Korea-Japan Joint Research O Development of Seismic Capacity
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KAERI/RR-2392/2003 Korea-Japan Joint Research on Development of Seismic Capacity Evaluation and Enhancement Technology Considering Near-Fault Effect (Annual Report 2003) Research Organizations Korea Atomic Energy Research Institute Central Research Institute of Electric Power Industry Central Research Institute of Electric Power Industry SUMMARY I . Project Title Korea-Japan Joint Research on Development of Seismic Capacity Evaluation and Enhancement Technology Considering Near-Fault Effects n. Objective and Importance of the Project Recently, the safety of nuclear power plants against near fault earthquakes has received a great attention in Korea. The objectives of this collaboration are to develop a seismic capacity evaluation methodology and enhancement technology, such as isolation system. In the analysis, the effects of near-faults on seismic responses are focused on. HI. Scope and Contents of Project In the frame of the CRIEPI-KAERI collaboration following three research topics will be done: (1) Generate scenario earthquakes Seismic sources affected to a specific site will be first identified based on the PSHA and then the parameters for scenario earthquakes will be assumed. The attenuation equations of response spectra are used for generating input ground motions. (2) Assess PSHA in Korea sites The PSHA will be carried out for Korean nuclear sites. The results evaluated in CRIEPI will then be compared with those in KAERI. In addition, the contribution factors at specific sites are evaluated. (3) Develop PSA methodology The PSA methodology for nuclear facility enhanced by seismic isolation system will be developed. Then, the probability of failure between conventional and isolated NPPs will be compared. IV. Result of Project From the research in this fiscal year, following results were drawn: In the research on seismic source model, the bases of earthquake source modeling are reviewed and discussed. The kinematic source model, which assumes the shape of slip function a priori, with finite extent of fault is very effective and useful model for evaluation of strong ground motions, especially near-fault region. Future works should investigate the characteristics of strong ground motions based on these kinds of source models. In the research on seismic hazard analysis, the concept of hazard de-aggregation and the methodology of Probabilistic scenario Earthquakes (PSE) are first explained. Next, several cases in which PSHA have been practically used are introduced. Finally, seismic hazard curves and PSE for Wolsung NPP site are evaluated based on SHA when Peak Ground Acceleration is adopted as an index of earthquake motions. In the research on seismic PSA, a prototype system for seismic PSA, in which TDAP III is adopted as the core solver, is developed. The system facilitates the evaluation of variation of earthquakes. Then, method for generating fragility curves are illustrated based on the review of the methods for piping systems and building structures for nuclear power plants. Moreover, a conversion methodology for ground motion index of fragility curves is introduced. The illustrated i method realizes that fragility curves are efficiently and accurately evaluated and the comparison between seismically isolated and conventional systems, those have different dynamic characteristics, can be done. In the analysis of ground motion and historical earthquakes in Korea, 4097 ground motion records observed at twelve stations and 1859 historical records were analyzed. From the analysis of ground motion records it was found that the dominant period was 0.1 [s] and the spectral intensities were weaker than that of design earthquake in Japan. From the analysis of the historical records, it was found that the earthquakes are more frequently occurred southern area up to north latitude of 37° . u CONTENTS 1. Summary of Collaboration ......................................................................................................... 1 1.1 Title of collaboration ...................... .................................................................................... 1 1.2 Research code at CRIEPI........................ .. * ....................................................................... 1 1.3 Objectives.....................................................................................................* ...................... 1 1.4 Researchers • • * ..................................................................................................................... 1 1.5 Research term....................................................................................................................... 1 1.6 Research plan for phase I * * * * ............................................................................................. 2 2. Evaluation of input ground motion ............................................................................................. 4 2.1 Introduction - Kinematic source model -...................... - • .............................................. 4 2.2 Formulation of seismic wave radiation based on the dislocation model on finite fault plane ................................................................................................................. 4 2.3 Similarity law of seismic source - relationship between the magnitude of earthquake and source parameters -.................................. * ........................................................................ 10 2.4 Kinematic heterogeneous source model ............................................................................... 14 3. Research on seismic hazard analysis ...................................................................................... 29 3.1 General.............................................................................*.................................................. 29 3.2 Probabilistic seismic hazard analysis .......................................................* .......................... 29 3.3 Hazard de-aggregation and probabilistic scenario earthquakes .........................* ♦.............. 32 3.4 Practical applications of PSH A................ * ........................* .............................................. 34 3.5 PS HA examples for Korean site........................................................................................... 39 4. Research on seismic PSA.......................................................................................................... 69 4.1 Development of prototype system for seismic PSA............................................................. 69 4.2 Method for evaluating fragility curve for seismic isolation system .......... *.................... * * 72 4.3 Conversion methodology for ground motion index of fragility curves............................... 73 5. Analysis of ground motion records and historical earthquakes in Korea .............. .................... 110 5.1 Summary of analysis .................... ....................................................................................... 110 5.2 Analysis of ground motion records ....................................................................................... 110 5.3 Analysis of historical earthquakes .......................................................................................... Ill 5.4 Conclusions ......................................................................................................................... 112 6. Conclusions of this year ....................................................................................................... * • 154 6.1 Research on input ground motion ....................................................................................... 154 6.2 Research on seismic hazard analysis .............................................. * .................................. 154 6.3 Research on seismic PSA............................................................ 154 6.4 Analysis of ground motion records and historical earthquakes in Korea ............................ 154 Appendix A Terminologies ............................................................................................................. 155 Appendix B Relationships between Mw and other magnitude ---- * ........................................ * * 156 Appendix C Information on computer programs for PSHA...........................................................157 C-l Procedures in CRIEPI's program .................................... * ...................................... 157 C-2 Computer program for attenuation equations which are used in the PSHA.......... 158 iii 8 #: i. aimmEoag ..................................................................................................................... i 1.1 l ....................................................................................................... 1 1.3 1 1.4 i 1.5 i 1.6 7^-Xl<D#%#fm................................................................................................... 2 2. ............................................... 4 2.1 ...................... 4 2.2 #"Pg(D±# 4 2.3 mmofmm-^ 10 2.4 ............................................. 14 3. ............................................ 29 3.1 #C&tc................................................................................... 29 s. 2 - K##'................................................... 29 3.3 ..................... 32 3.4 KM^mmey.......................................... 34 3.5#gmf^r m#^j.............. 39 4. mmpsAKMf 5#%.................................................