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Okuda, Takahiro; Takahashi, Hideki*; Watakabe, Tomoyoshi
Mechanical Engineering Journal (Internet), 10(4), p.23-00075_1 - 23-00075_9, 2023/08
In recent years, to make the seismic design more rational for the piping systems in nuclear power plants, it has been expected to develop a design method considering plastic deformation and the accompanying energy dissipation of the piping itself. In this study, an extensive series of seismic response analyses was conducted to investigate the degree of influence of the plastic deformation of the pipe support structures on the seismic response of the entire piping system. The analyses include; plasticity is considered for (1) none, (2) the piping only, (3) the support structure only, and (4) both the piping and the support structure.
Hayafune, Hiroki; Chikazawa, Yoshitaka; Kamide, Hideki; Iwasaki, Mikinori*; Shoji, Takashi*
Proceedings of International Conference on Fast Reactors and Related Fuel Cycles; Next Generation Nuclear Systems for Sustainable Development (FR-17) (USB Flash Drive), 11 Pages, 2017/06
Design studies on a next generation sodium-cooled fast reactor (SFR) considering the safety design criteria (SDC) developed in the generation IV international forum (GIF) was summarized. To meet SDC including the lessons learned from the TEPCO's Fukushima Dai-ichi Nuclear Power Plants accident, the heat removal function was enhanced to avoid loss of the function even if any internal events exceeding design basis or severe external event happen. Several design options have been investigated and auxiliary core cooling system using air as ultimate heat sink has been selected as an additional cooling system regarding system reliability and diversification. Even though the next generation SFR already adopts seismic isolation system, main component designs have been improved considering revised earthquake conditions. For other external events, design measures for various external events are taken into account. Reactor building design has been improved and important safety components are diversified and located separately improving independency. Those design studies and evaluations on the next generation sodium-cooled reactor have contributed to the development of safety design guidelines (SDG) which is under discussion in the GIF framework.
Tanai, Kenji; Horita, M.*; Dewa, Katsuyuki*; Goke, Mitsuo*
JNC TN8410 2001-026, 116 Pages, 2002/03
JNC-TN8410-2001-026.pdf:9.19MB
Earthquake resistance for the underground structure is higher than the ground structure. Therefore, the case of examining the earthquake resistance of underground structure was little. However, it carries out the research on the aseismic designing method of underground structure, since the tunnel was struck by Hyogo-ken Nanbu Earthquake, and it has obtained a much knowledge. However, an object of the most study was behavior at earthquake of the comparatively shallow underground structure in the alluvial plain board, and it not carry out the examination on behavior at earthquake of underground structure in the deep rock mass. In the meantime, underground disposal facility of the high level radioactive waste constructs in the deep underground, and it carries out the operation in these tunnels. In addition, it has made almost the general process of including from the construction start to the backfilling to be about 60 years (Japan Nuclear Fuel Cycle Development Institute, 1999). During these periods, it is necessary to also consider the earthquake resistance as underground structure from the viewpoint of the safety of facilities. Then, it extracted future problem as one of the improvement of the basis information for the decision of the safety standard and guideline of the country on earthquake-resistant design of the underground disposal facility, while it carried out investigation and arrangement of earthquake-resistant design cases, guidelines and analysis method on existing underground structure, etc.. And, the research item for the earthquake resistance assessment of underground structure as case study of the underground research laboratory.
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.
PNC TN1410 98-018, 69 Pages, 1998/09
This report collects the results of safety research in nuclear fuel cycle at power reactor ans nuclear fuel development corporation, in order to answer to the questionnaire of OECD/NEA. The questionnaire request to inelude information concerning to research topic, description, main results (if available), reference documents, research institutes involved, sponsoring organization and other pertinent information about followings: (1) Recently completed reseach projects (2) Ongoing (current) research projects achievements on following items are omitted by request of oecd/nea. Uranium mining and milling, uranium refining and conversion to UF
, uranium enrichment, fuel manufacturers, spent fuel storage, radioactive waste management, transport of radioactive materials, decommissioning we select topics from the fields of a (1) Nuclear installation, (2) Seismic, and (3) PSA, in projects from frame of annual safety research plan for nuclear installations established by nuclear safety ...
*; *; *; *; ; Sakuraba, Koichi; Izawa, Naoki; Takeshita, Isao
JAERI-Tech 97-010, 276 Pages, 1997/03
no abstracts in English
; *; *; *; Abe, Kiyoharu
JAERI-Research 96-059, 73 Pages, 1996/11
JAERI-Research-96-059.pdf:2.72MB
no abstracts in English
; Suzuki, Takehiro*; *
JAERI-M 88-206, 20 Pages, 1988/10
no abstracts in English
Okuda, Takahiro; Takahashi, Hideki*; Morishita, Masaki
no journal, ,
This paper describes the results of a series of seismic analyses conducted to clarify how plastic deformation of a pipe and its support structures affect the seismic response of the entire piping system. The first analyses include; plasticity is considered for (1) none, (2) the piping only, (3) the support structure only and (4) both the piping and the support structure. The second analyses are parametric survey of yield load and post yield stiffness of the restoring force characteristics of support structures.
Okuda, Takahiro; Watakabe, Tomoyoshi; Morishita, Masaki; Takahashi, Hideki*
no journal, ,
This paper describes the results of a series of seismic analyses conducted to clarify how plastic deformation of a pipe and its support structures affect the seismic response of the entire piping system. The first analyses include; plasticity is considered for (1) none, (2) the piping only, (3) the support structure only and (4) both the piping and the support structure. The second analyses are parametric survey of yield load and post yield stiffness of the restoring force characteristics of support structures. The results of the first analyses have revealed important implications on the seismic design of piping systems by elastic-plastic response analysis.
Okuda, Takahiro; Watakabe, Tomoyoshi; Morishita, Masaki; Abe, Kenji*
no journal, ,
This paper describes the results of a series of seismic analyses to clarify how the plastic deformation of some support structures affects the seismic response of the entire piping system. The results of these analyses have revealed important implications for the seismic design of piping systems by elastic-plastic response analysis. First, regarding the order of the support structure considering plasticity, it is more effective to give priority to the plastic characteristics of the support structure showing a large load in the linear response analysis. Second, partially considering plasticity is more effective in reducing the burden of the entire design work than considering the plasticity of the entire support structure.
Takada, Tsuyoshi; Tsutsumi, Hideaki*; Kawata, Manabu
no journal, ,
The 2006 seismic design review guide requires results of their site-specific probabilistic seismic hazard assessment (PSHA) for setting Design Basis Ground Motions (DBGMs) to verify seismic safety of Nuclear Power Plants (NPPs). All electric utilities have submitted their results of their DBGMs to the NRA (Nuclear Regulatory Authority) together with the results of their PSHA. The AEPs (Annual Exceedance Probabilities) of DBGMs reflect not only the site-specific physical earthquake environment but also degree of design conservatisms which each electric utility wants to maintain for their NPPs. The present paper, based on the publicly available documents submitted to NRA, demonstrates the AEPs of the DBGMs of 16 NPPs in Japan and shows the regulatory requirements as well as utilities' decision by statistically analyzing the AEPs, which certainly can lead to risk-informed decision-making activities for nuclear safety assurance in Japan.
