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Seismic Response Evaluation of NPP Structures Considering Different Numerical Models and Frequency Contents of Earthquakes

다양한 수치해석 모델과 지진 주파수 성분을 고려한 원전구조물의 지진 응답 평가

  • Thusa, Bidhek (Department of Civil and Environmental Engineering, Konkuk University) ;
  • Nguyen, Duy-Duan (Department of Civil and Environmental Engineering, Konkuk University) ;
  • Park, Hyosang (Department of Civil and Environmental Engineering, Konkuk University) ;
  • Lee, Tae-Hyung (Department of Civil and Environmental Engineering, Konkuk University)
  • Received : 2019.11.05
  • Accepted : 2019.11.22
  • Published : 2020.02.29

Abstract

The purpose of this study is to investigate the effects of the application of various numerical models and frequency contents of earthquakes on the performances of the reactor containment building (RCB) in a nuclear power plant (NPP) equipped with an advanced power reactor 1400. Two kinds of numerical models are developed to perform time-history analyses: a lumped-mass stick model (LMSM) and a full three-dimensional finite element model (3D FEM). The LMSM is constructed in SAP2000 using conventional beam elements with concentrated masses, whereas the 3D FEM is built in ANSYS using solid elements. Two groups of ground motions considering low- and high-frequency contents are applied in time-history analyses. The low-frequency motions are created by matching their response spectra with the Nuclear Regulatory Commission 1.60 design spectrum, whereas the high-frequency motions are artificially generated with a high-frequency range from 10Hz to 100Hz. Seismic responses are measured in terms of floor response spectra (FRS) at the various elevations of the RCB. The numerical results show that the FRS of the structure under low-frequency motions for two numerical models are highly matched. However, under high-frequency motions, the FRS obtained by the LMSM at a high natural frequency range are significantly different from those of the 3D FEM, and the largest difference is found at the lower elevation of the RCB. By assuming that the 3D FEM approximates responses of the structure accurately, it can be concluded that the LMSM produces a moderate discrepancy at the high-frequency range of the FRS of the RCB.

본 연구의 목적은 원자로 1400(APR 1400) 원자력 발전소(NPP)의 원자로 격납건물(RCB) 내진성능에 대해 상이한 수치모델과 지진 주파수 성분의 영향을 평가하는 것이다. 집중 질량 막대 모델(lumped-mass stick model, LMSM)과 3차원 유한요소모델(three-dimensional finite element model, 3D FEM)의 두 가지 수치 모델이 시간이력해석을 수행하기 위해 개발되었다. LMSM은 기존의 집중 질량 보-요소를 사용하여 SAP2000으로 구성하였으며, 3D FEM은 각기둥 입체-요소를 사용하여 ANSYS로 작성되었다. 저주파수 및 고주파수 성분을 고려한 두 그룹의 지진파를 시간이력해석에 적용하였다. 저주파수 지진파의 응답스펙트럼을 NRC 1.60의 설계 스펙트럼과 일치되도록 조정하여 작성하였으며, 고주파수 지진파는 10Hz ~ 100Hz의 고주파수 범위를 갖도록 생성하였다. RCB의 지진응답은 다양한 높이에서 층응답스펙트럼으로 검토하였다. 수치해석 결과, 저주파수 지진에 의한 구조물의 FRS 결과는 두 수치 모델에서 매우 유사한 결과를 보였다. 하지만, 고주파수 지진에 의한 LMSM의 FRS 결과는 고차 고유 주파수 영역에서 3D FEM과 큰 차이를 보였으며, RCB의 낮은 높이에서 명확한 차이를 보였다. 3D FEM이 정확한 구조물의 응답을 나타내는 것으로 가정한다면, RCB의 LMSM은 고주파수 지진에 의한 FRS 결과의 고차 고유 주파수 영역에서 일정 수준의 불일치성을 내포하고 있다.

