• Title/Summary/Keyword: Nuclear power plant sites

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SHAKING TABLE TEST OF STEEL FRAME STRUCTURES SUBJECTED TO SCENARIO EARTHQUAKES

  • CHOI IN-KlL;KIM MIN KYU;CHOUN YOUNG-SUN;SEO JEONG-MOON
    • Nuclear Engineering and Technology
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    • v.37 no.2
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    • pp.191-200
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    • 2005
  • Shaking table tests of the seismic behavior of a steel frame structure model were performed. The purpose of these tests was to estimate the effects of a near-fault ground motion and a scenario earthquake based on a probabilistic seismic hazard analysis for nuclear power plant structures. Three representative kinds of earthquake ground motions were used for the input motions: the design earthquake ground motion for the Korean nuclear power plants, the scenario earthquakes for Korean nuclear power plant sites, and the near-fault earthquake record from the Chi-Chi earthquake. The probability-based scenario earthquakes were developed for the Korean nuclear power plant sites using the PSHA data. A 4-story steel frame structure was fabricated to perform the tests. Test results showed that the high frequency ground motions of the scenario earthquake did not damage the structure at the nuclear power plant site; however, the ground motions had a serious effect on the equipment installed on the high floors of the building. This shows that the design earthquake is not conservative enough to demonstrate the actual danger to safety related nuclear power plant equipment.

Uniform Hazard Spectrum Evaluation Method for Nuclear Power Plants on Soil Sites based on the Hazard Spectra of Bedrock Sites (암반 지반의 재해도 스펙트럼에 기반한 토사지반 원전 부지의 등재해도 스펙트럼 평가 기법)

  • Hahm, Dae-Gi;Seo, Jeong-Moon;Choi, In-Kil;Rhee, Hyun-Me
    • Journal of the Earthquake Engineering Society of Korea
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    • v.16 no.3
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    • pp.35-42
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    • 2012
  • We propose a probabilistic method to evaluate the uniform hazard spectra (UHS) of the soil of nuclear power plant(NPP) sites corresponding to that of a bedrock site. To do this, amplification factors on the surface of soil sites were estimated through site response analysis while considering the uncertainty in the earthquake ground motion and soil deposit characteristics. The amplification factors were calculated by regression analysis with spectral acceleration because these two factors are mostly correlated. The proposed method was applied to the evaluation of UHS for the KNGR (Korean Next Generation Reactor) and the APR1400 (Advanced Power Reactor 1400) nuclear power plant sites of B1, B4, C1 and C3. The most dominant frequency range with respect to the annual frequency of earthquakes was evaluated from the UHS analysis. It can be expected that the proposed method will improve the results of integrated risk assessments of NPPs rationally. We expect also that the proposed method will be applied to the evaluation of the UHS and of many other kinds of soil sites.

STATUS OF THE PSHA IN KOREA FOR NUCLEAR POWER PLANT SITES

  • Seo, Jeong-Moon;Noh, Myung-Hyun;Chang, Chun-Joong;Yun, Kwan-Hee
    • Nuclear Engineering and Technology
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    • v.41 no.10
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    • pp.1255-1262
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    • 2009
  • This paper introduces the status of and issues related to the PSHA (Probabilistic Seismic Hazard Analysis) of Korean Nuclear Power Plant sites. PSHA was first introduced to the nuclear industry in the mid-1980s. The Korean PSHA is based on Cornell and accommodates the modem approach for eliciting expertise and statistical treatment. Due to the low seismicity in Korea, large uncertainties exist in the PSHA database including seismic source maps, seismicity parameters of seismic sources, and attenuation formulae. Though research in seismology, geology, and earthquake engineering since the mid-1990s has significantly reduced uncertainties, a considerable amount still exists. Considering the low seismicity of the Korean Peninsula, especially the lack of strong motion data, further reduction will take several decades.

