Seismic risk assessment for road in Indonesia

Science.gov (United States)

Toyfur, Mona Foralisa; Pribadi, Krishna S.

2016-05-01

Road networks in Indonesia consist of 446,000 km of national, provincial and local roads as well as toll highways. Indonesia is one of countries that exposed to various natural hazards, such as earthquakes, floods, landslides, etc. Within the Indonesian archipelago, several global tectonic plates interact, such as the Indo-Australian, Pacific, Eurasian, resulting in a complex geological setting, characterized by the existence of seismically active faults and subduction zones and a chain of more than one hundred active volcanoes. Roads in Indonesia are vital infrastructure needed for people and goods movement, thus supporting community life and economic activities, including promoting regional economic development. Road damages and losses due to earthquakes have not been studied widely, whereas road disruption caused enormous economic damage. The aim of this research is to develop a method to analyse risk caused by seismic hazard to roads. The seismic risk level of road segment is defined using an earthquake risk index, adopting the method of Earthquake Disaster Risk Index model developed by Davidson (1997). Using this method, road segments' risk level can be defined and compared, and road risk map can be developed as a tool for prioritizing risk mitigation programs for road networks in Indonesia.

Cities at risk: status of Italian planning system in reducing seismic and hydrogeological risks

Directory of Open Access Journals (Sweden)

Grazia Di Giovanni

2016-03-01

Full Text Available Italy and its urban systems are under high seismic and hydrogeological risks. The awareness about the role of human activities in the genesis of disasters is achieved in the scientific debate, as well as the role of urban and regional planning in reducing risks. The paper reviews the state of Italian major cities referred to hydrogeological and seismic risk by: 1 extrapolating data and maps about seismic hazard and landslide risk concerning cities with more than 50.000 inhabitants and metropolitan contexts, and 2 outlining how risk reduction is framed in Italian planning system (at national and regional levels. The analyses of available data and the review of the normative framework highlight the existing gaps in addressing risk reduction: nevertheless a wide knowledge about natural risks afflicting Italian territory and an articulated regulatory framework, the available data about risks are not exhaustive, and risk reduction policies and multidisciplinary pro-active approaches are only partially fostered and applied.

Seismic risk control of nuclear power plants using seismic protection systems in stable continental regions: The UK case

Energy Technology Data Exchange (ETDEWEB)

Medel-Vera, Carlos, E-mail: cbmedel@uc.cl; Ji, Tianjian, E-mail: tianjian.ji@manchester.ac.uk

2016-10-15

Highlights: • Strategies to reduce seismic risk for nuclear power stations in the UK are analysed. • Efficiency of devices to reduce risk: viscous-based higher than hysteretic-based. • Scenario-based incremental dynamic analysis is introduced for use in nuclear stations. • Surfaces of seismic unacceptable performance for nuclear stations are proposed. - Abstract: This article analyses three different strategies on the use of seismic protection systems (SPS) for nuclear power plants (NPPs) in the UK. Such strategies are based on the experience reported elsewhere of seismically protected nuclear reactor buildings in other stable continental regions. Analyses are conducted using an example of application based on a 1000 MW Pressurised Water Reactor building located in a representative UK nuclear site. The efficiency of the SPS is probabilistically assessed to achieve possible risk reduction for both rock and soil sites in comparison with conventionally constructed NPPs. Further analyses are conducted to study how the reduction of risk changes when all controlling scenarios of the site are included. This is done by introducing a scenario-based incremental dynamic analysis aimed at the generation of surfaces for unacceptable performance of NPPs as a function of earthquake magnitude (M{sub w}) and distance-to-site (R{sub epi}). General guidelines are proposed to potentially use SPS in future NPPs in the UK. Such recommendations can be used by the British nuclear industry in the future development of 12 new reactors to be built in the next two decades to generate 16 GWe of new nuclear capacity.

Seismic risk analysis for the Westinghouse Electric facility, Cheswick, Pennsylvania

International Nuclear Information System (INIS)

1977-01-01

This report presents the results of a detailed seismic risk analysis of the Westinghouse Electric plutonium fuel development facility at Cheswick, Pennsylvania. This report focuses on earthquakes. The historical seismic record was established after a review of available literature, consultation with operators of local seismic arrays and examination of appropriate seismic data bases. Because of the aseismicity of the region around the site, an analysis different from the conventional closest approach in a tectonic province was adapted. Earthquakes as far from the site as 1,000 km were included, as were the possibility of earthquakes at the site. In addition, various uncertainties in the input were explicitly considered in the analysis. For example, allowance was made for both the uncertainty in predicting maximum possible earthquakes in the region and the effect of the dispersion of data about the best fit attenuation relation. The attenuation relationship is derived from two of the most recent, advanced studies relating earthquake intensity reports and acceleration. Results of the risk analysis, which include a Bayesian estimate of the uncertainties, are presented as return period accelerations. The best estimate curve indicates that the Westinghouse facility will experience 0.05 g every 220 years and 0.10 g every 1400 years. The accelerations are very insensitive to the details of the source region geometries or the historical earthquake statistics in each region and each of the source regions contributes almost equally to the cumulative risk at the site

Seismic risk analysis for the fast breeder prototype SNR-300 in Kalkar (FRG)

International Nuclear Information System (INIS)

Hosser, D.

1983-01-01

This paper summarizes the seismic part of the SNR-300 Risk Oriented Analysis. Two different approaches were used for the seismic hazard description. In the first one, similar to the German Risk Study for PWR, the seismic input was given by a site-independent mean acceleration response spectrum and duration of strong motion prescribed for the design of the plant; the spectrum was scaled with the peak ground acceleration the probability of exceedance of which at the site Kalkar had been calculated in a former seismic hazard tudy. For the second approach, site- and intensity- dependent mean acceleration response spectra and duration of strong motion were derived and the probability of exceedance of the site intensity was evaluated in a probabilistic seismic hazard analysis. The seismic responses of safety related and other important buildings were calculated by time-history analyses using artificial acceleration time-histories with the given frequency content and duration of strong motion. The influence of uncertainties in dynamic soil parameters and structural modelling was assessed in parametric studies. Some important structural elements within the buildings were investigated in more detail. Their seismic performance was evaluated using ultimate limit state definitions according to the respective design codes or rotation limits for nonlinear dynamic calculations. (orig./RW)

Geomorphology and seismic risk

Science.gov (United States)

Panizza, Mario

1991-07-01

The author analyses the contributions provided by geomorphology in studies suited to the assessment of seismic risk: this is defined as function of the seismic hazard, of the seismic susceptibility, and of the vulnerability. The geomorphological studies applicable to seismic risk assessment can be divided into two sectors: (a) morpho-neotectonic investigations conducted to identify active tectonic structures; (b) geomorphological and morphometric analyses aimed at identifying the particular situations that amplify or reduce seismic susceptibility. The morpho-neotectonic studies lead to the identification, selection and classification of the lineaments that can be linked with active tectonic structures. The most important geomorphological situations that can condition seismic susceptibility are: slope angle, debris, morphology, degradational slopes, paleo-landslides and underground cavities.

Seismic risk assessment of a BWR

International Nuclear Information System (INIS)

Wells, J.E.; Bernreuter, D.L.; Chen, J.C.; Lappa, D.A.; Chuang, T.Y.; Murray, R.C.; Johnson, J.J.

1987-01-01

The simplified seismic risk methodology developed in the USNRC Seismic Safety Margins Research Program (SSMRP) was demonstrated by its application to the Zion nuclear power plant (PWR). The simplified seismic risk methodology was developed to reduce the costs associated with a seismic risk analysis while providing adequate results. A detailed model of Zion, including systems analysis models (initiating events, event trees, and fault trees), SSI and structure models, and piping models, was developed and used in assessing the seismic risk of the Zion nuclear power plant (FSAR). The simplified seismic risk methodology was applied to the LaSalle County Station nuclear power plant, a BWR; to further demonstrate its applicability, and if possible, to provide a basis for comparing the seismic risk from PWRs and BWRs. (orig./HP)

Seismic activity parameters of the Finnish potential repository sites

International Nuclear Information System (INIS)

Saari, J.

2000-10-01

Posiva Oy has started a project for estimating the possible earthquake induced rock movements on the deposition holes containing canisters of spent nuclear fuel. These estimates will be made for the four investigation sites, Romuvaara, Kivetty, Olkiluoto and Haestholmen. This study deals with the current and future seismicity associated with the above mentioned sites. Seismic belts that participate the seismic behaviour of the studied sites have been identified and the magnitude-frequency distributions of these belts have been estimated. The seismic activity parameters of the sites have been deduced from the characteristics of the seismic belts in order to forecast the seismicity during the next 100,000 years. The report discusses the possible earthquakes induced by future glaciation. The seismic interpretation seems to indicate that the previous postglacial faults in Finnish Lapland have been generated in compressional environment. The orientation of the rather uniform compression has been NW-SE, which coincide with the current stress field. It seems that, although the impact of postglacial crustal rebound must have been significant, the impact of plate tectonics has been dominant. A major assumption of this study has been that future seismicity will generally resemble the current seismicity. However, when the postglacial seismicity is concerned, the magnitude-frequency distribution is likely different and the expected maximum magnitude will be higher. Maximum magnitudes of future postglacial earthquakes have been approximated by strain release examinations. Seismicity has been examined within the framework of the lineament maps, in order to associate the future significant earthquakes with active fault zones in the vicinity of the potential repository sites. (orig.)

Analysis of parameter uncertainties in the assessment of seismic risk for nuclear power plants

International Nuclear Information System (INIS)

Yucemen, S.M.

1981-04-01

Probabilistic and statistical methods are used to develop a procedure by which the seismic risk at a specific site can be systematically analyzed. The proposed probabilistic procedure provides a consisted method for the modelling, analysis and updating of uncertainties that are involved in the seismic risk analysis for nuclear power plants. Methods are proposed for including these uncertainties in the final value of calculated risks. Two specific case studies are presented in detail to illustrate the application of the probabilistic method of seismic risk evaluation and to investigate the sensitivity of results to different assumptions

Review of seismic probabilistic risk assessment and the use of sensitivity analysis

International Nuclear Information System (INIS)

Shiu, K.K.; Reed, J.W.; McCann, M.W. Jr.

1985-01-01

This paper presents results of sensitivity reviews performed to address a range of questions which arise in the context of seismic probabilistic risk assessment (PRA). In a seismic PRA, sensitivity evaluations can be divided into three areas: hazard, fragility, and system modeling. As a part of the review of standard boiling water reactor seismic PRA which was performed by General Electric (GE), a reassessment of the plant damage states frequency and a detailed sensitivity analysis were conducted at Brookhaven National Laboratory. The rationale for such an undertaking is that in this case: (1) the standard plant may be sited anywhere in the eastern US (i.e., in regions with safety shutdown earthquake (SSE) values equal to or less than 0.3g peak ground acceleration), (2) it may have equipment whose fragility values could vary over a wide range; and (3) there are variations in system designs outside the original defined scope. Seismic event trees and fault trees were developed to model the different system and plant accident sequences. Hazard curves which represent various sites on the east coast were obtained; alternate structure and equipment fragility data were postulated. Various combinations of hazard and fragility data were analyzed. In addition, system modeling was perturbed to examine the impact upon the final results. Orders of magnitude variation were observed in the plant damage state frequency among the different cases. 7 references, 3 figures, 2 tables

Evaluating Seismic Site Effects at Cultural Heritage Sites in the Mediterranean Area

Science.gov (United States)

Imposa, S.; D'Amico, S.; Panzera, F.; Lombardo, G.; Grassi, S.; Betti, M.; Muscat, R.

2017-12-01

frequencies of the soil and to highlight potential site-to-structure resonance. The achieved findings can represent useful clues for further additional engineering investigations aiming at reducing the seismic risk, highlighting how the structural complexity and the local seismic response play an important role on building damage.

Seismic risk map for Southeastern Brazil

International Nuclear Information System (INIS)

Mioto, J.A.

1984-01-01

During the last few years, some studies regarding seismic risk were prepared for three regions of Brazil. They were carried on account of two basic interests: first, toward the seismic history and recurrence of Brazilian seismic events; second, in a way as to provide seismic parameters for the design and construction of hydro and nuclear power plants. The first seismic risk map prepared for the southeastern region was elaborated in 1979 by 6he Universidade de Brasilia (UnB-Brasilia Seismological Station). In 1981 another seismic risk map was completed on the basis of seismotectonic studies carried out for the design and construction of the Nuclear power plants of Itaorna Beach (Angra dos Reis, Rio de Janeiro) by IPT (Mining and Applied Geology Division). In Brazil, until 1984, seismic studies concerning hydro and nuclear power plants and other civil construction of larger size did not take into account the seismic events from the point of view of probabilities of seismic recurrences. Such analysis in design is more important than the choice of a level of intensity or magnitude, or adoption of a seismicity level ased on deterministic methods. In this way, some considerations were made, concerning the use of seisms in Brazilian designs of hydro and nuclear power plants, as far as seismic analysis is concerned, recently altered over the current seismic risk panorama. (D.J.M.) [pt

Seismic hazard, risk, and design for South America

Science.gov (United States)

Petersen, Mark D.; Harmsen, Stephen; Jaiswal, Kishor; Rukstales, Kenneth S.; Luco, Nicolas; Haller, Kathleen; Mueller, Charles; Shumway, Allison

2018-01-01

We calculate seismic hazard, risk, and design criteria across South America using the latest data, models, and methods to support public officials, scientists, and engineers in earthquake risk mitigation efforts. Updated continental scale seismic hazard models are based on a new seismicity catalog, seismicity rate models, evaluation of earthquake sizes, fault geometry and rate parameters, and ground‐motion models. Resulting probabilistic seismic hazard maps show peak ground acceleration, modified Mercalli intensity, and spectral accelerations at 0.2 and 1 s periods for 2%, 10%, and 50% probabilities of exceedance in 50 yrs. Ground shaking soil amplification at each site is calculated by considering uniform soil that is applied in modern building codes or by applying site‐specific factors based on VS30">VS30 shear‐wave velocities determined through a simple topographic proxy technique. We use these hazard models in conjunction with the Prompt Assessment of Global Earthquakes for Response (PAGER) model to calculate economic and casualty risk. Risk is computed by incorporating the new hazard values amplified by soil, PAGER fragility/vulnerability equations, and LandScan 2012 estimates of population exposure. We also calculate building design values using the guidelines established in the building code provisions. Resulting hazard and associated risk is high along the northern and western coasts of South America, reaching damaging levels of ground shaking in Chile, western Argentina, western Bolivia, Peru, Ecuador, Colombia, Venezuela, and in localized areas distributed across the rest of the continent where historical earthquakes have occurred. Constructing buildings and other structures to account for strong shaking in these regions of high hazard and risk should mitigate losses and reduce casualties from effects of future earthquake strong ground shaking. National models should be developed by scientists and engineers in each country using the best

Seismic refraction survey of the ANS preferred site

Energy Technology Data Exchange (ETDEWEB)

Davis, R.K. (Automated Sciences Group, Inc., Oak Ridge, TN (United States)); Hopkins, R.A. (Marrich, Inc., Knoxville, TN (United States)); Doll, W.E. (Oak Ridge National Lab., TN (United States))

1992-02-01

Between September 19, 1991 and October 8, 1991 personnel from Martin Marietta Energy Systems, Inc. (Energy Systems), Automated Sciences Group, Inc., and Marrich, Inc. performed a seismic refraction survey at the Advanced Neutron Source (ANS) preferred site. The purpose of this survey was to provide estimates of top-of-rock topography, based on seismic velocities, and to delineate variations in rock and soil velocities. Forty-four seismic refraction spreads were shot to determine top-of-rock depths at 42 locations. Nine of the seismic spreads were shot with long offsets to provide 216 top-of-rock depths for 4 seismic refraction profiles. The refraction spread locations were based on the grid for the ANS Phase I drilling program. Interpretation of the seismic refraction data supports the assumption that the top-of-rock surface generally follows the local topography. The shallow top-of-rock interface interpreted from the seismic refraction data is also supported by limited drill information at the site. Some zones of anomalous data are present that could be the result of locally variable weathering, a localized variation in shale content, or depth to top-of-rock greater than the site norm.

Seismic assessment of a site using the time series method

International Nuclear Information System (INIS)

Krutzik, N.J.; Rotaru, I.; Bobei, M.; Mingiuc, C.; Serban, V.; Androne, M.

1997-01-01

To increase the safety of a NPP located on a seismic site, the seismic acceleration level to which the NPP should be qualified must be as representative as possible for that site, with a conservative degree of safety but not too exaggerated. The consideration of the seismic events affecting the site as independent events and the use of statistic methods to define some safety levels with very low annual occurrence probability (10 -4 ) may lead to some exaggerations of the seismic safety level. The use of some very high value for the seismic acceleration imposed by the seismic safety levels required by the hazard analysis may lead to very costly technical solutions that can make the plant operation more difficult and increase maintenance costs. The considerations of seismic events as a time series with dependence among the events produced, may lead to a more representative assessment of a NPP site seismic activity and consequently to a prognosis on the seismic level values to which the NPP would be ensured throughout its life-span. That prognosis should consider the actual seismic activity (including small earthquakes in real time) of the focuses that affect the plant site. The paper proposes the applications of Autoregressive Time Series to issue a prognosis on the seismic activity of a focus and presents the analysis on Vrancea focus that affects NPP Cernavoda site, by this method. The paper also presents the manner to analyse the focus activity as per the new approach and it assesses the maximum seismic acceleration that may affect NPP Cernavoda throughout its life-span (∼ 30 years). Development and applications of new mathematical analysis method, both for long - and short - time intervals, may lead to important contributions in the process of foretelling the seismic events in the future. (authors)

Non-Invasive Seismic Methods for Earthquake Site Classification Applied to Ontario Bridge Sites

Science.gov (United States)

Bilson Darko, A.; Molnar, S.; Sadrekarimi, A.

2017-12-01

How a site responds to earthquake shaking and its corresponding damage is largely influenced by the underlying ground conditions through which it propagates. The effects of site conditions on propagating seismic waves can be predicted from measurements of the shear wave velocity (Vs) of the soil layer(s) and the impedance ratio between bedrock and soil. Currently the seismic design of new buildings and bridges (2015 Canadian building and bridge codes) requires determination of the time-averaged shear-wave velocity of the upper 30 metres (Vs30) of a given site. In this study, two in situ Vs profiling methods; Multichannel Analysis of Surface Waves (MASW) and Ambient Vibration Array (AVA) methods are used to determine Vs30 at chosen bridge sites in Ontario, Canada. Both active-source (MASW) and passive-source (AVA) surface wave methods are used at each bridge site to obtain Rayleigh-wave phase velocities over a wide frequency bandwidth. The dispersion curve is jointly inverted with each site's amplification function (microtremor horizontal-to-vertical spectral ratio) to obtain shear-wave velocity profile(s). We apply our non-invasive testing at three major infrastructure projects, e.g., five bridge sites along the Rt. Hon. Herb Gray Parkway in Windsor, Ontario. Our non-invasive testing is co-located with previous invasive testing, including Standard Penetration Test (SPT), Cone Penetration Test and downhole Vs data. Correlations between SPT blowcount and Vs are developed for the different soil types sampled at our Ontario bridge sites. A robust earthquake site classification procedure (reliable Vs30 estimates) for bridge sites across Ontario is evaluated from available combinations of invasive and non-invasive site characterization methods.

Seismic risk analysis for the Babcock and Wilcox facility, Leechburg, Pennsylvania

International Nuclear Information System (INIS)

1977-01-01

The results of a detailed seismic risk analysis of the Babcock and Wilcox Plutonium Fuel Fabrication facility at Leechburg, Pennsylvania are presented. This report focuses on earthquakes; the other natural hazards, being addressed in separate reports, are severe weather (strong winds and tornados) and floods. The calculational method used is based on Cornell's work (1968); it has been previously applied to safety evaluations of major projects. The historical seismic record was established after a review of available literature, consultation with operators of local seismic arrays and examination of appropriate seismic data bases. Because of the aseismicity of the region around the site, an analysis different from the conventional closest approach in a tectonic province was adapted. Earthquakes as far from the site as 1,000 km were included, as were the possibility of earthquakes at the site. In addition, various uncertainties in the input were explicitly considered in the analysis. The results of the risk analysis, which include a Bayesian estimate of the uncertainties, are presented, expressed as return period accelerations. The best estimate curve indicates that the Babcock and Wilcox facility will experience 0.05 g every 220 years and 0.10 g every 1400 years. The bounding curves roughly represent the one standard deviation confidence limits about the best estimate, reflecting the uncertainty in certain of the input. Detailed examination of the results show that the accelerations are very insensitive to the details of the source region geometries or the historical earthquake statistics in each region and that each of the source regions contributes almost equally to the cumulative risk at the site. If required for structural analysis, acceleration response spectra for the site can be constructed by scaling the mean response spectrum for alluvium in WASH 1255 by these peak accelerations

Seismic Risk Assessment and Loss Estimation for Tbilisi City

Science.gov (United States)

Tsereteli, Nino; Alania, Victor; Varazanashvili, Otar; Gugeshashvili, Tengiz; Arabidze, Vakhtang; Arevadze, Nika; Tsereteli, Emili; Gaphrindashvili, Giorgi; Gventcadze, Alexander; Goguadze, Nino; Vephkhvadze, Sophio

2013-04-01

The proper assessment of seismic risk is of crucial importance for society protection and city sustainable economic development, as it is the essential part to seismic hazard reduction. Estimation of seismic risk and losses is complicated tasks. There is always knowledge deficiency on real seismic hazard, local site effects, inventory on elements at risk, infrastructure vulnerability, especially for developing countries. Lately great efforts was done in the frame of EMME (earthquake Model for Middle East Region) project, where in the work packages WP1, WP2 , WP3 and WP4 where improved gaps related to seismic hazard assessment and vulnerability analysis. Finely in the frame of work package wp5 "City Scenario" additional work to this direction and detail investigation of local site conditions, active fault (3D) beneath Tbilisi were done. For estimation economic losses the algorithm was prepared taking into account obtained inventory. The long term usage of building is very complex. It relates to the reliability and durability of buildings. The long term usage and durability of a building is determined by the concept of depreciation. Depreciation of an entire building is calculated by summing the products of individual construction unit' depreciation rates and the corresponding value of these units within the building. This method of calculation is based on an assumption that depreciation is proportional to the building's (constructions) useful life. We used this methodology to create a matrix, which provides a way to evaluate the depreciation rates of buildings with different type and construction period and to determine their corresponding value. Finally loss was estimated resulting from shaking 10%, 5% and 2% exceedance probability in 50 years. Loss resulting from scenario earthquake (earthquake with possible maximum magnitude) also where estimated.

Assessment of the impact of degraded shear wall stiffnesses on seismic plant risk and seismic design loads

International Nuclear Information System (INIS)

Klamerus, E.W.; Bohn, M.P.; Johnson, J.J.; Asfura, A.P.; Doyle, D.J.

1994-02-01

Test results sponsored by the USNRC have shown that reinforced shear wall (Seismic Category I) structures exhibit stiffnesses and natural frequencies which are smaller than those calculated in the design process. The USNRC has sponsored Sandia National Labs to perform an evaluation of the effects of the reduced frequencies on several existing seismic PRAs in order to determine the seismic risk implications inherent in these test results. This report presents the results for the re-evaluation of the seismic risk for three nuclear power plants: the Peach Bottom Atomic Power Station, the Zion Nuclear Power Plant, and Arkansas Nuclear One -- Unit 1 (ANO-1). Increases in core damage frequencies for seismic initiated events at Peach Bottom were 25 to 30 percent (depending on whether LLNL or EPRI hazard curves were used). At the ANO-1 site, the corresponding increases in plant risk were 10 percent (for each set of hazard curves). Finally, at Zion, there was essentially no change in the computed core damage frequency when the reduction in shear wall stiffness was included. In addition, an evaluation of deterministic ''design-like'' structural dynamic calculations with and without the shear stiffness reductions was made. Deterministic loads calculated for these two cases typically increased on the order of 10 to 20 percent for the affected structures

Seismic assessment of a site using the time series method

International Nuclear Information System (INIS)

Krutzik, N.J.; Rotaru, I.; Bobei, M.; Mingiuc, C.; Serban, V.; Androne, M.

2001-01-01

1. To increase the safety of a NPP located on a seismic site, the seismic acceleration level to which the NPP should be qualified must be as representative as possible for that site, with a conservative degree of safety but not too exaggerated. 2. The consideration of the seismic events affecting the site as independent events and the use of statistic methods to define some safety levels with very low annual occurrence probabilities (10 -4 ) may lead to some exaggerations of the seismic safety level. 3. The use of some very high values for the seismic accelerations imposed by the seismic safety levels required by the hazard analysis may lead to very expensive technical solutions that can make the plant operation more difficult and increase the maintenance costs. 4. The consideration of seismic events as a time series with dependence among the events produced may lead to a more representative assessment of a NPP site seismic activity and consequently to a prognosis on the seismic level values to which the NPP would be ensured throughout its life-span. That prognosis should consider the actual seismic activity (including small earthquakes in real time) of the focuses that affect the plant site. The method is useful for two purposes: a) research, i.e. homogenizing the history data basis by the generation of earthquakes during periods lacking information and correlation of the information with the existing information. The aim is to perform the hazard analysis using a homogeneous data set in order to determine the seismic design data for a site; b) operation, i.e. the performance of a prognosis on the seismic activity on a certain site and consideration of preventive measures to minimize the possible effects of an earthquake. 5. The paper proposes the application of Autoregressive Time Series to issue a prognosis on the seismic activity of a focus and presents the analysis on Vrancea focus that affects Cernavoda NPP site by this method. 6. The paper also presents the

Overview of seismic probabilistic risk assessment for structural analysis in nuclear facilities

International Nuclear Information System (INIS)

Reed, J.W.

1989-01-01

Probabilistic Risk Assessment (PRA) for seismic events is currently being performed for nuclear and DOE facilities. The background on seismic PRA is presented along with a basic description of the method. The seismic PRA technique is applicable to other critical facilities besides nuclear plants. The different approaches for obtained structure fragility curves are discussed and their applications to structures and equipment, in general, are addressed. It is concluded that seismic PRA is a useful technique for conducting probability analysis for a wide range of classes of structures and equipment

Seismic Hazard and Risk Assessments for Beijing-Tianjin-Tangshan, China, Area

Science.gov (United States)

Xie, Furen; Wang, Zhenming; Liu, Jingwei

2011-03-01

Seismic hazard and risk in the Beijing-Tianjin-Tangshan, China, area were estimated from 500-year intensity observations. First, we digitized the intensity observations (maps) using ArcGIS with a cell size of 0.1 × 0.1°. Second, we performed a statistical analysis on the digitized intensity data, determined an average b value (0.39), and derived the intensity-frequency relationship (hazard curve) for each cell. Finally, based on a Poisson model for earthquake occurrence, we calculated seismic risk in terms of a probability of I ≥ 7, 8, or 9 in 50 years. We also calculated the corresponding 10 percent probability of exceedance of these intensities in 50 years. The advantages of assessing seismic hazard and risk from intensity records are that (1) fewer assumptions (i.e., earthquake source and ground motion attenuation) are made, and (2) site-effect is included. Our study shows that the area has high seismic hazard and risk. Our study also suggests that current design peak ground acceleration or intensity for the area may not be adequate.

Surface 3-D reflection seismics - implementation at the Olkiluoto site

Energy Technology Data Exchange (ETDEWEB)

Saksa, P.; Lehtimaeki, T.; Heikkinen, E. [Poeyry Environment Oy, Vantaa (Finland)

2007-03-15

Posiva Oy takes care of the final disposal of spent nuclear fuel in Finland. In year 2001 Olkiluoto was selected for the site of final disposal. Construction of the underground research facility, ONKALO, is going on at the Olkiluoto site. The aim of this work was to study the possibilities for surface 3-D seismics and to review experiences for design before field work. The physical parameters and geometric properties of the site, as well as efficient survey layout and source arrangements, were considered in this work. Reflection seismics is most used geophysical investigation method in oil exploration and earth studies in sedimentary environment. Recently method has also been applied in crystalline bedrock for ore exploration and nuclear waste disposal site investigations. The advantage of the method is high accuracy combined with large depth of investigation. The principles of seismic 2-D and 3-D soundings are well known and advanced. 3-D sounding is a straightforward expansion of 2-D line based surveying. In investigation of crystalline bedrock, the high frequency wave sources and receivers, their right use in measurements and careful processing procedure (refraction static corrections in particular) are important. Using the site parameters in 2-D numerical modeling, two cases of faulted thin layer at depths of 200, 400 and 600 meters were studied. The first case was a layer with vertical dislocation (a ramp) and the other a layer having limited width of dislocated part. Central frequencies were 100, 200, 400 and 700 Hz. Results indicate that 10 - 20 m dislocation is recognizable, but for depths greater than 600 m, over 20 meters is required. Width of the dislocated part will affect the detectability of vertical displacement. At depths of 200 m and 400 m 10 - 50 m wide parts appear as point-like scatterers, wider areas have more continuity. Dislocations larger than 20 m can be seen. From depth of 600 m over 100 m wide parts are discernible, narrower are visible

Surface 3-D reflection seismics - implementation at the Olkiluoto site

International Nuclear Information System (INIS)

Saksa, P.; Lehtimaeki, T.; Heikkinen, E.

2007-03-01

Posiva Oy takes care of the final disposal of spent nuclear fuel in Finland. In year 2001 Olkiluoto was selected for the site of final disposal. Construction of the underground research facility, ONKALO, is going on at the Olkiluoto site. The aim of this work was to study the possibilities for surface 3-D seismics and to review experiences for design before field work. The physical parameters and geometric properties of the site, as well as efficient survey layout and source arrangements, were considered in this work. Reflection seismics is most used geophysical investigation method in oil exploration and earth studies in sedimentary environment. Recently method has also been applied in crystalline bedrock for ore exploration and nuclear waste disposal site investigations. The advantage of the method is high accuracy combined with large depth of investigation. The principles of seismic 2-D and 3-D soundings are well known and advanced. 3-D sounding is a straightforward expansion of 2-D line based surveying. In investigation of crystalline bedrock, the high frequency wave sources and receivers, their right use in measurements and careful processing procedure (refraction static corrections in particular) are important. Using the site parameters in 2-D numerical modeling, two cases of faulted thin layer at depths of 200, 400 and 600 meters were studied. The first case was a layer with vertical dislocation (a ramp) and the other a layer having limited width of dislocated part. Central frequencies were 100, 200, 400 and 700 Hz. Results indicate that 10 - 20 m dislocation is recognizable, but for depths greater than 600 m, over 20 meters is required. Width of the dislocated part will affect the detectability of vertical displacement. At depths of 200 m and 400 m 10 - 50 m wide parts appear as point-like scatterers, wider areas have more continuity. Dislocations larger than 20 m can be seen. From depth of 600 m over 100 m wide parts are discernible, narrower are visible

Probabilistic seismic hazard at the archaeological site of Gol Gumbaz in Vijayapura, south India

Science.gov (United States)

Patil, Shivakumar G.; Menon, Arun; Dodagoudar, G. R.

2018-03-01

Probabilistic seismic hazard analysis (PSHA) is carried out for the archaeological site of Vijayapura in south India in order to obtain hazard consistent seismic input ground-motions for seismic risk assessment and design of seismic protection measures for monuments, where warranted. For this purpose the standard Cornell-McGuire approach, based on seismogenic zones with uniformly distributed seismicity is employed. The main features of this study are the usage of an updated and unified seismic catalogue based on moment magnitude, new seismogenic source models and recent ground motion prediction equations (GMPEs) in logic tree framework. Seismic hazard at the site is evaluated for level and rock site condition with 10% and 2% probabilities of exceedance in 50 years, and the corresponding peak ground accelerations (PGAs) are 0.074 and 0.142 g, respectively. In addition, the uniform hazard spectra (UHS) of the site are compared to the Indian code-defined spectrum. Comparisons are also made with results from National Disaster Management Authority (NDMA 2010), in terms of PGA and pseudo spectral accelerations (PSAs) at T = 0.2, 0.5, 1.0 and 1.25 s for 475- and 2475-yr return periods. Results of the present study are in good agreement with the PGA calculated from isoseismal map of the Killari earthquake, {M}w = 6.4 (1993). Disaggregation of PSHA results for the PGA and spectral acceleration ({S}a) at 0.5 s, displays the controlling scenario earthquake for the study region as low to moderate magnitude with the source being at a short distance from the study site. Deterministic seismic hazard (DSHA) is also carried out by taking into account three scenario earthquakes. The UHS corresponding to 475-yr return period (RP) is used to define the target spectrum and accordingly, the spectrum-compatible natural accelerograms are selected from the suite of recorded accelerograms.

Seismic Imaging of the Source Physics Experiment Site with the Large-N Seismic Array

Science.gov (United States)

Chen, T.; Snelson, C. M.; Mellors, R. J.

2017-12-01

The Source Physics Experiment (SPE) consists of a series of chemical explosions at the Nevada National Security Site. The goal of SPE is to understand seismic wave generation and propagation from these explosions. To achieve this goal, we need an accurate geophysical model of the SPE site. A Large-N seismic array that was deployed at the SPE site during one of the chemical explosions (SPE-5) helps us construct high-resolution local geophysical model. The Large-N seismic array consists of 996 geophones, and covers an area of approximately 2 × 2.5 km. The array is located in the northern end of the Yucca Flat basin, at a transition from Climax Stock (granite) to Yucca Flat (alluvium). In addition to the SPE-5 explosion, the Large-N array also recorded 53 weight drops. Using the Large-N seismic array recordings, we perform body wave and surface wave velocity analysis, and obtain 3D seismic imaging of the SPE site for the top crust of approximately 1 km. The imaging results show clear variation of geophysical parameter with local geological structures, including heterogeneous weathering layer and various rock types. The results of this work are being incorporated in the larger 3D modeling effort of the SPE program to validate the predictive models developed for the site.

Development of probabilistic seismic hazard analysis for international sites, challenges and guidelines

Energy Technology Data Exchange (ETDEWEB)

Fernandez Ares, Antonio, E-mail: antonio.fernandez@rizzoassoc.com [Paul C. Rizzo Associates, Inc., 500 Penn Center Boulevard, Penn Center East, Suite 100, Pittsburgh, PA 15235 (United States); Fatehi, Ali, E-mail: ali.fatehi@rizzoassoc.com [Paul C. Rizzo Associates, Inc., 500 Penn Center Boulevard, Penn Center East, Suite 100, Pittsburgh, PA 15235 (United States)

2013-06-15

Research highlights: ► Site-specific seismic hazard study and suggestions for overcoming those challenges that are inherent to the significant amounts of epistemic uncertainty for sites at remote locations. ► Main aspects of probabilistic seismic hazard analysis (PSHA). ► Regional and site geology in the context of a probabilistic seismic hazard analysis (PSHA), including state-of-the-art ground motion estimation methods, and geophysical conditions. ► Senior seismic hazard analysis (SSHAC) as a mean to incorporate the opinions and contributions of the informed scientific community. -- Abstract: This article provides guidance to conduct a site-specific seismic hazard study, giving suggestions for overcoming those challenges that are inherent to the significant amounts of epistemic uncertainty for sites at remote locations. The text follows the general process of a seismic hazard study, describing both the deterministic and probabilistic approaches. Key and controversial items are identified in the areas of recorded seismicity, seismic sources, magnitude, ground motion models, and local site effects. A case history corresponding to a seismic hazard study in the Middle East for a Greenfield site in a remote location is incorporated along the development of the recommendations. Other examples of analysis case histories throughout the World are presented as well.

Seismic site evaluation practice and seismic design guide for NPP in Continent of China

Energy Technology Data Exchange (ETDEWEB)

Yuxian, Hu [State Seismological Bureau, Beijing, BJ (China). Inst. of Geophysics

1997-03-01

Energy resources, seismicity, NPP and related regulations of the Continent of China are briefly introduced in the beginning and two codes related to the seismic design of NPP, one on siting and another on design, are discussed in some detail. The one on siting is an official code of the State Seismological Bureau, which specifies the seismic safety evaluation requirements of various kinds of structures, from the most critic and important structures such as NPP to ordinary buildings, and including also engineering works in big cities. The one on seismic design of NPP is a draft subjected to publication now, which will be an official national code. The first one is somewhat unique but the second one is quite similar to those in the world. (author)

Seismic site evaluation practice and seismic design guide for NPP in Continent of China

International Nuclear Information System (INIS)

Hu Yuxian

1997-01-01

Energy resources, seismicity, NPP and related regulations of the Continent of China are briefly introduced in the beginning and two codes related to the seismic design of NPP, one on siting and another on design, are discussed in some detail. The one on siting is an official code of the State Seismological Bureau, which specifies the seismic safety evaluation requirements of various kinds of structures, from the most critic and important structures such as NPP to ordinary buildings, and including also engineering works in big cities. The one on seismic design of NPP is a draft subjected to publication now, which will be an official national code. The first one is somewhat unique but the second one is quite similar to those in the world. (author)

Geo-Proxy-Based Site Classification for Regional Zonation of Seismic Site Effects in South Korea

Directory of Open Access Journals (Sweden)

Chang-Guk Sun

2018-02-01

Full Text Available Seismic site effects and topographic effects related to ground motion occur during an earthquake due to site-specific geotechnical or geological characteristics, including the geological or geographical structure and the characteristics of near-surface sub-soil layers. Site-specific site effects due to geological conditions have been confirmed in recent earthquake events. Earthquake-induced damage has mainly occurred at accumulated soft soil layers under basins or along coasts and rivers. An alternative method has recently been proposed for evaluating regional seismic site effects and amplification factors using digital elevation models (DEM. High-quality DEMs at high resolutions may be employed to resolve finer-scale variations in topographic gradients and consequently, correlated site response parameters. Because there are many regions in South Korea lacking borehole datasets, which are insufficient for site classification only using borehole datasets, a DEM-based proxy for seismic zonation can be effective. Thus, in this study, geo-proxy-based site classification was proposed based on empirical correlations with site response parameters and conducted for regional zonation of seismic site effects to identify the amplification of characteristics in the western metropolitan areas of South Korea, depending on the site-specific geo-spatial conditions.

A Community Seismic Experiment in the ENAM Primary Site

Science.gov (United States)

Van Avendonk, H. J.

2012-12-01

Eastern North America (ENAM) was chosen as a GeoPRISMS Rift Initiation and Evolution primary site because it represents a mature continental margin with onshore and offshore rift basins in which the record of extension and continental break-up is preserved. The degree to which syn-rift magmatism and preexisting lithospheric weaknesses controlled the evolution of the margin can be further investigated if we image its 3-D structure at small and large length scales with active-source and earthquake seismic imaging. In the Summer of 2012 we submitted a proposal to the US National Science Foundation for an ambitious plan for data acquisition on a 400 km wide section of the mid-Atlantic East Coast margin around Cape Hatteras, from unextended continental lithosphere onshore to mature oceanic lithosphere offshore. This area includes an important along-strike transition in the morphology of the margin from the Carolina Trough to the Baltimore Canyon Trough, and two major fracture zones that are associated with significant offsets at the modern Mid-Atlantic Ridge. The study area also covers several features representing the post-rift modification of the margin by slope instability and fluid flow. As the Earthscope Transportable Array reaches the East Coast of the US in 2013 and 2014, we will have an unprecedented opportunity to image the detailed structure of the rifted margin. To make effective use of the research infrastructure, including the seismic vessel R/V Marcus Langseth, the Earthscope seismic instrumentation, and US OBS Instrument Pool, we propose to collect a suite of seismic data at the mid-Atlantic margin in the context of a community-driven experiment with completely open data access. This multi-faceted seismic experiment offers an immense opportunity for education of young scientists. We propose an integrated education effort during and after acquisition. The science and field parties for data acquisition will largely consist of young scientists, who will be

Seismic Hazard Assessment in Site Evaluation for Nuclear Installations: Ground Motion Prediction Equations and Site Response

International Nuclear Information System (INIS)

2016-07-01

The objective of this publication is to provide the state-of-the-art practice and detailed technical elements related to ground motion evaluation by ground motion prediction equations (GMPEs) and site response in the context of seismic hazard assessments as recommended in IAEA Safety Standards Series No. SSG-9, Seismic Hazards in Site Evaluation for Nuclear Installations. The publication includes the basics of GMPEs, ground motion simulation, selection and adjustment of GMPEs, site characterization, and modelling of site response in order to improve seismic hazard assessment. The text aims at delineating the most important aspects of these topics (including current practices, criticalities and open problems) within a coherent framework. In particular, attention has been devoted to filling conceptual gaps. It is written as a reference text for trained users who are responsible for planning preparatory seismic hazard analyses for siting of all nuclear installations and/or providing constraints for anti-seismic design and retrofitting of existing structures

Hanford annual second quarter seismic report, fiscal year 1998: Seismicity on and near the Hanford Site, Pasco, Washington

Energy Technology Data Exchange (ETDEWEB)

Hartshorn, D.C.; Reidel, S.P.; Rohay, A.C.

1998-06-01

Hanford Seismic Monitoring provides an uninterrupted collection of high quality raw and processed seismic data from the Hanford Seismic Network (HSN) for the US Department of Energy and its contractors. The staff also locates and identifies sources of seismic activity and monitors changes in the historical pattern of seismic activity at the Hanford Site. The data are compiled, archived, and published for use by the Hanford Site for waste management, Natural Phenomena Hazards assessments, and engineering design and construction. In addition, the seismic monitoring organization works with the Hanford Site Emergency Services Organization to provide assistance in the event of an earthquake on the Hanford Site. The HSN and the Eastern Washington Regional Network (ENN) consist of 42 individual sensor sites and 15 radio relay sites maintained by the Hanford Seismic Monitoring staff. The operational rate for the second quarter of FY98 for stations in the HSN was 99.92%. The operational rate for the second quarter of FY98 for stations of the EWRN was 99.46%. For the second quarter of FY98, the acquisition computer triggered 159 times. Of these triggers 14 were local earthquakes: 7 (50%) in the Columbia River Basalt Group, 3 (21%) in the pre-basalt sediments, and 4 (29%) in the crystalline basement. The geologic and tectonic environments where these earthquakes occurred are discussed in this report. The most significant seismic event for the second quarter was on March 23, 1998 when a 1.9 Mc occurred near Eltopia, WA and was felt by local residents. Although this was a small event, it was felt at the surface and is an indication of the potential impact on Hanford of seismic events that are common to the Site.

Seismic hazard for the Savannah River Site: A comparative evaluation of the EPRI and LLNL assessments

International Nuclear Information System (INIS)

Wingo, H.E.

1992-01-01

This report was conducted to: (1) develop an understanding of causes for the vast differences between the two comprehensive studies, and (2) using a methodology consistent with the reconciled methods employed in the two studies, develop a single seismic hazard for the Savannah River Site suitable for use in seismic probabilistic risk assessments with emphasis on the K Reactor. Results are presented for a rock site which is a typical because detailed evaluations of soil characteristics at the K Reactor are still in progress that account for the effects of a soil stablizing grouting program. However when the soils analysis is completed, the effects of soils can be included with this analysis with the addition of a single factor that will decrease slightly the seismic hazard for a rock site

Savannah River Site disaggregated seismic spectra

International Nuclear Information System (INIS)

Stephenson, D.E.

1993-02-01

The objective of this technical note is to characterize seismic ground motion at the Savannah River Site (SRS) by postulated earthquakes that may impact facilities at the site. This task is accomplished by reviewing the deterministic and probabilistic assessments of the seismic hazard to establish the earthquakes that control the hazard to establish the earthquakes that control the hazard at the site and then evaluate the associated seismic ground motions in terms of response spectra. For engineering design criteria of earthquake-resistant structures, response spectra serve the function of characterizing ground motions as a function of period or frequency. These motions then provide the input parameters that are used in the analysis of structural response. Because they use the maximum response, the response spectra are an inherently conservative design tool. Response spectra are described in terms of amplitude, duration, and frequency content, and these are related to source parameters, travel path, and site conditions. Studies by a number of investigators have shown by statistical analysis that for different magnitudes the response spectrum values are different for differing periods. These facts support Jennings' position that using different shapes of design spectra for earthquakes of different magnitudes and travel paths is a better practice than employing a single, general-purpose shape. All seismic ground motion characterization results indicate that the PGA is controlled by a local event with M w < 6 and R < 30km. The results also show that lower frequencies are controlled by a larger, more distant event, typically the Charleston source. The PGA of 0.2 g, based originally on the Blume study, is consistent with LLNL report UCRL-15910 (1990) and with the DOE position on LLNL/EPRI

Seismic site-response characterization of high-velocity sites using advanced geophysical techniques: application to the NAGRA-Net

Science.gov (United States)

Poggi, V.; Burjanek, J.; Michel, C.; Fäh, D.

2017-08-01

The Swiss Seismological Service (SED) has recently finalised the installation of ten new seismological broadband stations in northern Switzerland. The project was led in cooperation with the National Cooperative for the Disposal of Radioactive Waste (Nagra) and Swissnuclear to monitor micro seismicity at potential locations of nuclear-waste repositories. To further improve the quality and usability of the seismic recordings, an extensive characterization of the sites surrounding the installation area was performed following a standardised investigation protocol. State-of-the-art geophysical techniques have been used, including advanced active and passive seismic methods. The results of all analyses converged to the definition of a set of best-representative 1-D velocity profiles for each site, which are the input for the computation of engineering soil proxies (traveltime averaged velocity and quarter-wavelength parameters) and numerical amplification models. Computed site response is then validated through comparison with empirical site amplification, which is currently available for any station connected to the Swiss seismic networks. With the goal of a high-sensitivity network, most of the NAGRA stations have been installed on stiff-soil sites of rather high seismic velocity. Seismic characterization of such sites has always been considered challenging, due to lack of relevant velocity contrast and the large wavelengths required to investigate the frequency range of engineering interest. We describe how ambient vibration techniques can successfully be applied in these particular conditions, providing practical recommendations for best practice in seismic site characterization of high-velocity sites.

Characterizing the Benefits of Seismic Isolation for Nuclear Structures: A Framework for Risk-Based Decision Making

Energy Technology Data Exchange (ETDEWEB)

Bolisetti, Chandrakanth [Idaho National Lab. (INL), Idaho Falls, ID (United States); Yu, Chingching [Idaho National Lab. (INL), Idaho Falls, ID (United States); Coleman, Justin [Idaho National Lab. (INL), Idaho Falls, ID (United States); Whittaker, Andrew [Idaho National Lab. (INL), Idaho Falls, ID (United States); Kosbab, Ben [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2016-11-01

This report provides a framework for assessing the benefits of seismic isolation and exercises the framework on a Generic Department of Energy Nuclear Facility (GDNF). These benefits are (1) reduction in the risk of unacceptable seismic performance and a dramatic reduction in the probability of unacceptable performance at beyond-design basis shaking, and (2) a reduction in capital cost at sites with moderate to high seismic hazard. The framework includes probabilistic risk assessment and estimates of overnight capital cost for the GDNF.

Assessing the seismic risk potential of South America

Science.gov (United States)

Jaiswal, Kishor; Petersen, Mark D.; Harmsen, Stephen; Smoczyk, Gregory M.

2016-01-01

We present here a simplified approach to quantifying regional seismic risk. The seismic risk for a given region can be inferred in terms of average annual loss (AAL) that represents long-term value of earthquake losses in any one year caused from a long-term seismic hazard. The AAL are commonly measured in the form of earthquake shaking-induced deaths, direct economic impacts or indirect losses caused due to loss of functionality. In the context of South American subcontinent, the analysis makes use of readily available public data on seismicity, population exposure, and the hazard and vulnerability models for the region. The seismic hazard model was derived using available seismic catalogs, fault databases, and the hazard methodologies that are analogous to the U.S. Geological Survey’s national seismic hazard mapping process. The Prompt Assessment of Global Earthquakes for Response (PAGER) system’s direct empirical vulnerability functions in terms of fatality and economic impact were used for performing exposure and risk analyses. The broad findings presented and the risk maps produced herein are preliminary, yet they do offer important insights into the underlying zones of high and low seismic risks in the South American subcontinent. A more detailed analysis of risk may be warranted by engaging local experts, especially in some of the high risk zones identified through the present investigation.

A risk-mitigation approach to the management of induced seismicity

Science.gov (United States)

Bommer, Julian J.; Crowley, Helen; Pinho, Rui

2015-04-01

Earthquakes may be induced by a wide range of anthropogenic activities such as mining, fluid injection and extraction, and hydraulic fracturing. In recent years, the increased occurrence of induced seismicity and the impact of some of these earthquakes on the built environment have heightened both public concern and regulatory scrutiny, motivating the need for a framework for the management of induced seismicity. Efforts to develop systems to enable control of seismicity have not yet resulted in solutions that can be applied with confidence in most cases. The more rational approach proposed herein is based on applying the same risk quantification and mitigation measures that are applied to the hazard from natural seismicity. This framework allows informed decision-making regarding the conduct of anthropogenic activities that may cause earthquakes. The consequent risk, if related to non-structural damage (when re-location is not an option), can be addressed by appropriate financial compensation. If the risk poses a threat to life and limb, then it may be reduced through the application of strengthening measures in the built environment—the cost of which can be balanced against the economic benefits of the activity in question—rather than attempting to ensure that some threshold on earthquake magnitude or ground-shaking amplitude is not exceeded. However, because of the specific characteristics of induced earthquakes—which may occur in regions with little or no natural seismicity—the procedures used in standard earthquake engineering need adaptation and modification for application to induced seismicity.