Keywords

References

  1. Ahmed, K., Kim, D., Lee, S.H. (2018) Effect of the Incoherent Earthquake Motion on Responses of Seismically Isolated Nuclear Power Plant Structure, Earthq. & Struct., 14(1), pp.33-44. https://doi.org/10.12989/EAS.2018.14.1.033
  2. Choi, I.K., Choun, Y.S., Seo, J.M. (2002) Re-evaluation of Seismic Fragility Parameters on Nuclear Power Plant Components Considering Uniform Hazard Spectrum, J. Korean Nucl. Soc., 34(6), pp.586-595.
  3. Choi, I.K., Choun, Y.S., Ahn, S.M., Seo, J.M. (2006) Seismic Fragility Analysis of a CANDU Type NPP Containment Building for Near-fault Ground Motions, KSCE J. Civil Eng., 10(2), pp.105-112. https://doi.org/10.1007/BF02823928
  4. Choi, I.K., Choun, Y.S., Ahn, S.M., Seo, J.M. (2008) Probabilistic Seismic Risk Analysis of CANDU Containment Structure for Near-fault Earthquakes, Nucl. Eng. & Des., 238(6), pp.1382-1391. https://doi.org/10.1016/j.nucengdes.2007.11.001
  5. Choi, I.K., Choun, Y.S., Seo, J.M., Lee, J.R. (2003) Consideration of High Frequency Ground Motion Effects on the Seismic Fragility of NPP Components, Internal Symposium on Seismic Evaluation of Existing Nuclear Facilities, Vienna, Austria.
  6. Choun, Y.S., Park, J., Choi. I.K. (2014) Effects of Mechanical Property Variability in Lead Rubber Bearings on the Response of Seismic Isolation System for Different Ground Motions, Nucl. Eng. & Technol., 46(5), pp.605-618. https://doi.org/10.5516/NET.09.2014.718
  7. Elkhoraibi, T., Hashemi, A., Ostadan, F. (2016) Effect of High Frequency Seismic Excitation on Standard Plant Design, 3rd Conference on Technological Innovations in Nuclear Civil Engineering (TINCE), Paris, France.
  8. EPRI (2014) High Frequency Program: High Frequency Testing Summary, Technical Report 3002002997, Electric Power Research Institute (EPRI), Palo Alto, CA, USA.
  9. EPRI (2017) Advanced Nuclear Technology: High-Frequency Seismic Loading Evaluation For Standard Nuclear Power Plants, Technical Report 3002009429, Electric Power Research Institute (EPRI), Palo Alto, CA, USA.
  10. Eem, S.H., Choi, I.K. (2018) Seismic Response Analysis of Nuclear Power Plant Structures and Equipment due to the Pohang Earthquake, J. Earthq. Eng. Soc. Korea, 22(3), pp.113-119. https://doi.org/10.5000/EESK.2018.22.3.113
  11. Ghiocel, D.M., Todorovski, L., Fuyama, H., Mitsuzawa, D. (2010) Seismic SSI Response of Reactor Building Structures, OECD NEA Seismic SSI Workshop, Ottawa, Canada.
  12. Joe, Y.H., Choi, S.G. (2003) Seismic Fragility Analyses of Nuclear Power Plant Structures based on the Recorded Earthquake Data in Korea, Transactions of the 17th International Conference on Structural Mechanics in Reactor Technology (SMiRT-17), Prague, Czech Republic.
  13. Jung, J.W., Jang, H.W., Kim, J.H., Hong, J.W. (2017) Effect of Second Hardening on Floor Response Spectrum of a Base-Isolated Nuclear Power Plant, Nucl. Eng. & Des., 322, pp.138-147. https://doi.org/10.1016/j.nucengdes.2017.06.004
  14. Jung, J.W., Lee, S., Hong, J.W. (2016) Floor Response Spectrum Analysis of a Base-isolated Nuclear Power Plant, J. Comput. Struct. Eng. Inst. Korea, 29(4), pp.355-362. https://doi.org/10.7734/COSEIK.2016.29.4.355
  15. Kwag, S., Kwak, J., Lee, H., Oh, J., Koo, G.H. (2019) A Numerical Study on Improvement in Seismic Performance of Nuclear Components by Applying Dynamic Absorber, J. Comput. Struct. Eng. Inst. Korea, 32(1), pp.17-27. https://doi.org/10.7734/COSEIK.2019.32.1.17
  16. Kim, G.J., Yang, K.K., Kim, B.S., Kim, H.J., Yun, S.J., Song, J.K. (2016) Seismic Response Evaluation of Seismically Isolated Nuclear Power Plant Structure Subjected to Gyeong-Ju Earthquake, J. Earthq. Eng. Soc. Korea, 20(7), pp.453-460. https://doi.org/10.5000/EESK.2016.20.7.453