Radioactivity data analysis of 137Cs in marine sediments near severely damaged Chernobyl and Fukushima nuclear power plants

  • Song, Ji Hyoun;Kim, TaeJun;Yeon, Jei-Won
    • Nuclear Engineering and Technology
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    • v.52 no.2
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    • pp.366-372
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    • 2020
  • Using several accessible published data sets, we analyzed the temporal change of 137Cs radioactivity (per unit mass of sample) in marine sediments and investigated the effect of the water content of sediment on the 137Cs radioactivity, to understand the behavior of 137Cs present in marine environments. The 137Cs radioactivity in sediments decreased more slowly in the Baltic Sea (near the Chernobyl nuclear power plant) than in the ocean near the Fukushima Daiichi nuclear power plant (FDNPP). The 137Cs radioactivity in the sediment near the FDNPP tended to increase as the water content increased, and the water content decreased at certain sampling sites near the FDNPP for several years. Additionally, the decrease in the water content contributed to 51.2% of the average 137Cs radioactivity decrease rate for the same period. Thus, it may be necessary to monitor both the 137Cs radioactivity and the water content for marine sediments to track the 137Cs that was discharged from the sites of Chernobyl and Fukushima nuclear power plants where severe accidents occurred.

Suggestion on Seismic Hazard Assessment of Nuclear Power Plant Sites in Korea (국내 원전부지 지진재해도 평가를 위한 제언)

  • Kang, Tae-Seob;Yoo, Hyun Jae
    • Economic and Environmental Geology
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    • v.51 no.2
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    • pp.203-211
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    • 2018
  • Issues with past practice in seismic hazard analysis of nuclear power plant sites in Korea are addressed. Brief review on both deterministic and probabilistic methods in seismic hazard analysis is given, and most of the continuing discussion is focussed on the probabilistic seismic hazard analysis. Causes of uncertainty are traced on the basis of the cases that the assessment methodology was applied to the nuclear power plant sites. Considerations on the assessment include the role of experts, a representative seismic catalog, seismic source zonation, earthquake ground-motion relationship, and evaluation process. Factors increasing uncertainty in each item are analyzed and some feasible solutions are discussed.

The Status of Power Plant Simulation Technology and KEPCO's Plan for Self-Reliance of the Technology (발전소 시뮬레이터 기술동향 및 국내 기술자립 계획)

  • Shin, Yeong-Cheol;Lee, Yong-Kwan
    • Proceedings of the KIEE Conference
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    • 1993.07a
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    • pp.525-528
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    • 1993
  • KEPCO Research Center is carrying out a simulator(full scope replica type) development project for two nuclear power plants(Kori-2, Younggwang-3,4) and one fossil power plant(Poryong-3,4). In this project, we aim not only the installation of high performance simulators at the power plant sites but also the realization of self reliance of power plant simulation technology in Korea. In the course of preparing procurement specification for the 3 simulators, the present status of power plant simulation technology has been surveyed and is presented in this paper. The fidelity of simulation and the automation of simulation model production has been greatly improved due to the ever increasing computing power of today's workstations. The need and importance of the application of high fidelity simulators to the operator training is refocused since the accident at TMI Nuclear Power Plant, U.S.A.

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Multi-unit Level 1 probabilistic safety assessment: Approaches and their application to a six-unit nuclear power plant site

