto, Kazumi; M
ller, G.*; Weisenburger, A.*; Heinzel, A.*; Inoue, Masaki; Okuda, Takanari*; Abe, Fujio*; Onuki, Somei*; et al.
Journal of Nuclear Materials, 386-388, p.507 - 510, 2009/04
Times Cited Count：57 Percentile：96.28(Materials Science, Multidisciplinary)The corrosion resistance of ODS steels with 0
3.5 wt% Al and 13.717.3 wt% Cr and of a 12Cr steel were examined. The experiments were conducted at 550 and 650 C up to 3,000 h in stagnant LBE containing 10 and 10
wt% oxygen for the ODS steels and at 550 C up to 5,000 h in stagnant LBE containing 10 wt% oxygen for the 12Cr steel, respectively. Protective Al oxide scales were formed on the surfaces of ODS steels with about 3.5 wt% Al and 13.717.3 wt% Cr. The addition of Al is very effective to improve the corrosion resistance of ODS steels. The ODS steel with 16 wt% Cr and no Al does not show any corrosion resistance except for the specimen exposed to LBE with 10 wt% oxygen at 650 C. It is not expected to improve the corrosion resistance by increasing solely Cr content.