  17. Kim, J.M., Lee, E.H. (2015) Development and Verification of Simplified Beam-Stick Model of Seismically Isolated ARP1400 Nuclear Power Plant Structure, Research report, Central Research Institute of KHNP, KETEP Project No. 2014151010170B.
  18. Lee, E.H., Kim, J.M., Joo, K.H., Kim, H. (2016) Evaluation of the Soil-Structure Interaction Effect on Seismically Isolated Nuclear Power Plant Structures, J. Earthq. Eng. Soc. Korea, 20(6), pp.379-389. https://doi.org/10.5000/EESK.2016.20.6.379
  19. Lee, J.H., Song, J.K. (2015) Comparison of Seismic Responses of Seismically Isolated NPP Containment Structures using Equivalent Linear-and Nonlinear-Lead-Rubber Bearing Modeling, J. Earthq. Eng. Soc. Korea, 19(1), pp.1-11. https://doi.org/10.5000/EESK.2015.19.1.001
  20. Moreschi, L.M., Pan, Q., Wang, S., Malushte, S.R. (2012) Generation of In-Structure Response Spectra for Nuclear Power Plants Subjected to High-Frequency Ground Motion, 20th International Conference on Nuclear Engineering, California, USA.
  21. Nguyen, D.D., Thusa, B., Lee, T.H. (2018) Seismic Fragility of Base-Isolated Nuclear Power Plant considering Near-Fault Ground Motions, J. Korean Soc. Hazard Mitig., 18(7), pp.315-321. https://doi.org/10.9798/KOSHAM.2018.18.7.315
  22. Nguyen, D.D., Thusa, B., Lee, T.H. (2019a) Effects of Significant Duration of Ground Motions on Seismic Responses of Base-Isolated Nuclear Power Plant, J. Earthq. Eng. Soc. Korea, 23(3), pp.149-157. https://doi.org/10.5000/EESK.2019.23.3.149
  23. Nguyen, D.D., Thusa, B., Park, H., Lee, H., Lee, T.H. (2019b) Effects of Mechanical Properties of LRB on Seismic Performance of Base-Isolated NPP Structures, Transaction of the 25th Structural Mechanics in Reactor Technology (SMiRT-25) Conference, Charlotte, NC, USA.
  24. Nguyen, D.D., Thusa, B., Han, T.S., Lee, T.H. (2020) Identifying Significant Earthquake Intensity Measures for Evaluating Seismic Damage and Fragility of Nuclear Power Plant Structures, Nucl. Eng. & Technol., DOI: https://doi.org/10.1016/j.net.2019.06.013.
  25. NRC (1973) Regulatory Guide 1.60: Design Response Spectra for Seismic Design of Nuclear Power Plants, US Nuclear Regulatory Commission, Rockville, Maryland, USA.
  26. Pan, Q., Moreschi, M., Lu, G. (2013) Effects of High Frequency Ground Motion on the Local Seismic Responses of Safety-Related Nuclear Structures, Transactions of the 22nd International Conference on Structural Mechanics in Reactor Technology (SMiRT-22), California, USA.
  27. Park, H.S., Nguyen, D.D., Lee, T.H. (2017) Effect of High-Frequency Ground Motions on the Response of NPP Components: A State-of-the-Art Review, J. Korean Soc. Hazard Mitig., 17(6), pp.285-294. https://doi.org/10.9798/KOSHAM.2017.17.6.285
  28. Rydell, C. (2014) Seismic High-Frequency Content Loads on Structures and Components within Nuclear Facilities, Licentiate Thesis, KTH Royal Institute of Technology, Stockholm, Sweden.
  29. RspMatch (2014) Earthquake Generation using Time Domain Method, Kunsan National University, Korea.
  30. SeismoSignal (2017) A Computer Program for Signal Processing of Strong-Motion Data, Available from http://www.seismosoft.com.
  31. Tran, T.T., Nguyen, T.H., Kim, D. (2018) Seismic Incidence on Base-Isolated Nuclear Power Plants considering Uni-And Bi-Directional Ground Motions, J. Struct. Integr. & Maint., 3(2), pp.86-94. https://doi.org/10.1080/24705314.2018.1461547
  32. Uwizerimana, S. (2015) Structural Modeling and Dynamic Analysis of Nuclear Power Plant Structures, Master Dissertation, The Ohio State University, USA.
  33. Xie, W.C, Jiang, W., Ni, S.H., Liu, W. (2019) Seismic Risk Analysis of Nuclear Power Plants, Cambridge University Press.