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Zhou, L.*; Zhang, H.*; Qin, T. Y.*; Hu, F. F.*; Xu, P. G.; Ao, N.*; Su, Y. H.; He, L. H.*; Li, X. H.*; Zhang, J. R.*; et al.
Metallurgical and Materials Transactions A, 11 Pages, 2024/00
Times Cited Count：0Tanaka, Masaaki; Miyake, Yasuhiro*
Nihon Kikai Gakkai M&M 2015 Zairyo Rikigaku Kanfarensu Koen Rombunshu (Internet), 3 Pages, 2015/11
A prototype coupling method consisting of the fluid-structure thermal interaction simulation code MUGTHES and the structural thermal stress analysis code FINAS with interface program MUFIN has been developed in order to estimate the thermal fatigue in the SFRs. As a fundamental validation of the coupled method, it was applied to the water experiment for thermal mixing phenomena in a T-junction piping system. In the experiment, thermal interaction between the fluid and the structure made of aluminum installed to the branch pipe side wall was considered. Through the numerical simulations, applicability of the coupled method was confirmed.
Tanaka, Masaaki; Miyake, Yasuhiro*; Karakida, Yasuhisa*
Proceedings of 2nd International Conference on Maintenance Science and Technology (ICMST-Kobe 2014), p.79 - 80, 2014/11
A coupled method of fluid-structure thermal interaction simulation and thermal stress analysis has been developed through the interface program to carry out direct numerical estimation of the thermal fatigue. The prototype method was applied to the thermal mixing phenomena in T-junction Piping System.
Tsuchiya, Katsuhiko; Kizu, Kaname; Takahashi, Hiroyuki*; Ando, Toshinari*; Matsukawa, Makoto; Tamai, Hiroshi
IEEE Transactions on Applied Superconductivity, 16(2), p.922 - 925, 2006/06
Times Cited Count：1 Percentile：11.95(Engineering, Electrical & Electronic)no abstracts in English
Nishihara, Tetsuo; Sakaki, Akihiro*; Inagaki, Yoshiyuki; Takami, Kazuo*
Nihon Genshiryoku Gakkai Wabun Rombunshi, 3(4), p.381 - 387, 2004/12
JAERI has been carried out research and development on the HTTR hydrogen production system. One of the key components in this system is a high temperature isolation valve (HTIV) installed on the hot helium gas piping penetrating the reactor containment vessel. Angle valve with inner thermal insulator was selected for HTIV and conceptual design was performed. The structural integrity of HTIV was clarified by the stress analyses. Allowable helium leak rate of HTIV was discussed. Helium leak tests using small-scaled valve seat models were performed to decide the seat surface shape and valve closing force. The test results show that the leak rate of wedge shape seat increased in proportion to the number of simulated temperature and stress cycles loaded on the seat models before helium leak test, however that of flat seat did not depend on the number of cycles. So flat seat is adopted for HTIV. It was found that the seat closing force of 30 MPa is reasonable to meet the allowable helium leak rate.
Tsuchiya, Katsuhiko; Kizu, Kaname; Miura, Yushi; Ando, Toshinari*; Sakasai, Akira; Matsukawa, Makoto; Tamai, Hiroshi; Ishida, Shinichi
IEEE Transactions on Applied Superconductivity, 14(2), p.1427 - 1430, 2004/06
Times Cited Count：1 Percentile：11.57(Engineering, Electrical & Electronic)no abstracts in English
Yamada, Susumu; Shimizu, Futoshi; Kaji, Yoshiyuki; Kaburaki, Hideo
Keisan Kogaku Koenkai Rombunshu, 7(1), p.167 - 170, 2002/05
no abstracts in English
Nishi, Hiroshi; Eto, Motokuni; Tachibana, Katsumi; Koizumi, Koichi; Nakahira, Masataka; Takahashi, Hiroyuki*
Fusion Engineering and Design, 58-59, p.869 - 873, 2001/11
Times Cited Count：2 Percentile：19.66(Nuclear Science & Technology)no abstracts in English
Moriai, Atsushi; Onodera, Akifumi*; Amita, Fujitsugu*; Otomo, Akitoshi; Minakawa, Nobuaki
Journal of the Physical Society of Japan, Vol.70, Supplement A, p.531 - 533, 2001/05
no abstracts in English
Takago, S.*; Sasaki, Toshihiko*; Minakawa, Nobuaki; Morii, Yukio; Hirose, Yukio*
Nihon Zairyo Gakkai Dai-36-Kai X Sen Zairyo Kyodo Ni Kansuru Shimpojiumu Koen Rombunshu, p.266 - 271, 2000/09
no abstracts in English
Tsukimori, Kazuyuki; Furuhashi, Ichiro*
JNC TN9400 2000-049, 93 Pages, 2000/03
JNC-TN9400-2000-049.pdf:2.82MB