The Role of Tectonic and Seismicity in Siting of Nuclear Power Plant

International Nuclear Information System (INIS)

Abdel Aziz, M.A.H.

2008-01-01

The site selection for the a nuclear power plant (NPP) is controlled by many criteria. One of the most important criterion is the tectonic and seismicity of the site and its surroundings. Since, it is preferable the site in concern is characterized by low tectonic and low seismicity to avoid the damage effects associated with the occurrence of destructive earthquakes. The investigation of the tectonic and seismicity maps of egypt has been carried out to candidate potential areas or sites for nuclear power plant installation from seismicity point of view. Also, the design basis ground motion in terms of peak ground acceleration and response spectra of some of the potential sites are defined through the conduct of probabilistic seismic hazard analysis The study revealed that although there is no criterion to exclude areas of high tectonic and high seismicity as potential sites for nuclear power plant installation but, it is preferable avoiding such areas. This is attributed to the critical seismic curve that characterizes such areas and is required high seismic design levels to resist the destructive vibratory ground motion associated with the expected earthquake. Consequently, the required high seismic design levels will have a negative impact on the economic cost of the facility compared with that built in low and moderate seismic areas. Hence, areas like the gulf of suez, the northern part of the Red Sea and the southern part of Sinai Peninsula should be avoided as potential sites for NPP from the tectonic and seismicity point of view. On the other hand, areas like Nile delta and its valley, the Northern and Southern parts of Western desert and the central and southern parts of the Eastern Desert should be candidate as potential sites on condition, the other criteria meet the IAEA's regulations. Also, the seismic hazard curve of the Northwest littoral zone reflects low design basis ground motion values compared with the Nile delta region

Seismic hazard analysis of the NPP Kozloduy site

International Nuclear Information System (INIS)

Petrovski, D.; Stamatovska, S.; Arsovski, M.; Hadzievski, D.; Sokerova, D.; Solakov, D.; Vaptzarov, I.; Satchanski, S.

1993-01-01

The principal objective of this study is to define the seismic hazard for the NPP Kozloduy site. Seismic hazard is by rule defined by the probability distribution function of the peak value of the chosen ground motion parameter in a defined time interval. The overall study methodology consists of reviewing the existing geological, seismological and tectonic information to formulate this information into a mathematical model of seismic activity of the region and using this assess earthquake ground motion in terms of probability. Detailed regional and local seismological investigations have been performed. Regional investigations encompass the area within a radius of 320 km from the NPP Kozloduy site. The results of these investigations include all seismological parameters that are necessary for determination of the mathematical model of the seismicity of the region needed for the seismic hazard analysis. Regional geological and neotectonic investigations were also performed for the wider area including almost the whole territory of Bulgaria, a large part of Serbia, part of Macedonia and almost the whole south part of Romania

A scenario-based procedure for seismic risk analysis

International Nuclear Information System (INIS)

Kluegel, J.-U.; Mualchin, L.; Panza, G.F.

2006-12-01

A new methodology for seismic risk analysis based on probabilistic interpretation of deterministic or scenario-based hazard analysis, in full compliance with the likelihood principle and therefore meeting the requirements of modern risk analysis, has been developed. The proposed methodology can easily be adjusted to deliver its output in a format required for safety analysts and civil engineers. The scenario-based approach allows the incorporation of all available information collected in a geological, seismotectonic and geotechnical database of the site of interest as well as advanced physical modelling techniques to provide a reliable and robust deterministic design basis for civil infrastructures. The robustness of this approach is of special importance for critical infrastructures. At the same time a scenario-based seismic hazard analysis allows the development of the required input for probabilistic risk assessment (PRA) as required by safety analysts and insurance companies. The scenario-based approach removes the ambiguity in the results of probabilistic seismic hazard analysis (PSHA) which relies on the projections of Gutenberg-Richter (G-R) equation. The problems in the validity of G-R projections, because of incomplete to total absence of data for making the projections, are still unresolved. Consequently, the information from G-R must not be used in decisions for design of critical structures or critical elements in a structure. The scenario-based methodology is strictly based on observable facts and data and complemented by physical modelling techniques, which can be submitted to a formalised validation process. By means of sensitivity analysis, knowledge gaps related to lack of data can be dealt with easily, due to the limited amount of scenarios to be investigated. The proposed seismic risk analysis can be used with confidence for planning, insurance and engineering applications. (author)

Seismic risk assessment of a BWR: status report

International Nuclear Information System (INIS)

Chuang, T.Y.; Bernreuter, D.L.; Wells, J.E.; Johnson, J.J.

1985-02-01

The seismic risk methodology developed in the US NRC Seismic Safety Margins Research Program (SSMRP) was demonstrated by its application to the Zion nuclear power plant, a pressurized water reactor (PWR). A detailed model of Zion, including systems analysis models (initiating events, event trees, and fault trees), SSI and structure models, and piping models was developed and analyzed. The SSMRP methodology can equally be applied to a boiling water reactor (BWR). To demonstrate its applicability, to identify fundamental differences in seismic risk between a PWR and a BWR, and to provide a basis of comparison of seismic risk between a PWR and a BWR when analyzed with comparable methodology and assumptions, a seismic risk analysis is being performed on the LaSalle County Station nuclear power plant

Methodology to evaluate the site standard seismic motion to a nuclear facility

International Nuclear Information System (INIS)

Soares, W.A.

1983-01-01

For the seismic design of nuclear facilities, the input motion is normally defined by the predicted maximum ground horizontal acceleration and the free field ground response spectrum. This spectrum is computed on the basis of records of strong motion earthquakes. The pair maximum acceleration-response spectrum is called the site standard seismic motion. An overall view of the subjects involved in the determination of the site standard seismic motion to a nuclear facility is presented. The main topics discussed are: basic principles of seismic instrumentation; dynamic and spectral concepts; design earthquakes definitions; fundamentals of seismology; empirical curves developed from prior seismic data; available methodologies and recommended procedures to evaluate the site standard seismic motion. (Author) [pt

Seismic risk analysis for the Atomics International Nuclear Materials Development Facility, Santa Susana California

International Nuclear Information System (INIS)

1978-01-01

This report presents the results of a detailed seismic risk analysis of the Nuclear Materials Development Facility (NMDF) operated by Atomics International at Santa Susana, California. The historical seismic record was established after a review of available literature, consultation with operators of local seismic arrays and examination of appropriate seismic data bases including the USGS, California Institute of Technology and NEIS data bases. The resulting seismic record, covering the period 1969 to 1977, was used to identify all possible sources of seismicity that could affect the site. The best estimate curve indicates that the facility will experience 30% g with a return period of 55 years and 60% g with a return period of 750 years

Seismic risk analysis for the Atomics International Nuclear Materials Development Facility, Santa Susana California

Energy Technology Data Exchange (ETDEWEB)

1978-12-29

This report presents the results of a detailed seismic risk analysis of the Nuclear Materials Development Facility (NMDF) operated by Atomics International at Santa Susana, California. The historical seismic record was established after a review of available literature, consultation with operators of local seismic arrays and examination of appropriate seismic data bases including the USGS, California Institute of Technology and NEIS data bases. The resulting seismic record, covering the period 1969 to 1977, was used to identify all possible sources of seismicity that could affect the site. The best estimate curve indicates that the facility will experience 30% g with a return period of 55 years and 60% g with a return period of 750 years.

Seismic risk evaluation within the technology neutral framework

International Nuclear Information System (INIS)

Johnson, B.C.; Apostolakis, G.E.

2012-01-01

Highlights: ► We examine seismic risk within the Technology Neutral Framework (TNF). ► We find that the risk goals in the TNF to be stringent compared with current goals. ► We note that the current fleet reactors would not meet the TNF goals. ► We recommend that an initiating frequency cutoff of 10 −5 per year be use in evaluating seismic risk. - Abstract: The NRC Office of Nuclear Regulatory Research has proposed a risk-informed and performance-based licensing process that is referred to as the technology neutral framework (TNF). In the TNF, licensing basis events (LBEs), determined using probabilistic risk assessment methods, take the place of design basis accidents. These LBEs are constructed by grouping together accident sequences with similar phenomenology. All event sequences with a mean frequency greater than 10 −7 per reactor year are to be considered as part of the licensing basis. Imposing such a limit would require that earthquakes with a mean return period of ten million years be considered as part of the licensing basis. It is difficult to get seismic hazards (i.e., ground accelerations) from expert seismologists at such low frequencies. This is because it is difficult or impossible to confidently say what the seismic hazard might be at these extremely low frequencies. A linear extrapolation in log-log space of hazard curves at the Clinton site down to 10 −7 per year leads to a peak ground acceleration of about 4.5 g. A Weibull distribution is also used to fit the curve leading to a peak ground acceleration of about 2.6 g. These extrapolations demonstrate the extreme nature of rare earthquakes. Even when seismic isolation is implemented, the TNF goal is not met. The problem appears to be that there is no limit on initiating event frequency in the TNF. Demonstrating that a design meets the goals of the TNF would be nearly impossible. A frequency limit for earthquakes could be imposed at a frequency of about 10 −5 per year to focus on

Methodology to evaluate the site standard seismic motion for a nuclear facility

International Nuclear Information System (INIS)

Soares, W.A.

1983-03-01

An overall view of the subjects involved in the determination of the site standard seismic motion to a nuclear facility is presented. The main topics discussed are: basic priciples of seismic instrumentation; dynamic and spectral concepts; design earthquakes definitions; fundamentals of seismology; empirical curves developed from prior seismic data; avalable methodologies and recommended procedures to evaluate the site standard seismic motion. (E.G.) [pt

Magnitudes and frequencies of earthquakes in relation to seismic risk

International Nuclear Information System (INIS)

Sharma, R.D.

1989-01-01

Estimating the frequencies of occurrence of earthquakes of different magnitudes on a regional basis is an important task in estimating seismic risk at a construction site. Analysis of global earthquake data provides an insight into the magnitudes frequency relationship in a statistical manner. It turns out that, whereas a linear relationship between the logarithm of earthquake occurrence rates and the corresponding earthquake magnitudes fits well in the magnitude range between 5 and 7, a second degree polynomial in M, the earthquake magnitude provides a better description of the frequencies of earthquakes in a much wider range of magnitudes. It may be possible to adopt magnitude frequency relation for regions, for which adequate earthquake data are not available, to carry out seismic risk calculations. (author). 32 refs., 8 tabs., 7 figs

Risk perception versus seismic risk: An introduction

International Nuclear Information System (INIS)

Cubeddu, Francesca

2015-01-01

A seismic event generally has consequences on the social relationships, economy and culture of the impacted territory. As Mary Douglas quotes, a change into the social perception of risk as consequence of an earthquake may have effects on the lifestyle of the local community. The above mentioned statement is the starting point of this article. illustrating the difference between peril and risk is the second point. According to the Aristotelian theory of categories, risk can be considered as a human characteristic depending on social and cultural factors. Risk is here intended as a social category and cannot be de facto reported as a statistical or stochastic function based on a mathematical formula, as long assumed in the past. This approach, then, requires a deep revision. In this sense, and following the concept of risk perception, seismic risk is analysed in this article in terms of impacts, precautionary measures, risk assessment and management. Knowledge of this topic cannot be intended as a simple philosophical exercise, since right on awareness depend risk reduction, humans and goods too [it

Seismic hazard and risk assessment for large Romanian dams situated in the Moldavian Platform

Science.gov (United States)

Moldovan, Iren-Adelina; Popescu, Emilia; Otilia Placinta, Anica; Petruta Constantin, Angela; Toma Danila, Dragos; Borleanu, Felix; Emilian Toader, Victorin; Moldoveanu, Traian

2016-04-01

Besides periodical technical inspections, the monitoring and the surveillance of dams' related structures and infrastructures, there are some more seismic specific requirements towards dams' safety. The most important one is the seismic risk assessment that can be accomplished by rating the dams into seismic risk classes using the theory of Bureau and Ballentine (2002), and Bureau (2003), taking into account the maximum expected peak ground motions at the dams site - values obtained using probabilistic hazard assessment approaches (Moldovan et al., 2008), the structures vulnerability and the downstream risk characteristics (human, economical, historic and cultural heritage, etc) in the areas that might be flooded in the case of a dam failure. Probabilistic seismic hazard (PSH), vulnerability and risk studies for dams situated in the Moldavian Platform, starting from Izvorul Muntelui Dam, down on Bistrita and following on Siret River and theirs affluent will be realized. The most vulnerable dams will be studied in detail and flooding maps will be drawn to find the most exposed downstream localities both for risk assessment studies and warnings. GIS maps that clearly indicate areas that are potentially flooded are enough for these studies, thus giving information on the number of inhabitants and goods that may be destroyed. Geospatial servers included topography is sufficient to achieve them, all other further studies are not necessary for downstream risk assessment. The results will consist of local and regional seismic information, dams specific characteristics and locations, seismic hazard maps and risk classes, for all dams sites (for more than 30 dams), inundation maps (for the most vulnerable dams from the region) and possible affected localities. The studies realized in this paper have as final goal to provide the local emergency services with warnings of a potential dam failure and ensuing flood as a result of an large earthquake occurrence, allowing further

Reflection seismic imaging of the upper crystalline crust for characterization of potential repository sites: Fine tuning the seismic source

Energy Technology Data Exchange (ETDEWEB)

Juhlin, C.; Palm, H.; Bergman, B. [Uppsala Univ. (Sweden). Dept. of Earth Sciences

2001-09-01

SKB is currently carrying out studies to determine which seismic techniques, and how, they will be used for investigations prior to and during the building of a high-level nuclear waste repository. Active seismic methods included in these studies are refraction seismics, reflection seismics, and vertical seismic profiling (VSP). The main goal of the active seismic methods is to locate fracture zones in the crystalline bedrock. Plans are to use longer reflection seismic profiles (3.4 km) in the initial stages of the site investigations. The target depth for these seismic profiles is 100-1500 m. Prior to carrying out the seismic surveys over actual candidate waste repository sites it has been necessary to carry out a number of tests to determine the optimum acquisition parameters. This report constitutes a summary of the tests carried out by Uppsala University. In addition, recommended acquisition and processing parameters are presented at the end of the report. A major goal in the testing has been to develop a methodology for acquiring high-resolution reflection seismic data over crystalline rock in as a cost effective manner as possible. Since the seismic source is generally a major cost in any survey, significant attention has been given to reducing the cost of the source. It was agreed upon early in the study that explosives were the best source from a data quality perspective and, therefore, only explosive source methods have been considered in this study. The charge size and shot hole dimension required to image the upper 1-1.5 km of bedrock is dependent upon the conditions at the surface. In this study two types of shot hole drilling methods have been employed depending upon whether the thickness of the loose sediments at the surface is greater or less than 0.5 m. The charge sizes and shot hole dimensions required are: Loose sediment thickness less than 0.5 m: 15 g in 90 cm deep 12 mm wide uncased shot holes. Loose sediment thickness greater than 0.5 m: 75 g

Preliminary evaluation of the seismic hazard at Cernavoda NPP site

International Nuclear Information System (INIS)

Mingiuc, C.; Serban, V.; Androne, M.

2001-01-01

The probabilistic seismic hazard analysis (PSHA) is a methodology by which one evaluates the probability of exceeding different parameters of the ground motions (the maximum ground acceleration - PGA and the ground response spectrum - SA) as effect of the seismic action, on a given site at a future time moment. Due to the large uncertainties in the geological, geophysical, seismological input data, as well as, in the models utilised, various interpretation schemes are applied in the PSHA analyses. This interpretation schemes lead to opinion discrepancies among specialists which finally lead to disagreements in estimating the values of the seismic design for a given site. In order to re-evaluate the methodology and to improve the PSHA result stability, U.S. Nuclear Regulatory Commission (NRC), U.S. Department of Energy (DOE) and Electric Power Research Institute (EPRI) sponsored a project for defining methodological guides of performing PSHA analyses. The project was implemented by a panel of 7 experts, the Senior Seismic Hazard Analysis Committee - SSHAC. This paper presents a preliminary evaluation of the seismic hazard for the Cernavoda NPP site by application of the methodology mentioned, by taking into account the possible sources which could affect the site (the Vrancea focus, Galati - Tulcea fault, Sabla - Dulovo fault and local earthquakes)

Probabilistic Seismic Hazard Assessment Method for Nonlinear Soil Sites based on the Hazard Spectrum of Bedrock Sites

International Nuclear Information System (INIS)

Hahm, Dae Gi; Seo, Jeong Moon; Choi, In Kil

2011-01-01

For the probabilistic safety assessment of the nuclear power plants (NPP) under seismic events, the rational probabilistic seismic hazard estimation should be performed. Generally, the probabilistic seismic hazard of NPP site is represented by the uniform hazard spectrum (UHS) for the specific annual frequency. In most case, since that the attenuation equations were defined for the bedrock sites, the standard attenuation laws cannot be applied to the general soft soil sites. Hence, for the probabilistic estimation of the seismic hazard of soft soil sites, a methodology of probabilistic seismic hazard analysis (PSHA) coupled with nonlinear dynamic analyses of the soil column are required. Two methods are commonly used for the site response analysis considering the nonlinearity of sites. The one is the deterministic method and another is the probabilistic method. In the analysis of site response, there exist many uncertainty factors such as the variation of the magnitude and frequency contents of input ground motion, and material properties of soil deposits. Hence, nowadays, it is recommended that the adoption of the probabilistic method for the PSHA of soft soil deposits considering such uncertainty factors. In this study, we estimated the amplification factor of the surface of the soft soil deposits with considering the uncertainties of the input ground motions and the soil material properties. Then, we proposed the probabilistic methodology to evaluate the UHS of the soft soil site by multiplying the amplification factor to that of the bedrock site. The proposed method was applied to four typical target sites of KNGR and APR1400 NPP site categories

Risk based seismic design criteria

International Nuclear Information System (INIS)

Kennedy, R.P.

1999-01-01

In order to develop a risk based seismic design criteria the following four issues must be addressed: (1) What target annual probability of seismic induced unacceptable performance is acceptable? (2) What minimum seismic margin is acceptable? (3) Given the decisions made under Issues 1 and 2, at what annual frequency of exceedance should the safe-shutdown-earthquake (SSE) ground motion be defined? (4) What seismic design criteria should be established to reasonably achieve the seismic margin defined under Issue 2? The first issue is purely a policy decision and is not addressed in this paper. Each of the other three issues are addressed. Issues 2 and 3 are integrally tied together so that a very large number of possible combinations of responses to these two issues can be used to achieve the target goal defined under Issue 1. Section 2 lays out a combined approach to these two issues and presents three potentially attractive combined resolutions of these two issues which reasonably achieves the target goal. The remainder of the paper discusses an approach which can be used to develop seismic design criteria aimed at achieving the desired seismic margin defined in resolution of Issue 2. Suggestions for revising existing seismic design criteria to more consistently achieve the desired seismic margin are presented. (orig.)

Siting of nuclear desalination plants in Saudi Arabia: A seismic study

International Nuclear Information System (INIS)

Aljohani, M.S.; Abdul-Fattah, A.F.; Almarshad, A.I.

2005-01-01

This paper presents the selection criteria generally and seismic criteria specifically to select a suitable site in Saudi Arabia for a nuclear desalination plant. These criteria include geological, meteorological, cooling water supply discharge, transport infrastructure, population, electric grid, water network capacity, environmental impact and airport movement. The seismicity of the Arabian peninsula for the locations of seismic activity along the Red Sea and the Arabian Gulf coastlines from 1973 to 2000 was studied carefully. This study included towns and locations along the east and west coastlines and their distances from the seismic event site. The results showed that Rabigh City along the west coast of Saudi Arabia is a good site to build a nuclear desalination plant. This is because of the following reasons: good seismic stability; good weather statistics; no flooding; mild wave conditions; good supply and discharge; good transportation infrastructure; low population area; very close to the huge electric grid. (author)

Seismic risk analysis in the German risk study phase B

International Nuclear Information System (INIS)

Hasser, D.; Liemersdorf, J.

1989-01-01

The paper discusses some aspects of the seismic risk part of the German risk study for nuclear power plants, phase B. First simplified analyses in phase A of the study allowed a rough classification of structures and systems of the PWR reference plant according to their seismic risk contribution. These studies were extended in phase B using improved models for the dynamic analyses of buildings, structures and components as well as for the probabilistic analyses of seismic loading, failure probabilities and event trees. The methodology of deriving probabilistic seismic load descriptions is explained and compared with the methods in phase A of the study and in other studies. Some details of the linear and nonlinear dynamic analyses of structures are reported, in order to demonstrate the influence of different assumptions for material behavior and failure criteria. The probabilistic structural and event tree analyses are discussed with respect to the distribution assumptions, acceptable simplifications, special results for the PWR reference plant and, finally, the influence of model uncertainties

Seismic risk analyses in the German Risk Study, phase B

International Nuclear Information System (INIS)

Hosser, D.; Liemersdorf, H.

1991-01-01

The paper discusses some aspects of the seismic risk part of the German Risk Study for Nuclear Power Plants, Phase B. First simplified analyses in Phase A of the study allowed only a rough classification of structures and systems of the PWR reference plant according to their seismic risk contribution. These studies were extended in Phase B using improved models for the dynamic analyses of buildings, structures and components as well as for the probabilistic analyses of seismic loading, failure probabilities and event trees. The methodology of deriving probabilistic seismic load descriptions is explained and compared with the methods in Phase A of the study and in other studies. Some details of the linear and nonlinear dynamic analyses of structures are reported in order to demonstrate the influence of different assumptions for material behaviour and failure criteria. The probabilistic structural and event tree analyses are discussed with respect to distribution assumptions, acceptable simplifications and model uncertainties. Some results for the PWR reference plant are given. (orig.)

Comparison of seismic margin assessment and probabilistic risk assessment in seismic IPE

International Nuclear Information System (INIS)

Reed, J.W.; Kassawara, R.P.

1993-01-01

A comparison of technical requirements and managerial issues between seismic margin assessment (SMA) and seismic probabilistic risk assessment (SPRA) in a seismic Individual Plant Examination (IPE) is presented and related to requirements for an Unresolved Safety Issue (USI) A-46 review which is required for older nuclear power plants. Advantages and disadvantages are discussed for each approach. Technical requirements reviewed for a seismic IPE include: scope of plants covered, seismic input, scope of review, selection of equipment, required experience and training of engineers, walkdown procedure, evaluation of components, relay review, containment review, quality assurance, products, documentation requirements, and closure procedure. Managerial issues discussed include regulatory acceptability, compatibility with seismic IPE, compliance with seismic IPE requirements, ease of use by utilities, and relative cost

Development of seismic hazard analysis in Japan

International Nuclear Information System (INIS)

Itoh, T.; Ishii, K.; Ishikawa, Y.; Okumura, T.

1987-01-01

In recent years, seismic risk assessment of the nuclear power plant have been conducted increasingly in various countries, particularly in the United States to evaluate probabilistically the safety of existing plants under earthquake loading. The first step of the seismic risk assessment is the seismic hazard analysis, in which the relationship between the maximum earthquake ground motions at the plant site and their annual probability of exceedance, i.e. the seismic hazard curve, is estimated. In this paper, seismic hazard curves are evaluated and examined based on historical earthquake records model, in which seismic sources are modeled with area-sources, for several different sites in Japan. A new evaluation method is also proposed to compute the response spectra of the earthquake ground motions in connection with estimating the probabilistic structural response. Finally the numerical result of probabilistic risk assessment for a base-isolated three story RC structure, in which the frequency of seismic induced structural failure is evaluated combining the seismic hazard analysis, is described briefly

Seismic Risk Assessment for the Kyrgyz Republic

Science.gov (United States)

Pittore, Massimiliano; Sousa, Luis; Grant, Damian; Fleming, Kevin; Parolai, Stefano; Fourniadis, Yannis; Free, Matthew; Moldobekov, Bolot; Takeuchi, Ko

2017-04-01

The Kyrgyz Republic is one of the most socially and economically dynamic countries in Central Asia, and one of the most endangered by earthquake hazard in the region. In order to support the government of the Kyrgyz Republic in the development of a country-level Disaster Risk Reduction strategy, a comprehensive seismic risk study has been developed with the support of the World Bank. As part of this project, state-of-the-art hazard, exposure and vulnerability models have been developed and combined into the assessment of direct physical and economic risk on residential, educational and transportation infrastructure. The seismic hazard has been modelled with three different approaches, in order to provide a comprehensive overview of the possible consequences. A probabilistic seismic hazard assessment (PSHA) approach has been used to quantitatively evaluate the distribution of expected ground shaking intensity, as constrained by the compiled earthquake catalogue and associated seismic source model. A set of specific seismic scenarios based on events generated from known fault systems have been also considered, in order to provide insight on the expected consequences in case of strong events in proximity of densely inhabited areas. Furthermore, long-span catalogues of events have been generated stochastically and employed in the probabilistic analysis of expected losses over the territory of the Kyrgyz Republic. Damage and risk estimates have been computed by using an exposure model recently developed for the country, combined with the assignment of suitable fragility/vulnerability models. The risk estimation has been carried out with spatial aggregation at the district (rayon) level. The obtained results confirm the high level of seismic risk throughout the country, also pinpointing the location of several risk hotspots, particularly in the southern districts, in correspondence with the Ferghana valley. The outcome of this project will further support the local

Hanford quarterly seismic report - 97B seismicity on and near the Hanford Site, Pasco Basin, Washington, January 1, 1997--March 31, 1997

Energy Technology Data Exchange (ETDEWEB)

Hartshorn, D.C.; Reidel, S.P.

1997-05-01

Hanford Seismic Monitoring provides an uninterrupted collection of high-quality raw and processed seismic data from the Hanford Seismic Network (HSN) for the U.S. Department of Energy and contractors. The staff also locates and identifies sources of seismic activity and monitors changes in the historical pattern of seismic activity at the Hanford Site. The data are compiled, archived, and published for use by the Hanford Site for activities ranging from waste management, Natural Phenomena Hazards assessments, and engineering design and construction. In addition, the seismic monitoring organizations works with the Hanford Site Emergency Services Organization to provide assistance in the event of an earthquake on the Hanford Site. The HSN and the Eastern Washington Regional Network (EWRN) consist of 41 individual sensor sites and 15 radio relay sites maintained by the Seismic Monitoring staff. Most stations and five relay sites are solar powered. The operational rate for the second quarter of FY97 for stations in the HSN was 97.23% and for stations of the EWRN was 99.93%. For fiscal year (FY) 1997 second quarter (97B), the acquisition computer triggered two hundred and forth-eight times. Of these triggers three were local earthquakes: one in the pre-basalt sediments, and two in the crystalline basement. The geologic and tectonic environments are discussed in the report.

Hanford quarterly seismic report - 97B seismicity on and near the Hanford Site, Pasco Basin, Washington, January 1, 1997 - March 31, 1997

International Nuclear Information System (INIS)

Hartshorn, D.C.; Reidel, S.P.

1997-05-01

Hanford Seismic Monitoring provides an uninterrupted collection of high-quality raw and processed seismic data from the Hanford Seismic Network (HSN) for the U.S. Department of Energy and contractors. The staff also locates and identifies sources of seismic activity and monitors changes in the historical pattern of seismic activity at the Hanford Site. The data are compiled, archived, and published for use by the Hanford Site for activities ranging from waste management, Natural Phenomena Hazards assessments, and engineering design and construction. In addition, the seismic monitoring organizations works with the Hanford Site Emergency Services Organization to provide assistance in the event of an earthquake on the Hanford Site. The HSN and the Eastern Washington Regional Network (EWRN) consist of 41 individual sensor sites and 15 radio relay sites maintained by the Seismic Monitoring staff. Most stations and five relay sites are solar powered. The operational rate for the second quarter of FY97 for stations in the HSN was 97.23% and for stations of the EWRN was 99.93%. For fiscal year (FY) 1997 second quarter (97B), the acquisition computer triggered two hundred and forth-eight times. Of these triggers three were local earthquakes: one in the pre-basalt sediments, and two in the crystalline basement. The geologic and tectonic environments are discussed in the report

Adapting standards to the site. Example of Seismic Base Isolation

International Nuclear Information System (INIS)

Viallet, Emmanuel

2014-01-01

Emmanuel Viallet, Civil Design Manager at EDF engineering center SEPTEN, concluded the morning's lectures with a presentation on how to adapt a standard design to site characteristics. He presented the example of the seismic isolation of the Cruas NPP for which the standard 900 MW design was indeed built on 'anti-seismic pads' to withstand local seismic load

Non-invasive shallow seismic source comparison for hazardous waste site investigations

International Nuclear Information System (INIS)

Doll, W.E.

1994-01-01

Many commonly used shallow seismic sources are unacceptable for hazardous waste site investigations because they risk exhumation of contaminants in the soil, they add contaminants (e.g. lead) which are not allowed by regulations, or they add new migration paths for contaminants. Furthermore, recently developed high frequency vibrators for shallow investigations could be more effective at some sites than non-invasive impulsive sources because of their ability to tailor the source spectrum and reduce interference. The authors show preliminary results of a comparison test of eight non-invasive impulsive and swept sources in preparation for seismic reflection profiling on the Oak Ridge Reservation, Tennessee. Well log data are used to determine geologic contacts and to generate synthetic seismograms for the site. Common midpoint (CMP) seismic data for each source were collected at 95 geophone groups from 125 shot points along a 400m test line. Hydrophone data were obtained at 1.5m spacing between 61m and 133m depth in a hole near the center of the CMP line. As of March, 1994, brute stacks have been completed for three of the eight sources. Depth penetration is demonstrated in brute stacks and shot gathers, which show a 200ms reflector for all of the sources tested along portions of the line. Source effectiveness will also be evaluated by comparing images of several shallower reflectors (40--150ms) which are apparent in many of the records. Imaging of these reflectors appears to depend upon the ability of the source to generate sufficient high frequency energy (>100 Hz)

Seismic rupture modelling, strong motion prediction and seismic hazard assessment: fundamental and applied approaches

International Nuclear Information System (INIS)

Berge-Thierry, C.

2007-05-01

The defence to obtain the 'Habilitation a Diriger des Recherches' is a synthesis of the research work performed since the end of my Ph D. thesis in 1997. This synthesis covers the two years as post doctoral researcher at the Bureau d'Evaluation des Risques Sismiques at the Institut de Protection (BERSSIN), and the seven consecutive years as seismologist and head of the BERSSIN team. This work and the research project are presented in the framework of the seismic risk topic, and particularly with respect to the seismic hazard assessment. Seismic risk combines seismic hazard and vulnerability. Vulnerability combines the strength of building structures and the human and economical consequences in case of structural failure. Seismic hazard is usually defined in terms of plausible seismic motion (soil acceleration or velocity) in a site for a given time period. Either for the regulatory context or the structural specificity (conventional structure or high risk construction), seismic hazard assessment needs: to identify and locate the seismic sources (zones or faults), to characterize their activity, to evaluate the seismic motion to which the structure has to resist (including the site effects). I specialized in the field of numerical strong-motion prediction using high frequency seismic sources modelling and forming part of the IRSN allowed me to rapidly working on the different tasks of seismic hazard assessment. Thanks to the expertise practice and the participation to the regulation evolution (nuclear power plants, conventional and chemical structures), I have been able to work on empirical strong-motion prediction, including site effects. Specific questions related to the interface between seismologists and structural engineers are also presented, especially the quantification of uncertainties. This is part of the research work initiated to improve the selection of the input ground motion in designing or verifying the stability of structures. (author)

Seismic Hazards in Site Evaluation for Nuclear Installations. Specific Safety Guide

Energy Technology Data Exchange (ETDEWEB)

NONE

2010-08-15

This Safety Guide was prepared under the IAEA programme for safety standards for nuclear installations. It supplements the Safety Requirements publication on Site Evaluation for Nuclear Installations. The present publication provides guidance and recommends procedures for the evaluation of seismic hazards for nuclear power plants and other nuclear installations. It supersedes Evaluation of Seismic Hazards for Nuclear Power Plants, IAEA Safety Standards Series No. NS-G-3.3 (2002). In this publication, the following was taken into account: the need for seismic hazard curves and ground motion spectra for the probabilistic safety assessment of external events for new and existing nuclear installations; feedback of information from IAEA reviews of seismic safety studies for nuclear installations performed over the previous decade; collective knowledge gained from recent significant earthquakes; and new approaches in methods of analysis, particularly in the areas of probabilistic seismic hazard analysis and strong motion simulation. In the evaluation of a site for a nuclear installation, engineering solutions will generally be available to mitigate, by means of certain design features, the potential vibratory effects of earthquakes. However, such solutions cannot always be demonstrated to be adequate for mitigating the effects of phenomena of significant permanent ground displacement such as surface faulting, subsidence, ground collapse or fault creep. The objective of this Safety Guide is to provide recommendations and guidance on evaluating seismic hazards at a nuclear installation site and, in particular, on how to determine: (a) the vibratory ground motion hazards, in order to establish the design basis ground motions and other relevant parameters for both new and existing nuclear installations; and (b) the potential for fault displacement and the rate of fault displacement that could affect the feasibility of the site or the safe operation of the installation at

Risk management considerations for seismic upgrading of an older facility for short-term residue stabilization

International Nuclear Information System (INIS)

Additon, S.L.; Peregoy, W.L.; Foppe, T.L.

1999-01-01

Building 707 and its addition, Building 707A, were selected, after the production mission of Rocky Flats was terminated a few years ago, to stabilize many of the plutonium residues remaining at the site by 2002. The facility had undergone substantial safety improvements to its safety systems and conduct of operations for resumption of plutonium operations in the early 1990s and appeared ideally suited for this new mission to support accelerated Site closure. During development of a new authorization basis, a seismic evaluation was performed. This evaluation addressed an unanalyzed expansion joint and suspect connection details for the precast concrete tilt-up construction and concluded that the seismic capacity of the facility is less than half of that determined by previous analysis. Further, potential seismic interaction was identified between a collapsing Building 707 and the seismically upgraded Building 707A, possibly causing the partial collapse of the latter. Both the operating contractor and the Department of Energy sought a sound technical basis for deciding how to proceed. This paper addresses the risks of the as-is facility and possible benefits of upgrades to support a decision on whether to upgrade the seismic capacity of Building 707, accept the risk of the as-is facility for its short remaining mission, or relocate critical stabilization missions. The paper also addresses the Department of Energy's policy on natural phenomena

New Site Coefficients and Site Classification System Used in Recent Building Seismic Code Provisions

Science.gov (United States)

Dobry, R.; Borcherdt, R.D.; Crouse, C.B.; Idriss, I.M.; Joyner, W.B.; Martin, G.R.; Power, M.S.; Rinne, E.E.; Seed, R.B.

2000-01-01

Recent code provisions for buildings and other structures (1994 and 1997 NEHRP Provisions, 1997 UBC) have adopted new site amplification factors and a new procedure for site classification. Two amplitude-dependent site amplification factors are specified: Fa for short periods and Fv for longer periods. Previous codes included only a long period factor S and did not provide for a short period amplification factor. The new site classification system is based on definitions of five site classes in terms of a representative average shear wave velocity to a depth of 30 m (V?? s). This definition permits sites to be classified unambiguously. When the shear wave velocity is not available, other soil properties such as standard penetration resistance or undrained shear strength can be used. The new site classes denoted by letters A - E, replace site classes in previous codes denoted by S1 - S4. Site classes A and B correspond to hard rock and rock, Site Class C corresponds to soft rock and very stiff / very dense soil, and Site Classes D and E correspond to stiff soil and soft soil. A sixth site class, F, is defined for soils requiring site-specific evaluations. Both Fa and Fv are functions of the site class, and also of the level of seismic hazard on rock, defined by parameters such as Aa and Av (1994 NEHRP Provisions), Ss and S1 (1997 NEHRP Provisions) or Z (1997 UBC). The values of Fa and Fv decrease as the seismic hazard on rock increases due to soil nonlinearity. The greatest impact of the new factors Fa and Fv as compared with the old S factors occurs in areas of low-to-medium seismic hazard. This paper summarizes the new site provisions, explains the basis for them, and discusses ongoing studies of site amplification in recent earthquakes that may influence future code developments.

Hanford annual first quarter seismic report, fiscal year 1998: Seismicity on and near the Hanford Site, Pasco Basin, Washington

Energy Technology Data Exchange (ETDEWEB)

Hartshorn, D.C.; Reidel, S.P.; Rohay, A.C.

1998-02-01

Hanford Seismic Monitoring provides an uninterrupted collection of high-quality raw and processed seismic data from the Hanford Seismic Network (HSN) for the US Department of Energy and its contractors. The staff also locates and identifies sources of seismic activity and monitors changes in the historical pattern of seismic activity at the hanford Site. The data are compiled, archived, and published for use by the Hanford Site for waste management, Natural Phenomena Hazards assessments, and engineering design and construction. In addition, the seismic monitoring organization works with the Hanford Site Emergency Services Organization to provide assistance in the event of an earthquake on the Hanford Site. The HSN and the Eastern Washington Regional Network (EWRN) consist of 41 individual sensor sites and 15 radio relay sites maintained by the Hanford Seismic Monitoring staff. The operational rate for the first quarter of FY98 for stations in the HSN was 98.5%. The operational rate for the first quarter of FY98 for stations of the EWRN was 99.1%. For the first quarter of FY98, the acquisition computer triggered 184 times. Of these triggers 23 were local earthquakes: 7 in the Columbia River Basalt Group, and 16 in the crystalline basement. The geologic and tectonic environments where these earthquakes occurred are discussed in this report. The most significant earthquakes in this quarter were a series of six events which occurred in the Cold Creek depression (approximately 4 km SW of the 200 West Area), between November 6 and November 11, 1997. All events were deep (> 15 km) and were located in the crystalline basement. The first event was the largest, having a magnitude of 3.49 M{sub c}. Two events on November 9, 1997 had magnitudes of 2.81 and 2.95 M{sub c}, respectively. The other events had magnitudes between 0.7 and 1.2 M{sub c}.

Seismic risk and heavy industrial facilities conference: proceedings

International Nuclear Information System (INIS)

1983-01-01

Summaries of over 50 papers related to seismic risk analysis were presented. The papers cover areas such as seismic input description, response of components and structures, assessment of risk and reliability including human factors, and results of integrated studies. Papers have been individually abstracted for the Energy Data Base

Progressive Seismic Failure, Seismic Gap, and Great Seismic Risk across the Densely Populated North China Basin

Science.gov (United States)

Yin, A.; Yu, X.; Shen, Z.

2014-12-01

Although the seismically active North China basin has the most complete written records of pre-instrumentation earthquakes in the world, this information has not been fully utilized for assessing potential earthquake hazards of this densely populated region that hosts ~200 million people. In this study, we use the historical records to document the earthquake migration pattern and the existence of a 180-km seismic gap along the 600-km long right-slip Tangshan-Hejian-Cixian (THC) fault zone that cuts across the North China basin. The newly recognized seismic gap, which is centered at Tianjin with a population of 11 million people and ~120 km from Beijing (22 million people) and Tangshan (7 million people), has not been ruptured in the past 1000 years by M≥6 earthquakes. The seismic migration pattern in the past millennium suggests that the epicenters of major earthquakes have shifted towards this seismic gap along the THC fault, which implies that the 180- km gap could be the site of the next great earthquake with M≈7.6 if it is ruptured by a single event. Alternatively, the seismic gap may be explained by aseismic creeping or seismic strain transfer between active faults.

Hanford Quarter Seismic Report - 98C Seismicity On and Near the Hanford Site, Pasco Basin, Washington: April 1, 1998 Through June 30, 1998

Energy Technology Data Exchange (ETDEWEB)

DC Hartshorn, SP Reidel, AC Rohay

1998-10-23

Hanford Seismic Monitoring provides an uninterrupted collection of high-quality raw and processed seismic data from the Hanford Seismic Network (HSN) for the U.S. Department of Energy and its contractors. The staff also locates aud identifies sources of seismic activity and monitors changes in the hi~orical pattern of seismic activity at the Hanford Site. The data are. compiled archived, and published for use by the Hanford Site for waste management Natural Phenomena Hazards assessments, and engineering design and construction. In addition, the seismic monitoring organization works with the Hanford Site Emergency Services Organization to provide assistance in the event of zin earthquake on the Hanford Site. The HSN and Ihe Eastern Washington Regional Network (EN/RN) consist-of 42 individual sensor sites and 15 radio relay sites maintained by the Hanford Seismic Monitoring staff. The operational rate for the third quarter of FY 1998 for stations in the HSN was 99.99%. The operational rate for the third quarter of FY 1998 for stations of the EWRN was 99.95%. For the third quarter of FY 1998, the acquisition computer triggered 133 times. Of these triggers 11 were local earthquakes: 5 (45Yo) in the Columbia River Basalt Group, 2(1 8%) in the pre-basalt sediments, and 4 (36%) in the crystalline basement. The geologic and tectonic environments where these earthquakes occurred are discussed in this report.

Seismic qualification of equipment by means of probabilistic risk assessment

International Nuclear Information System (INIS)

Azarm, M.A.; Farahzad, P.; Boccio, J.L.

1982-01-01

Upon the sponsorship of the Equipment Qualification Branch (EQB) of NRC, Brookhaven National Laboratory (BNL) has utilized a risk-based approach for identifying, in a generic fashion, seismically risk-sensitive equipment. It is anticipated that the conclusions drawn therefrom and the methodology employed will, in part, reconcile some of the concerns dealing with the seismic qualification of equipment in operating plants. The approach taken augments an existing sensitivity analysis, based upon the WASH-1400 Reactor Safety Study (RSS), by accounting for seismicity and component fragility with the Kennedy model and by essentially including the requisite seismic data presented in the Zion Probabilistic Safety Study (ZPSS). Parametrically adjusting the seismic-related variables and ascertaining their effects on overall plant risk, core-melt probability, accident sequence probability, etc., allows one to identify those seismically risk-sensitive systems and equipment. This paper describes the approach taken and highlights the results obtained thus far for a hypothetical pressurized water reactor

Probabilistic Seismic Hazard at the Archaeological Site of Gol ...

Indian Academy of Sciences (India)

9

seismic risk assessment and design of seismic protection measures for monuments, ... carried out by taking into account three scenario earthquakes. ... NGA-W2, NGA-East, pan-European models) is anticipated to minimise the ... Heritage structures are precious as they form inextricable components of history, culture and.

Hanford quarterly seismic report - 97C seismicity on and near the Hanford Site, Pasco Basin, Washington. Quarterly report, April 1, 1997--June 30, 1997

Energy Technology Data Exchange (ETDEWEB)

Hartshorn, D.C.; Reidel, S.P.; Rohay, A.C.

1997-08-01

Hanford Seismic Monitoring provides an uninterrupted collection of high-quality raw and processed seismic data from the Hanford Seismic Network (HSN) for the U.S. Department of Energy and contractors. The staff also locates and identifies sources of seismic activity and monitors changes in the historical pattern of seismic activity at the Hanford Site. The data are compiled, archived, and published for use by the Hanford Site for activities ranging from waste management, Natural Phenomena Hazards assessments, and engineering design and construction. In addition, the seismic monitoring organization works with the Hanford Site Emergency Services Organization to provide assistance in the event of an earthquake on the Hanford Site. The HSN and the Eastern Washington Regional Network (EWRN) consist of 41 individual sensor sites and 15 radio relay sites maintained by the Seismic Monitoring staff. Most stations and five relay sites are solar powered. The operational rate for the second quarter of FY97 for stations in the HSN was 100% and for stations of the EWRN was 99.99%. For fiscal year (FY) 1997 third quarter (97C), the acquisition computer triggered 183. Of these triggers twenty one were local earthquakes: sixteen in the Columbus River Basalt Group, one in the pre-basalt sediments, and four in the crystalline basement. The geologic and tectonic environments are discussed in the report.

Applicability of deterministic methods in seismic site effects modeling

International Nuclear Information System (INIS)

Cioflan, C.O.; Radulian, M.; Apostol, B.F.; Ciucu, C.

2005-01-01

The up-to-date information related to local geological structure in the Bucharest urban area has been integrated in complex analyses of the seismic ground motion simulation using deterministic procedures. The data recorded for the Vrancea intermediate-depth large earthquakes are supplemented with synthetic computations all over the city area. The hybrid method with a double-couple seismic source approximation and a relatively simple regional and local structure models allows a satisfactory reproduction of the strong motion records in the frequency domain (0.05-1)Hz. The new geological information and a deterministic analytical method which combine the modal summation technique, applied to model the seismic wave propagation between the seismic source and the studied sites, with the mode coupling approach used to model the seismic wave propagation through the local sedimentary structure of the target site, allows to extend the modelling to higher frequencies of earthquake engineering interest. The results of these studies (synthetic time histories of the ground motion parameters, absolute and relative response spectra etc) for the last 3 Vrancea strong events (August 31,1986 M w =7.1; May 30,1990 M w = 6.9 and October 27, 2004 M w = 6.0) can complete the strong motion database used for the microzonation purposes. Implications and integration of the deterministic results into the urban planning and disaster management strategies are also discussed. (authors)

Validation of seismic probabilistic risk assessments of nuclear power plants

International Nuclear Information System (INIS)

Ellingwood, B.

1994-01-01

A seismic probabilistic risk assessment (PRA) of a nuclear plant requires identification and information regarding the seismic hazard at the plant site, dominant accident sequences leading to core damage, and structure and equipment fragilities. Uncertainties are associated with each of these ingredients of a PRA. Sources of uncertainty due to seismic hazard and assumptions underlying the component fragility modeling may be significant contributors to uncertainty in estimates of core damage probability. Design and construction errors also may be important in some instances. When these uncertainties are propagated through the PRA, the frequency distribution of core damage probability may span three orders of magnitude or more. This large variability brings into question the credibility of PRA methods and the usefulness of insights to be gained from a PRA. The sensitivity of accident sequence probabilities and high-confidence, low probability of failure (HCLPF) plant fragilities to seismic hazard and fragility modeling assumptions was examined for three nuclear power plants. Mean accident sequence probabilities were found to be relatively insensitive (by a factor of two or less) to: uncertainty in the coefficient of variation (logarithmic standard deviation) describing inherent randomness in component fragility; truncation of lower tail of fragility; uncertainty in random (non-seismic) equipment failures (e.g., diesel generators); correlation between component capacities; and functional form of fragility family. On the other hand, the accident sequence probabilities, expressed in the form of a frequency distribution, are affected significantly by the seismic hazard modeling, including slopes of seismic hazard curves and likelihoods assigned to those curves

Site Specific Probabilistic Seismic Hazard and Risk Analysis for Surrounding Communities of The Geysers Geothermal Development Area

Science.gov (United States)

Miah, M.; Hutchings, L. J.; Savy, J. B.

2014-12-01

We conduct a probabilistic seismic hazard and risk analysis from induced and tectonic earthquakes for a 50 km radius area centered on The Geysers, California and for the next ten years. We calculate hazard with both a conventional and physics-based approach. We estimate site specific hazard. We convert hazard to risk of nuisance and damage to structures per year and map the risk. For the conventional PSHA we assume the past ten years is indicative of hazard for the next ten years from Mnoise. Then, we interpolate within each geologic unit in finely gridded points. All grid points within a unit are weighted by distance from each data collection point. The entire process is repeated for all of the other types of geologic units until the entire area is gridded and assigned a hazard value for every grid points. We found that nuisance and damage risks calculated by both conventional and physics-based approaches provided almost identical results. This is very surprising since they were calculated by completely independent means. The conventional approach used the actual catalog of the past ten years of earthquakes to estimate the hazard for the next ten year. While the physics-based approach used geotechnical modeling to calculate the catalog for the next ten years. Similarly, for the conventional PSHA, we utilized attenuation relations from past earthquakes recorded at the Geysers to translate the ground motion from the source to the site. While for the physics-based approach we calculated ground motion from simulation of actual earthquake rupture. Finally, the source of the earthquakes was the actual source for the conventional PSHA. While, we assumed random fractures for the physics-based approach. From all this, we consider the calculation of the conventional approach, based on actual data, to validate the physics-based approach used.

Seismic risk maps of Switzerland

International Nuclear Information System (INIS)

Saegesser, R.; Rast, B.; Merz, H.

1977-01-01

Seismic Risk Maps of Switzerland have been developed under the auspices of the Swiss Federal Division on Nuclear Safety. They are primarily destined for the use of owners of future nuclear power plants. The results will be mandatory for these future sites. The results will be shown as contourmaps of equal intensities for average return periods of 500, 1 000, 10 000... years. This general form will not restrict the use of the results to nuclear power plants only, rather allows their applicability to any site or installation of public interest (such as r.a. waste deposits, hydropower plants, etc.). This follows the recommendations of the UNESCO World Conference (Paris, February 1976). In the study MSK 64 INTENSITY was chosen. The detailed scale allowed a precise handling of historical data and separates the results from continuously changing state of the art correlations to acceleration and other input motion parameters. The method used is the probabilistic theory developed by C.A. Cornell and others at MIT in the late 1960's with the program in the version of the US Geological Survey by R. McGuire. (Auth.)

