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Sugita, Yutaka; Taniguchi, Naoki; Makino, Hitoshi; Kanamaru, Shinichiro*; Okumura, Taisei*
Nihon Genshiryoku Gakkai Wabun Rombunshi, 19(3), p.121 - 135, 2020/09
A series of structural analysis of disposal containers for direct disposal of spent fuel was carried out to provide preliminary estimates of the required pressure resistance thickness of the disposal container. Disposal containers were designed to contain either 2, 3 or 4 spent fuel assemblies in linear, triangular or square arrangements, respectively. The required pressure resistance thickness was evaluated using separation distance of the housing space for each spent fuel assembly as a key model parameter to obtain the required thickness of the body and then the lid of the disposal container. This work also provides additional analytical technical knowledge, such as the validity of the setting of the stress evaluation line and the effect of the model length on the analysis. These can then be referred to and used again in the future as a basis for conducting similar evaluations under different conditions or proceeding with more detailed evaluations.
Oigawa, Hiroyuki; Tsujimoto, Kazufumi; Kikuchi, Kenji; Kurata, Yuji; Sasa, Toshinobu; Umeno, Makoto*; Nishihara, Kenji; Saito, Shigeru; Mizumoto, Motoharu; Takano, Hideki*; et al.
Proceedings of 4th International Workshop on the Utilisation and Reliability of High Power Proton Accelerators, p.325 - 334, 2005/11
The Japan Atomic Energy Research Institute (JAERI) is conducting the research and development (R&D) on the Accelerator-Driven Subcritical System (ADS) for the effective transmutation of minor actinides (MAs). The ADS proposed by JAERI is the 800 MWth, Pb-Bi cooled, tank-type subcritical reactor loaded with (MA+Pu) nitride fuel. The Pb-Bi is also used as the spallation target. In this study, the feasibility of the ADS was discussed with putting the focus on the design around the beam window. The partition wall was placed between the target region and the ductless-type fuel assemblies to keep the good cooling performance for the hot-spot fuel pin. The flow control nozzle was installed to cool the beam window effectively. The thermal-hydraulic analysis showed that the maximum temperature at the outer surface of the beam window could be repressed below 500 
C even in the case of the maximum beam power of 30 MW. The stress caused by the external pressure and the temperature distribution of the beam window was also below the allowable limit.
Takeda, Nobukazu; Nakahira, Masataka
JAERI-Tech 2004-073, 59 Pages, 2005/01
JAERI-Tech-2004-073.pdf:11.36MB
The ITER toamak is composed of major components such as superconducting magnet and vacuum vessel whose operation temperatures are changed from room temperature to 4 K and room temperature to 200C, respectively. The gravity support of the tokamak is flexible in order to accept the thermal deformation caused by temperature change. This structural feature causes the complex behaviors of the tokamak during seismic events. Therefore, the mechanical characteristics of the flexible support have to be investigated in detail. The present report describes the global plan of the series of vibration tests to estimate the seismic performance of the ITER tokamak. Although it is ideal that the vibration tests are carried out using a full-scale model, scale models are planned due to the limitation of the test facilities. The test results can be estimated by a scaling law. When the scaling law cannot be applied to some performances, the test is performed using a full-scale model. In addition, the other tests such as vacuum vessel and small-scaled models of the support structure are also planned.
Tachibana, Yukio; Iyoku, Tatsuo
Nuclear Engineering and Design, 233(1-3), p.261 - 272, 2004/10
Times Cited Count：23 Percentile：79.66(Nuclear Science & Technology)no abstracts in English
Sakaba, Nariaki; Nakagawa, Shigeaki; Furusawa, Takayuki; Tachibana, Yukio
JAERI-Tech 2004-045, 67 Pages, 2004/04
JAERI-Tech-2004-045.pdf:4.74MB
Safety demonstration tests using the HTTR are now underway in order to verify the inherent safety features and to improve the safety design and evaluation technologies for HTGRs, as well as to contribute to research and development for the VHTR, which is one of the Generation IV reactors. In the safety demonstration tests, the coolant flow reduction test by tripping one or two out of three gas circulators is being performed between FY2002 and FY 2005 and by tripping all the three gas circulators will be conducted after FY2006. This paper describes the structural integrity assessment of the primary pressurised water cooler after one and two gas circulators run down. Also, the possibility of natural convection in the primary coolant after all the three gas circulator stopped was evaluated by the operation data of the reactor-scram test performed during the rise-to-power tests.
Ishikura, Shuichi*; Futakawa, Masatoshi; Kogawa, Hiroyuki; Meigo, Shinichiro; Maekawa, Fujio; Harada, Masahide; Sato, Hiroshi; Haga, Katsuhiro; Ikeda, Yujiro
JAERI-Tech 2004-028, 123 Pages, 2004/03
JAERI-Tech-2004-028.pdf:9.55MB
This report describes the structural design concept applied to the mercury target vessel used for the spallation neutron source installed in the material and life science experiment facility of J-PARC (Japan Proton Accelerator Complex), and the results evaluated on the basis of the concept. The features of the design concept are as follows: (1) The target vessel design is followed to "Law concerning Prevention from Radiation Hazards due to Radio-Isotopes". That is because (i) there is not the possibility in the target of the RIA (Reactivity Initiated Accident) generally considered in the nuclear power reactors, and (ii) the target vessel is not a permanent structure. (2) Therefore, the Class 1 Vessel of the JIS B-8270 [design code for pressure vessel] that is equivalent to a standard for nuclear power structural design is applicable as a design code for the target to sufficiently keep the safety of target system. The stresses for the design were evaluated using the linear elastic analysis based on the infinitesimal strain theory in order to confirm the safe and rational design.