lt is one of the important key points to reduce thermal stress of the primary piping system in the design of sodium coolant loop-type FBR plants. The objectives of this study are to understand the characteristics of the thermal stresses in the simple S-shaped hot leg piping systems which run from the outlet nozzle of the reactor vessel (R/V) to the inlet nozzle of the intermediate heat exchanger (IHX), and to propose some recommendable routings of piping systems. Results are summarized as follows. (1)Generally, the thermal stresses in elbows are severer than those at nozzles. The tendency was observed that the stress in elbow decreases with the increase of the distance between the outlet nozzle of R/V and the inlet nozzle of IHX and also the distance between the outlet nozzle of R/V and the liquid surface level. (2)lt is expected to reduce thermal stresses in elbow to big extent by adopting super 90 degree elbows. Therefore, in these cases the dimension region which satisfies the allowable stress is broad compared with that in the case of the conventional 90 degree elbow. (3)The stress estimations in elbow based on 'MITl notice No.501' become excessively large compared with the results by FEA using shell elements, when the maximum stress occurs at the end of elbow. ln these cases, the estimation can be rationalized by replacing the maximum stress by the mean of stresses at the end and at the middle of the elbow. (4)Two routings with 105 degree elbows are recommended. 0ne has the advantage from the view point of reduction of length of pipe and the other does from the view point of reduction of thermal stresses, compared with the routing with 90 degree elbows.
*;
JNC TN9400 2000-047, 114 Pages, 2000/03
JNC-TN9400-2000-047.pdf:8.25MB
Prediction of weld residual stresses by a general finite element code is beneficial to the improvement of the accuracy of integrity assessment and residual life assessment of FBR plants. This reports develops an evaluation method of weld residual stresses using FINAS. Firstly, we suggested a basic procedure derived from parametric analyses with a simple weld joint model. The procedure can be summarized as follows: (1)For heat conduction analysis, prepare different models corresponding to the number of layers to be modeled. Hand over the analytical results to the following model. (2)Use multi-linear stress-strain curves for modeling the stress-strain response of base metal and weld metal. Use the isotropic hardening rule. (3)When metals are melt, use a user-subroutine to keep stresses from arising. (4)Put the thermal expansion coefficient as zero when heat is being input. Then, using the above procedure and TIG welding, we predicted the weld residual stresses of plate and tube. The results agreed well with the other reports, showing the suggested procedure was reasonable.
Mori, Koji*; Neyama, Atsushi*; Nakagawa, Koichi*
JNC TJ8400 2000-064, 175 Pages, 2000/03
JNC-TJ8400-2000-064.pdf:5.23MB
In this study, the following tasks have been performed in order to evaluate the stability of earthquake resistance for the engineered barrier system(EBS) of High Level Waste (HLW) geological isolation system. (1)validation studies for the liquefaction model. The function of single-phase analysis without interaction between soil and pore water in three-dimensional effective stress analysis code, which had been developed in this study, have been verified using by actual vibration test data. This fiscal year, some validation studies for the function of liquefaction analysis was conducted usig by actual measured data through the laboratory liquefaction test. (2)Supplemental Studies for JNC Second Progress Report. Through the JNC second progress report, it was considered that the stability of earthquake resistance of the engineered barrier system would be maintained under the major seismic event. At the same time we have recognized that several model parameters for joint-crack element, which takes into account for the response behavior of material discontinuous surface such as between overpack and buffer material, will become important in the response behavior of the whole EBS. This year, we have studied about several topics, which arise from technical discussion on JNC second progress report and we have discussed about total seismic stability of EBS. (3)Supplemental Studies for joint study with NRIDP. At this fiscal year, the joint study with National Research Institute for Disaster Prevention (NRIDP) will be final stage. UP to this day, incremental validation studies had been continued using by mesuared data obtained from vibration test. In this final stage, validation analysis has been conducted again using by current version new analysis code and maintained the validation data which will be contribute to the joint study mentioned above.