A Site Characterization Protocol for Evaluating the Potential for Triggered or Induced Seismicity Resulting from Wastewater Injection and Hydraulic Fracturing

Science.gov (United States)

Walters, R. J.; Zoback, M. D.; Gupta, A.; Baker, J.; Beroza, G. C.

2014-12-01

Regulatory and governmental agencies, individual companies and industry groups and others have recently proposed, or are developing, guidelines aimed at reducing the risk associated with earthquakes triggered by waste water injection or hydraulic fracturing. While there are a number of elements common to the guidelines proposed, not surprisingly, there are also some significant differences among them and, in a number of cases, important considerations that are not addressed. The goal of this work is to develop a comprehensive protocol for site characterization based on a rigorous scientific understanding of the responsible processes. Topics addressed will include the geologic setting (emphasizing faults that might be affected), historical seismicity, hydraulic characterization of injection and adjacent intervals, geomechanical characterization to identify potentially active faults, plans for seismic monitoring and reporting, plans for monitoring and reporting injection (pressure, volumes, and rates), other factors contributing to risk (potentially affected population centers, structures, and facilities), and implementing a modified Probabilistic Seismic Hazard Analysis (PSHA). The guidelines will be risk based and adaptable, rather than prescriptive, for a proposed activity and region of interest. They will be goal oriented and will rely, to the degree possible, on established best practice procedures, referring to existing procedures and recommendations. By developing a risk-based site characterization protocol, we hope to contribute to the development of rational and effective measures for reducing the risk posed by activities that potentially trigger earthquakes.

Seismicity, seismic input and site effects in the Sahel-Algiers region (north Algeria)

International Nuclear Information System (INIS)

Harbi, A.; Maouche, S.; Oussadou, F.; Vaccari, F.; Aoudia, A.; Panza, G.F.; Benouar, D.

2005-07-01

Algiers city is located in a seismogenic zone. To reduce the impact of seismic risk in this capital city, a realistic modelling of the seismic ground motion using the hybrid method that combines the finite-differences method and the modal summation, is conducted. For this purpose, a complete database in terms of geological, geophysical and earthquake data is constructed. A critical re-appraisal of the seismicity of the zone (2.25 deg. E-3.50 deg. E, 36.50 deg. N-37.00 deg. N) is performed and an earthquake list, for the period 1359-2002, is compiled. The analysis of existing and newly retrieved macroseismic information allowed the definition of earthquake parameters of macroseismic events for which a degree of reliability is assigned. Geological cross-sections have been built up to model the seismic ground motion in the city, caused by the 1989 Mont-Chenoua and the 1924 Douera earthquakes; a set of synthetic seismograms and response spectral ratio is produced for Algiers. The numerical results show that the soft sediments in Algiers centre are responsible of the noticed amplification of the seismic ground motion. (author)

Towards Improved Considerations of Risk in Seismic Design (Plinius Medal Lecture)

Science.gov (United States)

Sullivan, T. J.

2012-04-01

The aftermath of recent earthquakes is a reminder that seismic risk is a very relevant issue for our communities. Implicit within the seismic design standards currently in place around the world is that minimum acceptable levels of seismic risk will be ensured through design in accordance with the codes. All the same, none of the design standards specify what the minimum acceptable level of seismic risk actually is. Instead, a series of deterministic limit states are set which engineers then demonstrate are satisfied for their structure, typically through the use of elastic dynamic analyses adjusted to account for non-linear response using a set of empirical correction factors. From the early nineties the seismic engineering community has begun to recognise numerous fundamental shortcomings with such seismic design procedures in modern codes. Deficiencies include the use of elastic dynamic analysis for the prediction of inelastic force distributions, the assignment of uniform behaviour factors for structural typologies irrespective of the structural proportions and expected deformation demands, and the assumption that hysteretic properties of a structure do not affect the seismic displacement demands, amongst other things. In light of this a number of possibilities have emerged for improved control of risk through seismic design, with several innovative displacement-based seismic design methods now well developed. For a specific seismic design intensity, such methods provide a more rational means of controlling the response of a structure to satisfy performance limit states. While the development of such methodologies does mark a significant step forward for the control of seismic risk, they do not, on their own, identify the seismic risk of a newly designed structure. In the U.S. a rather elaborate performance-based earthquake engineering (PBEE) framework is under development, with the aim of providing seismic loss estimates for new buildings. The PBEE framework

Characterization of Seismic Noise at Selected Non-Urban Sites

Science.gov (United States)

2010-03-01

Field sites for seismic recordings: Scottish moor (upper left), Enfield, NH (upper right), and vicinity of Keele, England (bottom). ERDC...three sites. The sites are: a wind farm on a remote moor in Scotland, a ~13 acre field bounded by woods in a rural Enfield, NH neigh- borhood, and a site...in a rural Enfield, NH, neighborhood, and a site transitional from developed land to farmland within 1 km of the six-lane M6 motorway near Keele

FE Modelling of the Seismic Behavior of Wide Beam-Column Joints Strengthened with CFRP Systems

Directory of Open Access Journals (Sweden)

Giuseppe Santarsiero

2018-02-01

Full Text Available A large share of reinforced concrete (RC framed buildings is provided with wide beams being a type of beam allowing greater freedom in the architectural arrangement of interiors, beyond further advantage due to fewer formworks needed during the construction. Nevertheless, little attention has been devoted to the seismic vulnerability of this kind of framed RC buildings as well as to the study of strengthening systems purposely developed for wide beams and wide beam-column connections. Under these premises, this paper proposes simple strengthening solutions made by Fibre Reinforced Polymers (FRP systems able to effectively improve seismic capacity through feasible arrangement suitable in case a wide beam is present. On the basis of wide beam-column joints previously tested without strengthening system, detailed nonlinear finite element models were calibrated. Then, an FRP strengthening intervention based on a brand new arrangement was modeled in order to perform additional simulations under seismic actions. This way, the effectiveness of the strengthening intervention was assessed finding out that significant strength and ductility increments were achieved with a relatively simple and cheap strengthening arrangement. Additional research would be desirable in the form of experimental tests on the simulated wide beam-column joints.

Site study plan for EDBH [Engineering Design Boreholes] seismic surveys, Deaf Smith County site, Texas: Revision 1

International Nuclear Information System (INIS)

Hume, H.

1987-12-01

This site study plan describes seismic reflection surveys to run north-south and east-west across the Deaf Smith County site, and intersecting near the Engineering Design Boreholes (EDBH). Both conventional and shallow high-resolution surveys will be run. The field program has been designed to acquire subsurface geologic and stratigraphic data to address information/data needs resulting from Federal and State regulations and Repository program requirements. The data acquired by the conventional surveys will be common-depth- point, seismic reflection data optimized for reflection events that indicate geologic structure near the repository horizon. The data will also resolve the basement structure and shallow reflection events up to about the top of the evaporite sequence. Field acquisition includes a testing phase to check/select parameters and a production phase. The field data will be subjected immediately to conventional data processing and interpretation to determine if there are any anamolous structural for stratigraphic conditions that could affect the choice of the EDBH sites. After the EDBH's have been drilled and logged, including vertical seismic profiling, the data will be reprocessed and reinterpreted for detailed structural and stratigraphic information to guide shaft development. The shallow high-resulition seismic reflection lines will be run along the same alignments, but the lines will be shorter and limited to immediate vicinity of the EDBH sites. These lines are planned to detect faults or thick channel sands that may be present at the EDBH sites. 23 refs. , 7 figs., 5 tabs

Coupling mode-destination accessibility with seismic risk assessment to identify at-risk communities

International Nuclear Information System (INIS)

Miller, Mahalia; Baker, Jack W.

2016-01-01

In this paper, we develop a framework for coupling mode-destination accessibility with quantitative seismic risk assessment to identify communities at high risk for travel disruptions after an earthquake. Mode-destination accessibility measures the ability of people to reach destinations they desire. We use a probabilistic seismic risk assessment procedure, including a stochastic set of earthquake events, ground-motion intensity maps, damage maps, and realizations of traffic and accessibility impacts. For a case study of the San Francisco Bay Area, we couple our seismic risk framework with a practical activity-based traffic model. As a result, we quantify accessibility risk probabilistically by community and household type. We find that accessibility varies more strongly as a function of travelers' geographic location than as a function of their income class, and we identify particularly at-risk communities. We also observe that communities more conducive to local trips by foot or bike are predicted to be less impacted by losses in accessibility. This work shows the potential to link quantitative risk assessment methodologies with high-resolution travel models used by transportation planners. Quantitative risk metrics of this type should have great utility for planners working to reduce risk to a region's infrastructure systems. - Highlights: • We couple mode-destination accessibility with probabilistic seismic risk assessment. • Results identify communities at high risk for post-earthquake travel disruptions. • Accessibility varies more as a function of home location than by income. • Our model predicts reduced accessibility risk for more walking-friendly communities.

Seismotectonic Conditions and Seismic Risk in Gori

International Nuclear Information System (INIS)

Varazanashvili, O.; Tsereteli, N.; Sumbadze, B.; Mukhadze, T.

2006-01-01

The seismic history and seismotectonic conditions of earthquake initiation are investigated in Gori and surrounding area. The main parameters of the newly discovered past earthquake at Takhtisdziri are estimated. The levels of seismic risk of 7,8 and 9 intensity scenario earthquakes estimated in Gori. Also damage of sity caused by destroying Kartli earthquake of 1920 is estimated. (author)

Seismic surface wave tomography of waste sites. 1997 annual progress report

International Nuclear Information System (INIS)

Long, T.L.

1997-01-01

'The objective of the Seismic Surface Wave Tomography of Waste Sites is to develop a robust technique for field acquisition and analysis of surface wave data for the interpretation of shallow structures, such as those associated with the burial of wastes. The analysis technique is to be developed and tested on an existing set of seismic data covering the K-901 burial site at the East Tennessee Technology Park. Also, a portable prototype for a field acquisition system will be designed and developed to obtain additional data for analysis and testing of the technique. The K-901 data have been examined and a preliminary Single Valued Decomposition inversion has been obtained. The preliminary data indicates a need for additional seismic data to ground-truth the inversion. The originally proposed gravity data acquisition has been dropped because sufficient gravity data are now available for a preliminary analysis and because the seismic data are considered more critical to the interpretation. The proposed prototype for the portable acquisition and analysis system was developed during the first year and will be used in part of the acquisition of additional seismic data.'

Site-specific probabilistic seismic hazard analyses for the Idaho National Engineering Laboratory. Volume 1: Final report

International Nuclear Information System (INIS)

1996-05-01

This report describes and summarizes a probabilistic evaluation of ground motions for the Idaho National Engineering Laboratory (INEL). The purpose of this evaluation is to provide a basis for updating the seismic design criteria for the INEL. In this study, site-specific seismic hazard curves were developed for seven facility sites as prescribed by DOE Standards 1022-93 and 1023-96. These sites include the: Advanced Test Reactor (ATR); Argonne National Laboratory West (ANL); Idaho Chemical Processing Plant (ICPP or CPP); Power Burst Facility (PBF); Radioactive Waste Management Complex (RWMC); Naval Reactor Facility (NRF); and Test Area North (TAN). The results, probabilistic peak ground accelerations and uniform hazard spectra, contained in this report are not to be used for purposes of seismic design at INEL. A subsequent study will be performed to translate the results of this probabilistic seismic hazard analysis to site-specific seismic design values for the INEL as per the requirements of DOE Standard 1020-94. These site-specific seismic design values will be incorporated into the INEL Architectural and Engineering Standards

Seismic risk map of Korea

International Nuclear Information System (INIS)

Lee, S.H.; Lee, Y.K.; Eum, S.H.; Yang, S.J.; Chun, M.S.

1983-01-01

A study on seismic hazard level in Korea has been performed and the main results of the study are summarized as follows: 1. Historians suggest that the quality of historical earthquake data may be accurate in some degree and the data should be used in seismic risk analysis. 2. The historical damage events are conformed in historical literatures and their intensities are re-evaluated by joint researchers. The maximum MM intensity of them is VIII evaluated for 17 events. 3. The relation of earthquakes to surface fault is not clear. It seems resonable to related them to tectonic provinces. 4. Statistical seismic risk analysis shows that the acceleration expected within 50O year return period is less than 0.25G when only instrumental earthquakes are used and less than 0.10G if all of instrumental and historical earthquakes are used. The acceleration in Western Coast and Kyungsang area is higher than the other regions in Korea. 5. The maximum horizontal acceleration determined by conservative method is 0.26G when historical earthquake data are used and less than 0.20G if only instrumental earthquakes are used. The return period of 0.26G is 240 years in Kyungsang province and longer in other provinces. (Author)

Development of seismic risk analysis methodologies at JAERI

International Nuclear Information System (INIS)

Tanaka, T.; Abe, K.; Ebisawa, K.; Oikawa, T.

1988-01-01

The usefulness of probabilistic safety assessment (PSA) is recognized worldwidely for balanced design and regulation of nuclear power plants. In Japan, the Japan Atomic Energy Research Institute (JAERI) has been engaged in developing methodologies necessary for carrying out PSA. The research and development program was started in 1980. In those days the effort was only for internal initiator PSA. In 1985 the program was expanded so as to include external event analysis. Although this expanded program is to cover various external initiators, the current effort is dedicated for seismic risk analysis. There are three levels of seismic PSA, similarly to internal initiator PSA: Level 1: Evaluation of core damage frequency, Level 2: Evaluation of radioactive release frequency and source terms, and Level 3: Evaluation of environmental consequence. In the JAERI's program, only the methodologies for level 1 seismic PSA are under development. The methodology development for seismic risk analysis is divided into two phases. The Phase I study is to establish a whole set of simple methodologies based on currently available data. In the Phase II, Sensitivity study will be carried out to identify the parameters whose uncertainty may result in lage uncertainty in seismic risk, and For such parameters, the methodology will be upgraded. Now the Phase I study has almost been completed. In this report, outlines of the study and some of its outcomes are described

Historical seismicity in France. Its role in the assessment of seismic risk on French nuclear sites

International Nuclear Information System (INIS)

Levret, A.

1987-11-01

Since 1975 in order to be in conformity with the requirements of the French nuclear program, a review of historical seismicity was undertaken in France. The assessment of seismic hazard for the safety of nuclear plants is in fact based upon a seismotectonic approach which needs to take into account the seismic activity over as long a period of time as possible. The method adopted for reviewing historical earthquakes entails a systematic consultation of the original sources and a critical analysis there of in the light of the historical, geographical and political contexts of the time. The same standards apply where the acquisition of new elements of information is involved. Each item of information is assigned a degree of reliability, then compiled in a computer file, up-dated annually; this file currently contains more than 4.500 events covering a period of time of about a millenary

Seismic Risk Assessment of Italian Seaports Using GIS

International Nuclear Information System (INIS)

Bartolomei, Anna; Corigliano, Mirko; Lai, Carlo G.

2008-01-01

Seaports are crucial elements in the export and import of goods and/or on the flow of travellers in the tourism industry of many industrialised nations included Italy. Experience gained from recent earthquakes (e.g. 1989 Loma Prieta in USA, 1995 Hyogoken-Nanbu and 2003 Tokachi-Oki in Japan) have dramatically demonstrated the seismic vulnerability of seaport structures and the severe damage that can be caused by ground shaking. In Italy, the Department of Civil Protection has funded a research project to develop a methodology for the seismic design of new marginal wharves and assessment of existing structures at seaports located in areas of medium or high seismicity. This paper shows part of the results of this research project, currently underway, with particular reference to the seismic risk assessment through an interactive, geographically referenced database (GIS). Standard risk assessment have been carried out for the Gioia Tauro port in Calabria (Italy) using the empirical curves implemented by the National Institute of Building Sciences (NIBS, 2004)

Seismic Risk Assessment of Italian Seaports Using GIS

Science.gov (United States)

Bartolomei, Anna; Corigliano, Mirko; Lai, Carlo G.

2008-07-01

Seaports are crucial elements in the export and import of goods and/or on the flow of travellers in the tourism industry of many industrialised nations included Italy. Experience gained from recent earthquakes (e.g. 1989 Loma Prieta in USA, 1995 Hyogoken-Nanbu and 2003 Tokachi-Oki in Japan) have dramatically demonstrated the seismic vulnerability of seaport structures and the severe damage that can be caused by ground shaking. In Italy, the Department of Civil Protection has funded a research project to develop a methodology for the seismic design of new marginal wharves and assessment of existing structures at seaports located in areas of medium or high seismicity. This paper shows part of the results of this research project, currently underway, with particular reference to the seismic risk assessment through an interactive, geographically referenced database (GIS). Standard risk assessment have been carried out for the Gioia Tauro port in Calabria (Italy) using the empirical curves implemented by the National Institute of Building Sciences (NIBS, 2004).

The Contribution of Palaeoseismology to Seismic Hazard Assessment in Site Evaluation for Nuclear Installations

International Nuclear Information System (INIS)

2015-06-01

IAEA Safety Standards Series No. SSG-9, Seismic Hazards in Site Evaluation for Nuclear Installations, published in 2010, covers all aspects of site evaluation relating to seismic hazards and recommends the use of prehistoric, historical and instrumental earthquake data in seismic hazard assessments. Prehistoric data on earthquakes cover a much longer period than do historical and instrumental data. However, gathering such data is generally difficult in most regions of the world, owing to an absence of human records. Prehistoric data on earthquakes can be obtained through the use of palaeoseismic techniques. This publication describes the current status and practices of palaeoseismology, in order to support Member States in meeting the recommendations of SSG-9 and in establishing the necessary earthquake related database for seismic hazard assessment and reassessment. At a donors’ meeting of the International Seismic Safety Centre Extrabudgetary Project in January 2011, it was suggested to develop detailed guidelines on seismic hazards. Soon after the meeting, the disastrous Great East Japan Earthquake and Tsunami of 11 March 2011 and the consequent accident at the Fukushima Daiichi nuclear power plant occurred. The importance of palaeoseismology for seismic hazard assessment in site evaluation was highlighted by the lessons learned from the Fukushima Daiichi nuclear power plant accident. However, no methodology for performing investigations using palaeoseismic techniques has so far been available in an IAEA publication. The detailed guidelines and practical tools provided here will be of value to nuclear power plant operating organizations, regulatory bodies, vendors, technical support organizations and researchers in the area of seismic hazard assessment in site evaluation for nuclear installations, and the information will be of importance in support of hazard assessments in the future

Preliminary assessment of the ecological risks to wide-ranging wildlife species on the Oak Ridge Reservation

Energy Technology Data Exchange (ETDEWEB)

Sample, B.E.; Baron, L.A.; Jackson, B.L.

1995-08-01

Historically, ecological risk assessment at CERCLA sites [such as the Oak Ridge Reservation (ORR)], has focused on species that may be definitively associated with a contaminated area or source operable unit. Consequently the species that are generally considered are those with home ranges small enough such that multiple individuals or a distinct population can be expected to reside within the boundaries of the contaminated site. This approach is adequate for sites with single, discrete areas of contamination that only provide habitat for species with limited requirements. This approach is not adequate however for large sites with multiple, spatially separated contaminated areas that provide habitat for wide-ranging wildlife species. Because wide-ranging wildlife species may travel between and use multiple contaminated sites they may be exposed to and be at risk from contaminants from multiple locations. Use of a particular contaminated site by wide-ranging species will be dependent upon the amount of suitable habitat available at that site. Therefore to adequately evaluate risks to wide-ranging species at the ORR-wide scale, the use of multiple contaminated sites must be weighted by the amount of suitable habitat on OUs. This reservation-wide ecological risk assessment is intended to identify which endpoints are significantly at risk; which contaminants are responsible for this risk; and which OUs significantly contribute to risk.

Study of seismic design bases and site conditions for nuclear power plants

International Nuclear Information System (INIS)

1980-04-01

This report presents the results of an investigation of four topics pertinent to the seismic design of nuclear power plants: Design accelerations by regions of the continental United States; review and compilation of design-basis seismic levels and soil conditions for existing nuclear power plants; regional distribution of shear wave velocity of foundation materials at nuclear power plant sites; and technical review of surface-founded seismic analysis versus embedded approaches

Study of seismic design bases and site conditions for nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

1980-04-01

This report presents the results of an investigation of four topics pertinent to the seismic design of nuclear power plants: Design accelerations by regions of the continental United States; review and compilation of design-basis seismic levels and soil conditions for existing nuclear power plants; regional distribution of shear wave velocity of foundation materials at nuclear power plant sites; and technical review of surface-founded seismic analysis versus embedded approaches.

The historical seismicity in Spain. Analysis. Incidence over the nuclear sites

International Nuclear Information System (INIS)

Lopez Marinas, J.M.

1985-01-01

The lack of good instrumental registers till very recently and the great documental richness existing in Spain emphasize the importance of the historical seismicity. In the present report, the Spanish catalogues of earthquakes and the necessity of their revision are analyzed showing several examples. Finally the incidence of a historical seismicity datum over a nuclear site is discussed. (author)

Proceedings of the OECD/NEA workshop on seismic risk - Summary and conclusions - Committee on the Safety of Nuclear Installations PWG3 and PWG5

International Nuclear Information System (INIS)

2001-01-01

The objectives of the Workshop were: - To provide a forum to review the recent advances in methodology and application of seismic probabilistic safety assessment and seismic margin analysis of nuclear installations, - To discuss the effective uses of the seismic PSA/margin analysis with consideration of merits and limitations of probabilistic methods, - To review the state of the art methodology to provide guidance for conducting seismic PSA, and - To discuss methodological issues and identify areas in which further research is needed for enhancing the usefulness of seismic PSA. The emphasis of the Workshop was placed on the exchange of ideas on effective ways of using seismic PSA rather than the numerical PSA results for specific plants such as core damage frequencies or seismic hazard. From the presentations and discussions in this workshop, it can be concluded that the seismic PSA/Margin methods have been and are being used world-wide, providing useful information for safety improvement or decision making, and great amount of experience has been accumulated, although the status of programs in member countries vary widely. The objectives of such studies include the following: - To examine whether there are cost effective ways to improve safety from ALARP point of view - To assist in decision making in backfitting by identifying cost effective improvements - To demonstrate the seismic margin of existing or future plants - To examine the vulnerabilities in protection against severe accident - To improve design of future reactors by identifying relatively weak points - To assist in selection of new sites for NPPs. Although numerical results from seismic PSA have not been directly used in seismic design as an alternate or supplement to current deterministic analysis methods, some countries have already adopted the use of probabilistic seismic hazard analysis for determining design basis earthquakes (SSE in USA) and some activities are ongoing to develop methods for

Characterization of site conditions for selected seismic stations in eastern part of Romania

Science.gov (United States)

Grecu, B.; Zaharia, B.; Diaconescu, M.; Bala, A.; Nastase, E.; Constantinescu, E.; Tataru, D.

2018-02-01

Strong motion data are essential for seismic hazard assessment. To correctly understand and use this kind of data is necessary to have a good knowledge of local site conditions. Romania has one of the largest strong motion networks in Europe with 134 real-time stations. In this work, we aim to do a comprehensive site characterization for eight of these stations located in the eastern part of Romania. We make use of a various seismological dataset and we perform ambient noise and earthquake-based investigations to estimate the background noise level, the resonance frequencies and amplification of each site. We also derive the Vs30 parameter from the surface shear-wave velocity profiles obtained through the inversion of the Rayleigh waves recorded in active seismic measurements. Our analyses indicate similar results for seven stations: high noise levels for frequencies larger than 1 Hz, well defined fundamental resonance at low frequencies (0.15-0.29 Hz), moderate amplification levels (up to 4 units) for frequencies between 0.15 and 5-7 Hz and same soil class (type C) according to the estimated Vs30 and Eurocode 8. In contrast, the eighth station for which the soil class is evaluated of type B exhibits a very good noise level for a wide range of frequencies (0.01-20 Hz), a broader fundamental resonance at high frequencies ( 8 Hz) and a flat amplification curve between 0.1 and 3-4 Hz.

Seismic Evidence of A Widely Distributed West Napa Fault Zone, Hendry Winery, Napa, California

Science.gov (United States)

Goldman, M.; Catchings, R.; Chan, J. H.; Criley, C.

2015-12-01

Following the 24 August 2014 Mw 6.0 South Napa earthquake, surface rupture was mapped along the West Napa Fault Zone (WNFZ) for a distance of ~ 14 km and locally within zones up to ~ 2 km wide. Near the northern end of the surface rupture, however, several strands coalesced to form a narrow, ~100-m-wide zone of surface rupture. To determine the location, width, and shallow (upper few hundred meters) geometry of the fault zone, we acquired an active-source seismic survey across the northern surface rupture in February 2015. We acquired both P- and S-wave data, from which we developed reflection images and tomographic images of Vp, Vs, Vp/Vs, and Poisson's ratio of the upper 100 m. We also used small explosive charges within surface ruptures located ~600 m north of our seismic array to record fault-zone guided waves. Our data indicate that at the latitude of the Hendry Winery, the WNFZ is characterized by at least five fault traces that are spaced 60 to 200 m apart. Zones of low-Vs, low-Vp/Vs, and disrupted reflectors highlight the fault traces on the tomography and reflection images. On peak-ground-velocity (PGV) plots, the most pronounced high-amplitude guided-wave seismic energy coincides precisely with the mapped surface ruptures, and the guided waves also show discrete high PGV zones associated with unmapped fault traces east of the surface ruptures. Although the surface ruptures of the WNFZ were observed only over a 100-m-wide zone at the Hendry Winery, our data indicate that the fault zone is at least 400 m wide, which is probably a minimum width given the 400-m length of our seismic profile. Slip on the WNFZ is generally considered to be low relative to most other Bay Area faults, but we suggest that the West Napa Fault is a zone of widely distributed shear, and to fully account for the total slip on the WNFZ, slip on all traces of this wide fault zone must be considered.

Seismic-reflection and ground penetrating radar for environmental site characterization. 1998 annual progress report

International Nuclear Information System (INIS)

Plumb, R.; Steeples, D.W.

1998-01-01

'The project''s goals are threefold: (1) to examine the complementary site-characterization capabilities of modern, three-component shallow-seismic techniques and ground-penetrating radar (GPR) methods at depths ranging from 2 to 8 m at an existing test site; (2) to demonstrate the usefulness of the two methods when used in concert to characterize, in three-dimensions, the cone of depression of a pumping well, which will serve as a proxy site for fluid-flow at an actual, polluted site; and (3) to use the site as an outdoor mesoscale laboratory to validate existing three-dimensional ground-penetrating radar and seismic-reflection computer models developed at the Univ. of Kansas. To do this, useful seismic and GPR data are being collected along the same line(s) and within the same depth range. The principal investigators selected a site in central Kansas as a primary location and, although the site itself is not environmentally sensitive, the location chosen offers particularly useful attributes for this research and will serve as a proxy site for areas that are contaminated. As part of an effort to evaluate the strengths of each method, the authors will repeat the seismic and GPR surveys on a seasonal basis to establish how the complementary information obtained varies over time. Because the water table fluctuates at this site on a seasonal basis, variations in the two types of data over time also can be observed. Such noninvasive in-situ methods of identifying and characterizing the hydrologic flow regimes at contaminated sites support the prospect of developing effective, cost-conscious cleanup strategies in the near future. As of the end of May 1998, the project is on schedule. The first field work was conducted using both of the geophysical survey methods in October of 1997, and the second field survey employed both methods in March of 1998. One of the stated tasks is to reoccupy the same survey line on a quarterly basis for two years to examine change in both

Seismic design of circular-section concrete-lined underground openings: Preclosure performance considerations for the Yucca Mountain Site

International Nuclear Information System (INIS)

Richardson, A.M.; Blejwas, T.E.

1992-01-01

Yucca Mountain, the potential site of a repository for high-level radioactive waste, is situated in a region of natural and man-made seismicity. Underground openings excavated at this site must be designed for worker safety in the seismic environment anticipated for the preclosure period. This includes accesses developed for site characterization regardless of the ultimate outcome of the repository siting process. Experience with both civil and mining structures has shown that underground openings are much more resistant to seismic effects than surface structures, and that even severe dynamic strains can usually be accommodated with proper design. This paper discusses the design and performance of lined openings in the seismic environment of the potential site. The types and ranges of possible ground motions (seismic loads) are briefly discussed. Relevant historical records of underground opening performance during seismic loading are reviewed. Simple analytical methods of predicting liner performance under combined in situ, thermal, and seismic loading are presented, and results of calculations are discussed in the context of realistic performance requirements for concrete-lined openings for the preclosure period. Design features that will enhance liner stability and mitigate the impact of the potential seismic load are reviewed. The paper is limited to preclosure performance concerns involving worker safety because present decommissioning plans specify maintaining the option for liner removal at seal locations, thus decoupling liner design from repository postclosure performance issues

Importance and sensitivity of parameters affecting the Zion Seismic Risk

International Nuclear Information System (INIS)

George, L.L.; O'Connell, W.J.

1985-06-01

This report presents the results of a study on the importance and sensitivity of structures, systems, equipment, components and design parameters used in the Zion Seismic Risk Calculations. This study is part of the Seismic Safety Margins Research Program (SSMRP) supported by the NRC Office of Nuclear Regulatory Research. The objective of this study is to provide the NRC with results on the importance and sensitivity of parameters used to evaluate seismic risk. These results can assist the NRC in making decisions dealing with the allocation of research resources on seismic issues. This study uses marginal analysis in addition to importance and sensitivity analysis to identify subject areas (input parameter areas) for improvements that reduce risk, estimate how much the improvement dfforts reduce risk, and rank the subject areas for improvements. Importance analysis identifies the systems, components, and parameters that are important to risk. Sensitivity analysis estimates the change in risk per unit improvement. Marginal analysis indicates the reduction in risk or uncertainty for improvement effort made in each subject area. The results described in this study were generated using the SEISIM (Systematic Evaluation of Important Safety Improvement Measures) and CHAIN computer codes. Part 1 of the SEISIM computer code generated the failure probabilities and risk values. Part 2 of SEISIM, along with the CHAIN computer code, generated the importance and sensitivity measures

Importance and sensitivity of parameters affecting the Zion Seismic Risk

Energy Technology Data Exchange (ETDEWEB)

George, L.L.; O' Connell, W.J.

1985-06-01

This report presents the results of a study on the importance and sensitivity of structures, systems, equipment, components and design parameters used in the Zion Seismic Risk Calculations. This study is part of the Seismic Safety Margins Research Program (SSMRP) supported by the NRC Office of Nuclear Regulatory Research. The objective of this study is to provide the NRC with results on the importance and sensitivity of parameters used to evaluate seismic risk. These results can assist the NRC in making decisions dealing with the allocation of research resources on seismic issues. This study uses marginal analysis in addition to importance and sensitivity analysis to identify subject areas (input parameter areas) for improvements that reduce risk, estimate how much the improvement dfforts reduce risk, and rank the subject areas for improvements. Importance analysis identifies the systems, components, and parameters that are important to risk. Sensitivity analysis estimates the change in risk per unit improvement. Marginal analysis indicates the reduction in risk or uncertainty for improvement effort made in each subject area. The results described in this study were generated using the SEISIM (Systematic Evaluation of Important Safety Improvement Measures) and CHAIN computer codes. Part 1 of the SEISIM computer code generated the failure probabilities and risk values. Part 2 of SEISIM, along with the CHAIN computer code, generated the importance and sensitivity measures.

Seismic hazard analysis for the NTS spent reactor fuel test site

International Nuclear Information System (INIS)

Campbell, K.W.

1980-01-01

An experiment is being directed at the Nevada Test Site to test the feasibility for storage of spent fuel from nuclear reactors in geologic media. As part of this project, an analysis of the earthquake hazard was prepared. This report presents the results of this seismic hazard assessment. Two distinct components of the seismic hazard were addressed: vibratory ground motion and surface displacement

From the Atlas to the Rif a Crustal seismic image across Morocco: The SIMA & RIFSEIS control source wide-angle seismic reflection data

Science.gov (United States)

Carbonell, Ramon; Ayarza, Puy; Gallart, Josep; Diaz, Jordi; Harnafi, Mimoun; Levander, Alan; Teixell, Antonio

2014-05-01

The velocity structure of the crust and the geometry of the Moho across Morocco has been the main target of two recently acquired wide-angle seismic reflection transects. One is the SIMA experiment which provided seismic constraints beneath the Atlas Mountains and the second has been the RIFSEIS experiment which sampled the RIF orogen. Jointly these controlled source wide-angle seismic reflection data results in an almost 700 km, seismic profile going from the the Sahara craton across the High and Middle Atlas and Rif Mountain till the Gibraltar-Arc (Alboran). Current work on the interpretation of the seismic data-set is based on forward modeling, ray-tracing, as well as low fold wide-angle stacking. The data has resulted in a detailed crustal structure and velocity model for the Atlas Mountains and a 700 km transect revealing the irregular topography of the Moho beneath these two mountain orogens. Results indicate that the High Atlas features a moderate crustal thickness and that shortening is resolved at depth through a crustal root where the Saharan crust under-thrusts below the Moroccan crust, defining a lower crust imbrication which locally places the Moho boundary at, approximately, 40 km depth. The P-wave velocity model is characterized, in averaged, by relatively low velocities. These low deep crustal velocities together with other geophysical observables such as: conductivity estimates derived from Mt measurements; moderate Bouguer gravity anomaly; surface exposures of recent alkaline volcanics; lead the interpretation to propose that partial melts are currently emplaced in the deep crustal levels and in the upper mantle. The Moho discontinuity defines a crust which is in average relatively thin beneath the Atlas which is almost a 4000 m high orogenic belt. The resulting model supports existence of mantle upwelling as a possible mechanism that contributes, significantly, to maintain the High Atlas topography.

Influence of the crustal and subcrustal Vrancea seismic sources on Cernavoda nuclear power plant site

International Nuclear Information System (INIS)

Marmureanu, Gheorghe; Popescu, Emilia; Mircea Radulian

2002-01-01

The basis of the seismic hazard assessment in different geographical regions with dense-populated areas and strategic objectives (dams, nuclear power plants, etc.) is the study of seismicity of the seismogenic sources which affect these sites. The purpose of this paper is to provide a complete set of information relative to the Vrancea seismic source (in the crust and the intermediate depth domains) that is fundamental for the seismic hazard evaluation at Cernavoda nuclear power plant site. The analysis that we propose has to deal with the following items: (1) geometrical definition of the seismic sources; (2) setting the earthquake catalog associated to each seismic source; (3) estimation of the maximum possible magnitude; (4) estimation of the frequency - magnitude relationship; (5) computation of the distribution function for focal distance; (6) correlation between focal depth and magnitude; (7) attenuation law. We discuss also the implications of the model parameters on the seismic hazard level. (authors)

Approach for seismic risk analysis for CANDU plants in Korea

Energy Technology Data Exchange (ETDEWEB)

Lee, B-S; Kim, T; Kang, S-K [Korea Power Engineering Co., Seoul (Korea, Republic of); Hong, S-Y; Roh, S-R [Korea Electric Power Corp., Taejon (Korea, Republic of). Research Centre

1996-12-31

A seismic risk analysis for CANDU type plants has never been performed. The study presented here suggested that the approach generally applied to LWR type plants could lead to unacceptable result, if directly applied to CANDU plants. This paper presents a modified approach for the seismic risk analysis of CANDU plants. (author). 5 refs., 2 tabs., 2 figs.

NCSRR digital seismic network in Romania

International Nuclear Information System (INIS)

Aldea, A.; Albota, E.; Demetriu, S.; Poiata, N.; Kashima, T.

2007-01-01

Digital seismic instrumentation donated by Japan International Cooperation Agency (JICA) to the National Center for Seismic Risk Reduction (NCSRR, Romania) allowed the installation in 2003 of a new Romanian seismic network. In 2005-2006 the network was developed by investments from NCSRR within the budget ensured by Ministry of Transports, Construction and Tourism (MTCT). The NCSRR seismic network contains three types of instrumentation: (i) free-field stations - outside the capital city Bucharest (8 accelerometers), (ii) instrumented buildings - in Bucharest (5 buildings), and (iii) stations with free-field and borehole sensors - in Bucharest (8 sites with ground surface sensor and sensors in 15 boreholes with depths up to 153 m). Since its installation, the NCSRR network recorded more than 170 seismic motions from 26 earthquakes with moment magnitudes ranging from 3.2 to 6.0. The seismic instrumentation was accompanied by investigations of ground conditions and site response: PS logging tests, single-station and array microtremor measurements. The development of seismic monitoring in Romania is a major contribution of JICA Project, creating the premises for a better understanding and modelling of earthquake ground motion, site effects and building response. (authors)

A GIS approach to seismic risk assessment with an application to mining-related seismicity in Johannesburg, South Africa

Science.gov (United States)

Liebenberg, Keagen; Smit, Ansie; Coetzee, Serena; Kijko, Andrzej

2017-08-01

The majority of seismic activity in South Africa is related to extensive mining operations, usually in close proximity to densely populated areas where a relatively weak seismic event could cause damage. Despite a significant decrease in mining operations in the Witwatersrand area, the number of seismic events appears to be increasing and is attributed to the acid mine drainage problem. The increased seismicity is raising concern amongst disaster management centres and in the insurance industry. A better understanding is required of the vulnerability and the size of the potential loss of people and infrastructure in densely populated Johannesburg and its surrounding areas. Results of a deterministic seismic risk, vulnerability, and loss assessment are presented by making use of a geographic information system (GIS). The results illustrate the benefits of using GIS and contribute to a better understanding of the risk, which can assist in improving disaster preparedness.

Seismically-induced soil amplification at the DOE Paducah Gaseous Diffusion Plant site

International Nuclear Information System (INIS)

Sykora, D.W.; Haynes, M.E.

1991-01-01

A site-specific earthquake site response (soil amplification) study is being conducted for the Department of Energy (DOE), Paducah Gaseous Diffusion Plant (PGDP). This study is pursuant to an upgraded Final Safety Analysis Report in accordance with requirements specified by DOE. The seismic hazard at PGDP is dominated by the New Madrid Seismic Zone. Site-specific synthetic earthquake records developed by others were applied independently to four soil columns with heights above baserock of about 325 ft. The results for the 1000-year earthquake event indicate that the site period is between 1.0 and 1.5 sec. Incident shear waves are amplified at periods of motion greater than 0.15 sec. The peak free-field horizontal acceleration, occurring at very low periods, is 0.28 g. 13 refs., 13 figs

Seismically-induced soil amplification at the DOE Paducah Gaseous Diffusion Plant Site

International Nuclear Information System (INIS)

Sykora, D.W.; Hynes, M.E.; Brock, W.R.; Hunt, R.J.; Shaffer, K.E.

1991-01-01

A site-specific earthquake site response (soil amplification) study is being conducted for the Department of Energy (DOE), Paducah Gaseous Diffusion Plant (PGDP). This study is pursuant to an upgraded Final Safety Analysis Report in accordance with requirements specified by DOE. The seismic hazard at PGDP is dominated by the New Madrid Seismic Zone. Site-specific synthetic earthquake records developed by others were applied independently to four soil columns with heights above baserock of about 325 ft. The results for the 1000-year earthquake event indicate that the site period is between 1.0 and 1.5 sec. Incident shear waves are strongly amplified at periods of motion greater than 0.3 sec. The peak free-field horizontal acceleration, occurring at very low periods, is 0.28 g

Application of the neo-deterministic seismic microzonation procedure in Bulgaria and validation of the seismic input against Eurocode 8

International Nuclear Information System (INIS)

Paskaleva, I.; Kouteva, M.; Vaccari, F.; Panza, G.F.

2008-03-01

The earthquake record and the Code for design and construction in seismic regions in Bulgaria have shown that the territory of the Republic of Bulgaria is exposed to a high seismic risk due to local shallow and regional strong intermediate-depth seismic sources. The available strong motion database is quite limited, and therefore not representative at all of the real hazard. The application of the neo-deterministic seismic hazard assessment procedure for two main Bulgarian cities has been capable to supply a significant database of synthetic strong motions for the target sites, applicable for earthquake engineering purposes. The main advantage of the applied deterministic procedure is the possibility to take simultaneously and correctly into consideration the contribution to the earthquake ground motion at the target sites of the seismic source and of the seismic wave propagation in the crossed media. We discuss in this study the result of some recent applications of the neo-deterministic seismic microzonation procedure to the cities of Sofia and Russe. The validation of the theoretically modeled seismic input against Eurocode 8 and the few available records at these sites is discussed. (author)

A procedure for seismic risk reduction in Campania Region

International Nuclear Information System (INIS)

Zuccaro, G.; Palmieri, M.; Cicalese, S.; Grassi, V.; Rauci, M.; Maggio, F.

2008-01-01

The Campania Region has set and performed a peculiar procedure in the field of seismic risk reduction. Great attention has been paid to public strategic buildings such as town halls, civil protection buildings and schools. The Ordinance 3274 promulgate in the 2004 by the Italian central authority obliged the owners of strategic buildings to perform seismic analyses within 2008 in order to check the safety of the structures and the adequacy to the use. In the procedure the Campania region, instead of the local authorities, ensure the complete drafting of seismic checks through financial resources of the Italian Government. A regional scientific technical committee has been constituted, composed of scientific experts, academics in seismic engineering. The committee has drawn up guidelines for the processing of seismic analyses. At the same time, the Region has issued a public competition to select technical seismic engineering experts to appoint seismic analysis in accordance with guidelines. The scientific committee has the option of requiring additional documents and studies in order to approve the safety checks elaborated. The Committee is supported by a technical and administrative secretariat composed of a group of expert in seismic engineering. At the moment several seismic safety checks have been completed. The results will be presented in this paper. Moreover, the policy to mitigate the seismic risk, set by Campania region, was to spend the most of the financial resources available on structural strengthening of public strategic buildings rather than in safety checks. A first set of buildings of which the response under seismic action was already known by data and studies of vulnerability previously realised, were selected for immediate retrofitting designs. Secondly, an other set of buildings were identified for structural strengthening. These were selected by using the criteria specified in the Guide Line prepared by the Scientific Committee and based on

A procedure for seismic risk reduction in Campania Region

Science.gov (United States)

Zuccaro, G.; Palmieri, M.; Maggiò, F.; Cicalese, S.; Grassi, V.; Rauci, M.

2008-07-01

The Campania Region has set and performed a peculiar procedure in the field of seismic risk reduction. Great attention has been paid to public strategic buildings such as town halls, civil protection buildings and schools. The Ordinance 3274 promulgate in the 2004 by the Italian central authority obliged the owners of strategic buildings to perform seismic analyses within 2008 in order to check the safety of the structures and the adequacy to the use. In the procedure the Campania region, instead of the local authorities, ensure the complete drafting of seismic checks through financial resources of the Italian Government. A regional scientific technical committee has been constituted, composed of scientific experts, academics in seismic engineering. The committee has drawn up guidelines for the processing of seismic analyses. At the same time, the Region has issued a public competition to select technical seismic engineering experts to appoint seismic analysis in accordance with guidelines. The scientific committee has the option of requiring additional documents and studies in order to approve the safety checks elaborated. The Committee is supported by a technical and administrative secretariat composed of a group of expert in seismic engineering. At the moment several seismic safety checks have been completed. The results will be presented in this paper. Moreover, the policy to mitigate the seismic risk, set by Campania region, was to spend the most of the financial resources available on structural strengthening of public strategic buildings rather than in safety checks. A first set of buildings of which the response under seismic action was already known by data and studies of vulnerability previously realised, were selected for immediate retrofitting designs. Secondly, an other set of buildings were identified for structural strengthening. These were selected by using the criteria specified in the Guide Line prepared by the Scientific Committee and based on

Nonlinear Time Domain Seismic Soil-Structure Interaction (SSI) Deep Soil Site Methodology Development

International Nuclear Information System (INIS)

Spears, Robert Edward; Coleman, Justin Leigh

2015-01-01

Currently the Department of Energy (DOE) and the nuclear industry perform seismic soil-structure interaction (SSI) analysis using equivalent linear numerical analysis tools. For lower levels of ground motion, these tools should produce reasonable in-structure response values for evaluation of existing and new facilities. For larger levels of ground motion these tools likely overestimate the in-structure response (and therefore structural demand) since they do not consider geometric nonlinearities (such as gaping and sliding between the soil and structure) and are limited in the ability to model nonlinear soil behavior. The current equivalent linear SSI (SASSI) analysis approach either joins the soil and structure together in both tension and compression or releases the soil from the structure for both tension and compression. It also makes linear approximations for material nonlinearities and generalizes energy absorption with viscous damping. This produces the potential for inaccurately establishing where the structural concerns exist and/or inaccurately establishing the amplitude of the in-structure responses. Seismic hazard curves at nuclear facilities have continued to increase over the years as more information has been developed on seismic sources (i.e. faults), additional information gathered on seismic events, and additional research performed to determine local site effects. Seismic hazard curves are used to develop design basis earthquakes (DBE) that are used to evaluate nuclear facility response. As the seismic hazard curves increase, the input ground motions (DBE's) used to numerically evaluation nuclear facility response increase causing larger in-structure response. As ground motions increase so does the importance of including nonlinear effects in numerical SSI models. To include material nonlinearity in the soil and geometric nonlinearity using contact (gaping and sliding) it is necessary to develop a nonlinear time domain methodology. This

Robust site security using smart seismic array technology and multi-sensor data fusion

Science.gov (United States)

Hellickson, Dean; Richards, Paul; Reynolds, Zane; Keener, Joshua

2010-04-01

Traditional site security systems are susceptible to high individual sensor nuisance alarm rates that reduce the overall system effectiveness. Visual assessment of intrusions can be intensive and manually difficult as cameras are slewed by the system to non intrusion areas or as operators respond to nuisance alarms. Very little system intrusion performance data are available other than discrete sensor alarm indications that provide no real value. This paper discusses the system architecture, integration and display of a multi-sensor data fused system for wide area surveillance, local site intrusion detection and intrusion classification. The incorporation of a novel seismic array of smart sensors using FK Beamforming processing that greatly enhances the overall system detection and classification performance of the system is discussed. Recent test data demonstrates the performance of the seismic array within several different installations and its ability to classify and track moving targets at significant standoff distances with exceptional immunity to background clutter and noise. Multi-sensor data fusion is applied across a suite of complimentary sensors eliminating almost all nuisance alarms while integrating within a geographical information system to feed a visual-fusion display of the area being secured. Real-time sensor detection and intrusion classification data is presented within a visual-fusion display providing greatly enhanced situational awareness, system performance information and real-time assessment of intrusions and situations of interest with limited security operator involvement. This approach scales from a small local perimeter to very large geographical area and can be used across multiple sites controlled at a single command and control station.

Stratigraphic imaging of sub-basalt sediments using waveform tomography of wide-angle seismic data

Science.gov (United States)

Sain, K.; Gao, F.; Pratt, G.; Zelt, C. A.

2003-12-01

The oil industry is interested in imaging the fine structures of sedimentary formations masked below basalt flows for commercial exploration of hydrocarbons. Seismic exploration of sediments hidden below high-velocity basalt cover is a difficult problem because near-vertical reflection data are contaminated with multiples, converted waves and scattering noise generated by interbeds, breccia and vesicles within the basalt. The noise becomes less prominent as the source-receiver offset increases, and the signals carrying sub-surface information stand out at the wide-angle range. The tomography of first arrival traveltime data can provide little information about the underlying low-velocity sediments. Traveltime inversion of wide-angle seismic data including both first arrivals and identifiable wide-angle reflected phases has been an important tool in the delineation of the large-scale velocity structure of sub-basalt sediments, although it lacks the small-scale velocity details. Here we apply 2-D full-waveform inversion ("waveform tomography") to wide-angle seismic data with a view to extracting the small-scale stratigraphic features of sedimentary formations. Results from both synthetic data, generated for a realistic earth model, and field dataset from the basalt covered Saurashtra peninsula, India, will be presented. This approach has potential to delineate thin sedimentary layers hidden below thick basalt cover also, and may serve as a powerful tool to image sedimentary basins, where they are covered by high-velocity materials like basalts, salts, carbonates, etc. in various parts of the world.

Instrument Correction and Dynamic Site Profile Validation at the Central United States Seismic Observatory, New Madrid Seismic Zone

Science.gov (United States)

Brengman, C.; Woolery, E. W.; Wang, Z.; Carpenter, S.

2016-12-01

The Central United States Seismic Observatory (CUSSO) is a vertical seismic array located in southwestern Kentucky within the New Madrid seismic zone. It is intended to describe the effects of local geology, including thick sediment overburden, on seismic-wave propagation, particularly strong-motion. The three-borehole array at CUSSO is composed of seismic sensors placed on the surface, and in the bedrock at various depths within the 585 m thick sediment overburden. The array's deep borehole provided a unique opportunity in the northern Mississippi embayment for the direct geological description and geophysical measurement of the complete late Cretaceous-Quaternary sediment column. A seven layer, intra-sediment velocity model is interpreted from the complex, inhomogeneous stratigraphy. The S- and P-wave sediment velocities range between 160 and 875 m/s and between 1000 and 2300 m/s, respectively, with bedrock velocities of 1452 and 3775 m/s, respectively. Cross-correlation and direct comparisons were used to filter out the instrument response and determine the instrument orientation, making CUSSO data ready for analysis, and making CUSSO a viable calibration site for other free-field sensors in the area. The corrected bedrock motions were numerically propagated through the CUSSO soil profile (transfer function) and compared, in terms of both peak acceleration and amplitude spectra, to the recorded surface observations. Initial observations reveal a complex spectral mix of amplification and de-amplification across the array, indicating the site effect in this deep sediment setting is not simply generated by the shallowest layers.