Hanawa, Satoshi; Ishihara, Masahiro; Shibata, Taiju
Transactions of 17th International Conference on Structural Mechanics in Reactor Technology (SMiRT-17) (CD-ROM), 6 Pages, 2003/08
From a viewpoint of advanced design method of graphite components, it is important to apply the realistic fracture model in the design method. The applicability of the microstructure based brittle fracture model under multiaxial stress condition was, therefore, investigated. The fracture model is possible to treat grain size as well as pore size with fracture mechanics approach taking account of the crystal structure of the graphite. The model was applied to the biaxial strength prediction of near isotropic nuclear graphite using grain/pore related microstructural parameters. Prediction results were compared with biaxial strength data obtained by simultaneous loadings of inner pressure and longitudinal load with thin-walled cylindrical specimen. From this study, it was found that the fracture model predicted fairly good not only mean strength but also strength distribution under biaxial stress condition, and it was concluded that the microstructure based brittle fracture model would be applicable as the advanced design method.
Teraoku, Takuji*; Terada, Atsuhiko*; Maekawa, Fujio; Meigo, Shinichiro; Kaminaga, Masanori; Ishikura, Shuichi*; Hino, Ryutaro
JAERI-Tech 2003-026, 77 Pages, 2003/03
JAERI-Tech-2003-026.pdf:19.78MB
A 1-MW spallation neutron source aiming at materials and life science researches will be constructed under the JAERI-KEK Proton Accelerator Project(J-PARC). The proton beam window functions as a boundary wall between a high vacuum area and a helium atmosphere and it is cooled by light water because high heat-density is generated in the window material by interactions with the proton beam. Then, uniformity of the water flow is requested at the window to suppress a hot-spot that causes excessive thermal stress and cooling water boiling. Also, the window has to be strong enough in its structure for inner stress due to water pressure and thermal stress due to heat generation. In this report, we propose two types of proton beam windows, flat-type and curved-type. We evaluated the strength of structure and thermal hydraulic analysis. As a result, it was found that sufficient heat removal was assured with uniform water flow at the window, and the stress could be maintained below allowable stress values. Accordingly, it was confirmed that the proton beam window designs were feasible.
Takeda, Takeshi; Tachibana, Yukio; Nakagawa, Shigeaki
JAERI-Tech 2002-091, 45 Pages, 2002/12
JAERI-Tech-2002-091.pdf:1.77MB
no abstracts in English
Tada, Eisuke; Hada, Kazuhiko; Maruo, Takeshi; Safety Design/Evaluation Group
Purazuma, Kaku Yugo Gakkai-Shi, 78(11), p.1145 - 1156, 2002/11
no abstracts in English
Onishi, Ryoichi*; ; ; Guo, Z.*
Koku Uchu Gjutsu Kenkyujo Tokubetsu Shiryo, p.265 - 269, 1998/02
no abstracts in English
; ;
JAERI-Data/Code 96-031, 53 Pages, 1996/11
JAERI-Data-Code-96-031.pdf:1.82MB
no abstracts in English
Hishinuma, Akimichi
Purazuma, Kaku Yugo Gakkai-Shi, 70(7), p.697 - 703, 1994/07
no abstracts in English
; ; Kume, Etsuo
JAERI-M 91-197, 42 Pages, 1991/11
no abstracts in English
Nishiguchi, Isoharu; Tachibana, Yukio; Motoki, Yasuo; Shiozawa, Shusaku
JAERI-M 90-152, 31 Pages, 1990/09
no abstracts in English
Inagaki, Yoshiyuki; Iyoku, Tatsuo; ; ; Shiozawa, Shusaku
JAERI-M 90-020, 70 Pages, 1990/02
no abstracts in English
; ; Sanokawa, Konomo
Nihon Genshiryoku Gakkai-Shi, 23(7), p.470 - 476, 1981/00
Times Cited Count：0 Percentile：0.00(Nuclear Science & Technology)no abstracts in English
;
Oyo Kikai Kogaku, 20(10), p.24 - 29, 1979/00
no abstracts in English
Atsuryoku Gijutsu, 13(5), p.264 - 271, 1975/05
no abstracts in English
Tachibana, Yukio
no journal, ,
Japan Atomic Energy Agency (JAEA) has started the development of a domestic demonstration reactor based on the results of R&D activities conducted so far. In this presentation, an overview of the HTGR project, materials and operating conditions of HTTR high-temperature components will be presented, especially focusing on the development of intermediate heat exchangers and Hastelloy XR, and high-temperature structural design guidelines for HTGR Class 1 components will be introduced. In addition, future issues will be discussed.