  • Kim, Dong-San;Han, Sang Hoon;Park, Jin Hee;Lim, Ho-Gon;Kim, Jung Han
    • Nuclear Engineering and Technology
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    • v.50 no.8
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    • pp.1217-1233
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    • 2018
  • Following a surge of interest in multi-unit risk in the last few years, many recent studies have suggested methods for multi-unit probabilistic safety assessment (MUPSA) and addressed several related aspects. Most of the existing studies though focused on two-unit nuclear power plant (NPP) sites or used rather simplified probabilistic safety assessment (PSA) models to demonstrate the proposed approaches. When considering an NPP site with three or more units, some approaches are inapplicable or yield very conservative results. Since the number of such sites is increasing, there is a strong need to develop and validate practical approaches to the related MUPSA. This article provides several detailed approaches that are applicable to multi-unit Level 1 PSA for sites with up to six or more reactor units. To validate the approaches, a multi-unit Level 1 PSA model is developed and the site core damage frequency is estimated for each of four representative multi-unit initiators, as well as for the case of a simultaneous occurrence of independent single-unit initiators in multiple units. For this purpose, an NPP site with six identical OPR-1000 units is considered, with full-scale Level 1 PSA models for a specific OPR-1000 plant used as the base single-unit models.

미래형 대형풍력발전기 개발 추세 (Europe 지역의 Case Study)

  • 오철수
    • Proceedings of the Korea Society for Energy Engineering kosee Conference
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    • 1998.05a
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    • pp.271-277
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    • 1998
  • 1. Why Wind Power\ulcorner Advantages of Wind Energy : free cost, non-pollutant, free waste large unit is possible Disadvantages : intermittent of energy density limited sites Unit Capacity of various Power Plant Solar PP : 10 - 500㎾ Wind PP : 200 - 2000 ㎾ Nuclear PP 700 - 1000 MW Installation Cost of Power Plants Nuclear PP : $ 2,500/㎾ Solar PP : $ 6,000/㎾ Wind PP : $ 1.000 /kw.

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Tritium( $^3$H) Activity Measurement by the Liquid Scintillation Counting Method

  • Hwang, Sun-Tae;Oh, Pil-Jae;Lee, Min-Kie;Kim, Wi-Soo
    • Journal of Korean Society for Atmospheric Environment
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    • v.10 no.E
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    • pp.299-302
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    • 1994
  • At a nuclear power plant, environmental radioactivity monitoring is routine work for the radiation safety management For the environmental monitoring of tritium($^3$H) activity in water sampled liquid scintillation counting( LSC) method is applied to measure low- energy beta activity from tritium in the samples. The $^3$H activity is measured using the BECKMAN 5801 system at the KRISS( Korea Research Institute of Standards and Science) for evaluating the lower limits of detection( LLD) of $^3$H measurement and the measuring capability of low-level $^3$H activity at four nuclear Power Plant sites. The LSC systems used for low-level $^3$H activity measurements at the nuclear Power Plants are confirmed to satisfy throughout an intercomparison study under the experimental arrangements by the KRISS.

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Preliminary strong ground motion simulation at seismic stations within nuclear power plant sites in South Korea by a scenario earthquake on the causative fault of 2016 Gyeongju earthquake

  • Choi, Hoseon
    • Nuclear Engineering and Technology
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    • v.54 no.7
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    • pp.2529-2539
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    • 2022
  • Stochastic and an empirical Green's function (EGF) methods are preliminarily applied to simulate strong ground motions (SGMs) at seismic stations within nuclear power plant (NPP) sites in South Korea by an assumed large earthquake with MW6.5 (scenario earthquake) on the causative fault of the 2016 Gyeongju earthquake with MW5.5 (mainshock). In the stochastic method, a ratio of spectral amplitudes of observed and simulated waveforms for the mainshock is assumed to be an adjustment factor. In the EGF method, SGMs by the mainshock are simulated assuming SGMs by the 2016 Gyeongju earthquake with MW5.0 (foreshock) as the EGF. To simulate SGMs by the scenario earthquake, a ratio of fault length to width is assumed to be 2:1 in the stochastic method, and SGMs by the mainshock are assumed to be EGF in the EGF method. The results are similar based on a bias of the simulated response spectra by the two methods, and the simulated response spectra by the two methods exceeded commonly standard design response spectra anchored at 0.3 g of NPP sites slightly at a frequency band above 4 Hz, but considerable attention to interpretation is required since it is an indirect comparison.