Assessment of wind turbine seismic risk : existing literature and simple study of tower moment demand.

Energy Technology Data Exchange (ETDEWEB)

Prowell, Ian (University of California, San Diego, CA); Veers, Paul S.

2009-03-01

Various sources of risk exist for all civil structures, one of which is seismic risk. As structures change in scale, the magnitude of seismic risk changes relative to risk from other sources. This paper presents an introduction to seismic hazard as applied to wind turbine structures. The existing design methods and research regarding seismic risk for wind turbines is then summarized. Finally a preliminary assessment is made based on current guidelines to understand how tower moment demand scales as rated power increases. Potential areas of uncertainty in the application of the current guidelines are summarized.

Seismic Intensity Map Triggered by Observed Strong Motion Records Considering Site Amplification and its service based on Geo-spatial International Standard

International Nuclear Information System (INIS)

Matsuoka, Masashi

2014-01-01

Instrumental seismic intensity measurement is carried out at approximately 4,200 points in Japan, but the correct values at points without seismometers cannot always be provided because seismic motion depends on geologic and geomorphologic features. Quick provision of accurate information on seismic intensity distribution over wide areas is required for disaster mitigation. To estimate seismic intensity at specific points, it is important to prepare ground amplification characteristics for local areas beforehand and use an interpolation algorithm. The QuiQuake system (quick estimation system for earthquake maps triggered by using observation records from K-NET and KiK-net that have been released by the National Research Institute for Earth Science and Disaster Prevention), which uses these, was developed; it can be started up automatically using seismograms and can immediately display a seismic intensity distribution map. The calculation results are sent to IAEA and JNES in the form of strong motion evaluation maps with a mesh size of 250 x 250 m. These maps are also sent to the general public via social networking web sites. (author)

Seismic methodology in determining basis earthquake for nuclear installation

International Nuclear Information System (INIS)

Ameli Zamani, Sh.

2008-01-01

Design basis earthquake ground motions for nuclear installations should be determined to assure the design purpose of reactor safety: that reactors should be built and operated to pose no undue risk to public health and safety from earthquake and other hazards. Regarding the influence of seismic hazard to a site, large numbers of earthquake ground motions can be predicted considering possible variability among the source, path, and site parameters. However, seismic safety design using all predicted ground motions is practically impossible. In the determination of design basis earthquake ground motions it is therefore important to represent the influences of the large numbers of earthquake ground motions derived from the seismic ground motion prediction methods for the surrounding seismic sources. Viewing the relations between current design basis earthquake ground motion determination and modem earthquake ground motion estimation, a development of risk-informed design basis earthquake ground motion methodology is discussed for insight into the on going modernization of the Examination Guide for Seismic Design on NPP

Transparent Global Seismic Hazard and Risk Assessment

Science.gov (United States)

Smolka, Anselm; Schneider, John; Pinho, Rui; Crowley, Helen

2013-04-01

Vulnerability to earthquakes is increasing, yet advanced reliable risk assessment tools and data are inaccessible to most, despite being a critical basis for managing risk. Also, there are few, if any, global standards that allow us to compare risk between various locations. The Global Earthquake Model (GEM) is a unique collaborative effort that aims to provide organizations and individuals with tools and resources for transparent assessment of earthquake risk anywhere in the world. By pooling data, knowledge and people, GEM acts as an international forum for collaboration and exchange, and leverages the knowledge of leading experts for the benefit of society. Sharing of data and risk information, best practices, and approaches across the globe is key to assessing risk more effectively. Through global projects, open-source IT development and collaborations with more than 10 regions, leading experts are collaboratively developing unique global datasets, best practice, open tools and models for seismic hazard and risk assessment. Guided by the needs and experiences of governments, companies and citizens at large, they work in continuous interaction with the wider community. A continuously expanding public-private partnership constitutes the GEM Foundation, which drives the collaborative GEM effort. An integrated and holistic approach to risk is key to GEM's risk assessment platform, OpenQuake, that integrates all above-mentioned contributions and will become available towards the end of 2014. Stakeholders worldwide will be able to calculate, visualise and investigate earthquake risk, capture new data and to share their findings for joint learning. Homogenized information on hazard can be combined with data on exposure (buildings, population) and data on their vulnerability, for loss assessment around the globe. Furthermore, for a true integrated view of seismic risk, users can add social vulnerability and resilience indices to maps and estimate the costs and benefits

Seismic margin assessment of spanish nuclear power plants: a perspective from industry and regulators

International Nuclear Information System (INIS)

Garcia-Monge, Juan; Beltran, Francisco; Sanchez-Cabanero, Jose G.

2001-01-01

The worldwide experience with probabilistic safety analysis (PSA) of nuclear power plants shows that the risk derived from earthquakes can be a significant contributor to core damage frequency in some instances. As a consequence, no severe accident safety assessment can be considered complete without giving, due consideration to seismic risk. This fact has been recognized by some regulators. in particular, by the U.S. Nuclear Regulatory Commission (NRC), who has included seismic risk assessment in its severe accident policy. The NRC severe accident policy was adopted by the Spanish nuclear regulator. the Consejo de Seguridad Nuclear (CSN). As a result. all plants in Spain were asked to perform a seismic risk analysis according to Supplements No. 4 and 5 of Generic Letter 88-20 and NUREG-1407, which included the containment failure analysis. At present in Spain there arc nine operating reactors at seven sites: six Westinghouse-PWR, two GE-BWR and one Siemens/KW U-PWR. The vintages are very different: the oldest plant started commercial operation in 1968 and the most recent, in 1988. In this framework, the Spanish Owners Group (SOG) proposed to CSN in 1994 to carry out the seismic risk analysis of the plants using seismic margin methodologies. This kind of methods requires, as a starting point, the definition of a seismic margin earthquake (SNIE), also called review level earthquake (RLL). For this purpose, tile SOG sponsored a general Probabilistic Seismic Hazard Analysis (PSHA) for the seven Spanish sites. The results of this PSHA were used by the SOG to define tile RLE and the scope of the study for each plant (binning of plants). The proposal was submitted to the CSN for evaluation. The CSN evaluation was based on the NRC practical experience and was helped by the technical advise of US Lawrence Livermore National Laboratory. The review showed that the uncertainties on seismic hazard had not been fully captured and that it would have been justified to consider a

Seismic isolation of plants at risk of a severe accident

International Nuclear Information System (INIS)

Forni, Massimo

2015-01-01

More and more devastating earthquakes struck every year our planet. Many of these, though occurring in areas considered at high risk of earthquakes, far exceed the levels required by law. The industrial plants subjected to risk of severe accident, in particular petrochemical and nuclear power plants, are particularly exposed to this risk because of the number and the complexity of the structures and critical components of which they are composed. For this type of structures, anti-seismic techniques able to provide complete protection, even in case of unforeseen events, are needed. Seismic isolation is certainly the most promising technology of modern antiseismic as it allows not only to significantly reduce the dynamic load acting on the structures in case of seismic attack, but to provide safety margins against violent earthquakes, exceeding the assumed maximum design limit. [it

Probabilistic seismic vulnerability and risk assessment of stone masonry structures

Science.gov (United States)

Abo El Ezz, Ahmad

Earthquakes represent major natural hazards that regularly impact the built environment in seismic prone areas worldwide and cause considerable social and economic losses. The high losses incurred following the past destructive earthquakes promoted the need for assessment of the seismic vulnerability and risk of the existing buildings. Many historic buildings in the old urban centers in Eastern Canada such as Old Quebec City are built of stone masonry and represent un-measurable architectural and cultural heritage. These buildings were built to resist gravity loads only and generally offer poor resistance to lateral seismic loads. Seismic vulnerability assessment of stone masonry buildings is therefore the first necessary step in developing seismic retrofitting and pre-disaster mitigation plans. The objective of this study is to develop a set of probability-based analytical tools for efficient seismic vulnerability and uncertainty analysis of stone masonry buildings. A simplified probabilistic analytical methodology for vulnerability modelling of stone masonry building with systematic treatment of uncertainties throughout the modelling process is developed in the first part of this study. Building capacity curves are developed using a simplified mechanical model. A displacement based procedure is used to develop damage state fragility functions in terms of spectral displacement response based on drift thresholds of stone masonry walls. A simplified probabilistic seismic demand analysis is proposed to capture the combined uncertainty in capacity and demand on fragility functions. In the second part, a robust analytical procedure for the development of seismic hazard compatible fragility and vulnerability functions is proposed. The results are given by sets of seismic hazard compatible vulnerability functions in terms of structure-independent intensity measure (e.g. spectral acceleration) that can be used for seismic risk analysis. The procedure is very efficient for

Seismic imaging for an ocean drilling site survey and its verification in the Izu rear arc

Science.gov (United States)

Yamashita, Mikiya; Takahashi, Narumi; Tamura, Yoshihiko; Miura, Seiichi; Kodaira, Shuichi

2018-01-01

To evaluate the crustal structure of a site proposed for International Ocean Discovery Program drilling, the Japan Agency for Marine-Earth Science and Technology carried out seismic surveys in the Izu rear arc between 2006 and 2008, using research vessels Kaiyo and Kairei. High-resolution dense grid surveys, consisting of three kinds of reflection surveys, generated clear seismic profiles, together with a seismic velocity image obtained from a seismic refraction survey. In this paper, we compare the seismic profiles with the geological column obtained from the drilling. Five volcaniclastic sedimentary units were identified in seismic reflection profiles above the 5 km/s and 6 km/s contours of P-wave velocity obtained from the velocity image from the seismic refraction survey. However, some of the unit boundaries interpreted from the seismic images were not recognised in the drilling core, highlighting the difficulties of geological target identification in volcanic regions from seismic images alone. The geological core derived from drilling consisted of seven lithological units (labelled I to VII). Units I to V were aged at 0-9 Ma, and units VI and VII, from 1320-1806.5 m below seafloor (mbsf) had ages from 9 to ~15 Ma. The strong heterogeneity of volcanic sediments beneath the drilling site U1437 was also identified from coherence, calculated using cross-spectral analysis between grid survey lines. Our results suggest that use of a dense grid configuration is important in site surveys for ocean drilling in volcanic rear-arc situations, in order to recognise heterogeneous crustal structure, such as sediments from different origins.

Seismic study of soil dynamics at Garner Valley, California

International Nuclear Information System (INIS)

Archuleta, R.J.; Seale, S.H.

1990-01-01

The Garner Valley downhole array (GVDA) of force-balanced accelerometers was designed to determine the effect that near-surface soil layers have on surface ground motion by measuring in situ seismic waves at various depths. Although there are many laboratory, theoretical and numerical studies that are used to predict the effects that local site geology might have on seismic waves, there are very few direct measurements that can be used to confirm the predictions made by these methods. The effects of local site geology on seismic ground motions are critical for estimating the base motion of structures. The variations in site amplifications at particular periods can range over a factor of 20 or more in comparing amplitude spectra from rock and soil sites, e.g., Mexico City (1985) or San Francisco (1989). The basic phenomenon of nonlinear soil response, and by inference severe attenuation of seismic waves, has rarely been measured although it is commonly observed in laboratory experiments. The basic question is whether or not the local site geology amplifies are attenuates the seismic ground motion. Because the answer depends on the interaction between the local site geology and the amplitude as well as the frequency content of the incoming seismic waves, the in situ measurements must sample the depth variations of the local structure as well as record seismic waves over as wide a range as possible in amplitude and frequency

Analysis of the Seismic Performance of Site-Bolted Beam to Column Connections in Modularized Prefabricated Steel Structures

Directory of Open Access Journals (Sweden)

Xuechun Liu

2017-01-01

Full Text Available This paper proposes a site-bolted connection that is suitable for modularized prefabricated steel structures. Excellent ductility is achieved by various structural measures. Six connection specimens with different parameters were subjected to quasi-static loading tests and finite element analysis (FEA to determine the seismic performance of the proposed connection (e.g., hysteretic behavior, skeleton curve, ductility, and failure mode. The results of the tests and FEA showed that the connection underwent sufficient plastic deformation under cyclic loading and that its ultimate rotation angle could reach 0.09 rad. A clear plastic hinge formed on the beam before the connection failed, which suggests a ductile failure mode. The connection exhibited a wide hysteresis loop, which indicated good seismic performance. The results also showed that the connection does not slip under small earthquakes and could dissipate energy through slippage in the connection region under a moderate earthquake and through slippage in the connection region as well as plastic deformation at the beam end under a severe earthquake. The number of bolts was the main parameter that affected the seismic performance of the connection. The test and FEA results demonstrated that all six specimens had excellent seismic and ductile performance and an exceptional plastic rotation capacity.

Seismic Safety Of Simple Masonry Buildings

International Nuclear Information System (INIS)

Guadagnuolo, Mariateresa; Faella, Giuseppe

2008-01-01

Several masonry buildings comply with the rules for simple buildings provided by seismic codes. For these buildings explicit safety verifications are not compulsory if specific code rules are fulfilled. In fact it is assumed that their fulfilment ensures a suitable seismic behaviour of buildings and thus adequate safety under earthquakes. Italian and European seismic codes differ in the requirements for simple masonry buildings, mostly concerning the building typology, the building geometry and the acceleration at site. Obviously, a wide percentage of buildings assumed simple by codes should satisfy the numerical safety verification, so that no confusion and uncertainty have to be given rise to designers who must use the codes. This paper aims at evaluating the seismic response of some simple unreinforced masonry buildings that comply with the provisions of the new Italian seismic code. Two-story buildings, having different geometry, are analysed and results from nonlinear static analyses performed by varying the acceleration at site are presented and discussed. Indications on the congruence between code rules and results of numerical analyses performed according to the code itself are supplied and, in this context, the obtained result can provide a contribution for improving the seismic code requirements

Geotechnical investigation for seismic issues for K-reactor area at Savannah River Site

International Nuclear Information System (INIS)

Castro, G.; Reeves, C.Q.

1991-01-01

A geotechnical investigation has been completed at Savannah River Site to characterize the foundation conditions in K-Reactor Area and confirm soil design properties for use in seismic qualification of structures. The scope of field work included ten soil borings to a 200-foot depth with split-spoon and undisturbed sampling. Additionally, 42 cone penetrometer tests were performed with seismic down-hole measurements. Three cross-hole shear wave velocity tests were also completed to confirm the assumed dynamic properties which had been used in preliminary seismic analysis

Impact of ground motion characterization on conservatism and variability in seismic risk estimates

International Nuclear Information System (INIS)

Sewell, R.T.; Toro, G.R.; McGuire, R.K.

1996-07-01

This study evaluates the impact, on estimates of seismic risk and its uncertainty, of alternative methods in treatment and characterization of earthquake ground motions. The objective of this study is to delineate specific procedures and characterizations that may lead to less biased and more precise seismic risk results. This report focuses on sources of conservatism and variability in risk that may be introduced through the analytical processes and ground-motion descriptions which are commonly implemented at the interface of seismic hazard and fragility assessments. In particular, implication of the common practice of using a single, composite spectral shape to characterize motions of different magnitudes is investigated. Also, the impact of parameterization of ground motion on fragility and hazard assessments is shown. Examination of these results demonstrates the following. (1) There exists significant conservatism in the review spectra (usually, spectra characteristic of western U.S. earthquakes) that have been used in conducting past seismic risk assessments and seismic margin assessments for eastern U.S. nuclear power plants. (2) There is a strong dependence of seismic fragility on earthquake magnitude when PGA is used as the ground-motion characterization. When, however, magnitude-dependent spectra are anchored to a common measure of elastic spectral acceleration averaged over the appropriate frequency range, seismic fragility shows no important nor consistent dependence on either magnitude or strong-motion duration. Use of inelastic spectral acceleration (at the proper frequency) as the ground spectrum anchor demonstrates a very similar result. This study concludes that a single, composite-magnitude spectrum can generally be used to characterize ground motion for fragility assessment without introducing significant bias or uncertainty in seismic risk estimates

Impact of ground motion characterization on conservatism and variability in seismic risk estimates

Energy Technology Data Exchange (ETDEWEB)

Sewell, R.T.; Toro, G.R.; McGuire, R.K.

1996-07-01

This study evaluates the impact, on estimates of seismic risk and its uncertainty, of alternative methods in treatment and characterization of earthquake ground motions. The objective of this study is to delineate specific procedures and characterizations that may lead to less biased and more precise seismic risk results. This report focuses on sources of conservatism and variability in risk that may be introduced through the analytical processes and ground-motion descriptions which are commonly implemented at the interface of seismic hazard and fragility assessments. In particular, implication of the common practice of using a single, composite spectral shape to characterize motions of different magnitudes is investigated. Also, the impact of parameterization of ground motion on fragility and hazard assessments is shown. Examination of these results demonstrates the following. (1) There exists significant conservatism in the review spectra (usually, spectra characteristic of western U.S. earthquakes) that have been used in conducting past seismic risk assessments and seismic margin assessments for eastern U.S. nuclear power plants. (2) There is a strong dependence of seismic fragility on earthquake magnitude when PGA is used as the ground-motion characterization. When, however, magnitude-dependent spectra are anchored to a common measure of elastic spectral acceleration averaged over the appropriate frequency range, seismic fragility shows no important nor consistent dependence on either magnitude or strong-motion duration. Use of inelastic spectral acceleration (at the proper frequency) as the ground spectrum anchor demonstrates a very similar result. This study concludes that a single, composite-magnitude spectrum can generally be used to characterize ground motion for fragility assessment without introducing significant bias or uncertainty in seismic risk estimates.

Seismic fragilities for nuclear power plant risk studies

International Nuclear Information System (INIS)

Kennedy, R.P.; Ravindra, M.K.

1983-01-01

Seismic fragilities of critical structures and equipment are developed as families of conditional failure frequency curves plotted against peak ground acceleration. The procedure is based on available data combined with judicious extrapolation of design information on plant structures and equipment. Representative values of fragility parameters for typical modern nuclear power plants are provided. Based on the fragility evaluation for about a dozen nuclear power plants, it is proposed that unnecessary conservatism existing in current seismic design practice could be removed by properly accounting for inelastic energy absorption capabilities of structures. The paper discusses the key contributors to seismic risk and the significance of possible correlation between component failures and potential design and construction errors

Seismic analysis of APR1400 RCS for site envelope using big mass method

International Nuclear Information System (INIS)

Kim, J. Y.; Jeon, J. H.; Lee, D. H.; Park, S. H.

2002-01-01

One of design concepts of APR1400 is the site envelope considering various soil sites as well as rock site. The KSNP's are constructed on the rock site where only the translational excitations are directly transferred to the plant. On the other hand, the rotational motions affect the responses of the structures in the soil cases. In this study, a Big Mass Method is used to consider rotational motions as excitations at the foundation in addition to translational ones to obtain seismic responses of the APR1400 RCS main components. The seismic analyses for the APR1400 excited simultaneously by translation and rotational motions were performed. The results show that the effect of soil sites is not significant for the design of main components and supports of the RCS, but it may be considerable for the design of reactor vessel internals, piping, and nozzles which have lower natural frequencies

SITE-2, Power Plant Siting, Cost, Environment, Seismic and Meteorological Effects

International Nuclear Information System (INIS)

Frigerio, N.A.; Habegger, L.J.; King, R.F.; Hoover, L.J.; Clark, N.A.; Cobian, J.M.

1977-01-01

1 - Description of problem or function: SITE2 is designed to (1) screen candidate energy facility sites or areas within an electric utility region, based on the region's physical and socioeconomic attributes, the planned facility's characteristics, and impact assessments, and (2) evaluate the cumulative regional impacts associated with alternate energy supply options and inter-regional energy import/export practices, specifically, comparison of different energy technologies and their regional distribution in clustered or dispersed patterns. 2 - Method of solution: The SITE2 methodology is based on the quantification of three major site-related vectors. A cost vector is determined which identifies site-specific costs, such as transmission costs, cooling costs as related to water availability, and costs of specific controls needed to protect the surrounding environment. An impact vector is also computed for each potential site, using models of health and environmental impacts incurred in areas adjacent to the site. Finally, a site attribute vector is developed which reflects such characteristics as population, seismic conditions, meteorology, land use, and local ecological systems. This vector can be used to eliminate certain sites because of their inability to satisfy specific constraints. These three vectors can be displayed as density maps and combined in a simple overlay approach, similar to that developed by I. L. McHarg in reference 2, to identify candidate sites. Alternatively, the vector elements can be computationally combined into a weighted sum to obtain quantitative indicators of site suitability

SITE-2, Power Plant Siting, Cost, Environment, Seismic and Meteorological Effects

Energy Technology Data Exchange (ETDEWEB)

Frigerio, N A [Environmental Impact Studies, Argonne National Laboratory 9700 South Cass Avenue, Argonne, Illinois 60439 (United States); Habegger, L J; King, R F; Hoover, L J [Energy and Environmental Systems Division, Argonne National Laboratory 9700 South Cass Avenue, Argonne, Illinois 60439 (United States); Clark, N A [Applied Mathematics Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States); Cobian, J M [Northwestern University, Evanston, Illinois 60201 (United States)

1977-08-01

1 - Description of problem or function: SITE2 is designed to (1) screen candidate energy facility sites or areas within an electric utility region, based on the region's physical and socioeconomic attributes, the planned facility's characteristics, and impact assessments, and (2) evaluate the cumulative regional impacts associated with alternate energy supply options and inter-regional energy import/export practices, specifically, comparison of different energy technologies and their regional distribution in clustered or dispersed patterns. 2 - Method of solution: The SITE2 methodology is based on the quantification of three major site-related vectors. A cost vector is determined which identifies site-specific costs, such as transmission costs, cooling costs as related to water availability, and costs of specific controls needed to protect the surrounding environment. An impact vector is also computed for each potential site, using models of health and environmental impacts incurred in areas adjacent to the site. Finally, a site attribute vector is developed which reflects such characteristics as population, seismic conditions, meteorology, land use, and local ecological systems. This vector can be used to eliminate certain sites because of their inability to satisfy specific constraints. These three vectors can be displayed as density maps and combined in a simple overlay approach, similar to that developed by I. L. McHarg in reference 2, to identify candidate sites. Alternatively, the vector elements can be computationally combined into a weighted sum to obtain quantitative indicators of site suitability.

Seismic and geologic investigations of the Sandia Livermore Laboratory site

International Nuclear Information System (INIS)

Anon.

1978-01-01

This report describes results of a seismic and geologic investigation in the vicinity of Sandia Laboratories property and Sandia's Tritium Building at Livermore, California. The investigation was done to define any seismically capable faults in the immediate area and to obtain necessary information to support estimates of future possible or probable ground motions. The work included a variety of geophysical measurements, trenching, seismologic studies, geologic examination, and evaluation of possible ground surface rupture at the site. Ground motions due to the maximum potential earthquake are estimated, and probability of exceedance for various levels of peak ground acceleration is calculated. Descriptions of the various calculations and investigative techniques used and the data obtained are presented. Information obtained from other sources relevant to subsurface geology and faulting is also given. Correlation and evaluation of the various lines of evidence and conclusions regarding the seismic hazard to the Tritium Building are included

French practice in the area of seismic hazard assessment on nuclear facility sites and related research

International Nuclear Information System (INIS)

Mohammadioun, B.

1986-06-01

The methodology put into practice in the analysis of seismic hazard on the site of a nuclear facility relies upon a deterministic approach and endeavors to account for the particularities of every site considered insofar as available data and techniques allow. The calculation of a seismic reference motion for use in the facilities' design calls upon two basic sets of data. Regional seismicity over the past millennium, from historical sources, revised while preparing the seismotectonic map of France, is fundamental to this analysis. It is completed by instrumental data from the last quarter century. A collection of strong-motion accelerograph data from seismic areas worldwide reflects a variety of source characteristics and site conditions. A critical overview of current practice in France and elsewhere highlights shortcomings and areas of particular need both in experimental data and in methodology, and namely the scarcity of near-field data, the predominance of California records, and inaccurate approaches to integrating soil effects into ground-motion calculations. 16 refs

Vrancea earthquakes. Specific actions to mitigate seismic risk

International Nuclear Information System (INIS)

Marmureanu, Gheorghe; Marmureanu, Alexandru

2005-01-01

natural disasters given by earthquakes, there is a need to reverse trends in seismic risk mitigation to future events. Main courses of specific action to mitigate the seismic risks from strong deep Vrancea earthquakes should be considered as key to future development projects, including: - Early warning system for industrial facilities; - Short and long term prediction program of strong Vrancea earthquakes; - Seismic hazard map of Romania; - Seismic microzonation of large populated cities; - Shake map; - Seismic tomography of dams for avoiding disasters. The quality of life and the security of infrastructure (including human services, civil and industrial structures, financial infrastructure, information transmission and processing systems) in every nation are increasingly vulnerable to disasters caused by events that have geological, atmospheric, hydrologic, and technological origins. As UN Secretary General Kofi Annan pointed out, 'Building a culture of prevention is not easy. While the costs of prevention have to be paid in the present, its benefits lie in a distant future'. In other words: Prevention pays off. This may not always become apparent immediately, but, in the long run, the benefits from prevention measures will always outweigh their costs by far. Romania is an earthquake prone area and these main specific actions are really contributing to seismic risk mitigation. These specific actions are provided for in Law nr. 372/March 18,2004 -'The National Program of Seismic Risk Management'. (authors)

Passive seismic monitoring at the ketzin CCS site -Magnitude estimation

NARCIS (Netherlands)

Paap, B.F.; Steeghs, T.P.H.

2014-01-01

In order to allow quantification of the strength of local micro-seismic events recorded at the CCS pilot site in Ketzin in terms of local magnitude, earthquake data recorded by standardized seismometers were used. Earthquakes were selected that occurred in Poland and Czech Republic and that were

Seismic qualification of safety class components in non-reactor nuclear facilities at Hanford site

International Nuclear Information System (INIS)

Ocoma, E.C.

1989-01-01

This paper presents the methods used during the walkdowns to compile as-built structural information to seismically qualify or verify the seismic adequacy of safety class components in the Plutonium Finishing Plant complex. The Plutonium finishing Plant is a non-reactor nuclear facility built during the 1950's and was designed to the Uniform Building Code criteria for both seismic and wind events. This facility is located at the US Department of Energy Hanford Site near Richland, Washington

Handbook of nuclear power plant seismic fragilities, Seismic Safety Margins Research Program

International Nuclear Information System (INIS)

Cover, L.E.; Bohn, M.P.; Campbell, R.D.; Wesley, D.A.

1983-12-01

The Seismic Safety Margins Research Program (SSMRP) has a gola to develop a complete fully coupled analysis procedure (including methods and computer codes) for estimating the risk of an earthquake-induced radioactive release from a commercial nuclear power plant. As part of this program, calculations of the seismic risk from a typical commercial nuclear reactor were made. These calculations required a knowledge of the probability of failure (fragility) of safety-related components in the reactor system which actively participate in the hypothesized accident scenarios. This report describes the development of the required fragility relations and the data sources and data reduction techniques upon which they are based. Both building and component fragilities are covered. The building fragilities are for the Zion Unit 1 reactor which was the specific plant used for development of methodology in the program. Some of the component fragilities are site-specific also, but most would be usable for other sites as well

Crustal structure of the North Iberian continental margin from seismic refraction/wide-angle reflection profiles

Science.gov (United States)

Ruiz, M.; Díaz, J.; Pedreira, D.; Gallart, J.; Pulgar, J. A.

2017-10-01

The structure and geodynamics of the southern margin of the Bay of Biscay have been investigated from a set of 11 multichannel seismic reflection profiles, recorded also at wide angle offsets in an onshore-offshore network of 24 OBS/OBH and 46 land sites. This contribution focuses on the analysis of the wide-angle reflection/refraction data along representative profiles. The results document strong lateral variations of the crustal structure along the margin and provide an extensive test of the crustal models previously proposed for the northern part of the Iberian Peninsula. Offshore, the crust has a typical continental structure in the eastern tip of the bay, which disappears smoothly towards the NW to reach crustal thickness close to 10 km at the edge of the studied area ( 45°N, 6°W). The analysis of the velocity-depth profiles, altogether with additional information provided by the multichannel seismic data and magnetic surveys, led to the conclusion that the crust in this part of the bay should be interpreted as transitional from continental to oceanic. Typical oceanic crust has not been imaged in the investigated area. Onshore, the new results are in good agreement with previous results and document the indentation of the Bay of Biscay crust into the Iberian crust, forcing its subduction to the North. The interpreted profiles show that the extent of the southward indentation is not uniform, with an Alpine root less developed in the central and western sector of the Basque-Cantabrian Basin. N-S to NE-SW transfer structures seem to control those variations in the indentation degree.

Site response assessment using borehole seismic records

Energy Technology Data Exchange (ETDEWEB)

Park, Donghee; Chang, Chunjoong; Choi, Weonhack [KHNP Central Research Institute, Daejeon (Korea, Republic of)

2014-05-15

In regions with high seismic activity, such as Japan, the Western United States and Taiwan, borehole seismometers installed deep underground are used to monitor seismic activity during the course of seismic wave propagation at various depths and to study the stress changes due to earthquakes and analyze the connection to fault movements. The Korea Meteorological Administration (KMA) and the Korea Institute of Geology and Mining (KIGAM) have installed and are operating borehole seismometers at a depth of 70∼100 meters for the precise determination of epicenters. Also, Korea Hydro and Nuclear Power Co., Ltd. (KHNP) has installed and is operating 2 borehole seismic stations near Weolseong area to observe at a depth of 140 meters seismic activities connected to fault activity. KHNP plans to operate in the second half of 2014 a borehole seismic station for depths less than 300 and 600 meters in order to study the seismic response characteristics in deep strata. As a basic study for analyzing ground motion response characteristics at depths of about 300 to 600 meters in connection with the deep geological disposal of spent nuclear fuel, the present study examined the background noise response characteristics of the borehole seismic station operated by KHNP. In order to analyze the depth-dependent impact of seismic waves at deeper depths than in Korea, seismic data collected by Japan's KIK-net seismic stations were used and the seismic wave characteristics analyzed by size and depth. In order to analyze the borehole seismic observation data from the seismic station operated by KHNP, this study analyzed the background noise characteristics by using a probability density function.

Site response assessment using borehole seismic records

International Nuclear Information System (INIS)

Park, Donghee; Chang, Chunjoong; Choi, Weonhack

2014-01-01

In regions with high seismic activity, such as Japan, the Western United States and Taiwan, borehole seismometers installed deep underground are used to monitor seismic activity during the course of seismic wave propagation at various depths and to study the stress changes due to earthquakes and analyze the connection to fault movements. The Korea Meteorological Administration (KMA) and the Korea Institute of Geology and Mining (KIGAM) have installed and are operating borehole seismometers at a depth of 70∼100 meters for the precise determination of epicenters. Also, Korea Hydro and Nuclear Power Co., Ltd. (KHNP) has installed and is operating 2 borehole seismic stations near Weolseong area to observe at a depth of 140 meters seismic activities connected to fault activity. KHNP plans to operate in the second half of 2014 a borehole seismic station for depths less than 300 and 600 meters in order to study the seismic response characteristics in deep strata. As a basic study for analyzing ground motion response characteristics at depths of about 300 to 600 meters in connection with the deep geological disposal of spent nuclear fuel, the present study examined the background noise response characteristics of the borehole seismic station operated by KHNP. In order to analyze the depth-dependent impact of seismic waves at deeper depths than in Korea, seismic data collected by Japan's KIK-net seismic stations were used and the seismic wave characteristics analyzed by size and depth. In order to analyze the borehole seismic observation data from the seismic station operated by KHNP, this study analyzed the background noise characteristics by using a probability density function

Heat-flow and lateral seismic-velocity heterogeneities near Deep Sea Drilling Project-Ocean Drilling Program Site 504

Science.gov (United States)

Lowell, Robert P.; Stephen, Ralph A.

1991-11-01

Both conductive heat-flow and seismic-velocity data contain information relating to the permeability of the oceanic crust. Deep Sea Drilling Project-Ocean Drilling Program Site 504 is the only place where both detailed heat-flow and seismic-velocity field studies have been conducted at the same scale. In this paper we examine the correlation between heat flow and lateral heterogeneities in seismic velocity near Site 504. Observed heterogeneities in seismic velocity, which are thought to be related to variations in crack density in the upper 500 m of the basaltic crust, show little correlation with the heat-flow pattern. This lack of correlation highlights some of the current difficulties in using seismic-velocity data to infer details of spatial variations in permeability that are significant in controlling hydrothermal circulation.

Seismic risk and safety of nuclear installations. A look at the Cadarache Centre

International Nuclear Information System (INIS)

Verrhiest-Leblanc, G.; Chevallier, A.

2010-01-01

After a brief recall of some important seismic events which occurred in the past in the south-eastern part of France, the authors indicate the nuclear installations present in this region. They outline the difference between requirements for a usual building and for basic nuclear installations. They indicate laws and regulations which are to be applied to these installations like to any hazardous industrial installation. They describe the seismic risk as it has been determined for the Cadarache area, and evoke the para-seismic design of new nuclear installations which are to be built in Cadarache and actions for a para-seismic reinforcement of existing constructions. Finally, they evoke organisational aspects (emergency plans) and the approach for a better information and transparency about the seismic risk

The exponential rise of induced seismicity with increasing stress levels in the Groningen gas field and its implications for controlling seismic risk

Science.gov (United States)

Bourne, S. J.; Oates, S. J.; van Elk, J.

2018-06-01

Induced seismicity typically arises from the progressive activation of recently inactive geological faults by anthropogenic activity. Faults are mechanically and geometrically heterogeneous, so their extremes of stress and strength govern the initial evolution of induced seismicity. We derive a statistical model of Coulomb stress failures and associated aftershocks within the tail of the distribution of fault stress and strength variations to show initial induced seismicity rates will increase as an exponential function of induced stress. Our model provides operational forecasts consistent with the observed space-time-magnitude distribution of earthquakes induced by gas production from the Groningen field in the Netherlands. These probabilistic forecasts also match the observed changes in seismicity following a significant and sustained decrease in gas production rates designed to reduce seismic hazard and risk. This forecast capability allows reliable assessment of alternative control options to better inform future induced seismic risk management decisions.

Intelligent seismic risk mitigation system on structure building

Science.gov (United States)

Suryanita, R.; Maizir, H.; Yuniorto, E.; Jingga, H.

2018-01-01

Indonesia located on the Pacific Ring of Fire, is one of the highest-risk seismic zone in the world. The strong ground motion might cause catastrophic collapse of the building which leads to casualties and property damages. Therefore, it is imperative to properly design the structural response of building against seismic hazard. Seismic-resistant building design process requires structural analysis to be performed to obtain the necessary building responses. However, the structural analysis could be very difficult and time consuming. This study aims to predict the structural response includes displacement, velocity, and acceleration of multi-storey building with the fixed floor plan using Artificial Neural Network (ANN) method based on the 2010 Indonesian seismic hazard map. By varying the building height, soil condition, and seismic location in 47 cities in Indonesia, 6345 data sets were obtained and fed into the ANN model for the learning process. The trained ANN can predict the displacement, velocity, and acceleration responses with up to 96% of predicted rate. The trained ANN architecture and weight factors were later used to build a simple tool in Visual Basic program which possesses the features for prediction of structural response as mentioned previously.

Probabilistic and Scenario Seismic and Liquefaction Hazard Analysis of the Mississippi Embayment Incorporating Nonlinear Site Effects

Science.gov (United States)

Cramer, C. H.; Dhar, M. S.

2017-12-01

The influence of deep sediment deposits of the Mississippi Embayment (ME) on the propagation of seismic waves is poorly understood and remains a major source of uncertainty for site response analysis. Many researchers have studied the effects of these deposits on seismic hazard of the area using available information at the time. In this study, we have used updated and newly available resources for seismic and liquefaction hazard analyses of the ME. We have developed an improved 3D geological model. Additionally, we used surface geological maps from Cupples and Van Arsdale (2013) to prepare liquefaction hazard maps. Both equivalent linear and nonlinear site response codes were used to develop site amplification distributions for use in generating hazard maps. The site amplification distributions are created using the Monte Carlo approach of Cramer et al. (2004, 2006) on a 0.1-degree grid. The 2014 National Seismic Hazard model and attenuation relations (Petersen et al., 2014) are used to prepare seismic hazard maps. Then liquefaction hazard maps are generated using liquefaction probability curves from Holzer (2011) and Cramer et al. (2015). Equivalent linear response (w/ increased precision, restricted nonlinear behavior with depth) shows similar hazard for the ME compared to nonlinear analysis (w/o pore pressure) results. At short periods nonlinear deamplification dominates the hazard, but at long periods resonance amplification dominates. The liquefaction hazard tends to be high in Holocene and late Pleistocene lowland sediments, even with lowered ground water levels, and low in Pleistocene loess of the uplands. Considering pore pressure effects in nonlinear site response analysis at a test site on the lowlands shows amplification of ground motion at short periods. PGA estimates from ME liquefaction and MMI observations are in the 0.25 to 0.4 g range. Our estimated M7.5 PGA hazard within 10 km of the fault can exceed this. Ground motion observations from

A basis for standardized seismic design (SSD) for nuclear power plants/critical facilities

International Nuclear Information System (INIS)

O'Hara, T.F.; Jacobson, J.P.; Bellini, F.X.

1991-01-01

US Nuclear Power Plants (NPP's) are designed, engineered and constructed to stringent standards. Their seismic adequacy is assured by compliance with regulatory standards and demonstrated by both probabilistic risk assessments (PRAs) and seismic margin studies. However, present seismic siting criteria requires improvement. Proposed changes to siting criteria discussed here will provide a predictable licensing process and a stable regulatory environment. Two recent state-of-the-art studies evaluate the seismic design for all eastern US (EUS) NPP'S: a Lawrence Livermore National Labs study (LLNL, 1989) funded by the NRC and similar research by the Electric Power Research Institute (EPRI, 1989) supported by the utilities. Both confirm that Appendix A 10CFR Part 100 has not provided consistent seismic design levels for all sites. Standardized Seismic Design (SSD) uses a probabilistic framework to accommodate alternative deterministic interpretations. It uses seismic hazard input from EPRI or LLNL to produce consistent bases for future seismic design. SSD combines deterministic and probabilistic insights to provide a comprehensive approach for determining a future site's acceptable seismic design basis

Seismic hazard assessment of Iran

Directory of Open Access Journals (Sweden)

M. Ghafory-Ashtiany

1999-06-01

Full Text Available The development of the new seismic hazard map of Iran is based on probabilistic seismic hazard computation using the historical earthquakes data, geology, tectonics, fault activity and seismic source models in Iran. These maps have been prepared to indicate the earthquake hazard of Iran in the form of iso-acceleration contour lines, and seismic hazard zoning, by using current probabilistic procedures. They display the probabilistic estimates of Peak Ground Acceleration (PGA for the return periods of 75 and 475 years. The maps have been divided into intervals of 0.25 degrees in both latitudinal and longitudinal directions to calculate the peak ground acceleration values at each grid point and draw the seismic hazard curves. The results presented in this study will provide the basis for the preparation of seismic risk maps, the estimation of earthquake insurance premiums, and the preliminary site evaluation of critical facilities.

A Framework for Understanding Uncertainty in Seismic Risk Assessment.

Science.gov (United States)

Foulser-Piggott, Roxane; Bowman, Gary; Hughes, Martin

2017-10-11

A better understanding of the uncertainty that exists in models used for seismic risk assessment is critical to improving risk-based decisions pertaining to earthquake safety. Current models estimating the probability of collapse of a building do not consider comprehensively the nature and impact of uncertainty. This article presents a model framework to enhance seismic risk assessment and thus gives decisionmakers a fuller understanding of the nature and limitations of the estimates. This can help ensure that risks are not over- or underestimated and the value of acquiring accurate data is appreciated fully. The methodology presented provides a novel treatment of uncertainties in input variables, their propagation through the model, and their effect on the results. The study presents ranges of possible annual collapse probabilities for different case studies on buildings in different parts of the world, exposed to different levels of seismicity, and with different vulnerabilities. A global sensitivity analysis was conducted to determine the significance of uncertain variables. Two key outcomes are (1) that the uncertainty in ground-motion conversion equations has the largest effect on the uncertainty in the calculation of annual collapse probability; and (2) the vulnerability of a building appears to have an effect on the range of annual collapse probabilities produced, i.e., the level of uncertainty in the estimate of annual collapse probability, with less vulnerable buildings having a smaller uncertainty. © 2017 Society for Risk Analysis.

Seismic risk analysis for General Electric Plutonium Facility, Pleasanton, California

International Nuclear Information System (INIS)

1978-01-01

This report presents the results of a seismic risk analysis that focuses on all possible sources of seismic activity, with the exception of the postulated Verona Fault. The best estimate curve indicates that the Vallecitos facility will experience 30% g with a return period of roughly 130 years and 60% g with a return period of roughly 700 years

A seismic design of nuclear reactor building structures applying seismic isolation system in a seismicity region-a feasibility case study in Japan

Energy Technology Data Exchange (ETDEWEB)

Kubo, Tetsuo [The University of Tokyo, Tokyo (Japan); Yamamoto, Tomofumi; Sato, Kunihiko [Mitsubishi Heavy Industries, Ltd., Kobe (Japan); Jimbo, Masakazu [Toshiba Corporation, Yokohama (Japan); Imaoka, Tetsuo [Hitachi-GE Nuclear Energy, Ltd., Hitachi (Japan); Umeki, Yoshito [Chubu Electric Power Co. Inc., Nagoya (Japan)

2014-10-15

A feasibility study on the seismic design of nuclear reactor buildings with application of a seismic isolation system is introduced. After the Hyogo-ken Nanbu earthquake in Japan of 1995, seismic isolation technologies have been widely employed for commercial buildings. Having become a mature technology, seismic isolation systems can be applied to NPP facilities in areas of high seismicity. Two reactor buildings are discussed, representing the PWR and BWR buildings in Japan, and the application of seismic isolation systems is discussed. The isolation system employing rubber bearings with a lead plug positioned (LRB) is examined. Through a series of seismic response analyses using the so-named standard design earthquake motions covering the design basis earthquake motions obtained for NPP sites in Japan, the responses of the seismic isolated reactor buildings are evaluated. It is revealed that for the building structures examined herein: (1) the responses of both isolated buildings and isolating LRBs fulfill the specified design criteria; (2) the responses obtained for the isolating LRBs first reach the ultimate condition when intensity of motion is 2.0 to 2.5 times as large as that of the design-basis; and (3) the responses of isolated reactor building fall below the range of the prescribed criteria.

Real-time risk assessment in seismic early warning and rapid response: a feasibility study in Bishkek (Kyrgyzstan)

Science.gov (United States)

Picozzi, M.; Bindi, D.; Pittore, M.; Kieling, K.; Parolai, S.

2013-04-01

intensity from Fourier amplitude spectra; and the Tyagunov et al. (Nat Hazard Earth Syst Sci 6:573-586, 2006) approach for risk computation. Innovatively, all these methods are jointly applied to assess in real time the seismic risk of a particular target site, namely the city of Bishkek. Finally, the site amplification and vulnerability datasets considered in the proposed methodology are taken from previous studies, i.e., Parolai et al. (Bull Seismol Soc Am, 2010) and Bindi et al. (Soil Dyn Earthq Eng, 2011), respectively.

SHEAT: a computer code for probabilistic seismic hazard analysis, user's manual

International Nuclear Information System (INIS)

Ebisawa, Katsumi; Kondo, Masaaki; Abe, Kiyoharu; Tanaka, Toshiaki; Takani, Michio.

1994-08-01

The SHEAT code developed at Japan Atomic Energy Research Institute is for probabilistic seismic hazard analysis which is one of the tasks needed for seismic Probabilistic Safety Assessment (PSA) of a nuclear power plant. Seismic hazard is defined as an annual exceedance frequency of occurrence of earthquake ground motions at various levels of intensity at a given site. With the SHEAT code, seismic hazard is calculated by the following two steps: (1) Modeling of earthquake generation around a site. Future earthquake generation (locations, magnitudes and frequencies of postulated earthquakes) is modelled based on the historical earthquake records, active fault data and expert judgement. (2) Calculation of probabilistic seismic hazard at the site. An earthquake ground motion is calculated for each postulated earthquake using an attenuation model taking into account its standard deviation. Then the seismic hazard at the site is calculated by summing the frequencies of ground motions by all the earthquakes. This document is the user's manual of the SHEAT code. It includes: (1) Outlines of the code, which include overall concept, logical process, code structure, data file used and special characteristics of the code, (2) Functions of subprograms and analytical models in them, (3) Guidance of input and output data, and (4) Sample run results. The code has widely been used at JAERI to analyze seismic hazard at various nuclear power plant sites in japan. (author)

Seismicity and seismic monitoring in the Asse salt mine

International Nuclear Information System (INIS)

Flach, D.; Gommlich, G.; Hente, B.

1987-01-01

Seismicity analyses are made in order to assess the safety of candidate sites for ultimate disposal of hazardous wastes. The report in hand reviews the seismicity history of the Asse salt mine and presents recent results of a measuring campaign made in the area. The monitoring network installed at the site supplies data and information on the regional seismicity, on seismic amplitudes under ground and above ground, and on microseismic activities. (DG) [de

Improvements of Real Time First Motion Focal Mechanism and Noise Characteristics of New Sites at the Puerto Rico Seismic Network

Science.gov (United States)

Williams, D. M.; Lopez, A. M.; Huerfano, V.; Lugo, J.; Cancel, J.

2011-12-01

Seismic networks need quick and efficient ways to obtain information related to seismic events for the purposes of seismic activity monitoring, risk assessment, and scientific knowledge among others. As part of an IRIS summer internship program, two projects were performed to provide a tool for quick faulting mechanism and improve seismic data at the Puerto Rico Seismic Network (PRSN). First, a simple routine to obtain a focal mechanisms, the geometry of the fault, based on first motions was developed and implemented for data analysts routine operations at PRSN. The new tool provides the analyst a quick way to assess the probable faulting mechanism that occurred while performing the interactive earthquake location procedure. The focal mechanism is generated on-the-fly when data analysts pick P wave arrivals onsets and motions. Once first motions have been identified, an in-house PRSN utility is employed to obtain the double couple representation and later plotted using GMT's psmeca utility. Second, we addressed the issue of seismic noise related to thermal fluctuations inside seismic vaults. Seismic sites can be extremely noisy due to proximity to cultural activities and unattended thermal fluctuations inside sensor housings, thus resulting in skewed readings. In the past, seismologists have used different insulation techniques to reduce the amount of unwanted noise that a seismometers experience due to these thermal changes with items such as Styrofoam, and fiber glass among others. PRSN traditionally uses Styrofoam boxes to cover their seismic sensors, however, a proper procedure to test how these method compare to other new techniques has never been approached. The deficiency of properly testing these techniques in the Caribbean and especially Puerto Rico is that these thermal fluctuations still happen because of the intense sun and humidity. We conducted a test based on the methods employed by the IRIS Transportable Array, based on insulation by sand burial of

Hanford Site's Integrated Risk Assessment Program: No-intervention risk assessment

International Nuclear Information System (INIS)

Mahaffey, J.A.; Dukelow, J.S. Jr.; Stenner, R.D.

1994-08-01

The long-term goal of the Integrated Risk Assessment program (IRAP) is to estimate risks to workers, the public, organizations, and groups with reserved rights to Site access, the ecosystem, and natural resources to aid in managing environmental restoration and waste management at the Hanford Site. For each of these, information is needed about current risks, risks during cleanup, and endstate risks. The objective is three-fold: to determine if and when to remediate, and to what extent; to identify information unavailable but needed to make better cleanup decisions; to establish technology performance criteria for achieving desired cleanup levels; to understand costs and benefits of activities from a Site-wide perspective. The no-intervention risk, assessment is the initial evaluation of public health risks conducted under IRAP. The objective is to identify types of activities that the US Department of Energy (DOE) must accomplish for closure of the Hanford Site, defined as no further DOE intervention. There are two primary conclusions from the no-intervention risk assessment. First, some maintenance and operations activities at Hanford must be continued to protect the public from grave risks. However, when large Hanford expenditures are compared to cleanup progress, funds expended for maintenance and operations must be put in proper perspective. Second, stakeholder's emphasis on public risks at Hanford, as indicated by remediation priorities, are not in line with those estimated. The focus currently is on compliance with regulations, and on dealing with issues which are visible to stakeholders

Seismic isolation of nuclear power plants using sliding isolation bearings

Science.gov (United States)

Kumar, Manish

eight sites across the United States to show that the factor is equal to 1.0 for seismically isolated NPPs, if the risk is dominated by horizontal earthquake shaking. Response-history analyses using different models of seismically isolated NPPs are performed to understand the importance of the choice of friction model, model complexity and vertical ground motion for calculating horizontal displacement response across a wide range of sites and shaking intensities. A friction model for the single concave FP bearing should address heating. The pressure- and velocity-dependencies were not important for the models and sites studied. Isolation-system displacements can be computed using a macro model comprising a single FP bearing.