Uwaba, Tomoyuki; ;
JNC TN9400 2000-006, 50 Pages, 1999/11
JNC-TN9400-2000-006.pdf:2.17MB
In the fast reactor the swelling of the fuel cladding occur due to the irradiation. Under the irradiation, the temperature gradient of the cladding through the direction of its thickness causes the swelling gradient and this will cause the secondary stress. In this study, we analyzed this secondary stress using the finite element model of the irradiation induced deformation of the cladding by FINAS code. The result of this analysis is summarized as follows. (1)The secondary stress is mainly caused by the gradient of the incubation period of the swelling, The secondary stress becomes very small at the end of irradiation due to the relieving of the stress by the irradiation creep deformation accelerated by the swelling. (2)The calculated maximum stress including the secondary stress under the irradiation is compared with the design value of the ultimate tensile strength for PNC316 for trial. The calculated value are lower than the design value. (3)The effect of the swelling accelerated by the stress is analyzed using the correlation between the swelling and the stress. The result shows that the increasing of the secondary stress due to the acceleration of the swelling is very small because the irradiation creep deformation relieves the stress more effectively by the acceleration of the irradiation creep rate due to the swelling.
*; *; Tanai, Kenji
JNC TN8400 99-048, 85 Pages, 1999/11
This paper reports the results of design analysis and trial manufacturing of full-scale titanium-carbon steel composite overpacks. The overpack is one of the key components of the engineered barrier system, hence, it is necessary to confirm the applicability of current technique in their manufacture. The required thickness was calculated according to mechanical resistance analysis, based on models used in current nuclear facilities. The Adequacy of the calculated dimensions was confirmed by finite-element methods. To investigate the necessity of a radiation shielding function of the overpack, the irradiation from vitrified waste has been calculated. As a result, it was shown that shielding on handling and transport equipment is a more reasonable and practical approach than to increase thickness of overpack to attain a self-shielding capability. After the above investigation, trial manufacturing of full-scale model of titanium-carbon steel composite overpack has been carried out. For corrosion-resistant material, ASTM Grade-2 titanium was selected. The titanium layer was bonded individually to a cylindrical shell and flat cover plates (top and bottom) made of carbon steel. For the cylindrical shell portion, a cylindrically formed titanium layer was fitted to the inner carbon steel vessel by shrinkage. For the flat cover plates (top and bottom), titanium plate material was coated by explosive bonding. Electron beam welding and gas metal arc welding were combined to weld of the cover plates to the body. No significant failure was evident from inspections of the fabrication process, and the applicability of current technology for manufacturing titanium-carbon steel composite overpack was confirmed. Future research and development items regarding titanium-carbon steel composite overpacks are also discussed.
Nishihara, Tetsuo; Iwatsuki, Jin*
JAERI-Tech 99-078, p.55 - 0, 1999/11
no abstracts in English
Morii, Yukio; Minakawa, Nobuaki
Kessho Kaiseki Handobukku, p.472 - 476, 1999/09
no abstracts in English
JNC TN9400 99-041, 187 Pages, 1999/05
lt is widely recognized that the current seismic design methods for piping involve a large amount of safety margin. From this viewpoint, a series of seismic analyses and evaluations with various design codes were made on typical LMFBR main sodium piping systems. Actual capability against seismic loads were also estimated on the piping systems. Margins contained in the current codes were quantified based on these results, and potential benefits and impacts to the piping seismic design were assessed on possible mitigation of the current code allowables. From the study, the following points were clarified; (1)A combination of inelastic time history analysis and true(without margin) strength capability allows several to twenty times as large seismic load compared with the allowable load with the current methods. (2)The new rule of the ASME is relatively compatible with the results of inelastic analysis evaluation. Hence, this new rule might be a goal for the mitigation of seismic design rule. (3)With this mitigation, seismic design accommodation such as equipping with a large number of seismic supports may become unnecessary.
Kasahara, Naoto; Yacumpai, A.*; Takasho, Hideki*
JNC TN9400 99-019, 34 Pages, 1999/02
At incomplete mixing area of high temperature and low temperature fluids near the surface of structures, temperature fluctuation of fluid gives thermal fatigue damage to wall structures. This thermohydraulic and thermomechanical coupled phenomenon is called thermal striping, which has so complex mechanism and sometimes causes crack initiation on the structural surfaces that rational evaluation methods are required for screening rules in design codes. In this study, frequency response characteristics of structures and its mechanism were investigated by both numerical and theoretical methods. Based on above investigation, a structural response diagram was derived, which can predict stress amplitude of structures from temperature amplitude and frequency of fluids. Furthermore, this diagram was generalized to be the Non-dimensional structural response diagram by introducing non-dimensional parameters such as Biot number, non-dimensional frequency, and non-dimensional stress. The use of the Non-dimensional structural response diagram appears to evaluate thermal stress caused by thermal striping, rapidly without structural analysis, and rationally with considering attenuation by non-stationary heat transfer and thermal unloading. This diagram can also give such useful information as sensitive frequency range to adjust coupled thermohydraulic and thermomechanical analysis models taking account of four kinds of attenuation factors: turbulent mixing, molecular diffusion, non-stationaly heat transfer, and thermal unloading.