Management of environmental risks associated with landfills in seismically active regions in the New Independent States of Central Asia

International Nuclear Information System (INIS)

Webb, S.M.

2009-01-01

Sustainable waste management and disposal is a societal challenge in terms of economics, public health and environmental impact. The situation in developing countries, and in particular those subject to extreme natural hazards, results in increased overall risk as governments prioritize investments to issues of perceived higher economic importance. This dissertation investigates environmental risks associated with landfills in seismically active regions in the New Independent States of Central Asia. Environmental risk from municipal solid waste landfill sites encompasses a wide range of topics within socio-economics, physical sciences and engineering and therefore necessitates a multi-disciplinary approach. The underlying study is an accumulative result of a three-year collaborative research project (Contract No. INCO-CT-2005-516732) funded within the Eu Sixth Framework Programme (FP6). The international cooperation involved European, Russian and Central Asian research partners forming a multi-disciplinary consortium covering: GIS technologies, geology / hydrogeology geophysics and geotechnical engineering; landfill design and operation and waste management. understanding the relevant socio-economic aspects and legislative frameworks was necessary to prepare results and recommendations to address stakeholders in the Central Asian countries: Kazakhstan, Kyrgyzstan,Tajikistan,Turkmenistan and uzbekistan. (author) [de

Seismic stability evaluation using 2-D FEM analysis for modeling nuclear power plants sited on gravel soil

International Nuclear Information System (INIS)

Iba, T.; Konno, T.; Irino, K.; Hama, I.; Oguro, E.; Iizuka, S.; Enami, A.

1995-01-01

Throughout Europe and the United States, many nuclear power plants have been built on Quaternary deposit sites. While in Japan, all nuclear power plants have been built at rock sites primarily to maintain a high seismic resistivity. However, as more nuclear power plants are planned for the future, it has become necessary to develop new siting technology from the stand point of expanding the available range of site selection and effective utilization of land. A draft on guidelines of the seismic design for siting on Quaternary deposits is being carried out with a purpose to ensure proper design and construction for such sites. (author). 10 figs., 2 tabs

Seismic risk maps of Switzerland

International Nuclear Information System (INIS)

Saegesser, R.; Rast, B.; Merz, H.

1977-01-01

Seismic Risk Maps of Switzerland have been developed under the auspices of the Swiss Federal Division on Nuclear Safety. They are primarily destined for the use of owners of future nuclear power plants. The results will be mandatory for these future sites. The results will be shown as contourmaps of equal intensities for average return periods of 500, 1000, 10 000... years. This general form will not restrict the use of the results to nuclear power plants only, rather allows their applicability to any site or installation of public interest (such as r.a. waste deposits, hydropower plants, etc.). This follows the recommendations of the UNESCO World Conference (Paris, February 1976). In the study MSK 64 INTENSITY was chosen. The detailed scale allowed a precise handling of historical data and separates the results from continuously changing state-of-the-art correlations to acceleration and other input motion parameters. The method used is the probabilistic theory developed by C.A. Cornell and others at MIT in the late 1960's with the program in the version of the US Geological Survey by R. McGuire. In the study, the program was extended for the use of the continuous attenuation law by Sponheuer, azimuth-dependency in the attenuation relation, a quadratic intensity-frequency relation, large number of gross sources and output modifications with respect to the mapping program used. To determine the basic parameters, more than 3000 independent events in an area of approximately 240 000km 2 -Switzerland with its neighbouring parts of Italy, Austria, Germany and France- were systematically classified (and relocated where necessary)

A Fiber-Optic Borehole Seismic Vector Sensor System for Geothermal Site Characterization and Monitoring

Energy Technology Data Exchange (ETDEWEB)

Paulsson, Bjorn N.P. [Paulsson, Inc., Van Nuys, CA (United States); Thornburg, Jon A. [Paulsson, Inc., Van Nuys, CA (United States); He, Ruiqing [Paulsson, Inc., Van Nuys, CA (United States)

2015-04-21

Seismic techniques are the dominant geophysical techniques for the characterization of subsurface structures and stratigraphy. The seismic techniques also dominate the monitoring and mapping of reservoir injection and production processes. Borehole seismology, of all the seismic techniques, despite its current shortcomings, has been shown to provide the highest resolution characterization and most precise monitoring results because it generates higher signal to noise ratio and higher frequency data than surface seismic techniques. The operational environments for borehole seismic instruments are however much more demanding than for surface seismic instruments making both the instruments and the installation much more expensive. The current state-of-the-art borehole seismic instruments have not been robust enough for long term monitoring compounding the problems with expensive instruments and installations. Furthermore, they have also not been able to record the large bandwidth data available in boreholes or having the sensitivity allowing them to record small high frequency micro seismic events with high vector fidelity. To reliably achieve high resolution characterization and long term monitoring of Enhanced Geothermal Systems (EGS) sites a new generation of borehole seismic instruments must therefore be developed and deployed. To address the critical site characterization and monitoring needs for EGS programs, US Department of Energy (DOE) funded Paulsson, Inc. in 2010 to develop a fiber optic based ultra-large bandwidth clamped borehole seismic vector array capable of deploying up to one thousand 3C sensor pods suitable for deployment into ultra-high temperature and high pressure boreholes. Tests of the fiber optic seismic vector sensors developed on the DOE funding have shown that the new borehole seismic sensor technology is capable of generating outstanding high vector fidelity data with extremely large bandwidth: 0.01 – 6,000 Hz. Field tests have shown

Evolution of a seismic risk assessment technique

International Nuclear Information System (INIS)

Wells, J.E.; Cummings, G.E.

1985-01-01

To assist the NRC in its licensing evaluation role the Seismic Safety Margins Research Program (SSMRP) was started at LLNL in 1978. Its goal was to develop tools and data bases to evaluate the probability of earthquake caused radioactive releases from commercial nuclear power plants. The methodology was finalized in 1982 and a seismic risk assessment of the Zion Nuclear Power Plant was finished in 1983. Work continues on the study of the LaSalle Boiling Water Reactor. This paper will discuss some of the effects of the assumptions made during development of the systems analysis techniques used in SSMRP in light of the results obtained on studies to date. 5 refs

Earth modeling and estimation of the local seismic ground motion due to site geology in complex volcanoclastic areas

Directory of Open Access Journals (Sweden)

V. Di Fiore

2002-06-01

Full Text Available Volcanic areas often show complex behaviour as far as seismic waves propagation and seismic motion at surface are concerned. In fact, the finite lateral extent of surface layers such as lava flows, blocks, differential welding and/or zeolitization within pyroclastic deposits, introduces in the propagation of seismic waves effects such as the generation of surface waves at the edge, resonance in lateral direction, diffractions and scattering of energy, which tend to modify the amplitude as well as the duration of the ground motion. The irregular topographic surface, typical of volcanic areas, also strongly influences the seismic site response. Despite this heterogeneity, it is unfortunately a common geophysical and engineering practice to evaluate even in volcanic environments the subsurface velocity field with monodimensional investigation method (i.e. geognostic soundings, refraction survey, down-hole, etc. prior to the seismic site response computation which in a such cases is obviously also made with 1D algorithms. This approach often leads to highly inaccurate results. In this paper we use a different approach, i.e. a fully 2D P-wave Çturning rayÈ tomographic survey followed by 2D seismic site response modeling. We report here the results of this approach in three sites located at short distance from Mt. Vesuvius and Campi Flegrei and characterized by overburdens constituted by volcanoclastic deposits with large lateral and vertical variations of their elastic properties. Comparison between 1D and 2D Dynamic Amplification Factor shows in all reported cases entirely different results, both in terms of peak period and spectral contents, as expected from the clear bidimensionality of the geological section. Therefore, these studies suggest evaluating carefully the subsoil geological structures in areas characterized by possible large lateral and vertical variations of the elastic properties in order to reach correct seismic site response

Systems considerations in seismic margin evaluations

International Nuclear Information System (INIS)

Buttermer, D.R.

1987-01-01

Increasing knowledge in the geoscience field has led to the understanding that, although highly unlikely, it is possible for a nuclear power plant to be subjected to earthquake ground motion greater than that for which the plant was designed. While it is recognized that there are conservatisms inherent in current design practices, interest has developed in evaluating the seismic risk of operating plants. Several plant-specific seismic probabilistic risk assessments (SPRA) have been completed to address questions related to the seismic risk of a plant. The results from such SPRAs are quite informative, but such studies may entail a considerable amount of expensive analysis of large portions of the plant. As an alternative to an SPRA, it may be more practical to select an earthquake level above the design basis for which plant survivability is to be demonstrated. The principal question to be addressed in a seismic margin evaluation is: At what ground motion levels does one have a high confidence that the probability of seismically induced core damage is sufficiently low? In a seismic margin evaluation, an earthquake level is selected (based on site-specific geoscience considerations) for which a stable, long-term safe shutdown condition is to be demonstrated. This prespecified earthquake level is commonly referred to as the seismic margin earthquake (SME). The Electric Power Research Institute is currently supporting a research project to develop procedures for use by the utilities to allow them to perform nuclear plant seismic margin evaluations. This paper describes the systems-related aspects of these procedures

Seismic structure from multi-channel seismic reflection and wide-angle data of Transect 0E in the Southern Gulf of California

Science.gov (United States)

Paramo, P.; Holbrook, W.; Brown, H.; Lizarralde, D.; Fletcher, J.; Umhoefer, P.; Kent, G.; Harding, A.; Gonzalez, A.; Axen, G.

2005-12-01

We present a velocity model from wide-angle data along with coincident prestack depth migration sections from seismic reflection data collected in the southern Gulf of California. Transect 0E runs NE to SW from the hills of Sierra Madre in mainland Mexico near Mazatlan to approximately 115 km into Gulf of California waters. Wide-angle data were recorded by 9 ocean bottom seismometers, deployed by the R/V New Horizon and 10 Reftek seismometers located along onshore extension of the transect. The average spacing for the OBS and Refteks is ~12 km and shots were fired from the R/V Maurice Ewing at 150 m intervals. Transect 0E crosses what it is believed to be extended continental crust and lies in the initial direction of extension characteristic of the proto-gulf. Preliminary results from the velocity model show upper crustal velocities of 6.1-6.3 km/s and lower crustal velocities of 6.7-7.0 km/s along the entire transect. Seismic velocities and crustal thicknesses observed along transect 0E are characteristic of non-volcanic margins.

The KnowRISK project - Know your city, Reduce seISmic risK through non-structural elements

Science.gov (United States)

Sousa Oliveria, Carlos; Amaral Ferreira, Mónica; Lopez, Mário; Sousa Silva, Delta; Musacchio, Gemma; Rupakhety, Rajesh; Falsaperla, Susanna; Meroni, Fabrizio; Langer, Horst

2016-04-01

Historically, there is a tendency to focus on seismic structural performance of buildings, neglecting the potential for damage of non-structural elements. In particular, non-structural elements of buildings are their architectural parts (i.e. partitions, ceilings, cladding), electrical and mechanical components (i.e., distribution panels, piping, plumbing), and contents (e.g., furniture, bookcases, computers and desktop equipment). Damage of these elements often contributes significantly to earthquake impacts. In the 1999 Izmit Earthquake, Turkey, 50% of the injuries and 3% of human losses were caused by non-structural failures. In the 2010-2011 Christchurch Earthquakes (New Zealand), 40% of building damage was induced by non-structural malfunctions. Around 70%-85% of construction cost goes into these elements, and their damage can strongly influence the ability of communities to cope with and recover from earthquakes. The project Know your city, Reduce seISmic risK through non-structural elements (KnowRISK) aims at facilitating local communities' access to expert knowledge on non-structural seismic protection solutions. The project will study seismic scenarios critical for non-structural damage, produce a portfolio of non-structural protection measures and investigate the level of awareness in specific communities. We will implement risk communication strategies that will take into account the social and cultural background and a participatory approach to raise awareness in local communities. The paradox between the progress of scientific knowledge and the ongoing increase of losses from natural disasters worldwide is a well-identified gap in the UN Hyogo Framework for Action 2005-2015, in which one of the main priorities is the investment on "knowledge use, innovation and education to build a culture of safety and resilience". The KnowRISK is well aligned with these priorities and will contribute to participatory action aimed at: i) transferring expert knowledge

Seismic site-response characterization of high-velocity sites using advanced geophysical techniques: application to the NAGRA-Net

Czech Academy of Sciences Publication Activity Database

Poggi, V.; Burjánek, Jan; Michel, C.; Fäh, D.

2017-01-01

Roč. 210, č. 2 (2017), s. 645-659 ISSN 0956-540X Institutional support: RVO:67985530 Keywords : joint inversion * earthquake ground motions * seismic noise * site effects Subject RIV: DC - Siesmology, Volcanology, Earth Structure OBOR OECD: Volcanology Impact factor: 2.414, year: 2016

Site-specific seismic probabilistic tsunami hazard analysis: performances and potential applications

Science.gov (United States)

Tonini, Roberto; Volpe, Manuela; Lorito, Stefano; Selva, Jacopo; Orefice, Simone; Graziani, Laura; Brizuela, Beatriz; Smedile, Alessandra; Romano, Fabrizio; De Martini, Paolo Marco; Maramai, Alessandra; Piatanesi, Alessio; Pantosti, Daniela

2017-04-01

Seismic Probabilistic Tsunami Hazard Analysis (SPTHA) provides probabilities to exceed different thresholds of tsunami hazard intensity, at a specific site or region and in a given time span, for tsunamis caused by seismic sources. Results obtained by SPTHA (i.e., probabilistic hazard curves and inundation maps) represent a very important input to risk analyses and land use planning. However, the large variability of source parameters implies the definition of a huge number of potential tsunami scenarios, whose omission could lead to a biased analysis. Moreover, tsunami propagation from source to target requires the use of very expensive numerical simulations. At regional scale, the computational cost can be reduced using assumptions on the tsunami modeling (i.e., neglecting non-linear effects, using coarse topo-bathymetric meshes, empirically extrapolating maximum wave heights on the coast). On the other hand, moving to local scale, a much higher resolution is required and such assumptions drop out, since detailed inundation maps require significantly greater computational resources. In this work we apply a multi-step method to perform a site-specific SPTHA which can be summarized in the following steps: i) to perform a regional hazard assessment to account for both the aleatory and epistemic uncertainties of the seismic source, by combining the use of an event tree and an ensemble modeling technique; ii) to apply a filtering procedure which use a cluster analysis to define a significantly reduced number of representative scenarios contributing to the hazard of a specific target site; iii) to perform high resolution numerical simulations only for these representative scenarios and for a subset of near field sources placed in very shallow waters and/or whose coseismic displacements induce ground uplift or subsidence at the target. The method is applied to three target areas in the Mediterranean located around the cities of Milazzo (Italy), Thessaloniki (Greece) and

RELIABILITY AND ACCURACY ASSESSMENT OF INVASIVE AND NON- INVASIVE SEISMIC METHODS FOR SITE CHARACTERIZATION: FEEDBACK FROM THE INTERPACIFIC PROJECT

OpenAIRE

Garofalo , F.; Foti , S.; Hollender , F.; Bard , P.-Y.; Cornou , C.; Cox , B.R.; Dechamp , A.; Ohrnberger , M.; Sicilia , D.; Vergniault , C.

2017-01-01

International audience; The InterPacific project (Intercomparison of methods for site parameter and velocity profile characterization) aims to assess the reliability of seismic site characterization methods (borehole and surface wave methods) used for estimating shear wave velocity (VS) profiles and other related parameters (e.g., VS30). Three sites, representative of different geological conditions relevant for the evaluation of seismic site response effects, have been selected: (1) a hard r...

A SEISMIC DESIGN OF NUCLEAR REACTOR BUILDING STRUCTURES APPLYING SEISMIC ISOLATION SYSTEM IN A HIGH SEISMICITY REGION –A FEASIBILITY CASE STUDY IN JAPAN-

Directory of Open Access Journals (Sweden)

TETSUO KUBO

2014-10-01

Full Text Available A feasibility study on the seismic design of nuclear reactor buildings with application of a seismic isolation system is introduced. After the Hyogo-ken Nanbu earthquake in Japan of 1995, seismic isolation technologies have been widely employed for commercial buildings. Having become a mature technology, seismic isolation systems can be applied to NPP facilities in areas of high seismicity. Two reactor buildings are discussed, representing the PWR and BWR buildings in Japan, and the application of seismic isolation systems is discussed. The isolation system employing rubber bearings with a lead plug positioned (LRB is examined. Through a series of seismic response analyses using the so-named standard design earthquake motions covering the design basis earthquake motions obtained for NPP sites in Japan, the responses of the seismic isolated reactor buildings are evaluated. It is revealed that for the building structures examined herein: (1 the responses of both isolated buildings and isolating LRBs fulfill the specified design criteria; (2 the responses obtained for the isolating LRBs first reach the ultimate condition when intensity of motion is 2.0 to 2.5 times as large as that of the design-basis; and (3 the responses of isolated reactor building fall below the range of the prescribed criteria.

A study of local site effects in Benevento(Southern Italy by the analysis of seismic records of explosions

Directory of Open Access Journals (Sweden)

L. Mirabile

1995-06-01

Full Text Available In this paper we evalllate the seismic amplification effects in the town of Benevento llsing records of an explo- sion of 500 kg fired at abollt 7 km. Seismic records were obtained at 43 selected sites in the city by digital three-component stations. A data selection performed on the signal-to-noise ratio reduced the available data to 26 stations. We used the spectral ratio techniques to evaluate the amplification effects of each recording site compared both to the average spectrum calculated over 26 stations and to a reference seismic station. The shapes of the spectral ratios were classified according to the geological characteristics of the site. A characteristic shape of the spectral ratio was observed to be related to the specific structure of the subsoil. In particular, the sites on basin sediments (Lagonegro Unit and Middle Pleistocene conglomerates failed to show amplification effects; the sites on thick alluvial deposits showed amplification in the 5-9 Hz range; finally, sites on alluvial-lacustrine deposits amplified the seismic signal at frequencies depending on the characteristics and the thickness of the deposit. In addition, damage distribution caused by the 1688 earthquake in Benevento was related to the thickness of the surface layers in the ancient built-up area of the town. The study of the spectral ra- tios showed that these deposits amplify ground motion at frequencies between 9 and 12 Hz, i.e. frequencies close to the natural period of the most widespread buildings at that time in Benevento. Geological and seismic data were jointly used to carry out a zonation of the urban area of Benevento on the basis of homogeneous seismic responses. The validity of this analysis is limited to the main frequency band and amplitude of ground motion produced by the explosions.

Seismic risk assessment in the Mexican Nuclear Center applying the Gumbel-I distribution

International Nuclear Information System (INIS)

Flores R, J.H.; Arguelles F, R.; Camacho L, M.E.; Urrutia F, J.

1997-01-01

A licensing requirement for the operation of nuclear facilities is the performance of different kinds of studies, one of which is seismic risk assessment. This study is useful for the validation of the seismic coefficient applied in the structural design of the facilities. Thus, for the construction of a pilot nuclear fuel plant at Mexico Nuclear Centre of the Instituto Nacional de Investigaciones Nucleares (ININ), was necessary to make such study. The seismicity data for the period between 1912 and 1990 were used and the extreme values Gumbel-I distribution was applied to them. With this, ground acceleration seismic risk maps for recurrence periods of 1, 25 and 50 years were drawn up, showing maximum values of 1.2, 4.25, and 5.0 gales, respectively. (Author)

Ethical Implications of Seismic Risk Communication in Istanbul - Insights from a Transdisciplinary, Film-based Science Communication Workshop

Science.gov (United States)

Ickert, Johanna; Stewart, Iain S.

2016-04-01

's vulnerable building stock, the civic administration has initiated major seismic retrofitting and reconstruction projects. These projects have led to widespread civic unrest and social division, with inhabitants of urban transformation areas widely complaining that their views are neither represented in the procedures of the mitigation measures nor in the seismic risk communication that accompanies them. A growing lack of trust in risk mitigation measures adds to fatalistic attitudes to undermine individual and neighbourhood preparedness actions. It is in this contested, politicized arena of multi-stakeholder interests that geoscientists attempt to communicate Istanbul's acute seismic threat. Following a critical reflection on the geo-ethics of current science communication methods, we explore the potential of transdisciplinary film-based methods to provide alternative frameworks for communicating to and engaging with at-risk communities. We argue that such an approach offers novel opportunities to address key ethical concerns by bridging different communication cultures and promoting a greater reflexivity in science communication.

Evaluation of structural fragilities for an IPEEE seismic probabilistic risk assessment study

International Nuclear Information System (INIS)

Ghiocel, D.M.; Wilson, P.R.; Stevenson, J.D.

1995-01-01

The paper presents the main issues and results of a structural fragility analysis for a Seismic Probabilistic Risk Assessment (SPRA) study of a nuclear power plant (NPP) in the Eastern US. The fragility evaluations were performed for the Reactor Building, Auxiliary Building, Intake Structure and Diesel Generator Building. The random seismic input is defined in terms of the Uniform Hazard Spectrum (UHS) earthquake on the NPP site anchored to a reference level of 0.40 g Zero Period Ground Acceleration (ZPGA). Because of the soft soil conditions new Soil-Structure Interaction (SSI) analyses were performed using the original finite element (stick) structural models and the complex frequency approach. The soil deposit randomness was described by the variations in both the low strain soil shear modules and in its dependence with the shear strain. The probabilistic SSI analyses were performed using digital simulation techniques. The critical failure modes for each structure are investigated and the fragility evaluations are discussed. Concluding remarks and recommendations for improving the quality of the structural fragility analyses are included

Seismic Hazard and risk assessment for Romania -Bulgaria cross-border region

Science.gov (United States)

Simeonova, Stela; Solakov, Dimcho; Alexandrova, Irena; Vaseva, Elena; Trifonova, Petya; Raykova, Plamena

2016-04-01

Among the many kinds of natural and man-made disasters, earthquakes dominate with regard to their social and economical impact on the urban environment. Global seismic hazard and vulnerability to earthquakes are steadily increasing as urbanization and development occupy more areas that are prone to effects of strong earthquakes. The assessment of the seismic hazard and risk is particularly important, because it provides valuable information for seismic safety and disaster mitigation, and it supports decision making for the benefit of society. Romania and Bulgaria, situated in the Balkan Region as a part of the Alpine-Himalayan seismic belt, are characterized by high seismicity, and are exposed to a high seismic risk. Over the centuries, both countries have experienced strong earthquakes. The cross-border region encompassing the northern Bulgaria and southern Romania is a territory prone to effects of strong earthquakes. The area is significantly affected by earthquakes occurred in both countries, on the one hand the events generated by the Vrancea intermediate-depth seismic source in Romania, and on the other hand by the crustal seismicity originated in the seismic sources: Shabla (SHB), Dulovo, Gorna Orjahovitza (GO) in Bulgaria. The Vrancea seismogenic zone of Romania is a very peculiar seismic source, often described as unique in the world, and it represents a major concern for most of the northern part of Bulgaria as well. In the present study the seismic hazard for Romania-Bulgaria cross-border region on the basis of integrated basic geo-datasets is assessed. The hazard results are obtained by applying two alternative approaches - probabilistic and deterministic. The MSK64 intensity (MSK64 scale is practically equal to the new EMS98) is used as output parameter for the hazard maps. We prefer to use here the macroseismic intensity instead of PGA, because it is directly related to the degree of damages and, moreover, the epicentral intensity is the original

Seismic hazard and seismic risk assessment based on the unified scaling law for earthquakes: Himalayas and adjacent regions

Science.gov (United States)

Nekrasova, A. K.; Kossobokov, V. G.; Parvez, I. A.

2015-03-01

For the Himalayas and neighboring regions, the maps of seismic hazard and seismic risk are constructed with the use of the estimates for the parameters of the unified scaling law for earthquakes (USLE), in which the Gutenberg-Richter law for magnitude distribution of seismic events within a given area is applied in the modified version with allowance for linear dimensions of the area, namely, log N( M, L) = A + B (5 - M) + C log L, where N( M, L) is the expected annual number of the earthquakes with magnitude M in the area with linear dimension L. The spatial variations in the parameters A, B, and C for the Himalayas and adjacent regions are studied on two time intervals from 1965 to 2011 and from 1980 to 2011. The difference in A, B, and C between these two time intervals indicates that seismic activity experiences significant variations on a scale of a few decades. With a global consideration of the seismic belts of the Earth overall, the estimates of coefficient A, which determines the logarithm of the annual average frequency of the earthquakes with a magnitude of 5.0 and higher in the zone with a linear dimension of 1 degree of the Earth's meridian, differ by a factor of 30 and more and mainly fall in the interval from -1.1 to 0.5. The values of coefficient B, which describes the balance between the number of earthquakes with different magnitudes, gravitate to 0.9 and range from less than 0.6 to 1.1 and higher. The values of coefficient C, which estimates the fractal dimension of the local distribution of epicenters, vary from 0.5 to 1.4 and higher. In the Himalayas and neighboring regions, the USLE coefficients mainly fall in the intervals of -1.1 to 0.3 for A, 0.8 to 1.3 for B, and 1.0 to 1.4 for C. The calculations of the local value of the expected peak ground acceleration (PGA) from the maximal expected magnitude provided the necessary basis for mapping the seismic hazards in the studied region. When doing this, we used the local estimates of the

Seismic rupture modelling, strong motion prediction and seismic hazard assessment: fundamental and applied approaches; Modelisation de la rupture sismique, prediction du mouvement fort, et evaluation de l'alea sismique: approches fondamentale et appliquee

Energy Technology Data Exchange (ETDEWEB)

Berge-Thierry, C

2007-05-15

The defence to obtain the 'Habilitation a Diriger des Recherches' is a synthesis of the research work performed since the end of my Ph D. thesis in 1997. This synthesis covers the two years as post doctoral researcher at the Bureau d'Evaluation des Risques Sismiques at the Institut de Protection (BERSSIN), and the seven consecutive years as seismologist and head of the BERSSIN team. This work and the research project are presented in the framework of the seismic risk topic, and particularly with respect to the seismic hazard assessment. Seismic risk combines seismic hazard and vulnerability. Vulnerability combines the strength of building structures and the human and economical consequences in case of structural failure. Seismic hazard is usually defined in terms of plausible seismic motion (soil acceleration or velocity) in a site for a given time period. Either for the regulatory context or the structural specificity (conventional structure or high risk construction), seismic hazard assessment needs: to identify and locate the seismic sources (zones or faults), to characterize their activity, to evaluate the seismic motion to which the structure has to resist (including the site effects). I specialized in the field of numerical strong-motion prediction using high frequency seismic sources modelling and forming part of the IRSN allowed me to rapidly working on the different tasks of seismic hazard assessment. Thanks to the expertise practice and the participation to the regulation evolution (nuclear power plants, conventional and chemical structures), I have been able to work on empirical strong-motion prediction, including site effects. Specific questions related to the interface between seismologists and structural engineers are also presented, especially the quantification of uncertainties. This is part of the research work initiated to improve the selection of the input ground motion in designing or verifying the stability of structures. (author)

Underground measurements of seismic vibrations at the SSC site

International Nuclear Information System (INIS)

Shiltsev, V.D.; Parkhomchuk, V.V.; Weaver, H.J.

1995-01-01

The results of underground measurements of seismic vibrations at the tunnel depth of the Superconducting Super Collider (SSC) site are presented. Spectral analysis of the data obtained in the frequency band from 0.05 Hz to 1500 Hz is performed. It is found that amplitudes of ambient ground motion are less than requirements for the Collider, but cultural vibrations are unacceptably large and will cause fast growth of transverse emittance of the SSC beams

Cavola experiment site: geophysical investigations and deployment of a dense seismic array on a landslide

Directory of Open Access Journals (Sweden)

L. Martelli

2007-06-01

Full Text Available Geophysical site investigations have been performed in association with deployment of a dense array of 95 3-component seismometers on the Cavola landslide in the Northern Apennines. The aim of the array is to study propagation of seismic waves in the heterogeneous medium through comparison of observation and modelling. The small-aperture array (130 m×56 m operated continuously for three months in 2004. Cavola landslide consists of a clay body sliding over mudstone-shale basement, and has a record of historical activity, including destruction of a small village in 1960. The site investigations include down-hole logging of P- and S-wave travel times at a new borehole drilled within the array, two seismic refraction lines with both P-wave profiling and surface-wave analyses, geo-electrical profiles and seismic noise measurements. From the different approaches a consistent picture of the depths and seismic velocities for the landslide has emerged. Their estimates agree with resonance frequencies of seismic noise, and also with the logged depths to basement of 25 m at a new borehole and of 44 m at a pre-existing borehole. Velocities for S waves increase with depth, from 230 m/s at the surface to 625 m/s in basement immediately below the landslide.

Seismic hazard studies for the high flux beam reactor at Brookhaven National Laboratory

International Nuclear Information System (INIS)

Costantino, C.J.; Heymsfield, E.; Park, Y.J.; Hofmayer, C.H.

1991-01-01

This paper presents the results of a calculation to determine the site specific seismic hazard appropriate for the deep soil site at Brookhaven National Laboratory (BNL) which is to be used in the risk assessment studies being conducted for the High Flux Beam Reactor (HFBR). The calculations use as input the seismic hazard defined for the bedrock outcrop by a study conducted at Lawrence Livermore National Laboratory (LLNL). Variability in site soil properties were included in the calculations to obtain the seismic hazard at the ground surface and compare these results with those using the generic amplification factors from the LLNL study

Component fragility analysis methodology for seismic risk assessment projects. Proven PSA safety document processing and assessment procedures

International Nuclear Information System (INIS)

Kolar, Ladislav

2013-03-01

The seismic risk task assessment task should be structured as follows: (i) Define all reactor unit building structures, components and equipment involved in the creation of an initiating event (IE) induced by an seismic event or contributing to the reliability of reactor unit response to an IE; (ii) construct and estimate of the fragility curves for the building and component groups sub (i); (iii) determine the HCLPF for each group of buildings, components or equipment; (iv) determine the nuclear source's seismic resistance (SME) as the minimum HCLPF from the group of equipment in the risk-dominant scenarios; (v) define the risk-limiting group of components, equipment and building structures to the SME value; (vi) based on the fragility levels, identify component groups for which a more detailed fragility analysis is needed; and (vii) recommend groups of equipment or building structures that should be taken into account with respect to the seismic risk, i.e. such groups of equipment or building structures as exhibit a low seismic resistance (HCLPF) and, at the same time, are involved to a significant extent in the reactor unit's seismic risk (are present in the dominant risk scenarios). (P.A.)

Seismic rupture modelling, strong motion prediction and seismic hazard assessment: fundamental and applied approaches; Modelisation de la rupture sismique, prediction du mouvement fort, et evaluation de l'alea sismique: approches fondamentale et appliquee

Energy Technology Data Exchange (ETDEWEB)

Berge-Thierry, C

2007-05-15

The defence to obtain the 'Habilitation a Diriger des Recherches' is a synthesis of the research work performed since the end of my Ph D. thesis in 1997. This synthesis covers the two years as post doctoral researcher at the Bureau d'Evaluation des Risques Sismiques at the Institut de Protection (BERSSIN), and the seven consecutive years as seismologist and head of the BERSSIN team. This work and the research project are presented in the framework of the seismic risk topic, and particularly with respect to the seismic hazard assessment. Seismic risk combines seismic hazard and vulnerability. Vulnerability combines the strength of building structures and the human and economical consequences in case of structural failure. Seismic hazard is usually defined in terms of plausible seismic motion (soil acceleration or velocity) in a site for a given time period. Either for the regulatory context or the structural specificity (conventional structure or high risk construction), seismic hazard assessment needs: to identify and locate the seismic sources (zones or faults), to characterize their activity, to evaluate the seismic motion to which the structure has to resist (including the site effects). I specialized in the field of numerical strong-motion prediction using high frequency seismic sources modelling and forming part of the IRSN allowed me to rapidly working on the different tasks of seismic hazard assessment. Thanks to the expertise practice and the participation to the regulation evolution (nuclear power plants, conventional and chemical structures), I have been able to work on empirical strong-motion prediction, including site effects. Specific questions related to the interface between seismologists and structural engineers are also presented, especially the quantification of uncertainties. This is part of the research work initiated to improve the selection of the input ground motion in designing or verifying the stability of structures. (author)

Seismic risk assessment of Navarre (Northern Spain)

Science.gov (United States)

Gaspar-Escribano, J. M.; Rivas-Medina, A.; García Rodríguez, M. J.; Benito, B.; Tsige, M.; Martínez-Díaz, J. J.; Murphy, P.

2009-04-01

The RISNA project, financed by the Emergency Agency of Navarre (Northern Spain), aims at assessing the seismic risk of the entire region. The final goal of the project is the definition of emergency plans for future earthquakes. With this purpose, four main topics are covered: seismic hazard characterization, geotechnical classification, vulnerability assessment and damage estimation to structures and exposed population. A geographic information system is used to integrate, analyze and represent all information colleted in the different phases of the study. Expected ground motions on rock conditions with a 90% probability of non-exceedance in an exposure time of 50 years are determined following a Probabilistic Seismic Hazard Assessment (PSHA) methodology that includes a logic tree with different ground motion and source zoning models. As the region under study is located in the boundary between Spain and France, an effort is required to collect and homogenise seismological data from different national and regional agencies. A new homogenised seismic catalogue, merging data from Spanish, French, Catalonian and international agencies and establishing correlations between different magnitude scales, is developed. In addition, a new seismic zoning model focused on the study area is proposed. Results show that the highest ground motions on rock conditions are expected in the northeastern part of the region, decreasing southwards. Seismic hazard can be expressed as low-to-moderate. A geotechnical classification of the entire region is developed based on surface geology, available borehole data and morphotectonic constraints. Frequency-dependent amplification factors, consistent with code values, are proposed. The northern and southern parts of the region are characterized by stiff and soft soils respectively, being the softest soils located along river valleys. Seismic hazard maps including soil effects are obtained by applying these factors to the seismic hazard maps

U.S. Nuclear Regulatory Commission seismic regulations, research, and emerging trends

International Nuclear Information System (INIS)

Chokshi, N.C.; Shao, L.C.; Apostolakis, G.

1997-01-01

Historically in the United States, seismic issues have played an important role in determining site suitability and, in some cases, have determined the ultimate fate of power plants. During the late 1960s and early 1970s, a seismic design philosophy evolved as the licensing of the earlier plants was in progress. Concepts such as the Safe Shutdown Earthquake (SSE) and the Operating Basis Earthquake (OBE) emerged and were codified into the federal regulations with the publication in December 1973 of Appendix A, 'Seismic and Geologic Siting Criteria for Nuclear Power Plants,' to 10 CFR Part 100, 'Reactor Site Criteria.' Seismic considerations are also important in siting and design of other fuel cycle and waste facilities. In this paper, a brief overview of the current seismic siting and design regulations are described along with some recent and planned changes based on the past experience, advancement in the state-of-the-art, and research results. In particular, the recently revised siting rule and use of the probabilistic seismic hazard analysis in implementation of the rule will be described in more detail. The paper includes discussion of some recent seismic issues and research activities, including issues related to aging. Some emerging trends are highlighted. In particular, the paper focuses on use of 'expert opinion' in the probabilistic analysis and risk informed regulations and their implications to the seismic design. An additional focus is on international cooperative programs and how to initiate such programs such that better use can be made of limited resources to resolve issues of common interest. (author)

U.S. Nuclear Regulatory Commission seismic regulations, research, and emerging trends

Energy Technology Data Exchange (ETDEWEB)

Chokshi, N C; Shao, L C [Nuclear Regulatory Commission, Washington, DC (United States). Office of Nuclear Regulatory Research; Apostolakis, G

1997-03-01

Historically in the United States, seismic issues have played an important role in determining site suitability and, in some cases, have determined the ultimate fate of power plants. During the late 1960s and early 1970s, a seismic design philosophy evolved as the licensing of the earlier plants was in progress. Concepts such as the Safe Shutdown Earthquake (SSE) and the Operating Basis Earthquake (OBE) emerged and were codified into the federal regulations with the publication in December 1973 of Appendix A, `Seismic and Geologic Siting Criteria for Nuclear Power Plants,` to 10 CFR Part 100, `Reactor Site Criteria.` Seismic considerations are also important in siting and design of other fuel cycle and waste facilities. In this paper, a brief overview of the current seismic siting and design regulations are described along with some recent and planned changes based on the past experience, advancement in the state-of-the-art, and research results. In particular, the recently revised siting rule and use of the probabilistic seismic hazard analysis in implementation of the rule will be described in more detail. The paper includes discussion of some recent seismic issues and research activities, including issues related to aging. Some emerging trends are highlighted. In particular, the paper focuses on use of `expert opinion` in the probabilistic analysis and risk informed regulations and their implications to the seismic design. An additional focus is on international cooperative programs and how to initiate such programs such that better use can be made of limited resources to resolve issues of common interest. (author)

The shallow structure of Solfatara Volcano, Italy, revealed by dense, wide-aperture seismic profiling.

Science.gov (United States)

Bruno, Pier Paolo G; Maraio, Stefano; Festa, Gaetano

2017-12-12

Two active-source, high-resolution seismic profiles were acquired in the Solfatara tuff cone in May and November 2014, with dense, wide-aperture arrays. Common Receiver Surface processing was crucial in improving signal-to-noise ratio and reflector continuity. These surveys provide, for the first time, high-resolution seismic images of the Solfatara crater, depicting a ~400 m deep asymmetrical crater filled by volcanoclastic sediments and rocks and carved within an overall non-reflective pre-eruptive basement showing features consistent with the emplacement of shallow intrusive bodies. Seismic reflection data were interpreted using the trace complex attributes and clearly display several steep and segmented collapse faults, generally having normal kinematics and dipping toward the crater centre. Fault/fracture planes are imaged as sudden amplitude drops that generate narrow low-similarity and high-dip attributes. Uprising fluids degassed by a magmatic source are the most probable cause of the small-scale amplitude reduction. Seismic data also support the interpretation of the shallow structure of the Solfatara crater as a maar. Our results provides a solid framework to constrain the near-surface geological interpretation of such a complex area, which improves our understanding of the temporal changes of the structure in relation with other geophysical and geochemical measurements.

Effects of Permafrost and Seasonally Frozen Ground on the Seismic Response of Transportation Infrastructure Sites

Science.gov (United States)

2010-02-01

This interdisciplinary project combined seismic data recorded at bridge sites with computer models to identify how highway bridges built on permanently and seasonally frozen ground behave during an earthquake. Two sites one in Anchorage and one in...

End of mission report on seismic safety review mission for Belene NPP site

International Nuclear Information System (INIS)

Gurpinar, A.; Mohammadioun, B.; Schneider, H.; Serva, L.

1995-01-01

Upon the invitation of the Bulgarian government through the Committee for the Peaceful Uses of Atomic Energy and within the framework of the implementation of the Technical Cooperation project BUL/9/012 related to site and seismic of NPPs, a mission visited Sofia 3 - 7 July 1995. The mission constituted a follow-up of the interim review of subjects related to tectonic stability and seismic hazard characterization of the site which was performed in September 1993. The main objective of the mission was the final review of the subjects already reviewed in September 1993 as well as issues related to geotechnical engineering and foundation safety. The main terms of reference of the present mission was to verify the implementation of the recommendations of the Site Safety Review Mission of June 1990. This document gives findings on geology-tectonics, seismology and foundation safety. In the end conclusions and recommendations of the mission are presented

Vrancea earthquakes. Courses for specific actions to mitigate seismic risk

International Nuclear Information System (INIS)

Marmureanu, Gheorghe; Marmureanu, Alexandru

2005-01-01

Earthquakes in the Carpathian-Pannonian region are confined to the crust, except the Vrancea zone, where earthquakes with focal depth down to 200 Km occur. For example, the ruptured area migrated from 150 km to 180 km (November 10,1940, M w = 7.7) from 90 km to 110 km (March 4, 1977, M w 7.4), from 130 km to 150 km (August 30, 1986, M w = 7.1) and from 70 km to 90 km (May 30, 1990, M w = 6.9) depth. The depth interval between 110 km and 130 km remains not ruptured since 1802, October 26, when it was the strongest earthquake occurred in this part of Central Europe. The magnitude is assumed to be M w = 7.9 - 8.0 and this depth interval is a natural candidate for the next strong Vrancea event. While no country in the world is entirely safe, the lack of capacity to limit the impact of seismic hazards remains a major burden for all countries and while the world has witnessed an exponential increase in human and material losses due to natural disasters given by earthquakes, there is a need to reverse trends in seismic risk mitigation to future events. Main courses for specific actions to mitigate the seismic risk given by strong deep Vrancea earthquakes should be considered as key for development actions: - Early warning system for industrial facilities. Early warning is more than a technological instrument to detect, monitor and submit warnings. It should become part of a management information system for decision-making in the context of national institutional frameworks for disaster management and part of national and local strategies and programmers for risk mitigation; - Prediction program of Vrancea strong earthquakes of short and long term; - Hazard seismic map of Romania. The wrong assessment of the seismic hazard can lead to dramatic situations as those from Bucharest or Kobe. Before the 1977 Vrancea earthquake, the city of Bucharest was designed to intensity I = VII (MMI) and the real intensity was I = IX1/2-X (MMI); - Seismic microzonation of large populated

Deep seismic transect across the Tonankai earthquake area obtained from the onshore- offshore wide-angle seismic study

Science.gov (United States)

Nakanishi, A.; Obana, K.; Kodaira, S.; Miura, S.; Fujie, G.; Ito, A.; Sato, T.; Park, J.; Kaneda, Y.; Ito, K.; Iwasaki, T.

2008-12-01

In the Nankai Trough subduction seismogenic zone, M8-class great earthquake area can be divided into three segments; they are source regions of the Nankai, Tonankai and presumed Tokai earthquakes. The Nankai and Tonankai earthquakes had often occurred simultaneously, and caused a great event. Hypocenters of these great earthquakes were usually located off the cape Shiono, Kii Peninsula, and the rupture propagated westwards and eastwards, respectively. To obtain the deep structure of the down-dip limit of around the Nankai Trough seismogenic zone, the segment boundary and first break area off the Kii Peninsula, the onshore-offshore wide-angle seismic studies was conducted in the western and eastern part of the Kii Peninsula and their offshore area in 2004 and 2006, respectively. The result of the seismic study in 2004 is mainly shown here. Structural images along the onshore and offshore profiles have already been separately obtained. In this study, an onshore-offshore integrated image of the western part of the Kii Peninsula, ~400km in a total length, is obtained from first arrival tomography and traveltime mapping of reflection phases by combining dataset of 13 land explosions, 2269 land stations, 36 OBSs and 1806 offshore airgun shots. The subduction angle of the Philippine Sea plate (PSP) gradually increases landward up to ~20-25 degree. Beneath the onshore part, the subducting PSP is estimated at ~5km shallower than that previously derived from seismicity. Low frequency earthquakes (identified and picked by Japan Meteorological Agency) are relocated around the plate interface of the subducting PSP by using the deep seismic transect obtained in this study. The offshore research is part of 'Structure research on plate dynamics of the presumed rupture zone of the Tonankai-Nankai Earthquakes' funded by Ministry of Education, Culture, Sports, Science and Technology (MEXT). The onshore research carried by the Kyoto University is part of 'Special Project for

The SISIFO project: Seismic Safety at High Schools

Science.gov (United States)

Peruzza, Laura; Barnaba, Carla; Bragato, Pier Luigi; Dusi, Alberto; Grimaz, Stefano; Malisan, Petra; Saraò, Angela; Mucciarelli, Marco

2014-05-01

For many years, the Italian scientific community has faced the problem of the reduction of earthquake risk using innovative educational techniques. Recent earthquakes in Italy and around the world have clearly demonstrated that seismic codes alone are not able to guarantee an effective mitigation of risk. After the tragic events of San Giuliano di Puglia (2002), where an earthquake killed 26 school children, special attention was paid in Italy to the seismic safety of schools, but mainly with respect to structural aspects. Little attention has been devoted to the possible and even significant damage to non-structural elements (collapse of ceilings, tipping of cabinets and shelving, obstruction of escape routes, etc..). Students and teachers trained on these aspects may lead to a very effective preventive vigilance. Since 2002, the project EDURISK (www.edurisk.it) proposed educational tools and training programs for schools, at primary and middle levels. More recently, a nationwide campaign aimed to adults (www.iononrischio.it) was launched with the extensive support of civil protection volounteers. There was a gap for high schools, and Project SISIFO was designed to fill this void and in particular for those schools with technical/scientific curricula. SISIFO (https://sites.google.com/site/ogssisifo/) is a multidisciplinary initiative, aimed at the diffusion of scientific culture for achieving seismic safety in schools, replicable and can be structured in training the next several years. The students, helped by their teachers and by experts from scientific institutions, followed a course on specialized training on earthquake safety. The trial began in North-East Italy, with a combination of hands-on activities for the measurement of earthquakes with low-cost instruments and lectures with experts in various disciplines, accompanied by specifically designed teaching materials, both on paper and digital format. We intend to raise teachers and students knowledge of the

A methodology for assessment seismic risk in PSAs

International Nuclear Information System (INIS)

Jae, Moo Sung

2001-01-01

This paper suggested a new framework for assessing seismic risk in PSAs. The framework used the concepts of requirement and achievement in the reliability physics. The quantified correlation which is a function of the requirement variable (hazard curve) and the achievement variable (fragility curve) results in a quantity, the unconditional frequency of exceeding a damage lelvel. This framework can be applied to any other external safety assessment, such as Fire and Flood Risk in PSAs

Sensitivity of seismic hazard to various parameters and correlations for peak ground acceleration

International Nuclear Information System (INIS)

Ghosh, A.K.; Kushwaha, H.S.

1998-10-01

The design basis ground motion of a site is generally specified in terms of the peak ground acceleration (PGA), ground motion response spectrum and time history. The probability of exceedence of the design level PGA is one of the factors to quantify the seismic risk at the given site. The present paper extends the work of Cornell to consider an aerial source model and a more general form of the correlation for PGA to evaluate the seismic hazard. It is further recognised that the predicted seismic hazard can vary with various parameters involved. Numerical results have been presented to show this variability. These results will help to determine the seismic hazard at a given site and the associated uncertainties. (author)

Seismic Studies

Energy Technology Data Exchange (ETDEWEB)

R. Quittmeyer

2006-09-25

This technical work plan (TWP) describes the efforts to develop and confirm seismic ground motion inputs used for preclosure design and probabilistic safety 'analyses and to assess the postclosure performance of a repository at Yucca Mountain, Nevada. As part of the effort to develop seismic inputs, the TWP covers testing and analyses that provide the technical basis for inputs to the seismic ground-motion site-response model. The TWP also addresses preparation of a seismic methodology report for submission to the U.S. Nuclear Regulatory Commission (NRC). The activities discussed in this TWP are planned for fiscal years (FY) 2006 through 2008. Some of the work enhances the technical basis for previously developed seismic inputs and reduces uncertainties and conservatism used in previous analyses and modeling. These activities support the defense of a license application. Other activities provide new results that will support development of the preclosure, safety case; these results directly support and will be included in the license application. Table 1 indicates which activities support the license application and which support licensing defense. The activities are listed in Section 1.2; the methods and approaches used to implement them are discussed in more detail in Section 2.2. Technical and performance objectives of this work scope are: (1) For annual ground motion exceedance probabilities appropriate for preclosure design analyses, provide site-specific seismic design acceleration response spectra for a range of damping values; strain-compatible soil properties; peak motions, strains, and curvatures as a function of depth; and time histories (acceleration, velocity, and displacement). Provide seismic design inputs for the waste emplacement level and for surface sites. Results should be consistent with the probabilistic seismic hazard analysis (PSHA) for Yucca Mountain and reflect, as appropriate, available knowledge on the limits to extreme ground

Seismic Studies

International Nuclear Information System (INIS)

R. Quittmeyer

2006-01-01

This technical work plan (TWP) describes the efforts to develop and confirm seismic ground motion inputs used for preclosure design and probabilistic safety 'analyses and to assess the postclosure performance of a repository at Yucca Mountain, Nevada. As part of the effort to develop seismic inputs, the TWP covers testing and analyses that provide the technical basis for inputs to the seismic ground-motion site-response model. The TWP also addresses preparation of a seismic methodology report for submission to the U.S. Nuclear Regulatory Commission (NRC). The activities discussed in this TWP are planned for fiscal years (FY) 2006 through 2008. Some of the work enhances the technical basis for previously developed seismic inputs and reduces uncertainties and conservatism used in previous analyses and modeling. These activities support the defense of a license application. Other activities provide new results that will support development of the preclosure, safety case; these results directly support and will be included in the license application. Table 1 indicates which activities support the license application and which support licensing defense. The activities are listed in Section 1.2; the methods and approaches used to implement them are discussed in more detail in Section 2.2. Technical and performance objectives of this work scope are: (1) For annual ground motion exceedance probabilities appropriate for preclosure design analyses, provide site-specific seismic design acceleration response spectra for a range of damping values; strain-compatible soil properties; peak motions, strains, and curvatures as a function of depth; and time histories (acceleration, velocity, and displacement). Provide seismic design inputs for the waste emplacement level and for surface sites. Results should be consistent with the probabilistic seismic hazard analysis (PSHA) for Yucca Mountain and reflect, as appropriate, available knowledge on the limits to extreme ground motion at

Enhancing the seismic margin review methodology to obtain risk insights

International Nuclear Information System (INIS)

Budnitz, R.J.

1992-01-01

This paper discusses methods for obtaining risk insights from the seismic margin review (SMR) methodology. The SMR methodology was originally developed in 1984-1987 with the objective of analyzing an individual nuclear power plant to ascertain whether the plant has the ability to withstand earthquakes substantially beyond the design-basis earthquake without suffering a core-damage accident. Recently, in the context of Nuclear Regulatory Commission's (NRC's) Individual Plant Evaluation for External Events (IPEEE) program, the SMR methodology has been developed further by NRC to allow plants to identify plant-specific vulnerabilities (in the IPEEE sense) to seismic events. The objective of these enhancements has been to provide a methodology for IPEEE seismic review that is substantially less expensive than a full-scope seismic PRA, but that achieves the IPEEE's vulnerability-search objectives. In this paper, the steps involved in the enhanced methodology are discussed

The role of GIS in urban seismic risk studies: application to the city of Almería (southern Spain)

Science.gov (United States)

Rivas-Medina, A.; Gaspar-Escribano, J. M.; Benito, B.; Bernabé, M. A.

2013-11-01

This work describes the structure and characteristics of the geographic information system (GIS) developed for the urban seismic risk study of the city of Almería (southern Spain), identifying the stages in which the use of this tool proved to be very beneficial for adopting informed decisions throughout the execution of the work. After the completion of the regional emergency plans for seismic risk in Spain and its subsequent approval by the National Civil Defence Commission, the municipalities that need to develop specific local seismic risk plans have been identified. Hence, the next action is to develop urban seismic risk analyses at a proper scale (Urban Seismic Risk Evaluation - Risk-UR). For this evaluation, different factors influencing seismic risk such as seismic hazard, geotechnical soil characteristics, vulnerability of structures of the region, reparation costs of damaged buildings and exposed population are combined. All these variables are gathered and analysed within a GIS and subsequently used for seismic risk estimation. The GIS constitutes a highly useful working tool because it facilitates data interoperability, making the great volume of information required and the numerous processes that take part in the calculations easier to handle, speeding up the analysis and the interpretation and presentation of the results of the different working phases. The result of this study is based on a great set of variables that provide a comprehensive view of the urban seismic risk, such as the damage distribution of buildings and dwellings of different typologies, the mean damage and the number of uninhabitable buildings for the expected seismic motion, the number of dead and injured at different times of the day, the cost of reconstruction and repair of buildings, among others. These results are intended for interpretation and decision making in emergency management by unspecialised users (Civil Defence technicians and managers).

Extreme seismicity and disaster risks: Hazard versus vulnerability (Invited)

Science.gov (United States)

Ismail-Zadeh, A.

2013-12-01

Although the extreme nature of earthquakes has been known for millennia due to the resultant devastation from many of them, the vulnerability of our civilization to extreme seismic events is still growing. It is partly because of the increase in the number of high-risk objects and clustering of populations and infrastructure in the areas prone to seismic hazards. Today an earthquake may affect several hundreds thousand lives and cause significant damage up to hundred billion dollars; it can trigger an ecological catastrophe if occurs in close vicinity to a nuclear power plant. Two types of extreme natural events can be distinguished: (i) large magnitude low probability events, and (ii) the events leading to disasters. Although the first-type events may affect earthquake-prone countries directly or indirectly (as tsunamis, landslides etc.), the second-type events occur mainly in economically less-developed countries where the vulnerability is high and the resilience is low. Although earthquake hazards cannot be reduced, vulnerability to extreme events can be diminished by monitoring human systems and by relevant laws preventing an increase in vulnerability. Significant new knowledge should be gained on extreme seismicity through observations, monitoring, analysis, modeling, comprehensive hazard assessment, prediction, and interpretations to assist in disaster risk analysis. The advanced disaster risk communication skill should be developed to link scientists, emergency management authorities, and the public. Natural, social, economic, and political reasons leading to disasters due to earthquakes will be discussed.

Epistemic uncertainty in California-wide synthetic seismicity simulations

Science.gov (United States)

Pollitz, Fred F.

2011-01-01

The generation of seismicity catalogs on synthetic fault networks holds the promise of providing key inputs into probabilistic seismic-hazard analysis, for example, the coefficient of variation, mean recurrence time as a function of magnitude, the probability of fault-to-fault ruptures, and conditional probabilities for foreshock–mainshock triggering. I employ a seismicity simulator that includes the following ingredients: static stress transfer, viscoelastic relaxation of the lower crust and mantle, and vertical stratification of elastic and viscoelastic material properties. A cascade mechanism combined with a simple Coulomb failure criterion is used to determine the initiation, propagation, and termination of synthetic ruptures. It is employed on a 3D fault network provided by Steve Ward (unpublished data, 2009) for the Southern California Earthquake Center (SCEC) Earthquake Simulators Group. This all-California fault network, initially consisting of 8000 patches, each of ∼12 square kilometers in size, has been rediscretized into Graphic patches, each of ∼1 square kilometer in size, in order to simulate the evolution of California seismicity and crustal stress at magnitude M∼5–8. Resulting synthetic seismicity catalogs spanning 30,000 yr and about one-half million events are evaluated with magnitude-frequency and magnitude-area statistics. For a priori choices of fault-slip rates and mean stress drops, I explore the sensitivity of various constructs on input parameters, particularly mantle viscosity. Slip maps obtained for the southern San Andreas fault show that the ability of segment boundaries to inhibit slip across the boundaries (e.g., to prevent multisegment ruptures) is systematically affected by mantle viscosity.

Seismic imaging of the Formosa Ridge cold seep site offshore of southwestern Taiwan

Science.gov (United States)

Hsu, Ho-Han; Liu, Char-Shine; Morita, Sumito; Tu, Shu-Lin; Lin, Saulwood; Machiyama, Hideaki; Azuma, Wataru; Ku, Chia-Yen; Chen, Song-Chuen

2017-12-01

Multi-scale reflection seismic data, from deep-penetration to high-resolution, have been analyzed and integrated with near-surface geophysical and geochemical data to investigate the structures and gas hydrate system of the Formosa Ridge offshore of southwestern Taiwan. In 2007, dense and large chemosynthetic communities were discovered on top of the Formosa Ridge at water depth of 1125 m by the ROV Hyper-Dolphin. A continuous and strong BSR has been observed on seismic profiles from 300 to 500 ms two-way-travel-time below the seafloor of this ridge. Sedimentary strata of the Formosa Ridge are generally flat lying which suggests that this ridge was formed by submarine erosion processes of down-slope canyon development. In addition, some sediment waves and mass wasting features are present on the ridge. Beneath the cold seep site, a vertical blanking zone, or seismic chimney, is clearly observed on seismic profiles, and it is interpreted to be a fluid conduit. A thick low velocity zone beneath BSR suggests the presence of a gas reservoir there. This "gas reservoir" is shallower than the surrounding canyon floors along the ridge; therefore as warm methane-rich fluids inside the ridge migrate upward, sulfate carried by cold sea water can flow into the fluid system from both flanks of the ridge. This process may drive a fluid circulation system and the active cold seep site which emits both hydrogen sulfide and methane to feed the chemosynthetic communities.

State of the Art in Input Ground Motions for Seismic Fragility and Risk Assessment

Energy Technology Data Exchange (ETDEWEB)

Kim, Jung Han; Choi, In Kil; Kim, Min Kyu [KAERI, Daejeon (Korea, Republic of)

2016-05-15

The purpose of a Seismic Probabilistic Safety Analysis (SPSA) is to determine the probability distribution of core damage due to the potential effects of earthquakes. The SPSA is performed based on four steps, a seismic hazard analysis, a component fragility evaluation, a plant system and accident sequence analysis, and a consequence analysis. There are very different spectrum shapes in every ground motions. The structural response and the seismic load applied to equipment are greatly influenced by a spectral shape of the input ground motion. Therefore the input ground motion need to be determined under the same assumption in risk calculation. Several technic for the determination of input ground motions has developed and reviewed in this study. In this research, the methodologies of the determination of input ground motion for the seismic risk assessment are reviewed and discussed. It has developed to reduce the uncertainty in fragility curves and to remove the conservatism in risk values.

Measurement Of Compressional-Wave Seismic Velocities In 29 Wells At The Hanford Site

International Nuclear Information System (INIS)

Peterson, S.W.

2010-01-01

Check shot seismic velocity surveys were collected in 100 B/C, 200 East, 200-PO-1 Operational Unit (OU), and the Gable Gap areas in order to provide time-depth correlation information to aid the interpretation of existing seismic reflection data acquired at the Hanford Site (Figure 1). This report details results from 5 wells surveyed in fiscal year (FY) 2008, 7 wells in FY 2009, and 17 wells in FY 2010 and provides summary compressional-wave seismic velocity information to help guide future seismic survey design as well as improve current interpretations of the seismic data (SSC 1979/1980; SGW-39675; SGW-43746). Augmenting the check shot database are four surveys acquired in 2007 in support of the Bechtel National, Inc. Waste Treatment Plant construction design (PNNL-16559, PNNL-16652), and check shot surveys in three wells to support seismic testing in the 200 West Area (Waddell et al., 1999). Additional sonic logging was conducted during the late 1970s and early 1980s as part of the Basalt Waste Isolation Program (BWIP) (SSC 1979/1980) and check shot/sonic surveys as part of the safety report for the Skagit/Hanford Nuclear project (RDH/10-AMCP-0164). Check shot surveys are used to obtain an in situ measure of compressional-wave seismic velocity for sediment and rock in the vicinity of the well point, and provide the seismic-wave travel time to geologic horizons of interest. The check shot method deploys a downhole seismic receiver (geophone) to record the arrival of seismic waves generated by a source at the ground surface. The travel time of the first arriving seismic-wave is determined and used to create a time-depth function to correlate encountered geologic intervals with the seismic data. This critical tie with the underlying geology improves the interpretation of seismic reflection profile information. Fieldwork for this investigation was conducted by in house staff during the weeks of September 22, 2008 for 5 wells in the 200 East Area (Figure 2); June 1

seismic-py: Reading seismic data with Python

Directory of Open Access Journals (Sweden)

2008-08-01

Full Text Available The field of seismic exploration of the Earth has changed
dramatically over the last half a century. The Society of Exploration
Geophysicists (SEG has worked to create standards to store the vast
amounts of seismic data in a way that will be portable across computer
architectures. However, it has been impossible to predict the needs of the
immense range of seismic data acquisition systems. As a result, vendors have
had to bend the rules to accommodate the needs of new instruments and
experiment types. For low level access to seismic data, there is need for a
standard open source library to allow access to a wide range of vendor data
files that can handle all of the variations. A new seismic software package,
seismic-py, provides an infrastructure for creating and managing drivers for
each particular format. Drivers can be derived from one of the known formats
and altered to handle any slight variations. Alternatively drivers can be
developed from scratch for formats that are very different from any previously
defined format. Python has been the key to making driver development easy
and efficient to implement. The goal of seismic-py is to be the base system
that will power a wide range of experimentation with seismic data and at the
same time provide clear documentation for the historical record of seismic
data formats.

Korea-Japan Joint Research on Development of Seismic Capacity Evaluation and Enhancement Technology Considering Near-Fault Effect

Energy Technology Data Exchange (ETDEWEB)

Choun, Young Sun; Choi, In Kil; Kim, Min Kyu [KAERI, Daejon (Korea, Republic of); Ohtori, Yasuki; Shiba, Yoshiaki; Nakajima, Masato [Central Research Institute of Electric Power Industry, Tokyo (Japan)

2005-12-15

Several recent improved methods for the EGFM are introduced in order to avoid artificial holes seen in the synthetic acceleration spectrum. Furthermore evaluation of input ground motions at Wolsung NPP are performed by varying the source parameters that may control the high-frequency wave radiation and the deviation of the synthetic motions are revealed. The PSHA case studies for four NPP sites (Wolsung, Kori, Uljin, Younggwang) are performed. In the analysis, site-specific attenuation equations developed for Korean NPP sites are employed, and the seismic hazards for the target sites are evaluated in the case where the four kind of seismic source models are considered. Moreover, the PSHA for Wolsung and Younggwang are conducted by using the site-specific attenuation equation with the index of response spectra and the uniform hazard spectra are evaluated for the two sites. The supporting tool for seismic response analysis and the evaluation tool for evaluating annual probability of failure were integrated in the frame of the seismic risk assessment system. Then, the tools were applied to the seismic risk assessment of the conventional EDG and isolated EDG. General information such as earthquake parameters and regional distribution of seismic intensity is summarized on the 2005 West Off Fukuoka earthquake. Then, the observed strong motion records in Japan and Korea sites are compiled, and regional distribution of peak accelerations are represented. Moreover, the peak accelerations of the records are compared with the values estimated from the existing attenuation equations.

Review of the SQUG type seismic program at Savannah River Site

International Nuclear Information System (INIS)

Bitner, J.L.; Lin, C.W.; Anderson, N.R.; Bezler, P.

1991-01-01

The production reactors at Savannah River were shut down in 1988 because of questions about their safety. One question is whether they can withstand earthquakes. To answer the earthquake question, the site operator (Westinghouse Savannah River Company) developed a program to evaluate the capability of the safety systems in the K, L, and P reactors to function during and after an earthquake, and to upgrade them if necessary. The seismic program for Savannah River relies heavily on the Generic Implementation Procedure (GIP) developed by the Seismic qualification Utility Group. The GIP was originally developed for application to over 65 commercial power reactors throughout the U.S. It has been thoroughly reviewed by the U.S. Nuclear Regulatory Commission. The objectives of the ISWRT (Independent Seismic Walkdown Review Team) review were to: evaluate the program and evaluate its execution. The first objective was accomplished using an in-office review of the program. The second objective was accomplished using an in-office review and in-plant walkdown of selected safety systems. The ISWRT review and walkdown are summarized in this paper

Estimating of seismic return periods in Laguna Verde Nuclear Power Plant

International Nuclear Information System (INIS)

Flores R, J.H.

1993-01-01

The study of seismic risk in the site of Laguna Verde Nuclear Power Plant and surroundings was made considering the different periods of seismic return and the probability of occurrence in distinct time intervals (50, 75, 100, 125, 150 years) starting with the distribution of first type of extreme values of Gumbel (G1), the value used for the assessment of lifetime of lump was 50 years, and the rest of the periods are used to evaluate temporary nuclear cemeteries, it is to say for reducing the radioactivity of burned fuel assemblies. The seismic data belongs to the seismicity catalog (1920-1982) elaborated around the site, which average magnitude was 5 in the Richter Scale and are considered as shallow and are located in the Continental crust of North American shelf, and are induced by the pressure of the cocos shelf, being 36 % of the seismic movements of intermediate value and two seismic movements of deep value. (Author)

76 FR 57767 - Proposed Generic Communication; Draft NRC Generic Letter 2011-XX: Seismic Risk Evaluations for...

Science.gov (United States)

2011-09-16

... NUCLEAR REGULATORY COMMISSION [NRC-2011-0204] Proposed Generic Communication; Draft NRC Generic Letter 2011-XX: Seismic Risk Evaluations for Operating Reactors AGENCY: Nuclear Regulatory Commission... FR 54507), that requested public comment on Draft NRC Generic Letter 2011- XX: Seismic Risk...

Probability problems in seismic risk analysis and load combinations for nuclear power plants

International Nuclear Information System (INIS)

George, L.L.

1983-01-01

This workshop describes some probability problems in power plant reliability and maintenance analysis. The problems are seismic risk analysis, loss of load probability, load combinations, and load sharing. The seismic risk problem is to compute power plant reliability given an earthquake and the resulting risk. Component survival occurs if its peak random response to the earthquake does not exceed its strength. Power plant survival is a complicated Boolean function of component failures and survivals. The responses and strengths of components are dependent random processes, and the peak responses are maxima of random processes. The resulting risk is the expected cost of power plant failure

Integrating Risk Analyses and Tools at the DOE Hanford Site

International Nuclear Information System (INIS)

LOBER, R.W.

2002-01-01

Risk assessment and environmental impact analysis at the U.S. Department of Energy (DOE) Hanford Site in Washington State has made significant progress in refining the strategy for using risk analysis to support closing of several hundred waste sites plus 149 single-shell tanks at the Hanford Site. A Single-Shell Tank System Closure Work Plan outlines the current basis for closing the single-shell tank systems. An analogous site approach has been developed to address closure of aggregated groups of similar waste sites. Because of the complexity, decision time frames, proximity of non-tank farm waste sites to tank farms, scale, and regulatory considerations, various projects are providing integrated assessments to support risk analyses and decision-making. Projects and the tools that are being developed and applied at Hanford to support retrieval and cleanup decisions include: (1) Life Cycle Model (LCM) and Risk Receptor Model (RRM)--A site-level set of tools to support strategic analyses through scoping level risk management to assess different alternatives and options for tank closure. (2) Systems Assessment Capability for Integrated Groundwater Nadose Zone (SAC) and the Site-Wide Groundwater Model (SWGM)--A site-wide groundwater modeling system coupled with a risk-based uncertainty analysis of inventory, vadose zone, groundwater, and river interactions for evaluating cumulative impacts from individual and aggregate waste sites. (3) Retrieval Performance Evaluation (RPE)--A site-specific, risk-based methodology developed to evaluate performance of waste retrieval, leak detection and closure on a tank-specific basis as a function of past tank Leaks, potential leakage during retrieval operations, and remaining residual waste inventories following completion of retrieval operations. (4) Field Investigation Report (FIR)--A corrective action program to investigate the nature and extent of past tank leaks through characterization activities and assess future impacts to

Dynamic evaluation of seismic hazard and risks based on the Unified Scaling Law for Earthquakes

Science.gov (United States)

Kossobokov, V. G.; Nekrasova, A.

2016-12-01

We continue applying the general concept of seismic risk analysis in a number of seismic regions worldwide by constructing seismic hazard maps based on the Unified Scaling Law for Earthquakes (USLE), i.e. log N(M,L) = A + B•(6 - M) + C•log L, where N(M,L) is the expected annual number of earthquakes of a certain magnitude M within an seismically prone area of linear dimension L, A characterizes the average annual rate of strong (M = 6) earthquakes, B determines the balance between magnitude ranges, and C estimates the fractal dimension of seismic locus in projection to the Earth surface. The parameters A, B, and C of USLE are used to assess, first, the expected maximum magnitude in a time interval at a seismically prone cell of a uniform grid that cover the region of interest, and then the corresponding expected ground shaking parameters. After a rigorous testing against the available seismic evidences in the past (e.g., the historically reported macro-seismic intensity or paleo data), such a seismic hazard map is used to generate maps of specific earthquake risks for population, cities, and infrastructures. The hazard maps for a given territory change dramatically, when the methodology is applied to a certain size moving time window, e.g. about a decade long for an intermediate-term regional assessment or exponentially increasing intervals for a daily local strong aftershock forecasting. The of dynamical seismic hazard and risks assessment is illustrated by applications to the territory of Greater Caucasus and Crimea and the two-year series of aftershocks of the 11 October 2008 Kurchaloy, Chechnya earthquake which case-history appears to be encouraging for further systematic testing as potential short-term forecasting tool.

Seismic risk maps of Switzerland; description of the probabilistic method and discussion of some input parameters

International Nuclear Information System (INIS)

Mayer-Rosa, D.; Merz, H.A.

1976-01-01

The probabilistic model used in a seismic risk mapping project for Switzerland is presented. Some of its advantages and limitations are spelled out. In addition some earthquake parameters which should be carefully investigated before using them in a seismic risk analysis are discussed

Taking into account seismic risk on glove boxes

Energy Technology Data Exchange (ETDEWEB)

Ladurelle, Marie; Philipponneau, Yannick

2005-01-01

Built in 1981, the LEFCA is a Basic Nuclear Facility (BNF) in which experimental plutonium based fuels are produced and characterised in about a hundred Gloves Boxes (GB). Many safety rules are required, especially those concerning seismic risk. In order to prepare the December 2003 safety reconsideration, the following methodology has been proposed so that GB might resist the Safe Shutdown Earthquake. 1) The determination of a safety target: the GB static containment. 2) The realisation of an ''in situ'' assessment: the definition of several classes of GB, vibrating table tests and the modelling of the GB behaviour with seismic solicitations, 3) A strength diagnosis for equipment: filters, connecting tunnels and pipes holding. 4) A proposal for further strengthening modifications if necessary : fixing the frame, interlocking GB and the frame, taking internal or external GB missiles into account. This process has contributed to a reduction in the radiological potential seismic impact for the neighbouring populations. We shall present the implemented methodology and the strengthening works that have been approved by Safety Authorities. Reinforcement modifications will begin in 2004. (Author)

Taking into account seismic risk on glove boxes

International Nuclear Information System (INIS)

Ladurelle, Marie; Philipponneau, Yannick

2005-01-01

Built in 1981, the LEFCA is a Basic Nuclear Facility (BNF) in which experimental plutonium based fuels are produced and characterised in about a hundred Gloves Boxes (GB). Many safety rules are required, especially those concerning seismic risk. In order to prepare the December 2003 safety reconsideration, the following methodology has been proposed so that GB might resist the Safe Shutdown Earthquake. 1) The determination of a safety target: the GB static containment. 2) The realisation of an ''in situ'' assessment: the definition of several classes of GB, vibrating table tests and the modelling of the GB behaviour with seismic solicitations, 3) A strength diagnosis for equipment: filters, connecting tunnels and pipes holding. 4) A proposal for further strengthening modifications if necessary : fixing the frame, interlocking GB and the frame, taking internal or external GB missiles into account. This process has contributed to a reduction in the radiological potential seismic impact for the neighbouring populations. We shall present the implemented methodology and the strengthening works that have been approved by Safety Authorities. Reinforcement modifications will begin in 2004. (Author)

Temblor, an app focused on your seismic risk and how to reduce it

Science.gov (United States)

Stein, R. S.; Sevilgen, V.; Sevilgen, S.; Kim, A.; Madden, E.

2015-12-01

Half of the world's population lives near active faults, and so could suffer earthquake damage. Most do not know they are at risk; many of the rest do too little, too late. So, Temblor is intended to enable everyone in the United States, and eventually the world, to learn their seismic hazard, to determine what most ensures their safety, and to determine the risk reduction measures in their best financial interest. In our free web and mobile app, and Chrome extension for real estate websites, Temblor estimates the likelihood of seismic shaking from all quakes at their occurrence rates, and the consequences of the shaking for home damage. The app then shows how the damage or its costs could be decreased by buying or renting a seismically safer home, securing fragile objects inside your home, retrofitting an older home, or buying earthquake insurance. Temblor uses public data from the USGS in the U.S., SHARE in Europe, and the GEAR model (Bird et al, in press, BSSA) for the globe. Through publicly available modeling methods, the hazard data is combined with public data on homes (construction date and square footage) to make risk calculations. This means that Temblor's results are independently reproducible. The app makes many simplifying assumptions, but users can provide additional information on their site and home for refined estimates. Temblor also lets one see active faults and recent quakes on the screen as they drive through an area. Because fear tends to trigger either panic or denial, Temblor seeks to make the world of earthquakes more fascinating than frightening. We are neither scaring nor soothing people, but rather talking straight. Through maps, globes, push notifications, family connections, and costs and benefit estimates, Temblor emphasizes the personal, local, realtime, and most importantly, rational. Temblor's goal is to distill scientific and engineering information into lucid, trusted, and ideally actionable guidance to renters, home owners, and

Seismic hazard characterization of 69 nuclear plant sites east of the Rocky Mountains: Results and discussion for the Batch 4 sites

International Nuclear Information System (INIS)

Bernreuter, D.L.; Savy, J.B.; Mensing, R.W.; Chen, J.C.

1989-01-01

The EUS Seismic Hazard Characterization Project (SHC) is the outgrowth of an earlier study performed as part of the US Nuclear Regulatory Commission's (NRC) Systematic Evaluation Program (SEP). The objectives of the SHC were: (1) to develop a seismic hazard characterization methodology for the region east of the Rocky Mountains (EUS), and (2) the application of the methodology to 69 site locations, some of them with several local soil conditions. The method developed uses expert opinions to obtain the input to the analyses. An important aspect of the elicitation of the expert opinion process was the holding of two feedback meetings with all the experts in order to finalize the methodology and the input data bases. The hazard estimates are reported in terms of peak ground acceleration (PGA) and 5% damping velocity response spectra (PSV). A total of eight volumes make up this report which contains a thorough description of the methodology, the expert opinion's elicitation process, the input data base as well as a discussion, comparison and summary volume (Volume 6). Consistent with previous analyses, this study finds that there are large uncertainties associated with the estimates of seismic hazard in the EUS, and it identifies the ground motion modeling as the prime contributor to those uncertainties. This document, Volume 5, provides the seismic hazard estimates for the 17 sites in ''Batch 4''

Destructiveness criteria for seismic risk evaluation of nuclear power plant

International Nuclear Information System (INIS)

Saragoni, G.R.

1995-01-01

Two criteria of destructiveness for seismic risk evaluation of nuclear power plant are presented. The first one is a simple linear criterion that allows to compute average response spectra in terms of earthquake accelerogram characteristics. The second defines the destructiveness potential factor P D which measures the capacity of earthquake to produce nonlinear damage. This second criterion that shows large differences of destructiveness capacity for earthquake accelerograms of different seismic environment, specially between subductive and transcursive, is strongly recommended. (author). 8 refs., 1 fig. 1 tab

Seismic vulnerability of natural gas pipelines

International Nuclear Information System (INIS)

Lanzano, Giovanni; Salzano, Ernesto; Santucci de Magistris, Filippo; Fabbrocino, Giovanni

2013-01-01

This work deals with the analysis of the interaction of earthquakes with pipelines transporting and distributing natural gas for industrial and civil use. To this aim, a new large data-set of seismic information classified on the basis of selected seismological, geotechnical and structural parameters is presented and analyzed. Particular attention is devoted to continuous pipelines under strong ground shaking, which is the geotechnical effect due to passage of waves in soil. Results are provided in terms of the likelihood of the loss of containment with respect to Peak Ground Velocity (PGV), a seismic intensity parameter which may be easily retrieved either from local authorities and public databases or from site dependent hazard analysis. Fragility functions and seismic intensity threshold values for the failure and for the loss of containment of gas from pipeline systems are also given. The obtained functions can be easily implemented in existing codes and guidelines for industrial risk assessment, land-use planning, and for the design of public distribution network, with specific reference to Natural—Technological interaction (Na-Tech). -- Highlights: • The seismic vulnerability of natural gas pipelines is analyzed. • A collection of data for pipelines damaged by earthquake is given. • Damage states and risk states for pipelines are defined. • Consequence-based fragility formulations for the loss of containment are given • Seismic threshold values for public authority, risk assessment and gas distribution are shown

Seismic Microzonation for Refinement of Seismic Load Parameters

Energy Technology Data Exchange (ETDEWEB)

Savich, A. I.; Bugaevskii, A. G., E-mail: office@geodyn.ru, E-mail: bugaevskiy@geodyn.ru [Center of the Office of Geodynamic Observations in the Power Sector, an affiliate of JSC “Institut Gidroproekt” (Russian Federation)

2016-05-15

Functional dependencies are established for the characteristics of seismic transients recorded at various points of a studied site, which are used to propose a new approach to seismic microzonation (SMZ) that enables the creation of new SMZ maps of strong seismic motion, with due regard for dynamic parameters of recorded transients during weak earthquakes.

A methodology for the quantitative risk assessment of major accidents triggered by seismic events

International Nuclear Information System (INIS)

Antonioni, Giacomo; Spadoni, Gigliola; Cozzani, Valerio

2007-01-01

A procedure for the quantitative risk assessment of accidents triggered by seismic events in industrial facilities was developed. The starting point of the procedure was the use of available historical data to assess the expected frequencies and the severity of seismic events. Available equipment-dependant failure probability models (vulnerability or fragility curves) were used to assess the damage probability of equipment items due to a seismic event. An analytic procedure was subsequently developed to identify, evaluate the credibility and finally assess the expected consequences of all the possible scenarios that may follow the seismic events. The procedure was implemented in a GIS-based software tool in order to manage the high number of event sequences that are likely to be generated in large industrial facilities. The developed methodology requires a limited amount of additional data with respect to those used in a conventional QRA, and yields with a limited effort a preliminary quantitative assessment of the contribution of the scenarios triggered by earthquakes to the individual and societal risk indexes. The application of the methodology to several case-studies evidenced that the scenarios initiated by seismic events may have a relevant influence on industrial risk, both raising the overall expected frequency of single scenarios and causing specific severe scenarios simultaneously involving several plant units

Realistic modeling of seismic input for megacities and large urban areas

International Nuclear Information System (INIS)

Panza, Giuliano F.; Alvarez, Leonardo; Aoudia, Abdelkrim

2002-06-01

The project addressed the problem of pre-disaster orientation: hazard prediction, risk assessment, and hazard mapping, in connection with seismic activity and man-induced vibrations. The definition of realistic seismic input has been obtained from the computation of a wide set of time histories and spectral information, corresponding to possible seismotectonic scenarios for different source and structural models. The innovative modeling technique, that constitutes the common tool to the entire project, takes into account source, propagation and local site effects. This is done using first principles of physics about wave generation and propagation in complex media, and does not require to resort to convolutive approaches, that have been proven to be quite unreliable, mainly when dealing with complex geological structures, the most interesting from the practical point of view. In fact, several techniques that have been proposed to empirically estimate the site effects using observations convolved with theoretically computed signals corresponding to simplified models, supply reliable information about the site response to non-interfering seismic phases. They are not adequate in most of the real cases, when the seismic sequel is formed by several interfering waves. The availability of realistic numerical simulations enables us to reliably estimate the amplification effects even in complex geological structures, exploiting the available geotechnical, lithological, geophysical parameters, topography of the medium, tectonic, historical, palaeoseismological data, and seismotectonic models. The realistic modeling of the ground motion is a very important base of knowledge for the preparation of groundshaking scenarios that represent a valid and economic tool for the seismic microzonation. This knowledge can be very fruitfully used by civil engineers in the design of new seismo-resistant constructions and in the reinforcement of the existing built environment, and, therefore

Level-1 seismic probabilistic risk assessment for a PWR plant

International Nuclear Information System (INIS)

Kondo, Keisuke; Nishio, Masahide; Fujimoto, Haruo; Ichitsuka, Akihiro

2014-01-01

In Japan, revised Seismic Design Guidelines for the domestic light water reactors was published on September 19, 2006. These new guidelines have introduced the purpose to confirm that residual risk resulting from earthquake that exceeds the design limit seismic ground motion (Ss) is sufficiently small, based on the probabilistic risk assessment (PRA) method, in addition to conventional deterministic design base methodology. In response to this situation, JNES had been working to improve seismic PRA (SPRA) models for individual domestic light water reactors. In case of PWR in Japan, total of 24 plants were grouped into 11 categories to develop individual SPRA model. The new regulatory rules against the Fukushima dai-ichi nuclear power plants' severe accidents occurred on March 11, 2011, are going to be enforced in July 2013 and utilities are necessary to implement additional safety measures to avoid and mitigate severe accident occurrence due to external events such as earthquake and tsunami, by referring to the results of severe accident study including SPRA. In this paper a SPRA model development for a domestic 3-loop PWR plant as part of the above-mentioned 11 categories is described. We paid special attention to how to categorize initiating events that are specific to seismic phenomena and how to confirm the effect of the simultaneous failure probability calculation model for the multiple components on the result of core damage frequency evaluation. Simultaneous failure probability for multiple components has been evaluated by power multiplier method. Then tentative level-1 seismic probabilistic risk assessment (SPRA) has been performed by the developed SPSA model with seismic hazard and fragility data. The base case was evaluated under the condition with calculated fragility data and conventional power multiplier. The difference in CDF between the case of conventional power multiplier and that of power multiplier=1 (complete dependence) was estimated to be

Risk management guidelines for petroleum storage tank sites

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-10-01

These guidelines provide a site management process designed particularly for soil and groundwater pollution originating from existing or former petroleum storage tank (PST) facilities and provide uniform standards for the remediation of polluted PST sites in Alberta. The numerical criteria, risk management objectives and technical information described in this document were compiled from four documents including Remediation Guidelines for Petroleum Storage Tank Sites 1994, the Canada-Wide Standards for Petroleum Hydrocarbons in Soil, Alberta Soil and Water Quality Guidelines for Hydrocarbons at Upstream Oil and Gas Facilities, and Guidelines for Managing Risks at Contaminated Sites in Alberta. The changes in these updated guidelines reflect new remediation criteria and provide a process for determining alternate site-specific management objectives for more petroleum storage tank sites. The guidelines were developed using a risk-based approach that ensures the protection of human health, safety and the environment. The guidelines apply to aboveground and underground storage tank facilities that contain gasoline, diesel, heating oil, and aviation fuel. The guidelines specify requirements by Alberta Environment and the Alberta Fire Code. The chapter on risk management process included information on site investigation, determination of soil type, pollution source removal, land use assessment, selection of exposure pathways, depth of remediation, human inhalation and groundwater protection pathways, and verification of remediation. figs, 4 tabs., 2 appendices.

Acoustic-Seismic Coupling in Porous Ground - Measurements and Analysis for On-Site-Inspection Support

Science.gov (United States)

Liebsch, Mattes; Gorschlüter, Felix; Altmann, Jürgen

2014-05-01

During on-site inspections (OSI) of the Comprehensive Nuclear Test Ban Treaty Organisation (CTBTO) a local seismic network can be installed to measure seismic aftershock signals of an assumed underground nuclear explosion. These signals are caused by relaxation processes in and near the cavity created by the explosion and when detected can lead to a localisation of the cavity. This localisation is necessary to take gas samples from the ground which are analysed for radioactive noble gas isotopes to confirm or dismiss the suspicion of a nuclear test. The aftershock signals are of very low magnitude so they can be masked by different sources, in particular periodic disturbances caused by vehicles and aircraft in the inspection area. Vehicles and aircraft (mainly helicopters) will be used for the inspection activities themselves, e.g. for overhead imagery or magnetic-anomaly sensing. While vehicles in contact with the ground can excite soil vibrations directly, aircraft and vehicles alike emit acoustic waves which excite soil vibrations when hitting the ground. These disturbing signals are of periodic nature while the seismic aftershock signals are pulse-shaped, so their separation is possible. The understanding of the coupling of acoustic waves to the ground is yet incomplete, a better understanding is necessary to improve the performance of an OSI, e.g. to address potential consequences for the sensor placement, the helicopter trajectories etc. In a project funded by the Young Scientist Research Award of the CTBTO to one of us (ML), we investigated the acoustic-seismic coupling of airborne signals of jet aircraft and artificially induced ones by a speaker. During a measurement campaign several acoustic and seismic sensors were placed below the take-off trajectory of an airport at 4 km distance. Therefore taking off and landing jet aircraft passed nearly straightly above the setup. Microphones were placed close to the ground to record the sound pressure of incident

Seismic surface-wave tomography of waste sites. 1998 annual progress report

International Nuclear Information System (INIS)

Long, T.L.

1998-01-01

'The objective of the Seismic Surface Wave Tomography of Waste Sites is to develop a robust technique for field acquisition and analysis of surface wave data for the interpretation of shallow structures, such as those associated with the burial of wastes. The analysis technique is to be developed and tested on an existing set of seismic data covering the K-901 burial site at the East Tennessee Technology Park. Also, a portable prototype for a field acquisition system will be designed and developed to obtain additional data for analysis and testing of the technique. The portable analysis system will display an image representing the shear-wave velocity structure. The image would be developed in the field from successive data samples. As of May 1998, the author established compatibility with computer programs at Georgia Tech and computed a preliminary singular value decomposition solution for the K-901 data. The analysis included modeling of surface wave dispersion and analysis of velocity structure. The analysis demonstrated that the authors needed additional field data to verify the conclusions and provide independent confirmation of velocity structure. The K-901 site data were obtained with 8 Hz geophones. The frequencies below 8 Hz are strongly attenuated in such recording instruments and are difficult to analyze. In particular, group velocities can have multiple answers for a given frequency. Consequently, without a record of the low-frequency energy, the authors found it difficult to identify the portion of the dispersion curve responsible for the seismogram. In particular, it was difficult to determine if the reverse dispersion observed in the frequencies above 8 Hz was caused by a low velocity layer or caused by observing only the frequencies above the group velocity minimum. In either model, synthetic seismograms can be made to match the observed data for the higher frequencies. The contract for the proposed work was completed in December. The field work was

Role of seismic PRA in seismic safety decisions of nuclear power plants

International Nuclear Information System (INIS)

Ravindra, M.K.; Kennedy, R.P.; Sues, R.H.

1985-01-01

This paper highlights the important roles that seismic probabilistic risk assessments (PRAs) can play in the seismic safety decisions of nuclear power plants. If a seismic PRA has been performed for a plant, its results can be utilized to evaluate the seismic capability beyond the safe shutdown event (SSE). Seismic fragilities of key structures and equipment, fragilities of dominant plant damage states and the frequencies of occurrence of these plant damage states are reviewed to establish the seismic safety of the plant beyond the SSE level. Guidelines for seismic margin reviews and upgrading may be developed by first identifying the generic classes of structures and equipment that have been shown to be dominant risk contributors in the completed seismic PRAs, studying the underlying causes for their contribution and examining why certain other items (e.g., piping) have not proved to be high-risk-contributors

Estimated airborne release of plutonium from Westinghouse Cheswick site as a result of postulated damage from severe wind and seismic hazard

International Nuclear Information System (INIS)

Mishima, J.; Schwendiman, L.C.; Ayer, J.E.

1979-06-01

The potential airborne releases of plutonium (source terms) from postulated damage sustained by the Westinghouse Plutonium Fuel Development Laboratories at the Cheswick site in Pennsylvania as a result of various levels of wind and seismic hazard are estimated. The source terms are based on damage scenarios originated by other specialists and range up to 260 mph for wind hazard and in excess of 0.39 g ground acceleration for seismic hazard. The approaches and factors used to estimate the source terms (inventories of dispersible materials at risk, damage levels and ratios, fractional airborne releases of dispersible materials under stress, atmosphere exchange rates, and source term ranges) are discussed. Source term estimates range from less than 10 -7 g plutonium to greater than 130 g plutonium over a four-day period

Assessment of ecological risks to wide-ranging wildlife species on the Oak Ridge Reservation

International Nuclear Information System (INIS)

Sample, B.

1995-01-01

Ecological risk assessment at CERCLA sites generally focuses on species that may be definitively associated with a contaminated area. While appropriate for sites with single, discrete areas of contamination, this approach is not adequate for sites with multiple, spatially separated contaminated areas such as the Oak Ridge Reservation (ORR). Wide-ranging wildlife species may travel between and use multiple contaminated sites. These species may therefore be exposed to and be at risk from contaminants from multiple locations. Use of a site (and therefore exposure and risk) by wildlife is dependent upon the availability of habitat. Availability and distribution of habitat on the ORR was determined using satellite imagery. The proportion of habitat within contaminated areas was then determined by overlaying boundaries of contaminated areas (Operable Units or OUs) on the ORR habitat map. The likelihood of contaminant exposure was estimated by comparing the habitat requirements for wildlife species to the proportion of suitable habitat within OUs. OU-specific contaminant concentrations in surface water, soil, or biota were used to estimate the magnitude of risk presented by each DU. The proportion of ORR-wide population likely to be exposed was estimated using literature-derived population density data for each endpoint. At present, due to major data gaps (i.e., lack of data for all OUs, site-specific population density or habitat use data, etc.) uncertainty associated with conclusions is high. Results of this assessment must therefore be considered to be preliminary

Seismic hazards: New trends in analysis using geologic data

International Nuclear Information System (INIS)

Schwartz, D.P.; Coppersmith, K.J.

1986-01-01

In the late 1960s and early 1970s, largely in response to expansion of nuclear power plant siting and issuance of a code of federal regullations by the Nuclear Regulatory Commission referred to as Appendix A-10CFR100, the need to characterize the earthquake potential of individual faults for seismic design took on greater importance. Appendix A established deterministic procedures for assessing the seismic hazard at nuclear power plant sites. Bonilla and Buchanan, using data from historical suface-faulting earthquakes, developed a set of statistical correlations relating earthquake magnitude to surface rupture length and to surface displacement. These relationships have been refined and updated along with the relationship between fault area and magnitude and seismic moment and moment magnitude have served as the basis for selecting maximum earthquakes in a wide variety of design situations. In the paper presented, the authors discuss new trends in seismic hazard analysis using geologic data, with special emphasis on fault-zone segmentation and recurrence models and the way in which they provide a basis for evaluating long-term earthquake potential

The availability of hydrogeologic data associated with areas identified by the US Geological Survey as experiencing potentially induced seismicity resulting from subsurface injection

Science.gov (United States)

Barnes, Caitlin; Halihan, Todd

2018-05-01

A critical need exists for site-specific hydrogeologic data in order to determine potential hazards of induced seismicity and to manage risk. By 2015, the United States Geological Survey (USGS) had identified 17 locations in the USA that are experiencing an increase in seismicity, which may be potentially induced through industrial subsurface injection. These locations span across seven states, which vary in geological setting, industrial exposure and seismic history. Comparing the research across the 17 locations revealed patterns for addressing induced seismicity concerns, despite the differences between geographical locations. Most induced seismicity studies evaluate geologic structure and seismic data from areas experiencing changes in seismic activity levels, but the inherent triggering mechanism is the transmission of hydraulic pressure pulses. This research conducted a systematic review of whether data are available in these locations to generate accurate hydrogeologic predictions, which could aid in managing seismicity. After analyzing peer-reviewed research within the 17 locations, this research confirms a lack of site-specific hydrogeologic data availability for at-risk areas. Commonly, formation geology data are available for these sites, but hydraulic parameters for the seismically active injection and basement zones are not available to researchers conducting peer-reviewed research. Obtaining hydrogeologic data would lead to better risk management for injection areas and provide additional scientific evidential support for determining a potentially induced seismic area.

Annual Hanford seismic report - fiscal year 1996

International Nuclear Information System (INIS)

Hartshorn, D.C.; Reidel, S.P.

1996-12-01

Seismic monitoring (SM) at the Hanford Site was established in 1969 by the US Geological Survey (USGS) under a contract with the US Atomic Energy Commission. Since 1980, the program has been managed by several contractors under the US Department of Energy (USDOE). Effective October 1, 1996, the Seismic Monitoring workscope, personnel, and associated contracts were transferred to the USDOE Pacific Northwest National Laboratory (PNNL). SM is tasked to provide an uninterrupted collection and archives of high-quality raw and processed seismic data from the Hanford Seismic Network (HSN) located on and encircling the Hanford Site. SM is also tasked to locate and identify sources of seismic activity and monitor changes in the historical pattern of seismic activity at the Hanford Site. The data compiled are used by SM, Waste Management, and engineering activities at the Hanford Site to evaluate seismic hazards and seismic design for the Site

SHC, Seismic Hazard Assessment for Eastern US

International Nuclear Information System (INIS)

Savy, J.; Davis, B.

2001-01-01

1 - Description of program or function: SHC was developed as part of the Eastern United States (EUS) Seismic Hazard Characterization (SHC) Project to design an SHC methodology for the region east of the Rocky Mountains in a form suitable for probabilistic risk assessment and to apply that methodology to 69 site locations, some of them with local soil conditions. The method developed uses expert opinions to obtain the input to the analysis. SHC contains four modules which calculate the seismic hazard at a site located in a region of diffuse seismicity, where the seismicity is modeled by area sources. SHC integrates the opinions of 11 seismicity and five ground-motion experts. The PRDS model generates the discrete probability density function of the distances to the site for the various seismic source zones. These probability distributions are used by the COMAP module to generate the set of all alternative maps and the discrete probability density of the seismic zonation maps for each expert. The third module, ALEAS, uses these maps and their weights to calculate the best estimate and constant percentile hazard distribution resulting from the choice of a given seismicity expert for all ground-motion experts. This module can be used alone to perform a seismic hazard analysis as well as in conjunction with the other modules. The fourth module, COMB, combines the best- estimate and constant-percentile hazard over all seismicity experts, using the set of weights calculated by ALEAS, to produce the final probability distribution of the hazard for the site under consideration so that the hazard analysis can be performed for any location in the EUS. Local geological-site characteristics are incorporated in a generic fashion, and the data are developed in a generic manner. 2 - Method of solution: SHC uses a seismic-source approach utilizing statistical and geological evidence to define geographical regions with homogeneous Poisson activity throughout the zone, described by a

Site Specific Ground Response Analysis for Quantifying Site Amplification at A Regolith Site

Directory of Open Access Journals (Sweden)

Bambang Setiawan

2017-08-01

Full Text Available DOI: 10.17014/ijog.4.3.159-167A numerical model has demonstrated that it can simulate reasonably well earthquake motions at the ground level during a seismic event. The most widely used model is an equivalent linear approach. The equivalent linear model was used to compute the free-field response of Adelaide regolith during the 1997 Burra earthquake. The aim of this study is to quantify the amplification at the investigated site. The model computed the ground response of horizontally layered soil deposits subjected to transient and vertically propagating shear waves through a one-dimensional-soil column. Each soil layer was assumed to be homogeneous, visco-elastic, and infinite in the horizontal extent. The results of this study were compared to other studies and forward computation of the geotechnical dynamic parameters of the investigated site. The amplification triggered by the 1997 Burra seismic event was deduced. This study reveals the amplification factor up to 3.6 at the studied site.

Are seismic hazard assessment errors and earthquake surprises unavoidable?

Science.gov (United States)

Kossobokov, Vladimir

2013-04-01

Why earthquake occurrences bring us so many surprises? The answer seems evident if we review the relationships that are commonly used to assess seismic hazard. The time-span of physically reliable Seismic History is yet a small portion of a rupture recurrence cycle at an earthquake-prone site, which makes premature any kind of reliable probabilistic statements about narrowly localized seismic hazard. Moreover, seismic evidences accumulated to-date demonstrate clearly that most of the empirical relations commonly accepted in the early history of instrumental seismology can be proved erroneous when testing statistical significance is applied. Seismic events, including mega-earthquakes, cluster displaying behaviors that are far from independent or periodic. Their distribution in space is possibly fractal, definitely, far from uniform even in a single segment of a fault zone. Such a situation contradicts generally accepted assumptions used for analytically tractable or computer simulations and complicates design of reliable methodologies for realistic earthquake hazard assessment, as well as search and definition of precursory behaviors to be used for forecast/prediction purposes. As a result, the conclusions drawn from such simulations and analyses can MISLEAD TO SCIENTIFICALLY GROUNDLESS APPLICATION, which is unwise and extremely dangerous in assessing expected societal risks and losses. For example, a systematic comparison of the GSHAP peak ground acceleration estimates with those related to actual strong earthquakes, unfortunately, discloses gross inadequacy of this "probabilistic" product, which appears UNACCEPTABLE FOR ANY KIND OF RESPONSIBLE SEISMIC RISK EVALUATION AND KNOWLEDGEABLE DISASTER PREVENTION. The self-evident shortcomings and failures of GSHAP appeals to all earthquake scientists and engineers for an urgent revision of the global seismic hazard maps from the first principles including background methodologies involved, such that there becomes: (a) a

A probabilistic seismic risk assessment procedure for nuclear power plants: (II) Application

Science.gov (United States)

Huang, Y.-N.; Whittaker, A.S.; Luco, N.

2011-01-01

This paper presents the procedures and results of intensity- and time-based seismic risk assessments of a sample nuclear power plant (NPP) to demonstrate the risk-assessment methodology proposed in its companion paper. The intensity-based assessments include three sets of sensitivity studies to identify the impact of the following factors on the seismic vulnerability of the sample NPP, namely: (1) the description of fragility curves for primary and secondary components of NPPs, (2) the number of simulations of NPP response required for risk assessment, and (3) the correlation in responses between NPP components. The time-based assessment is performed as a series of intensity-based assessments. The studies illustrate the utility of the response-based fragility curves and the inclusion of the correlation in the responses of NPP components directly in the risk computation. ?? 2011 Published by Elsevier B.V.

Seismic risk assessment of Trani's Cathedral bell tower in Apulia, Italy

Science.gov (United States)

Diaferio, Mariella; Foti, Dora

2017-09-01

The present paper deals with the evaluation of the seismic vulnerability of slender historical buildings; these structures, in fact, may manifest a high risk with respect to seismic actions as usually they have been designed to resist to gravitational loads only, and are characterized by a high flexibility. To evaluate this behavior, the bell tower of the Trani's Cathedral is investigated. The tower is 57 m tall and is characterized by an unusual building typology, i.e., the walls are composed of a concrete core coupled with external masonry stones. The dynamic parameters and the mechanical properties of the tower have been evaluated on the basis of an extensive experimental campaign that made use of ambient vibration tests and ground penetrating radar tests. Such data have been utilized to calibrate a numerical model of the examined tower. A linear static analysis, a dynamic analysis and a nonlinear static analysis have been carried out on such model to evaluate the displacement capacity of the tower and the seismic risk assessment in accordance with the Italian guidelines.

A microseismic workflow for managing induced seismicity risk as CO₂ storage projects

Energy Technology Data Exchange (ETDEWEB)

Matzel, E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Morency, C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Pyle, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Templeton, D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); White, J. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2015-10-27

It is well established that fluid injection has the potential to induce earthquakes—from microseismicity to large, damaging events—by altering state-of-stress conditions in the subsurface. While induced seismicity has not been a major operational issue for carbon storage projects to date, a seismicity hazard exists and must be carefully addressed. Two essential components of effective seismic risk management are (1) sensitive microseismic monitoring and (2) robust data interpretation tools. This report describes a novel workflow, based on advanced processing algorithms applied to microseismic data, to help improve management of seismic risk. This workflow has three main goals: (1) to improve the resolution and reliability of passive seismic monitoring, (2) to extract additional, valuable information from continuous waveform data that is often ignored in standard processing, and (3) to minimize the turn-around time between data collection, interpretation, and decision-making. These three objectives can allow for a better-informed and rapid response to changing subsurface conditions.

Seismic risks at Elsie Lake Main Dam

International Nuclear Information System (INIS)

McCammon, N.R.; Momenzadeh, M.; Hawson, H.H.; Nielsen, N.M.

1991-01-01

The Elsie Lake dams are located on Vancouver Island in an area of high seismic risk. A safety review in 1986 indicated potential deficiencies in the earthfill main dam with respect to modern earthquake design standards. A detailed field investigation program comprising drilling and penetration tests was carried out and the results used in an assessment of seismic stability. A 0.8 m thick less dense layer in the granular shell of the dam, possibly caused by wet construction conditions, would likely liquefy in a major earthquake but sufficient residual strength would likely remain to prevent catastrophic failure. The dam shell might undergo some distortion, and an assessment was initiated to determine the requirements for reservoir drawdown following an extreme earthquake to ensure the timely lowering of the reservoir for inspection and repair. It was suggested that an adequate evacuation capability would be 25% and 50% drawdown in not more than 30 and 50 days, respectively. 9 refs., 11 figs., 1 tab

A Framework for Seismic Design of Items in Safety-Critical Facilities for Implementing a Risk-Informed Defense-in-Depth-Based Concept

Directory of Open Access Journals (Sweden)

Tatsuya Itoi

2017-05-01

Full Text Available Recently, especially after the 2011 off the Pacific coast of Tohoku earthquake and the Fukushima Daiichi nuclear power plant accident, the need for treating residual risks and cliff-edge effects in safety-critical facilities has been widely recognized as an extremely important issue. In this article, the sophistication of seismic designs in safety-critical facilities is discussed from the viewpoint of mitigating the consequences of accidents, such as the avoidance of cliff-edge effects. For this purpose, the implementation of a risk-informed defense-in-depth-based framework is proposed in this study. A basic framework that utilizes diversity in the dynamic characteristics of items and also provides additional seismic margin to items important for safety when needed is proposed to prevent common cause failure and to avoid cliff-edge effects as far as practicable. The proposed method is demonstrated to be effective using an example calculation.

Risk assessment and early warning systems for industrial facilities in seismic zones

International Nuclear Information System (INIS)

Salzano, Ernesto; Garcia Agreda, Anita; Di Carluccio, Antonio; Fabbrocino, Giovanni

2009-01-01

Industrial equipments and systems can suffer structural damage when hit by earthquakes, so that accidental scenarios as fire, explosion and dispersion of toxic substances can take place. As a result, overall damage to people, environment and properties increases. The present paper deals with seismic risk analysis of industrial facilities where atmospheric storage tanks (anchored or unanchored to ground), horizontal pressurised tanks, reactors and pumps are installed. Simplified procedures and methodologies based on historical database and literature data on natural-technological (Na-Tech) accidents for seismic risk assessment are discussed. Equipment-specific fragility curves have been thus derived depending on a single earthquake measure, peak ground acceleration (PGA). Fragility parameters have been then transformed to linear probit coefficients in order to obtain reliable threshold values for earthquake intensity measure, both for structural damage and loss of containment. These threshold values are of great interest when development of active and passive mitigation actions and systems, safety management, and the implementation of early warning system are concerned. The approach is general and can be implemented in any available code or procedure for risk assessment. Some results of seismic analysis of atmospheric storage tanks are also presented for validation.

An evaluation of applicability of seismic refraction method in identifying shallow archaeological features A case study at archaeological site

Science.gov (United States)

Jahangardi, Morteza; Hafezi Moghaddas, Naser; Keivan Hosseini, Sayyed; Garazhian, Omran

2015-04-01

We applied the seismic refraction method at archaeological site, Tepe Damghani located in Sabzevar, NE of Iran, in order to determine the structures of archaeological interests. This pre-historical site has special conditions with respect to geographical location and geomorphological setting, so it is an urban archaeological site, and in recent years it has been used as an agricultural field. In spring and summer of 2012, the third season of archaeological excavation was carried out. Test trenches of excavations in this site revealed that cultural layers were often disturbed adversely due to human activities such as farming and road construction in recent years. Conditions of archaeological cultural layers in southern and eastern parts of Tepe are slightly better, for instance, in test trench 3×3 m²1S03, third test trench excavated in the southern part of Tepe, an adobe in situ architectural structure was discovered that likely belongs to cultural features of a complex with 5 graves. After conclusion of the third season of archaeological excavation, all of the test trenches were filled with the same soil of excavated test trenches. Seismic refraction method was applied with12 channels of P geophones in three lines with a geophone interval of 0.5 meter and a 1.5 meter distance between profiles on test trench 1S03. The goal of this operation was evaluation of applicability of seismic method in identification of archaeological features, especially adobe wall structures. Processing of seismic data was done with the seismic software, SiesImager. Results were presented in the form of seismic section for every profile, so that identification of adobe wall structures was achieved hardly. This could be due to that adobe wall had been built with the same materials of the natural surrounding earth. Thus, there is a low contrast and it has an inappropriate effect on seismic processing and identifying of archaeological features. Hence the result could be that application of

The contribution of the Global Change Observatory Central Asia to seismic hazard and risk assessment in the Central Asian region

Science.gov (United States)

Parolai, S.; Bindi, D.; Haberland, C. A.; Pittore, M.; Pilz, M.; Rosenau, M.; Schurr, B.; Wieland, M.; Yuan, X.

2012-12-01

Central Asia has one of the world's highest levels of earthquake hazard, owing to its exceptionally high deformation rates. Moreover, vulnerability to natural disasters in general is increasing, due to rising populations and a growing dependence on complex lifelines and technology. Therefore, there is an urgent need to undertake seismic hazard and risk assessment in this region, while at the same time improving upon existing methodologies, including the consideration of temporal variability in the seismic hazard, and in structural and social vulnerability. Over the last few years, the German Research Center for Geosciences (GFZ), in collaboration with local partners, has initiated a number of scientific activities within the framework of the Global Change Observatory Central Asia (GCO-CA). The work is divided into projects with specific concerns: - The installation and maintenance of the Central-Asian Real-time Earthquake MOnitoring Network (CAREMON) and the setup of a permanent wireless mesh network for structural health monitoring in Bishkek. - The TIPAGE and TIPTIMON projects focus on the geodynamics of the Tien-Shan, Pamir and Hindu Kush region, the deepest and most active intra-continental subduction zone in the world. The work covers time scales from millions of years to short-term snapshots based on geophysical measurements of seismotectonic activity and of the physical properties of the crust and upper mantle, as well as their coupling with other surface processes (e.g., landslides). - Existing risk analysis methods assume time-independent earthquake hazard and risk, although temporal changes are likely to occur due to, for example, co- and post-seismic changes in the regional stress field. We therefore aim to develop systematic time-dependent hazard and risk analysis methods in order to undertake the temporal quantification of earthquake activity (PROGRESS). - To improve seismic hazard assessment for better loss estimation, detailed site effects studies

Assessing the cost-effectiveness of seismic risk reduction options in oil industry

International Nuclear Information System (INIS)

Nasserasadi, K.; Ghafory-Ashtiany, M.

2007-01-01

An integrated probabilistic methodology for cost-efficiency estimation of different sort of seismic risk management measures are introduced by adding Cost Benefit Analysis (CBA) module to an integrated seismic risk assessment model. An oil refinery in Iran has been selected for case study and cost-efficiency of software and hardware mitigation measures are evaluated. The results have shown that: (1) software mitigation measures have more benefit than hardware ones, (2) considering indirect loss in CBA lead to more benefit-cost ratio and (3) although increase of discount ratio decreases the benefit-cost ratio, the arrangement of mitigation measures from benefit-cost viewpoint are constant. (authors)

Seismic isolation - efficient procedure for seismic response assessement

International Nuclear Information System (INIS)

Zamfir, M. A.; Androne, M.

2016-01-01

The aim of this analysis is to reduce the dynamic response of a structure. The seismic isolation solution must take into consideration the specific site ground motion. In this paper will be presented results obtained by applying the seismic isolation method. Based on the obtained results, important conclusions can be outlined: the seismic isolation device has the ability to reduce seismic acceleration of the seismic isolated structure to values that no longer present a danger to people and environment; the seismic isolation solution is limiting devices deformations to safety values for ensuring structural integrity and stability of the entire system; the effective seismic energy dissipation and with no side effects both for the seismic isolated building and for the devices used, and the return to the initial position before earthquake occurence are obtained with acceptable permanent displacement. (authors)

Construction of Site Risk Model using Individual Unit Risk Model in a NPP Site

Energy Technology Data Exchange (ETDEWEB)

Lim, Ho Gon; Han, Sang Hoon [KAERI, Daejeon (Korea, Republic of)

2016-05-15

Since Fukushima accident, strong needs to estimate site risk has been increased to identify the possibility of re-occurrence of such a tremendous disaster and prevent such a disaster. Especially, in a site which has large fleet of nuclear power plants, reliable site risk assessment is very emergent to confirm the safety. In Korea, there are several nuclear power plant site which have more than 6 NPPs. In general, risk model of a NPP in terms of PSA is very complicated and furthermore, it is expected that the site risk model is more complex than that. In this paper, the method for constructing site risk model is proposed by using individual unit risk model. Procedure for the development of site damage (risk) model was proposed in the present paper. Since the site damage model is complicated in the sense of the scale of the system and dependency of the components of the system, conventional method may not be applicable in many side of the problem.

Probabilistic Seismic Hazard Analysis for Yemen

Directory of Open Access Journals (Sweden)

Rakesh Mohindra

2012-01-01

Full Text Available A stochastic-event probabilistic seismic hazard model, which can be used further for estimates of seismic loss and seismic risk analysis, has been developed for the territory of Yemen. An updated composite earthquake catalogue has been compiled using the databases from two basic sources and several research publications. The spatial distribution of earthquakes from the catalogue was used to define and characterize the regional earthquake source zones for Yemen. To capture all possible scenarios in the seismic hazard model, a stochastic event set has been created consisting of 15,986 events generated from 1,583 fault segments in the delineated seismic source zones. Distribution of horizontal peak ground acceleration (PGA was calculated for all stochastic events considering epistemic uncertainty in ground-motion modeling using three suitable ground motion-prediction relationships, which were applied with equal weight. The probabilistic seismic hazard maps were created showing PGA and MSK seismic intensity at 10% and 50% probability of exceedance in 50 years, considering local soil site conditions. The resulting PGA for 10% probability of exceedance in 50 years (return period 475 years ranges from 0.2 g to 0.3 g in western Yemen and generally is less than 0.05 g across central and eastern Yemen. The largest contributors to Yemen’s seismic hazard are the events from the West Arabian Shield seismic zone.

Assessing the induced seismicity by hydraulic fracturing at the Wysin site (Poland)

Science.gov (United States)

Ángel López Comino, José; Cesca, Simone; Kriegerowski, Marius; Heimann, Sebastian; Dahm, Torsten; Mirek, Janusz; Lasocky, Stanislaw

2017-04-01

Induced seismicity related to industrial processes including shale gas and oil exploitation is a current issues that implies enough reasons to be concerned. Hydraulic fracturing usually induces weak events. However, scenarios with larger earthquakes are possible, e.g. if the injected fluids alter friction conditions and trigger the failure of neighbouring faults. This work is focused on a hydrofracking experiment monitored in the framework of the SHEER (SHale gas Exploration and Exploitation induced Risks) EU project at the Wysin site, located in the central-western part of the Peribaltic synclise of Pomerania, Poland. A specific network setup has been installed combining surface installation with three small-scale arrays and a shallow borehole installation. The fracking operations were carried out in June and July 2016 at a depth 4000 m. The monitoring has been operational before, during and after the termination of hydraulic fracturing operations. We apply a recently developed automated full waveform detection algorithm based on the stacking of smooth characteristic function and the identification of high coherence in the signals recorded at different stations. The method was tested with synthetic data and different detector levels yielding values of magnitude of completeness around 0.1. An unsupervised detection catalogue is generated with real data for a time period May-September 2016. We identify strong temporal changes (day/night) of the detection performance. A manual revision of the detected signals reveals that most detections are associated to local and regional seismic signals. Only two events could be assigned to the volume potentially affected by the fracking operations.

Evaluation of Fourier and Response Spectra at Ichihasama and Koromogawa Seismic Intensity Observation Sites During the Iwate-Miyagi Nairiku Earthquake in 2008

Science.gov (United States)

Nishikawa, Hayato; Miyajima, Masakatsu

In this study, we evaluate an acceleration Fourier and response spectra at Ichihasama and Koromogawa seismic intensity observation sites which observed JMA seismic intensity of 6 upper but seismic waveform records don't exist during the Iwate-Miyagi Nairiku earthquake in 2008. Firstly, formula to evaluate acceleration Fourier and response spectra are developed using peak ground acceleration, JMA seismic intensity and predominant period of earthquake spectra based on records obtained from crustal earthquakes with Magnitude of 6 to 7. Acceleration Fourier and response spectra are evaluated for another local government site which are not chosen for development of the formula. The evaluated values mostly agree with the observed ones. Finally, acceleration Fourier and response spectra are evaluated for Ichihasama and Koromogawa observation sites. It is clarified that short period below 1 second was predominated in the evaluated spectra.

Seismic design principles for the German fast breeder reactor SNR2

International Nuclear Information System (INIS)

Rangette, A.M.; Peters, K.A.

1988-01-01

The leading aim of a seismic design is, besides protection against seismic impacts, not to enhance the overall risk in the absence of seismic vibrations and, secondly, to avoid competition between operational needs and a seismic structural design. This approach is supported by avoiding overconservatism in the assumption of seismic loads and in the calculation of the structural response. Accordingly the seismic principles are stated as follows: restriction to German or equivalent low seismicity sites with intensities (SSE) lower VIII at frequency lower than 10 -4 /year; best estimate of seismic input-data without further conservatism; no consideration of OBE. The structural design principles are: 1. The secondary character of the seismic excitation is explicitly accounted for; 2. Energy absorption is allowed for by ductility of materials and construction. Accordingly strain criteria are used for failure predictions instead of stress criteria. (author). 1 fig

Seismic behaviour of geotechnical structures

Directory of Open Access Journals (Sweden)

F. Vinale

2002-06-01

Full Text Available This paper deals with some fundamental considerations regarding the behaviour of geotechnical structures under seismic loading. First a complete definition of the earthquake disaster risk is provided, followed by the importance of performing site-specific hazard analysis. Then some suggestions are provided in regard to adequate assessment of soil parameters, a crucial point to properly analyze the seismic behaviour of geotechnical structures. The core of the paper is centered on a critical review of the analysis methods available for studying geotechnical structures under seismic loadings. All of the available methods can be classified into three main classes, including the pseudo-static, pseudo-dynamic and dynamic approaches, each of which is reviewed for applicability. A more advanced analysis procedure, suitable for a so-called performance-based design approach, is also described in the paper. Finally, the seismic behaviour of the El Infiernillo Dam was investigated. It was shown that coupled elastoplastic dynamic analyses disclose some of the important features of dam behaviour under seismic loading, confirmed by comparing analytical computation and experimental measurements on the dam body during and after a past earthquake.

OSI Passive Seismic Experiment at the Former Nevada Test Site

Energy Technology Data Exchange (ETDEWEB)

Sweeney, J J; Harben, P

2010-11-11

On-site inspection (OSI) is one of the four verification provisions of the Comprehensive Nuclear Test Ban Treaty (CTBT). Under the provisions of the CTBT, once the Treaty has entered into force, any signatory party can request an on-site inspection, which can then be carried out after approval (by majority voting) of the Executive Council. Once an OSI is approved, a team of 40 inspectors will be assembled to carry out an inspection to ''clarify whether a nuclear weapon test explosion or any other nuclear explosion has been carried out in violation of Article I''. One challenging aspect of carrying out an on-site inspection (OSI) in the case of a purported underground nuclear explosion is to detect and locate the underground effects of an explosion, which may include an explosion cavity, a zone of damaged rock, and/or a rubble zone associated with an underground collapsed cavity. The CTBT (Protocol, Section II part D, paragraph 69) prescribes several types of geophysical investigations that can be carried out for this purpose. One of the methods allowed by the CTBT for geophysical investigation is referred to in the Treaty Protocol as ''resonance seismometry''. This method, which was proposed and strongly promoted by Russia during the Treaty negotiations, is not described in the Treaty. Some clarification about the nature of the resonance method can be gained from OSI workshop presentations by Russian experts in the late 1990s. Our understanding is that resonance seismometry is a passive method that relies on seismic reverberations set up in an underground cavity by the passage of waves from regional and teleseismic sources. Only a few examples of the use of this method for detection of underground cavities have been presented, and those were done in cases where the existence and precise location of an underground cavity was known. As is the case with many of the geophysical methods allowed during an OSI under the Treaty, how

Development of a State-Wide 3-D Seismic Tomography Velocity Model for California

Science.gov (United States)

Thurber, C. H.; Lin, G.; Zhang, H.; Hauksson, E.; Shearer, P.; Waldhauser, F.; Hardebeck, J.; Brocher, T.

2007-12-01

We report on progress towards the development of a state-wide tomographic model of the P-wave velocity for the crust and uppermost mantle of California. The dataset combines first arrival times from earthquakes and quarry blasts recorded on regional network stations and travel times of first arrivals from explosions and airguns recorded on profile receivers and network stations. The principal active-source datasets are Geysers-San Pablo Bay, Imperial Valley, Livermore, W. Mojave, Gilroy-Coyote Lake, Shasta region, Great Valley, Morro Bay, Mono Craters-Long Valley, PACE, S. Sierras, LARSE 1 and 2, Loma Prieta, BASIX, San Francisco Peninsula and Parkfield. Our beta-version model is coarse (uniform 30 km horizontal and variable vertical gridding) but is able to image the principal features in previous separate regional models for northern and southern California, such as the high-velocity subducting Gorda Plate, upper to middle crustal velocity highs beneath the Sierra Nevada and much of the Coast Ranges, the deep low-velocity basins of the Great Valley, Ventura, and Los Angeles, and a high- velocity body in the lower crust underlying the Great Valley. The new state-wide model has improved areal coverage compared to the previous models, and extends to greater depth due to the data at large epicentral distances. We plan a series of steps to improve the model. We are enlarging and calibrating the active-source dataset as we obtain additional picks from investigators and perform quality control analyses on the existing and new picks. We will also be adding data from more quarry blasts, mainly in northern California, following an identification and calibration procedure similar to Lin et al. (2006). Composite event construction (Lin et al., in press) will be carried out for northern California for use in conventional tomography. A major contribution of the state-wide model is the identification of earthquakes yielding arrival times at both the Northern California Seismic

The forecast of mining-induced seismicity and the consequent risk of damage to the excavation in the area of seismic event

Directory of Open Access Journals (Sweden)

Jan Drzewiecki

2017-01-01

Full Text Available The Central Mining Institute has developed a method for forecasting the amount of seismic energy created by tremors induced by mining operations. The results of geophysical measurements of S wave velocity anomalies in a rock mass or the results of analytic calculations of the values of pressure on the horizon of the elastic layers are used in the process of calculating the energy. The calculation program which has been developed and adopted has been modified over recent years and it now enables not only the prediction of the energy of dynamic phenomena induced by mining but also the forecasting of the devastating range of seismic shock. The results obtained from this calculation, usually presented in a more readable graphic form, are useful for the macroscopic evaluation of locations that are potential sources of seismic energy. Forecasting of the maximum energy of seismic shock without prior knowledge of the location of the shock's source, does not allow shock attenuation that results from, for example, a distance of tremor source from the excavation which will be affected by seismic energy, to be taken into consideration. The phenomena of energy dissipation, which is taken into account in the forecasts, create a new quality of assessment of threat to the excavation. The paper presents the principle of a method of forecasting the seismic energy of a shock and the risk of damage to the excavation as a result of the impact of its energy wave. The solution assumes that the source of the energy shock is a resilient layer in which the sum of the gravitational stresses, resulting from natural disturbances and those induced by the conducted or planned mining exploitation, is estimated. The proposed solution assumes a spherical model for the tremor source, for which seismic energy is forecasted as a function of the longwall advance and the elementary value of seismic energy destroying the excavation. Subsequently, the following are calculated for the

Interactive web visualization tools to the results interpretation of a seismic risk study aimed at the emergency levels definition

Science.gov (United States)

Rivas-Medina, A.; Gutierrez, V.; Gaspar-Escribano, J. M.; Benito, B.

2009-04-01

Results of a seismic risk assessment study are often applied and interpreted by users unspecialised on the topic or lacking a scientific background. In this context, the availability of tools that help translating essentially scientific contents to broader audiences (such as decision makers or civil defence officials) as well as representing and managing results in a user-friendly fashion, are on indubitable value. On of such tools is the visualization tool VISOR-RISNA, a web tool developed within the RISNA project (financed by the Emergency Agency of Navarre, Spain) for regional seismic risk assessment of Navarre and the subsequent development of emergency plans. The RISNA study included seismic hazard evaluation, geotechnical characterization of soils, incorporation of site effects to expected ground motions, vulnerability distribution assessment and estimation of expected damage distributions for a 10% probability of exceedance in 50 years. The main goal of RISNA was the identification of higher risk area where focusing detailed, local-scale risk studies in the future and the corresponding urban emergency plans. A geographic information system was used to combine different information layers, generate tables of results and represent maps with partial and final results. The visualization tool VISOR-RISNA is intended to facilitate the interpretation and representation of the collection of results, with the ultimate purpose of defining actuation plans. A number of criteria for defining actuation priorities are proposed in this work. They are based on combinations of risk parameters resulting from the risk study (such as expected ground motion and damage and exposed population), as determined by risk assessment specialists. Although the values that these parameters take are a result of the risk study, their distribution in several classes depends on the intervals defined by decision takers or civil defense officials. These criteria provide a ranking of

Seismic Data Gathering and Validation

Energy Technology Data Exchange (ETDEWEB)

Coleman, Justin [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2015-02-01

Three recent earthquakes in the last seven years have exceeded their design basis earthquake values (so it is implied that damage to SSC’s should have occurred). These seismic events were recorded at North Anna (August 2011, detailed information provided in [Virginia Electric and Power Company Memo]), Fukushima Daichii and Daini (March 2011 [TEPCO 1]), and Kaswazaki-Kariwa (2007, [TEPCO 2]). However, seismic walk downs at some of these plants indicate that very little damage occurred to safety class systems and components due to the seismic motion. This report presents seismic data gathered for two of the three events mentioned above and recommends a path for using that data for two purposes. One purpose is to determine what margins exist in current industry standard seismic soil-structure interaction (SSI) tools. The second purpose is the use the data to validated seismic site response tools and SSI tools. The gathered data represents free field soil and in-structure acceleration time histories data. Gathered data also includes elastic and dynamic soil properties and structural drawings. Gathering data and comparing with existing models has potential to identify areas of uncertainty that should be removed from current seismic analysis and SPRA approaches. Removing uncertainty (to the extent possible) from SPRA’s will allow NPP owners to make decisions on where to reduce risk. Once a realistic understanding of seismic response is established for a nuclear power plant (NPP) then decisions on needed protective measures, such as SI, can be made.

Seismic site survey investigations in urban environments: The case of the underground metro project in Copenhagen, Denmark.

Science.gov (United States)

Martínez, K.; Mendoza, J. A.; Colberg-Larsen, J.; Ploug, C.

2009-05-01

Near surface geophysics applications are gaining more widespread use in geotechnical and engineering projects. The development of data acquisition, processing tools and interpretation methods have optimized survey time, reduced logistics costs and increase results reliability of seismic surveys during the last decades. However, the use of wide-scale geophysical methods under urban environments continues to face great challenges due to multiple noise sources and obstacles inherent to cities. A seismic pre-investigation was conducted to investigate the feasibility of using seismic methods to obtain information about the subsurface layer locations and media properties in Copenhagen. Such information is needed for hydrological, geotechnical and groundwater modeling related to the Cityringen underground metro project. The pre-investigation objectives were to validate methods in an urban environment and optimize field survey procedures, processing and interpretation methods in urban settings in the event of further seismic investigations. The geological setting at the survey site is characterized by several interlaced layers of clay, till and sand. These layers are found unevenly distributed throughout the city and present varying thickness, overlaying several different unit types of limestone at shallow depths. Specific results objectives were to map the bedrock surface, ascertain a structural geological framework and investigate bedrock media properties relevant to the construction design. The seismic test consisted of a combined seismic reflection and refraction analyses of a profile line conducted along an approximately 1400 m section in the northern part of Copenhagen, along the projected metro city line. The data acquisition was carried out using a 192 channels array, receiver groups with 5 m spacing and a Vibroseis as a source at 10 m spacing. Complementarily, six vertical seismic profiles (VSP) were performed at boreholes located along the line. The reflection

Induced seismicity hazard and risk by enhanced geothermal systems: an expert elicitation approach

Science.gov (United States)

Trutnevyte, Evelina; Azevedo, Inês L.

2018-03-01

Induced seismicity is a concern for multiple geoenergy applications, including low-carbon enhanced geothermal systems (EGS). We present the results of an international expert elicitation (n = 14) on EGS induced seismicity hazard and risk. Using a hypothetical scenario of an EGS plant and its geological context, we show that expert best-guess estimates of annualized exceedance probabilities of an M ≥ 3 event range from 0.2%-95% during reservoir stimulation and 0.2%-100% during operation. Best-guess annualized exceedance probabilities of M ≥ 5 event span from 0.002%-2% during stimulation and 0.003%-3% during operation. Assuming that tectonic M7 events could occur, some experts do not exclude induced (triggered) events of up to M7 too. If an induced M = 3 event happens at 5 km depth beneath a town with 10 000 inhabitants, most experts estimate a 50% probability that the loss is contained within 500 000 USD without any injuries or fatalities. In the case of an induced M = 5 event, there is 50% chance that the loss is below 50 million USD with the most-likely outcome of 50 injuries and one fatality or none. As we observe a vast diversity in quantitative expert judgements and underlying mental models, we conclude with implications for induced seismicity risk governance. That is, we suggest documenting individual expert judgements in induced seismicity elicitations before proceeding to consensual judgements, to convene larger expert panels in order not to cherry-pick the experts, and to aim for multi-organization multi-model assessments of EGS induced seismicity hazard and risk.

Seismic ground motion modelling and damage earthquake scenarios: A bridge between seismologists and seismic engineers

International Nuclear Information System (INIS)

Panza, G.F.; Romanelli, F.; Vaccari. F.; . E-mails: Luis.Decanini@uniroma1.it; Fabrizio.Mollaioli@uniroma1.it)

2002-07-01

The input for the seismic risk analysis can be expressed with a description of 'roundshaking scenarios', or with probabilistic maps of perhaps relevant parameters. The probabilistic approach, unavoidably based upon rough assumptions and models (e.g. recurrence and attenuation laws), can be misleading, as it cannot take into account, with satisfactory accuracy, some of the most important aspects like rupture process, directivity and site effects. This is evidenced by the comparison of recent recordings with the values predicted by the probabilistic methods. We prefer a scenario-based, deterministic approach in view of the limited seismological data, of the local irregularity of the occurrence of strong earthquakes, and of the multiscale seismicity model, that is capable to reconcile two apparently conflicting ideas: the Characteristic Earthquake concept and the Self Organized Criticality paradigm. Where the numerical modeling is successfully compared with records, the synthetic seismograms permit the microzoning, based upon a set of possible scenario earthquakes. Where no recordings are available the synthetic signals can be used to estimate the ground motion without having to wait for a strong earthquake to occur (pre-disaster microzonation). In both cases the use of modeling is necessary since the so-called local site effects can be strongly dependent upon the properties of the seismic source and can be properly defined only by means of envelopes. The joint use of reliable synthetic signals and observations permits the computation of advanced hazard indicators (e.g. damaging potential) that take into account local soil properties. The envelope of synthetic elastic energy spectra reproduces the distribution of the energy demand in the most relevant frequency range for seismic engineering. The synthetic accelerograms can be fruitfully used for design and strengthening of structures, also when innovative techniques, like seismic isolation, are employed. For these

A framework of risk-informed seismic safety evaluation of nuclear power plants in Japan

International Nuclear Information System (INIS)

Kondo, S.; Sakagami, M.; Hirano, M.; Shiba, M.

2001-01-01

A framework of risk-informed seismic design and safety evaluation of nuclear power plants is under consideration in Japan so as to utilize the progress in the seismic probabilistic safety assessment methodology. Issues resolved to introduce this framework are discussed after the concept, evaluation process and characteristics of the framework are described. (author)

Seismic hazard assessment: Issues and alternatives

Science.gov (United States)

Wang, Z.

2011-01-01

Seismic hazard and risk are two very important concepts in engineering design and other policy considerations. Although seismic hazard and risk have often been used inter-changeably, they are fundamentally different. Furthermore, seismic risk is more important in engineering design and other policy considerations. Seismic hazard assessment is an effort by earth scientists to quantify seismic hazard and its associated uncertainty in time and space and to provide seismic hazard estimates for seismic risk assessment and other applications. Although seismic hazard assessment is more a scientific issue, it deserves special attention because of its significant implication to society. Two approaches, probabilistic seismic hazard analysis (PSHA) and deterministic seismic hazard analysis (DSHA), are commonly used for seismic hazard assessment. Although PSHA has been pro-claimed as the best approach for seismic hazard assessment, it is scientifically flawed (i.e., the physics and mathematics that PSHA is based on are not valid). Use of PSHA could lead to either unsafe or overly conservative engineering design or public policy, each of which has dire consequences to society. On the other hand, DSHA is a viable approach for seismic hazard assessment even though it has been labeled as unreliable. The biggest drawback of DSHA is that the temporal characteristics (i.e., earthquake frequency of occurrence and the associated uncertainty) are often neglected. An alternative, seismic hazard analysis (SHA), utilizes earthquake science and statistics directly and provides a seismic hazard estimate that can be readily used for seismic risk assessment and other applications. ?? 2010 Springer Basel AG.

Reprocessing and interpretation, seismic reflection data: Hanford Site, Pasco Basin, south central Washington

International Nuclear Information System (INIS)

Berkman, E.

1983-01-01

The purpose of this project was to reprocess, evaluate, and reinterpret 14 line miles of seismic reflection data acquired at the Hanford Site. Regional and area-specific geology has been reviewed, the data acquisition parameters as they relate to the limitations inherent in the data have been discussed, and the reprocessing procedures have been described in detail along with an evaluation of the original processing. After initial testing, the focus of the reprocessing was placed on resolution of the geologic horizons at and near the top of the basalt. The reprocessed seismic data shows significant improvement over the original processing. The improvement is the result of the integrated processing and interpretation approach where each processing step has been tested in sequence and the intermediate results examined carefully in accordance with the project goals. The interpretation procedure placed strong reliance upon synthetic seismograms and models calculated based upon the physical parameters of the subsurface materials, and upon associated geophysical (reflection, gravity, magnetic) data. The final interpretation of the seismic data is in agreement with the structural contour maps based primarily on borehole information. The seismic interpretation has added important detail concerning areas which should be considered for further study. 60 figs., 1 tab

Seismic tomography investigation of the Down Ampney fault research site

International Nuclear Information System (INIS)

Jackson, P.D.; Greenwood, P.G.; Raines, M.G.; Rainsbury, M.P.

1991-01-01

High resolution tomographic cross-hole seismic surveys have been designed and undertaken for fault characterisation in mudrocks at a higher resolution than is currently used in site investigations. Compressional waves were generated at a frequency of 1.04 kHz and a wavelength of 1.6 m in the formation, and were used to tomographically image a normally faulted clay sequence (Oxford Clay and Kellaways Beds) overlying limestone. The fault plane and lithologies are clearly visible in the tomograms, a 10% difference in velocity between the Oxford Clay and Kellaways Beds, being particularly prominent. A zone of 5% lower ''tomographic - velocity'' was observed to correspond with the fault zone within the Oxford Clay (as predicted from the geological logging of the core) which indicates substantial alteration that could be fluid affected. Geological constraints were found to be a crucial imput to the tomographic inversion, and examples show erroneous results that can arise. Seismic attenuation was very low (reflection observed from 80 m depth) and larger ranges could have been used to investigate larger scale geological structures. (author)

Nuclear power plant of Fessenheim: evaluation of the seismic risk; Centrale Nucleaire de Fessenheim: appreciation du risque sismique

Energy Technology Data Exchange (ETDEWEB)

NONE

2007-07-01

The seismic risk taken into account during the sizing of the nuclear power plant of Fessenheim seems to have been under evaluated at this time. The revaluation of the seismic risk, as proposed, until this day by EDF in order to the third ten-year visit of the power plant, planned for 2009, leads to a significant under evaluation of the risk and then is not acceptable. The present expertise details point by point the weaknesses of these revaluation. The power plant has been sized in an elastic manner that is generally strongly for the safety side. It is imperative to proceed the most quickly as possible to a deep control of the seismic resistance of the power plant of Fessenheim and then after having proceeded to a revision of the seismic risk in taking into account the actual knowledge in this field. (N.C.)

Grimsel Test Site. Further Development of Seismic Tomography

International Nuclear Information System (INIS)

Albert, W.; Buehnemann, J.; Holliger, K.; Maurer, H.R.; Pratt, G.; Stekl, I.

1999-03-01

Experience gained by NAGRA and its partner organisations in the Grimsel underground rock laboratory has led to the identification of two main areas of investigation: The first part of the present project deals with the evaluation and testing of underground seismic sources suitable for large measurement distances. Various high-frequency seismic sources have been tested at the Grimsel Test Site (GTS) (Buehnemann, 1996; Buehnemann and Holliger, 1998). The tests were designed to facilitate future tomographic studies of potential radioactive waste disposal sites. A key objective was to identify borehole and tunnel seismic sources capable of generating and sustaining high-frequency signals over distances of up to 1000 m. Seismic sources were located in both water-filled boreholes (sparker, two piezo-electric sources, explosives) and at the tunnel wall (accelerated weight drop, minivibrator, bolt gun, buffalo gun, explosives). The second focal point of the project was dealing with improvement (and development) of analysis techniques in terms of stability, quality and resolution. 3 inversion techniques were tested and developed using the dataset US85 (Gelbke, 1988). Two travel time inversions - anisotropic velocity tomography - AVT (Pratt and Chapman, 1992) and coupled inversion - CI (Maurer, 1996; Maurer and Green, 1997) - and a wave field inversion (WFI Song et al., 1995) were used. Several problems occurred in the first inversion of the US85 dataset using the Simultaneous Iterative Reconstruction Technique (SIRT); these were due to the velocity anisotropy of the rock, the triggering inaccuracy of the shots and uncertainties regarding the source/receiver locations in the boreholes. In the AVT, the velocity anisotropy of the rock is taken into account as a free parameter. In addition to an 'isotropic' velocity image, this involves producing tomograms of anisotropy. Taking into account the anisotropy of the rock allows the artefacts of the SIRT inversion to be explained

Seismic evaluation of commercial plutonium fabrication plants in the United States

International Nuclear Information System (INIS)

Bernreuter, D.L.; Coats, D.W.; Murray, R.C.; Tokarz, F.J.

1979-01-01

This report is an overview of Lawrence Livermore National Laboratory's seismic assessment of six commercial plutonium fabrication plants licensed by the US Nuclear Regulatory Commission (NRC) before September 2, 1971. The seismic assessment generally has three parts: (1) documentation of the structural condition of each facility and its critical equipment; (2) characterization of the seismic hazard (i.e., determination of peak ground acceleration vs return period for each site); and (3) evaluation of seismic capacity to determine ground motion levels at which critical structures and equipment fail. The failure evaluation used structural capacities of median-centered strength characteristics of the as-built configurations from (1) and seismic hazard input from (2). Results of the assessment were partial input for an overall natural risks study by the NRC

Seismic soil-structure interaction with consideration of spatial incoherence of seismic ground motions: A case study

Energy Technology Data Exchange (ETDEWEB)

Tseng, Wen S., E-mail: wen.tseng@rizzoassoc.com [Paul C. Rizzo Associates, Inc., Western Region, 2201 Broadway, Suite 400, Oakland, CA 94612 (United States); Lilhanand, Kiat; Hamasaki, Don; Garcia, Julio A. [Paul C. Rizzo Associates, Inc., Western Region, 2201 Broadway, Suite 400, Oakland, CA 94612 (United States); Srinivasan, Ram [AREVA, NP, Inc., 6399 San Ignacio Avenue, San Jose, CA 95119 (United States)

2014-04-01

This paper presents a case study of seismic soil-structure interaction (SSI) analysis with consideration of spatial incoherence of seismic input ground motions. The SSI analyses were performed using the SASSI computer program for the Auxiliary Control Building (ACB) structure of an existing nuclear power plant on a hard rock site located in the Center and Eastern United States (CEUS) region. The incoherent seismic input motions for the hard rock site used for the analyses were generated using the computer program INCOH that works together with SASSI. The objective of the analyses was to generate maximum seismic response parameters for assessment of potential impact of newly developed site-specific (ground motion) response spectra (SSRS) on the seismic design of the ACB and potential benefits that could be gained by considering spatial incoherence of seismic input motions. Maximum seismic response values for selected response parameters of interest were generated with both SSRS-compatible coherent and incoherent seismic input motions. Comparisons were made of the corresponding maximum response parameter values and in-structure (acceleration) response spectra (ISRS) generated for both the coherent and incoherent motion inputs. These comparisons indicate that, by incorporating incoherence of ground motions in the seismic input, the maximum response values reduces and the ISRS peak amplitudes in the high frequency range (>10 Hz) also reduce from the corresponding response values resulting from the coherent motion input. The amount of ISRS-amplitude reduction increases as the spectral frequency increases, as expected. Such reductions can be as much as 20–50%. This case study demonstrates that, for a CEUS hard rock site where relatively high high-frequency in the seismic input response spectra exist, consideration of spatial incoherence of input motions would result in substantial benefits in reducing the high-frequency seismic responses. Such benefits are especially

France's seismic zoning

International Nuclear Information System (INIS)

Mohammadioun, B.

1997-01-01

In order to assess the seismic hazard in France in relation to nuclear plant siting, the CEA, EDF and the BRGM (Mine and Geology Bureau) have carried out a collaboration which resulted in a seismic-tectonic map of France and a data base on seismic history (SIRENE). These studies were completed with a seismic-tectonic zoning, taking into account a very long period of time, that enabled a probabilistic evaluation of the seismic hazard in France, and that may be related to adjacent country hazard maps

Urban seismic risk assessment: statistical repair cost data and probable structural losses based on damage scenario—correlation analysis

Science.gov (United States)

Eleftheriadou, Anastasia K.; Baltzopoulou, Aikaterini D.; Karabinis, Athanasios I.

2016-06-01

The current seismic risk assessment is based on two discrete approaches, actual and probable, validating afterwards the produced results. In the first part of this research, the seismic risk is evaluated from the available data regarding the mean statistical repair/strengthening or replacement cost for the total number of damaged structures (180,427 buildings) after the 7/9/1999 Parnitha (Athens) earthquake. The actual evaluated seismic risk is afterwards compared to the estimated probable structural losses, which is presented in the second part of the paper, based on a damage scenario in the referring earthquake. The applied damage scenario is based on recently developed damage probability matrices (DPMs) from Athens (Greece) damage database. The seismic risk estimation refers to 750,085 buildings situated in the extended urban region of Athens. The building exposure is categorized in five typical structural types and represents 18.80 % of the entire building stock in Greece. The last information is provided by the National Statistics Service of Greece (NSSG) according to the 2000-2001 census. The seismic input is characterized by the ratio, a g/ a o, where a g is the regional peak ground acceleration (PGA) which is evaluated from the earlier estimated research macroseismic intensities, and a o is the PGA according to the hazard map of the 2003 Greek Seismic Code. Finally, the collected investigated financial data derived from different National Services responsible for the post-earthquake crisis management concerning the repair/strengthening or replacement costs or other categories of costs for the rehabilitation of earthquake victims (construction and function of settlements for earthquake homeless, rent supports, demolitions, shorings) are used to determine the final total seismic risk factor.

Seismic sensitivity study of a generic CANDU nuclear power plant: Soil-structure interaction

International Nuclear Information System (INIS)

Lee, L.S.S.; Duff, C.G.

1983-01-01

The seismic sensitivity and capability study for a generic CANDU Plant is part of an overall development program of design standardization. The purpose of this paper is to investigate the sensitivities of structural responses and floor response spectra (FRS) to variations of structural and soil parameters. In the seismic design standardization, a wide range of soil conditions is considered and the envelopes of the resulting site spectra (soil-structure interaction effect) are then used for the design of the generic plant. The nuclear island structures considered herein have different relative stiffness and one of them has two layout/structure schemes: one is relatively flexible and the other is moderately stiff. In the preliminary phase of the seismic sensitivity study presented hereby, the soil-structure interaction seismic analysis is based on the half-space modelling (soil-spring lumped-mass) method and the response spectrum method for the seismic responses. Distinct patterns and sensitivity of the site spectrum analysis for structure schemes of different relative stiffness and for different structural elevations are observed and discussed. (orig.)

Recent Seismicity in Texas and Research Design and Progress of the TexNet-CISR Collaboration

Science.gov (United States)

Hennings, P.; Savvaidis, A.; Rathje, E.; Olson, J. E.; DeShon, H. R.; Datta-Gupta, A.; Eichhubl, P.; Nicot, J. P.; Kahlor, L. A.

2017-12-01

The recent increase in the rate of seismicity in Texas has prompted the establishment of an interdisciplinary, interinstitutional collaboration led by the Texas Bureau of Economic Geology which includes the TexNet Seismic Monitoring and Research project as funded by The State of Texas (roughly 2/3rds of our funding) and the industry-funded Center for Integrated Seismicity Research (CISR) (1/3 of funding). TexNet is monitoring and cataloging seismicity across Texas using a new backbone seismic network, investigating site-specific earthquake sequences by deploying temporary seismic monitoring stations, and conducting reservoir modeling studies. CISR expands TexNet research into the interdisciplinary realm to more thoroughly study the factors that contribute to seismicity, characterize the associated hazard and risk, develop strategies for mitigation and management, and develop methods of effective communication for all stakeholders. The TexNet-CISR research portfolio has 6 themes: seismicity monitoring, seismology, geologic and hydrologic description, geomechanics and reservoir modeling, seismic hazard and risk assessment, and seismic risk social science. Twenty+ specific research projects span and connect these themes. We will provide a synopsis of research progress including recent seismicity trends in Texas; Fort Worth Basin integrated studies including geological modeling and fault characterization, fluid injection data syntheses, and reservoir and geomechanical modeling; regional ground shaking characterization and mapping, infrastructure vulnerability assessment; and social science topics of public perception and information seeking behavior.

Seismic evaluation of a diesel generator system at the Savannah River Site using earthquake experience data

International Nuclear Information System (INIS)

Griffin, M.J.; Tong, Wen H.; Rawls, G.B.

1990-01-01

New equipment and systems have been seismically qualified traditionally by either two methods, testing or analysis. Testing programs are generally expensive and their input loadings are conservative. It is generally recognized that standard seismic analysis techniques produce conservative results. Seismic loads and response levels for equipment that are typically calculated exceed the values actually experienced in earthquakes. An alternate method for demonstrating the seismic adequacy of equipment has been developed which is based on conclusions derived from studying the performance of equipment that has been subjected to actual earthquake excitations. The conclusion reached from earthquake experience data is that damage or malfunction to most types of equipment subjected to earthquakes is less than that predicted by traditional testing and analysis techniques. The use of conclusions derived from experience data provides a realistic approach in assessing the seismic ruggedness of equipment. By recognizing the inherently higher capacity that exists in specific classes of equipment, commercial ''off-the-shelf'' equipment can be procured and qualified without the need to perform expensive modifications to meet requirements imposed by traditional conservative qualification analyses. This paper will present the seismic experience data methodology applied to demonstrate the seismic adequacy of several commercially supplied 800KW diesel powered engine driven generator sets with peripheral support components installed at the Savannah River Site (SRS)

Selecting the seismic HRA approach for Savannah River Plant PRA revision 1

International Nuclear Information System (INIS)

Papouchado, K.; Salaymeh, J.

1993-10-01

The Westinghouse Savannah River Company (WSRC) has prepared a level I probabilistic risk assessment (PRA), Rev. 0 of reactor operations for externally-initiated events including seismic events. The SRS PRA, Rev. 0 Seismic HRA received a critical review that expressed skepticism with the approach used for human reliability analysis because it had not been previously used and accepted in other published PRAs. This report provides a review of published probabilistic risk assessments (PRAs), the associated methodology guidance documents, and the psychological literature to identify parameters important to seismic human reliability analysis (HRA). It also describes a recommended approach for use in the Savannah River Site (SRS) PRA. The SRS seismic event PRA performs HRA to account for the contribution of human errors in the accident sequences. The HRA of human actions during and after a seismic event is an area subject to many uncertainties and involves significant analyst judgment. The approach recommended by this report is based on seismic HRA methods and associated issues and concerns identified from the review of these referenced documents that represent the current state-of-the- art knowledge and acceptance in the seismic HRA field

New Directions in Seismic Hazard Assessment Through Focused Earth Observation in the MARmara SuperSITE - Project Achievements

Science.gov (United States)

Meral OZel, Nurcan; Necmioǧlu, Öcal; Ergintav, Semih; Ozel, Oǧuz; Favali, Paolo; Bigarre, Pascal; Çakır, Ziyadin; Ozeren, Sinan; Geli, Louis; Douglas, John; Aochi, Hideo; Bossu, Remy; Zülfikar, Can; Şeşetyan, Karin; Erdik, Mustafa

2016-04-01

The MARsite Project, which started in November 2012,funded by the EC/ FP7-ENV.2012 6.4-2 (Grant 308417) identifies the Marmara region as a 'Supersite' within European initiatives to aggregate on-shore, off-shore and space-based observations, comprehensive geophysical monitoring, improved hazard and risk assessments encompassed in an integrated set of activities. MARsite aimed to harmonize geological, geophysical, geodetic and geochemical observations to provide a better view of the post-seismic deformation of the 1999 Izmit earthquake (in addition to the post-seismic signature of previous earthquakes), loading of submarine and inland active fault segments and transient pre-earthquake signals, related to stress loading with different tectonic properties in and around Marmara Sea. This presentation provides an overview of the achievements of MARSite which aimed to coordinate research groups ranging from seismology to gas geochemistry in a comprehensive monitoring activity developed in the Marmara Region based on collection of multidisciplinary data to be shared, interpreted and merged in consistent theoretical and practical models suitable for the implementation of good practices to move the necessary information to the end users in charge of seismic risk management of the region. In addition, processes involved in earthquake generation and the physics of short-term seismic transients, 4D deformations to understand earthquake cycle processes, fluid activity monitoring and seismicity under the sea floor using existing autonomous instrumentation, early warning and development of real-time shake and loss information, real- and quasi-real-time earthquake and tsunami hazard monitoring and earthquake-induced landslide hazard topics are also covered within MARSite. In particular, achievements and progress in the design and building of a multi-parameter borehole system consisting of very wide dynamic range and stable borehole (VBB) broad band seismic sensor, with

Demonstration of NonLinear Seismic Soil Structure Interaction and Applicability to New System Fragility Seismic Curves

Energy Technology Data Exchange (ETDEWEB)

Coleman, Justin [Idaho National Lab. (INL), Idaho Falls, ID (United States). Nuclear Science and Technology

2014-09-01

Risk calculations should focus on providing best estimate results, and associated insights, for evaluation and decision-making. Specifically, seismic probabilistic risk assessments (SPRAs) are intended to provide best estimates of the various combinations of structural and equipment failures that can lead to a seismic induced core damage event. However, in general this approach has been conservative, and potentially masks other important events (for instance, it was not the seismic motions that caused the Fukushima core melt events, but the tsunami ingress into the facility). SPRAs are performed by convolving the seismic hazard (the frequency of certain magnitude events) with the seismic fragility (the conditional probability of failure of a structure, system, or component given the occurrence of earthquake ground motion). In this calculation, there are three main pieces to seismic risk quantification, 1) seismic hazard and nuclear power plants (NPPs) response to the hazard, fragility or capacity of structures, systems and components (SSC), and systems analysis. Figure 1 provides a high level overview of the risk quantification process. The focus of this research is on understanding and removing conservatism (when possible) in the quantification of seismic risk at NPPs.

Methodology for seismic PSA of NPPs

International Nuclear Information System (INIS)

Jirsa, P.

1999-09-01

A general methodology is outlined for seismic PSA (probabilistic safety assessment). The main objectives of seismic PSA include: description of the course of an event; understanding the most probable failure sequences; gaining insight into the overall probability of reactor core damage; identification of the main seismic risk contributors; identification of the range of peak ground accelerations contributing significantly to the plant risk; and comparison of the seismic risk with risks from other events. The results of seismic PSA are typically compared with those of internal PSA and of PSA of other external events. If the results of internal and external PSA are available, sensitivity studies and cost benefit analyses are performed prior to any decision regarding corrective actions. If the seismic PSA involves analysis of the containment, useful information can be gained regarding potential seismic damage of the containment. (P.A.)

A new system for seismic yield estimation of underground explosions

International Nuclear Information System (INIS)

Murphy, J.R.

1991-01-01

Research conducted over the past decade has led to the development of a number of innovative procedures for estimating the yields of underground nuclear explosions based on systematic analyses of digital seismic data recorded from these tests. In addition, a wide variety of new data regarding the geophysical environments at Soviet test locations have now become available as a result of the Joint Verification Experiment (JVE) and associated data exchanges. The system described in this paper represents an attempt to integrate all these new capabilities and data into a comprehensive operational prototype which can be used to obtain optimum seismic estimates of explosion yield together with quantitative measures of the uncertainty in those estimates. The implementation of this system has involved a wide variety of technical tasks, including the development of a comprehensive seismic database and related database access software, formulation of a graphical test site information interface for accessing available information on explosion source conditions, design of an interactive seismic analyst station for use in processing the observed data to extract the required magnitude measures and the incorporation of formal statistical analysis modules for use in yield estimation and assessment

Fluid injection and induced seismicity

Science.gov (United States)

Kendall, Michael; Verdon, James

2016-04-01

The link between fluid injection, or extraction, and induced seismicity has been observed in reservoirs for many decades. In fact spatial mapping of low magnitude events is routinely used to estimate a stimulated reservoir volume. However, the link between subsurface fluid injection and larger felt seismicity is less clear and has attracted recent interest with a dramatic increase in earthquakes associated with the disposal of oilfield waste fluids. In a few cases, hydraulic fracturing has also been linked to induced seismicity. Much can be learned from past case-studies of induced seismicity so that we can better understand the risks posed. Here we examine 12 case examples and consider in particular controls on maximum event size, lateral event distributions, and event depths. Our results suggest that injection volume is a better control on maximum magnitude than past, natural seismicity in a region. This might, however, simply reflect the lack of baseline monitoring and/or long-term seismic records in certain regions. To address this in the UK, the British Geological Survey is leading the deployment of monitoring arrays in prospective shale gas areas in Lancashire and Yorkshire. In most cases, seismicity is generally located in close vicinity to the injection site. However, in some cases, the nearest events are up to 5km from the injection point. This gives an indication of the minimum radius of influence of such fluid injection projects. The most distant events are never more than 20km from the injection point, perhaps implying a maximum radius of influence. Some events are located in the target reservoir, but most occur below the injection depth. In fact, most events lie in the crystalline basement underlying the sedimentary rocks. This suggests that induced seismicity may not pose a leakage risk for fluid migration back to the surface, as it does not impact caprock integrity. A useful application for microseismic data is to try and forecast induced seismicity

Development of field-wide risk based remediation objectives for an aging oil field : Devon Canada Swan Hills Field

Energy Technology Data Exchange (ETDEWEB)

Brewster, M.; North, C.; Leighton-Boyce, G. [WorleyParsons Komex, Calgary, AB (Canada); Moore, D. [Devon Canada Corp., Calgary, AB (Canada)

2006-07-01

The development of field-wide risk based remediation objectives for the aging Devon Canada Swan Hills oil field was examined along with the key components of the closure strategy. These included source removal to the extent practical, long term monitoring, and achievable risk-based remedial objectives that were appropriate to the remote boreal forest setting of the Swan Hills field. A two stage approach was presented. The first stage involved a field wide background framework which included defining areas of common physical and ecological setting and developing appropriate exposure scenarios. The second stage involved site-specific risk assessments which included adjusting for site-specific conditions and an early demonstration project to prove the concept. A GIS approach was used to identify areas of common physical and ecological setting including: physiography; surface water; land use; vegetation ecozones; surficial and bedrock geology; and water well use. Species lists were compiled for vegetation, terrestrial wildlife (mammals, birds, amphibians), and aquatic species (fish and invertebrates). Major contaminant sources, problem formulation, vegetation bioassays, invertebrate bioassays, black spruce emergence, and guideline development were other topics covered during the presentation. Last, a summary of progress was presented. A field-wide review and development of risk zones and site-specific risk assessment has been completed. A regulatory review is underway. tabs., figs.

Seismic Safety Guide

International Nuclear Information System (INIS)

Eagling, D.G.

1985-01-01

The Seismic Safety Guide provides facilities managers with practical guidelines for administering a comprehensive earthquake safety program. Most facilities managers, unfamiliar with earthquake engineering, tend to look for answers in techniques more sophisticated than required to solve the actual problems in earthquake safety. Often the approach to solutions to these problems is so academic, legalistic, and financially overwhelming that mitigation of actual seismic hazards simply does not get done in a timely, cost-effective way. The objective of the Guide is to provide practical advice about earthquake safety so that managers and engineers can get the job done without falling into common pitfalls, prolonged diagnosis, and unnecessary costs. It is comprehensive with respect to earthquakes in that it covers the most important aspects of natural hazards, site planning, rehabilitation of existing buildings, design of new facilities, operational safety, emergency planning, non-structural elements, life lines, and risk management. 5 references

New "Risk-Targeted" Seismic Maps Introduced into Building Codes

Science.gov (United States)

Luco, Nicholas; Garrett, B.; Hayes, J.

2012-01-01

Throughout most municipalities of the United States, structural engineers design new buildings using the U.S.-focused International Building Code (IBC). Updated editions of the IBC are published every 3 years. The latest edition (2012) contains new "risk-targeted maximum considered earthquake" (MCER) ground motion maps, which are enabling engineers to incorporate a more consistent and better defined level of seismic safety into their building designs.

Seismic monitoring at the Decatur, Ill., CO2 sequestration demonstration site

Science.gov (United States)

Kaven, Joern; Hickman, Stephen H.; McGarr, Arthur F.; Walter, Steve R.; Ellsworth, William L.

2014-01-01

The viability of carbon capture and storage (CCS) to reduce emissions of greenhouse gases depends on the ability to safely sequester large quantities of CO2 over geologic time scales. One concern with CCS is the potential of induced seismicity. We report on ongoing seismic monitoring by the U.S. Geological Survey (USGS) at a CCS demonstration site in Decatur, IL, in an effort to understand the potential hazards posed by injection-induced seismicity associated with geologic CO2 sequestration. At Decatur, super-critical CO2 is injected at 2.1 km depth into the 550-m-thick Mt. Simon Sandstone, which directly overlies granitic basement. The primary sealing cap rock is the Eau Claire Shale, a 100- to 150-m-thick unit at a depth of roughly 1.5 km. The USGS seismic network consists of 12 stations, three of which have surface accelerometers and three-component borehole geophones. We derived a one-dimensional velocity models from a vertical seismic profile acquired by Archer-Daniels-Midland (ADM) and the Illinois State Geological Survey (ISGS) to a depth of 2.2 km, tied into shallow acoustic logs from our borehole stations and assuming a 6 km/sec P-wave velocity for granite below 2.2 km. We further assume a constant ratio of P- to S-wave velocities of 1.83, as derived from velocity model inversions. We use this velocity model to locate seismic events, all of which are within the footprint of our network. So far magnitudes of locatable events range from Mw = -1.52 to 1.07. We further improved the hypocentral precision of microseismic events when travel times and waveforms are sufficiently similar by employing double-difference relocation techniques, with relative location errors less than 80 m horizontally and 100 m vertically. We observe tend to group in three distinct clusters: ∼0.4 to 1.0 km NE, 1.6 to 2.4 km N, and ∼1.8 to 2.6 km WNW from the injection well. The first cluster of microseismicity forms a roughly linear trend, which may represent a pre-existing geologic

Mapping basin-wide subaquatic slope failure susceptibility as a tool to assess regional seismic and tsunami hazards

Science.gov (United States)

Strasser, Michael; Hilbe, Michael; Anselmetti, Flavio S.

2010-05-01

With increasing awareness of oceanic geohazards, submarine landslides are gaining wide attention because of their catastrophic impacts on both offshore infrastructures (e.g. pipelines, cables and platforms) and coastal areas (e.g. landslide-induced tsunamis). They also are of great interest because they can be directly related to primary trigger mechanisms including earthquakes, rapid sedimentation, gas release, glacial and tidal loading, wave action, or clathrate dissociation, many of which represent potential geohazards themselves. In active tectonic environments, for instance, subaquatic landslide deposits can be used to make inferences regarding the hazard derived from seismic activity. Enormous scientific and economic efforts are thus being undertaken to better determine and quantify causes and effects of natural hazards related to subaquatic landslides. In order to achieve this fundamental goal, the detailed study of past events, the assessment of their recurrence intervals and the quantitative reconstruction of magnitudes and intensities of both causal and subsequent processes and impacts are key requirements. Here we present data and results from a study using fjord-type Lake Lucerne in central Switzerland as a "model ocean" to test a new concept for the assessment of regional seismic and tsunami hazard by basin-wide mapping of critical slope stability conditions for subaquatic landslide initiation. Previously acquired high-resolution bathymetry and reflection seismic data as well as sedimentological and in situ geotechnical data, provide a comprehensive data base to investigate subaquatic landslides and related geohazards. Available data are implemented into a basin-wide slope model. In a Geographic Information System (GIS)-framework, a pseudo-static limit equilibrium infinite slope stability equation is solved for each model point representing reconstructed slope conditions at different times in the past, during which earthquake-triggered landslides

Proceedings of the twenty-fourth water reactor safety information meeting. Volume 3: PRA and HRA; Probabilistic seismic hazard assessment and seismic siting criteria

Energy Technology Data Exchange (ETDEWEB)

Monteleone, S. [comp.] [Brookhaven National Lab., Upton, NY (United States)

1997-02-01

This three-volume report contains papers presented at the Twenty-Fourth Water Reactor Safety Information Meeting held at the Bethesda Marriott Hotel, Bethesda, Maryland, October 21--23, 1996. The papers are printed in the order of their presentation in each session and describe progress and results of programs in nuclear safety research conducted in this country and abroad. Foreign participation in the meeting included papers presented by researchers from Czech Republic, Finland, France, Japan, Norway, Russia and United Kingdom. This volume is divided into the following sections: PRA and HRA and probabilistic seismic hazard assessment and seismic siting criteria. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.

Proceedings of the twenty-fourth water reactor safety information meeting. Volume 3: PRA and HRA; Probabilistic seismic hazard assessment and seismic siting criteria

International Nuclear Information System (INIS)

Monteleone, S.

1997-02-01

This three-volume report contains papers presented at the Twenty-Fourth Water Reactor Safety Information Meeting held at the Bethesda Marriott Hotel, Bethesda, Maryland, October 21--23, 1996. The papers are printed in the order of their presentation in each session and describe progress and results of programs in nuclear safety research conducted in this country and abroad. Foreign participation in the meeting included papers presented by researchers from Czech Republic, Finland, France, Japan, Norway, Russia and United Kingdom. This volume is divided into the following sections: PRA and HRA and probabilistic seismic hazard assessment and seismic siting criteria. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database

Seismic hazard analysis of nuclear installations in France. Current practice and research

Energy Technology Data Exchange (ETDEWEB)

Mohammadioun, B [CEA Centre d` Etudes de Fontenay-aux-Roses, 92 (France). Inst. de Protection et de Surete Nucleaire

1997-03-01

The methodology put into practice in France for the evaluation of seismic hazard on the sites of nuclear facilities is founded on data assembled country-wide over the past 15 years, in geology, geophysics and seismology. It is appropriate to the regional seismotectonic context (interplate), characterized notably by diffuse seismicity. Extensive use is made of information drawn from historical seismicity. The regulatory practice described in the RFS I.2.c is reexamined periodically and is subject to up-dating so as to take advantage of new earthquake data and of the results gained from research work. Acquisition of the basic data, such as the identification of active faults and the quantification of site effect, which will be needed to achieve improved preparedness versus severe earthquake hazard in the 21st century, will necessarily be the fruit of close international cooperation and collaboration, which should accordingly be actively promoted. (J.P.N.)

Seismic hazard analysis of nuclear installations in France. Current practice and research

International Nuclear Information System (INIS)

Mohammadioun, B.

1997-01-01

The methodology put into practice in France for the evaluation of seismic hazard on the sites of nuclear facilities is founded on data assembled country-wide over the past 15 years, in geology, geophysics and seismology. It is appropriate to the regional seismotectonic context (interplate), characterized notably by diffuse seismicity. Extensive use is made of information drawn from historical seismicity. The regulatory practice described in the RFS I.2.c is reexamined periodically and is subject to up-dating so as to take advantage of new earthquake data and of the results gained from research work. Acquisition of the basic data, such as the identification of active faults and the quantification of site effect, which will be needed to achieve improved preparedness versus severe earthquake hazard in the 21st century, will necessarily be the fruit of close international cooperation and collaboration, which should accordingly be actively promoted. (J.P.N.)

Seismic risks posed by mine flooding

CSIR Research Space (South Africa)

Goldbach, OD

2009-09-01

Full Text Available are allowed to flood. Such flooding-induced seismicity can have significant environmental, social and economic consequences, and may endanger neighbouring mines and surface communities. While fluid-induced seismicity has been observed in other settings (e...

Setting the Stage for Harmonized Risk Assessment by Seismic Hazard Harmonization in Europe (SHARE)

Science.gov (United States)

Woessner, Jochen; Giardini, Domenico; SHARE Consortium

2010-05-01

Probabilistic seismic hazard assessment (PSHA) is arguably one of the most useful products that seismology can offer to society. PSHA characterizes the best available knowledge on the seismic hazard of a study area, ideally taking into account all sources of uncertainty. Results form the baseline for informed decision making, such as building codes or insurance rates and provide essential input to each risk assessment application. Several large scale national and international projects have recently been launched aimed at improving and harmonizing PSHA standards around the globe. SHARE (www.share-eu.org) is the European Commission funded project in the Framework Programme 7 (FP-7) that will create an updated, living seismic hazard model for the Euro-Mediterranean region. SHARE is a regional component of the Global Earthquake Model (GEM, www.globalquakemodel.org), a public/private partnership initiated and approved by the Global Science Forum of the OECD-GSF. GEM aims to be the uniform, independent and open access standard to calculate and communicate earthquake hazard and risk worldwide. SHARE itself will deliver measurable progress in all steps leading to a harmonized assessment of seismic hazard - in the definition of engineering requirements, in the collection of input data, in procedures for hazard assessment, and in engineering applications. SHARE scientists will create a unified framework and computational infrastructure for seismic hazard assessment and produce an integrated European probabilistic seismic hazard assessment (PSHA) model and specific scenario based modeling tools. The results will deliver long-lasting structural impact in areas of societal and economic relevance, they will serve as reference for the Eurocode 8 (EC8) application, and will provide homogeneous input for the correct seismic safety assessment for critical industry, such as the energy infrastructures and the re-insurance sector. SHARE will cover the whole European territory, the

An assessment of the low seismic risk of the inherently safe sodium advanced fast reactor (SAFR)

International Nuclear Information System (INIS)

Rutherford, P.D.

1988-01-01

A recent probabilistic risk assessment (PRA) of the sodium advanced fast reactor (SAFR) demonstrated the inherently low risk of advanced liquid-metal, pool-type fast reactors with inherent safety systems. As a result, it was recognized that external events, especially seismic events, may not only be a major contributor to risk (as shown in several LWR PRAs) but also may completely dominate the risk. Accordingly, a seismic risk assessment has been completed for SAFR, which resulted in a core damage frequency of 2 x 10 -7 /year and a large release frequency of 4 x 10 -9 /year. This paper reports that public health risk in terms of early fatality risk and latent fatality risk were also several orders of magnitude below the NRC safety goals and below recent LWR risks reported in NUREB/CR1150

An investigation of major influences on the seismic response of APR1400 reactor vessel internals - 15145

International Nuclear Information System (INIS)

Byun, Y.J.; Kim, J.G.; Sung, K.K.; Lee, D.H.

2015-01-01

This paper deals with 3 topics concerning the APR1400 reactor vessel internals (RVI) seismic analysis: nonlinear problems, approaches to account for uncertainties of seismic model, and dynamic responses to various seismic excitations. First, the noticeable nonlinear characteristics of the RVI seismic model are discussed, and the modeling methods for properly simulating the nonlinear behaviors of RVI under seismic loads are presented. By applying these methods to the seismic model, the seismic analysis can correctly predict the dynamic response of RVI. Next, two approaches to account for the uncertainties of seismic model are evaluated: the time history broadening method, and the sensitivity analysis based on NUREG-0800, Section 4.2, Appendix A. From the evaluation results, it is confirmed that the time history broadening method employed in the seismic analysis of APR1400 RVI sufficiently accounts for the uncertainty of seismic model. Finally, the response characteristics of APR1400 RVI to various seismic excitations are investigated. The seismic excitations corresponding to various soil profiles, including the effects of cracked and un-cracked concrete stiffness on the reactor containment building structure, are used as forcing functions. From this study, the effects of various site conditions on the dynamic response of APR1400 RVI are identified. As a result, the enveloped seismic responses obtained from this study will contribute to the development of RVI seismic design that covers a wide range of potential site conditions. (authors)

Seismic hazard assessment in the Catania and Siracusa urban areas (Italy) through different approaches

Science.gov (United States)

Panzera, Francesco; Lombardo, Giuseppe; Rigano, Rosaria

2010-05-01

, through the site approach, for Catania area can be interpreted in terms of greater damage historically observed at this town and its smaller distance from the seismogenic structures. On the other hand, the higher level of hazard found for Siracusa, throughout the Esteva-Cornell approach, could be a consequence of the features of such method which spreads out the intensities over a wide area. However, in SHA the use of a combined approach is recommended for a mutual validation of obtained results and any choice between the two approaches is strictly linked to the knowledge of the local seismotectonic features. References Albarello D. and Mucciarelli M.; 2002: Seismic hazard estimates using ill?defined macroseismic data at site. Pure Appl. Geophys., 159, 1289?1304. Cornell C.A.; 1968: Engineering seismic risk analysis. Bull. Seism. Soc. Am., 58(5), 1583-1606. D'Amico V. and Albarello D.; 2007: Codice per il calcolo della pericolosità sismica da dati di sito (freeware). Progetto DPC-INGV S1, http://esse1.mi.ingv.it/d12.html Esteva L.; 1967: Criterios para la construcción de espectros para diseño sísmico. Proceedings of XII Jornadas Sudamericanas de Ingeniería Estructural y III Simposio Panamericano de Estructuras, Caracas, 1967. Published later in Boletín del Instituto de Materiales y Modelos Estructurales, Universidad Central de Venezuela, No. 19. Ordaz M., Aguilar A. and Arboleda J.; 2007: CRISIS2007, Program for computing seismic hazard. Version 5.4, Mexico City: UNAM. SSHAC (Senior Seismic Hazard Analysis Committee); 1997: Recommendations for probabilistic seismic hazard analysis: guidance on uncertainty and use of experts. NUREG/CR-6372.

International ENEA/ISMES/ENS specialist meeting on 'On-site experimental verification of the seismic behaviour of nuclear reactor structures and components'. Proceedings

International Nuclear Information System (INIS)

1988-01-01

The seismic verification of nuclear plants is a subject of increasing interest in all the industrial countries, with respect to both the safety aspects and the impact of the seismic event on the design and the costs of a nuclear reactor. This topic is especially of great interest for a country like Italy, whose territory is unfortunately characterized by non - negligible seismicity: we remember, not too many years ago, the catastrophic earthquakes of Frioul and Irpinia, that caused thousands of dead people. The meeting aimed at establishing the state-of-the-art on on-site testing of nuclear reactors structures and components, with particular attention to experiences and research programmes concerning: methodologies of on-site tests and interpretation of the experimental data; seismic monitoring systems, recorded data, their use and interpretation; calibration and validation of numerical analyses. Six technical sessions were held, during which 23 high papers were presented and discussed, and six panel discussions were held (the importance of discussion was emphasized in the meeting). The technical contributions consisted of: an introduction paper, summarizing the seismic studies performed in Italy for PEC reactor and explaining the reasons why on-site tests had been performed on this reactor; 6 invited lectures, one for each of the countries that are more deeply involved in seismic analysis, providing the state-of-the-art on the topics of interest for the meeting; 16 contributed papers dealing with more specific technical items, related to the various countries and international organizations

International ENEA/ISMES/ENS specialist meeting on 'On-site experimental verification of the seismic behaviour of nuclear reactor structures and components'. Proceedings

Energy Technology Data Exchange (ETDEWEB)

NONE

1988-07-01

The seismic verification of nuclear plants is a subject of increasing interest in all the industrial countries, with respect to both the safety aspects and the impact of the seismic event on the design and the costs of a nuclear reactor. This topic is especially of great interest for a country like Italy, whose territory is unfortunately characterized by non - negligible seismicity: we remember, not too many years ago, the catastrophic earthquakes of Frioul and Irpinia, that caused thousands of dead people. The meeting aimed at establishing the state-of-the-art on on-site testing of nuclear reactors structures and components, with particular attention to experiences and research programmes concerning: methodologies of on-site tests and interpretation of the experimental data; seismic monitoring systems, recorded data, their use and interpretation; calibration and validation of numerical analyses. Six technical sessions were held, during which 23 high papers were presented and discussed, and six panel discussions were held (the importance of discussion was emphasized in the meeting). The technical contributions consisted of: an introduction paper, summarizing the seismic studies performed in Italy for PEC reactor and explaining the reasons why on-site tests had been performed on this reactor; 6 invited lectures, one for each of the countries that are more deeply involved in seismic analysis, providing the state-of-the-art on the topics of interest for the meeting; 16 contributed papers dealing with more specific technical items, related to the various countries and international organizations.

Current Practices in Defining Seismic Input for Nuclear Facilities

International Nuclear Information System (INIS)

2015-05-01

This report has been written in the framework of seismic subgroup of the OECD/NEA CSNI Working Group on Integrity and Ageing of Components and Structures (WGIAGE) to provide a brief review of current practices regarding the definition of the seismic input for design and reevaluation of nuclear power plants. It is taken for granted that, prior to conducting the seismic design of a nuclear facility, a seismic hazard analysis (SHA) has been conducted for the site where the facility is located. This provides some reference motions for defining those that will later be used as input for the dynamic analyses of the facility. The objective of the report is to clarify the current practices in various OECD Member States for defining the seismic input to be used in the dynamic calculations of NPPs, once the SHA results are already at hand. Current practices have been summarized for Canada, Czech Republic, Finland, France, Germany, Japan, Slovenia, South Korea, Spain, Sweden, The Netherlands, United Kingdom and United States. The main findings of the report are: a) The approaches followed by the regulatory bodies of OECD Member States differ substantially, certainly in relation with the consideration of site effects, but also in the probability level of the event that a nuclear facility should be required to withstand. b) In many countries a probabilistic approach is adopted for the design, in some cases combined with a deterministic one; in other cases, like France, Japan or South Korea, a deterministic approach is followed. c) The US and Japan have the more complete guidelines in relation with site effects. The former provide specific approaches for definition of the seismic input. The latter clearly recognizes the need to propagate the bedrock motion to foundation level, thereby introducing the site effect in some way. d) The definition of bedrock is very heterogeneous in the various countries, although this should not constitute a serious problem if the starting

Review of earthquake hazard assessments of plant sites at Paducah, Kentucky and Portsmouth, Ohio

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-03-01

Members of the US Geological Survey staff in Golden, Colorado, have reviewed the submissions of Lawrence Livermore National Laboratory (LLNL) staff and of Risk Engineering, Inc. (REI) (Golden, Colorado) for seismic hazard estimates for Department of Energy facilities at Portsmouth, Ohio, and Paducah, Kentucky. We reviewed the historical seismicity and seismotectonics near the two sites, and general features of the LLNL and EPRI/SOG methodologies used by LLNL and Risk Engineering respectively, and also the separate Risk Engineering methodology used at Paducah. We discussed generic issues that affect the modeling of both sites, and performed alternative calculations to determine sensitivities of seismic hazard results to various assumptions and models in an attempt to assign reasonable bounding values of the hazard. In our studies we find that peak acceleration values of 0.08 g for Portsmouth and 0.32 g for Paducah represent central values of the, ground motions obtained at 1000-year return periods. Peak accelerations obtained in the LLNL and Risk Engineering studies have medians near these values (results obtained using the EPRI/SOG methodology appear low at both sites), and we believe that these medians are appropriate values for use in the evaluation of systems, structures, and components for seismic structural integrity and for the seismic design of new and improved systems, structures, and components at Portsmouth and Paducah.

Review of earthquake hazard assessments of plant sites at Paducah, Kentucky, and Portsmouth, Ohio

International Nuclear Information System (INIS)

1992-03-01

Members of the US Geological Survey staff in Golden, Colorado, have reviewed the submissions of Lawrence Livermore National Laboratory (LLNL) staff and of Risk Engineering, Inc. (REI) (Golden, Colorado) for seismic hazard estimates for Department of Energy facilities at Portsmouth, Ohio, and Paducah, Kentucky. We reviewed the historical seismicity and seismotectonics near the two sites, and general features of the LLNL and EPRI/SOG methodologies used by LLNL and Risk Engineering respectively, and also the separate Risk Engineering methodology used at Paducah. We discussed generic issues that affect the modeling of both sites, and performed alternative calculations to determine sensitivities of seismic hazard results to various assumptions and models in an attempt to assign reasonable bounding values of the hazard. In our studies we find that peak acceleration values of 0.08 g for Portsmouth and 0.32 g for Paducah represent central values of the ground motions obtained at 1000-year return periods. Peak accelerations obtained in the LLNL and Risk Engineering studies have medians near these values (results obtained using the EPRI/SOG methodology appear low at both sites), and we believe that these medians are appropriate values for use in the evaluation of systems, structures, and components for seismic structural integrity and for the seismic design of new and improved systems, structures, and components at Portsmouth and Paducah

Review of earthquake hazard assessments of plant sites at Paducah, Kentucky and Portsmouth, Ohio

International Nuclear Information System (INIS)

1997-01-01

Members of the US Geological Survey staff in Golden, Colorado, have reviewed the submissions of Lawrence Livermore National Laboratory (LLNL) staff and of Risk Engineering, Inc. (REI) (Golden, Colorado) for seismic hazard estimates for Department of Energy facilities at Portsmouth, Ohio, and Paducah, Kentucky. We reviewed the historical seismicity and seismotectonics near the two sites, and general features of the LLNL and EPRI/SOG methodologies used by LLNL and Risk Engineering respectively, and also the separate Risk Engineering methodology used at Paducah. We discussed generic issues that affect the modeling of both sites, and performed alternative calculations to determine sensitivities of seismic hazard results to various assumptions and models in an attempt to assign reasonable bounding values of the hazard. In our studies we find that peak acceleration values of 0.08 g for Portsmouth and 0.32 g for Paducah represent central values of the, ground motions obtained at 1000-year return periods. Peak accelerations obtained in the LLNL and Risk Engineering studies have medians near these values (results obtained using the EPRI/SOG methodology appear low at both sites), and we believe that these medians are appropriate values for use in the evaluation of systems, structures, and components for seismic structural integrity and for the seismic design of new and improved systems, structures, and components at Portsmouth and Paducah

Seismic Site Effects from the Seafloor Motion Recorded by the Short-period Ocean Bottom Seismometers

Science.gov (United States)

Lin, J. Y.; Cheng, W. B.; Chin, S. J.; Hsu, S. K.; Dong, J. J.

2014-12-01

For decades, it has been mentioned that submarine slope failures are spatially linked to the presence of gas hydrates/gas-charged sediments. When triggered by earthquakes, oversteepen and instable sediments may prompt breakouts of the slopes containing gas hydrates and cause submarine landslides and tsunamis. Widely distributed BSRs have been observed in the area offshore of southwestern Taiwan where the active accretionary complex meets with the passive China continental margin. In the region, large or small scale landslides were also reported based on seismic interpretations. In order to clarify the link between earthquake, landslide and the presence of gas hydrate, we evaluate the response of seafloor sediments in regard to passive dynamic loads. Horizontal-to-vertical (H/V) spectral ratios are used to characterize the local sediment response. Ambient noise as well as distant earthquakes are used as generators of the passive dynamic loads. Based on this study, we aim to characterize the site in terms of its physical properties and the local site effect produced by shallow marine sediments. The results show that the maximum H/V ratios appeared in the range of 5-10 Hz, where the horizontal amplitudes increased by an order of magnitude relative to the vertical amplitude. The stations located in the northwestern part of study area were characterized by another relatively small peak at proximately 2 Hz, which may indicates the presence of a discontinuity of sediments. For most stations, the H/V ratios estimated based on the earthquake (i.e. strong input signal) and noise (background, micro-seismic noise) records were characterized by different pattern. No distinct peak is observed for the H/V pattern calculated during earthquakes. This phenomenon may suggest that no clear sedimentary boundary exist when a stronger motion applies. Estimating H/V spectral ratios of data recorded by the seven short period OBSs (Ocean Bottom Seismometer) deployed in the southwest Taiwan

Investigating effects of near fault rupture directivity on seismic hazard assessment of the site of Tehran Research Reactor (TRR)

Energy Technology Data Exchange (ETDEWEB)

Sepanloo, Kamran; Saberi, Reza [Nuclear Science and Technology Research Institute, Tehran (Iran, Islamic Republic of); Alinejad, Majid [Atomic Energy Organization of Iran, Tehran (Iran, Islamic Republic of); Bazarchi, Ehsan [Tabriz Univ. (Iran, Islamic Republic of)

2017-10-15

It is estimated that the occurrence of a major-earthquake in Tehran, Iran, which is not far-fetched, would face the country with a huge amount of collapsed structures, economical losses and fatalities. The issue becomes more important while the site of interest is attributed to the nuclear facilities and any under-estimation in predicting the design ground motion may cause a real disaster. In this study, using calculations coded in MATLAB, PSHA was conducted for the site of TRR. It was concluded that most of the hazard for considered site in a 10000-year period comes from distances lower than 20 km and considering rupture directivity effects of the North Tehran fault, as the nearest seismicity source to considered site, using narrowband method affected the response spectrum significantly. Therefore, it is necessary to incorporate the near fault rupture directivity effects into the higher levels of seismic hazard assessment attributed to important sites.

Investigating effects of near fault rupture directivity on seismic hazard assessment of the site of Tehran Research Reactor (TRR)

International Nuclear Information System (INIS)

Sepanloo, Kamran; Saberi, Reza; Alinejad, Majid; Bazarchi, Ehsan

2017-01-01

It is estimated that the occurrence of a major-earthquake in Tehran, Iran, which is not far-fetched, would face the country with a huge amount of collapsed structures, economical losses and fatalities. The issue becomes more important while the site of interest is attributed to the nuclear facilities and any under-estimation in predicting the design ground motion may cause a real disaster. In this study, using calculations coded in MATLAB, PSHA was conducted for the site of TRR. It was concluded that most of the hazard for considered site in a 10000-year period comes from distances lower than 20 km and considering rupture directivity effects of the North Tehran fault, as the nearest seismicity source to considered site, using narrowband method affected the response spectrum significantly. Therefore, it is necessary to incorporate the near fault rupture directivity effects into the higher levels of seismic hazard assessment attributed to important sites.

Third Quarter Hanford Seismic Report for Fiscal Year 2000

Energy Technology Data Exchange (ETDEWEB)

DC Hartshorn; SP Reidel; AC Rohay

2000-09-01

Hanford Seismic Monitoring provides an uninterrupted collection of high-quality raw and processed seismic data from the Hanford Seismic Network (HSN) for the U.S. Department of Energy and its con-tractors. Hanford Seismic Monitoring also locates and identifies sources of seismic activity and monitors changes in the historical pattern of seismic activity at the Hanford Site. The data are compiled, archived, and published for use by the Hanford Site for waste management, Natural Phenomena Hazards assessments, and engineering design and construction. In addition, the seismic monitoring organization works with the Hanford Site Emergency Services Organization to provide assistance in the event of a significant earthquake on the Hanford Site. The HSN and the Eastern Washington Regional Network (E WRN) consist of 42 individual sensor sites and 15 radio relay sites maintained by the Hanford Seismic Monitoring staff. The HSN uses 21 sites and the EWRN uses 36 sites; both networks share 16 sites. The networks have 46 combined data channels because Gable Butte and Frenchman Hills East are three-component sites. The reconfiguration of the telemetry and recording systems was completed during the first quarter. All leased telephone lines have been eliminated and radio telemetry is now used exclusively. For the HSN, there were 818 triggers on two parallel detection and recording systems during the third quarter of fiscal year (FY) 2000. Thirteen seismic events were located by the Hanford Seismic Network within the reporting region of 46-47{degree} N latitude and 119-120{degree} W longitude; 7 were earthquakes in the Columbia River Basalt Group, 1 was an earthquake in the pre-basalt sediments, and 5 were earthquakes in the crystalline basement. Three earthquakes occurred in known swarm areas, and 10 earthquakes were random occurrences. No earthquakes triggered the Hanford Strong Motion Accelerometers during the third quarter of FY 2000.

Investigation of Nonlinear Site Response and Seismic Compression from Case History Analysis and Laboratory Testing

Science.gov (United States)

Yee, Eric

In this thesis I address a series of issues related to ground failure and ground motions during earthquakes. A major component is the evaluation of cyclic volumetric strain behavior of unsaturated soils, more commonly known as seismic compression, from advanced laboratory testing. Another major component is the application of nonlinear and equivalent linear ground response analyses to large-strain problems involving highly nonlinear dynamic soil behavior. These two components are merged in the analysis of a truly unique and crucial field case history of nonlinear site response and seismic compression. My first topic concerns dynamic soil testing for relatively small strain dynamic soil properties such as threshold strains, gammatv. Such testing is often conducted using specialized devices such as dual-specimen simple-shear, as devices configured for large strain testing produce noisy signals in the small strain range. Working with a simple shear device originally developed for large-strain testing, I extend its low-strain capabilities by characterizing noisy signals and utilizing several statistical methods to extract meaningful responses in the small strain range. I utilize linear regression of a transformed variable to estimate the cyclic shear strain from a noisy signal and the confidence interval on its amplitude. I utilize Kernel regression with the Nadaraya-Watson estimator and a Gaussian kernel to evaluate vertical strain response. A practical utilization of these techniques is illustrated by evaluating threshold shear strains for volume change with a procedure that takes into account uncertainties in the measured shear and vertical strains. My second topic concerns the seismic compression characteristics of non-plastic and low-plasticity silty sands with varying fines content (10 ≤ FC ≤ 60%). Simple shear testing was performed on various sand-fines mixtures at a range of modified Proctor relative compaction levels ( RC) and degrees-of-saturation (S

The application of seismic risk-benefit analysis to land use planning in Taipei City.

Science.gov (United States)

Hung, Hung-Chih; Chen, Liang-Chun

2007-09-01

In the developing countries of Asia local authorities rarely use risk analysis instruments as a decision-making support mechanism during planning and development procedures. The main purpose of this paper is to provide a methodology to enable planners to undertake such analyses. We illustrate a case study of seismic risk-benefit analysis for the city of Taipei, Taiwan, using available land use maps and surveys as well as a new tool developed by the National Science Council in Taiwan--the HAZ-Taiwan earthquake loss estimation system. We use three hypothetical earthquakes to estimate casualties and total and annualised direct economic losses, and to show their spatial distribution. We also characterise the distribution of vulnerability over the study area using cluster analysis. A risk-benefit ratio is calculated to express the levels of seismic risk attached to alternative land use plans. This paper suggests ways to perform earthquake risk evaluations and the authors intend to assist city planners to evaluate the appropriateness of their planning decisions.

Nuclear installations sites safety

International Nuclear Information System (INIS)

Barber, P.; Candes, P.; Duclos, P.; Doumenc, A.; Faure, J.; Hugon, J.; Mohammadioun, B.

1988-11-01

This report is divided into ten parts bearing: 1 Safety analysis procedures for Basis Nuclear Installations sites (BNI) in France 2 Site safety for BNI in France 3 Industrial and transport activities risks for BNI in France 4 Demographic characteristics near BNI sites in France 5 Meteorologic characteristics of BNI sites in France 6 Geological aspects near the BNI sites in France 7 Seismic studies for BNI sites in France 8 Hydrogeological aspects near BNI sites in France 9 Hydrological aspects near BNI sites in France 10 Ecological and radioecological studies of BNI sites in France [fr

Development of component failure data for seismic risk analysis

International Nuclear Information System (INIS)

Fray, R.R.; Moulia, T.A.

1981-01-01

This paper describes the quantification and utilization of seismic failure data used in the Diablo Canyon Seismic Risk Study. A single variable representation of earthquake severity that uses peak horizontal ground acceleration to characterize earthquake severity was employed. The use of a multiple variable representation would allow direct consideration of vertical accelerations and the spectral nature of earthquakes but would have added such complexity that the study would not have been feasible. Vertical accelerations and spectral nature were indirectly considered because component failure data were derived from design analyses, qualification tests and engineering judgment that did include such considerations. Two types of functions were used to describe component failure probabilities. Ramp functions were used for components, such as piping and structures, qualified by stress analysis. 'Anchor points' for ramp functions were selected by assuming a zero probability of failure at code allowable stress levels and unity probability of failure at ultimate stress levels. The accelerations corresponding to allowable and ultimate stress levels were determined by conservatively assuming a linear relationship between seismic stress and ground acceleration. Step functions were used for components, such as mechanical and electrical equipment, qualified by testing. Anchor points for step functions were selected by assuming a unity probability of failure above the qualification acceleration. (orig./HP)

Current status of ground motions evaluation in seismic design guide for nuclear power facilities. Investigation on IAEA and US.NRC

International Nuclear Information System (INIS)

Nakajima, Masato; Ito, Hiroshi; Hirata, Kazuta

2009-01-01

Recently, IAEA (International Atomic Energy Agency) and US.NRC (US. Nuclear Regulatory Commission) published several standards and technical reports on seismic design and safety evaluation for nuclear power facilities. This report summarizes the current status of the international guidelines on seismic design and safety evaluation for nuclear power facilities in order to explore the future research topics. The main results obtained are as follows: 1 IAEA: (1) In the safety standard series, two levels are defined as seismic design levels, and design earthquake ground motion is determined corresponding to each seismic design level. (2) A new framework on seismic design which consists of conventional deterministic method and risk-based method is discussed in the technical report although the framework is not adopted in the safety guidelines. 2 USA: (1) US.NRC discusses a performance-based seismic design framework which has been originally developed by the private organization (American Society of Civil Engineers). (2) Design earthquakes and earthquake ground motion are mainly evaluated and determined based on probabilistic seismic hazard evaluations. 3 Future works: It should be emphasized that IAEA and US.NRC have investigated the implementation of risk-based concept into seismic design. The implementation of risk-based concept into regulation and seismic design makes it possible to consider various uncertainties and to improve accountability. Therefore, we need to develop the methods for evaluating seismic risk of structures, and to correlate seismic margin and seismic risk quantitatively. Moreover, the probabilistic method of earthquake ground motions, that is required in the risk-based design, should be applied to sites in Japan. (author)

Third Quarter Hanford Seismic Report for Fiscal Year 2005

Energy Technology Data Exchange (ETDEWEB)

Reidel, Steve P.; Rohay, Alan C.; Hartshorn, Donald C.; Clayton, Ray E.; Sweeney, Mark D.

2005-09-01

Hanford Seismic Monitoring provides an uninterrupted collection of high-quality raw and processed seismic data from the Hanford Seismic Network for the U.S. Department of Energy and its contractors. Hanford Seismic Monitoring also locates and identifies sources of seismic activity and monitors changes in the historical pattern of seismic activity at the Hanford Site. The data are compiled, archived, and published for use by the Hanford Site for waste management, Natural Phenomena Hazards assessments, and engineering design and construction. In addition, the seismic monitoring organization works with the Hanford Site Emergency Services Organization to provide assistance in the event of a significant earthquake on the Hanford Site. The Hanford Seismic Network and the Eastern Washington Regional Network consist of 41 individual sensor sites and 15 radio relay sites maintained by the Hanford Seismic Monitoring staff. For the Hanford Seismic Network, there were 337 triggers during the third quarter of fiscal year 2005. Of these triggers, 20 were earthquakes within the Hanford Seismic Network. The largest earthquake within the Hanford Seismic Network was a magnitude 1.3 event May 25 near Vantage, Washington. During the third quarter, stratigraphically 17 (85%) events occurred in the Columbia River basalt (approximately 0-5 km), no events in the pre-basalt sediments (approximately 5-10 km), and three (15%) in the crystalline basement (approximately 10-25 km). During the first quarter, geographically five (20%) earthquakes occurred in swarm areas, 10 (50%) earthquakes were associated with a major geologic structure, and 5 (25%) were classified as random events.

Seismic Hazard Assessment for a Characteristic Earthquake Scenario: Probabilistic-Deterministic Method

Science.gov (United States)

mouloud, Hamidatou

2016-04-01

The objective of this paper is to analyze the seismic activity and the statistical treatment of seismicity catalog the Constantine region between 1357 and 2014 with 7007 seismic event. Our research is a contribution to improving the seismic risk management by evaluating the seismic hazard in the North-East Algeria. In the present study, Earthquake hazard maps for the Constantine region are calculated. Probabilistic seismic hazard analysis (PSHA) is classically performed through the Cornell approach by using a uniform earthquake distribution over the source area and a given magnitude range. This study aims at extending the PSHA approach to the case of a characteristic earthquake scenario associated with an active fault. The approach integrates PSHA with a high-frequency deterministic technique for the prediction of peak and spectral ground motion parameters in a characteristic earthquake. The method is based on the site-dependent evaluation of the probability of exceedance for the chosen strong-motion parameter. We proposed five sismotectonique zones. Four steps are necessary: (i) identification of potential sources of future earthquakes, (ii) assessment of their geological, geophysical and geometric, (iii) identification of the attenuation pattern of seismic motion, (iv) calculation of the hazard at a site and finally (v) hazard mapping for a region. In this study, the procedure of the earthquake hazard evaluation recently developed by Kijko and Sellevoll (1992) is used to estimate seismic hazard parameters in the northern part of Algeria.

Seismic changes industry

International Nuclear Information System (INIS)

Taylor, G.

1992-01-01

This paper discusses the growth in the seismic industry as a result of the recent increases in the foreign market. With the decline of communism and the opening of Latin America to exploration, seismic teams have moved out into these areas in support of the oil and gas industry. The paper goes on to discuss the improved technology available for seismic resolution and the subsequent use of computers to field-proof the data while the seismic team is still on-site. It also discusses the effects of new computer technology on reducing the amount of support staff that is required to both conduct and interpret seismic information

Study of the spectral ratios derived from seismic refraction data for evaluation of the local seismic effects in six sites between south of Mizil and west of Giurgiu

International Nuclear Information System (INIS)

Raileanu, Victor

2002-01-01

An analysis of spectral ratios derived from seismic records along the seismic refraction line Vrancea 99 is performed for six sites located south of Mizil. Records generated by four big shots (300 - 900 Kg charge) are analyzed in each size and 24 curves of spectral ratios are obtained. A first sight shows that the spectral ratios depend not only on the local geological and physical conditions but also on epicentral distance from source to the site as well as the magnitude of the released energy by the seismic source. Nevertheless it is noticed that the frequency windows with the high spectral ratios are about the same regardless of the position and magnitude of the source which suggests the influence of the local conditions. Generally, the sites from the north of Bucharest city, namely Parepa Rusani, Gradistea and Pantelimon show low spectral ratios while the southern sites, Singureni, Stanesti and Gaujani present higher spectral ratios in the frequency window from 0.1 - 10 Hz. The northern group of sites presents a diminution of the spectral ratios from about 2 Hz (0.5 s) to 7 - 8 Hz ( 0.14 - 0.12 s). The southern group has the peaks of spectral ratios within a better individualized frequency window, 3-6 Hz (0.33 - 0.16 s). A secondary peak is around 12 - 13 Hz (∼ 0.08 s). Such quite high resonance frequencies are generated by the shallow layers with thicknesses from a few tens meters (0.08 s corresponds to 32 m thickness) to one - two hundred meters (0.16/0.33/0.5 s → 60, 120, 190 m thickness). (author)

Seismic hazard assessment in intra-plate areas and backfitting

International Nuclear Information System (INIS)

Asmis, G.J.K.; Eng, P.

2001-01-01

Typically, fuel cycle facilities have been constructed over a 40 year time period incorporating various ages of seismic design provisions ranging from no specific seismic requirements to the life safety provisions normally incorporated in national building codes through to the latest seismic nuclear codes that provide not only for structural robustness but also include operational requirements for continued operation of essential safety functions. The task is to ensure uniform seismic risk in all facilities. Since the majority of the fuel cycle infrastructure has been built the emphasis is on re-evaluation and backfitting. The wide range of facilities included in the fuel cycle and the vastly varying hazard to safety, health and the environment suggest a performance based approach. This paper presents such an approach, placed in an intra-plate setting of a Stable Continental Region (SCR) typical to that found in Eastern Canada. (author)

Derivation of site-specific relationships between hydraulic parameters and p-wave velocities based on hydraulic and seismic tomography

Energy Technology Data Exchange (ETDEWEB)

Brauchler, R.; Doetsch, J.; Dietrich, P.; Sauter, M.

2012-01-10

In this study, hydraulic and seismic tomographic measurements were used to derive a site-specific relationship between the geophysical parameter p-wave velocity and the hydraulic parameters, diffusivity and specific storage. Our field study includes diffusivity tomograms derived from hydraulic travel time tomography, specific storage tomograms, derived from hydraulic attenuation tomography, and p-wave velocity tomograms, derived from seismic tomography. The tomographic inversion was performed in all three cases with the SIRT (Simultaneous Iterative Reconstruction Technique) algorithm, using a ray tracing technique with curved trajectories. The experimental set-up was designed such that the p-wave velocity tomogram overlaps the hydraulic tomograms by half. The experiments were performed at a wellcharacterized sand and gravel aquifer, located in the Leine River valley near Göttingen, Germany. Access to the shallow subsurface was provided by direct-push technology. The high spatial resolution of hydraulic and seismic tomography was exploited to derive representative site-specific relationships between the hydraulic and geophysical parameters, based on the area where geophysical and hydraulic tests were performed. The transformation of the p-wave velocities into hydraulic properties was undertaken using a k-means cluster analysis. Results demonstrate that the combination of hydraulic and geophysical tomographic data is a promising approach to improve hydrogeophysical site characterization.

Risk assessment to determine the advisability of seismic trip systems

International Nuclear Information System (INIS)

Cummings, G.E.; Wells, J.E.

1977-01-01

Seismic trip (scram) systems have been used for many years on certain research, test, and production reactors, but not on commercial power reactors. An assessment is made of the risks associated with the presence and absence of such trip systems on power reactors. An attempt was made to go beyond the reactor per se and to consider the risks to society as a whole; for example, the advantages of tripping to avoid an earthquake-caused accident were weighed against the disadvantages associated with interrupting electric power in a time when it would be needed for emergency services. The comparative risk assessment was performed by means of fault tree analysis

Japanese-South African collaboration to mitigate seismic risks in deep gold mines

CSIR Research Space (South Africa)

Ogasawara, H

2009-09-01

Full Text Available Japanese-South African collaborative project entitled "Observational study to mitigate seismic risks in mines". The project will build on previous studies carried out by Japanese seismologists in South African mines, and will develop human and instrumental...

Development and seismic evaluation of the seismic monitoring analysis system for HANARO

International Nuclear Information System (INIS)

Ryu, J. S.; Youn, D. B.; Kim, H. G.; Woo, J. S.

2003-01-01

Since the start of operation, the seismic monitoring system has been utilized for monitoring an earthquake at the HANARO site. The existing seismic monitoring system consists of field sensors and monitoring panel. The analog-type monitoring system with magnetic tape recorder is out-of-date model. In addition, the disadvantage of the existing system is that it does not include signal-analyzing equipment. Therefore, we have improved the analog seismic monitoring system except the field sensors into a new digital Seismic Monitoring Analysis System(SMAS) that can monitor and analyze earthquake signals. To achieve this objective for HANARO, the digital type hardware of the SMAS has been developed. The seismic monitoring and analysis programs that can provide rapid and precise information for an earthquake were developed. After the installation of the SMAS, we carried out the Site Acceptance Test (SAT) to confirm the functional capability of the newly developed system. The results of the SAT satisfy the requirements of the fabrication technical specifications. In addition, the seismic characteristics and structural integrity of the SMAS were evaluated. The results show that the cabinet of SMAS can withstand the effects of seismic loads and remain functional. This new SMAS is operating in the HANARO instrument room to acquire and analyze the signal of an earthquake

Revised seismic hazard map for the Kyrgyz Republic

Science.gov (United States)

Fleming, Kevin; Ullah, Shahid; Parolai, Stefano; Walker, Richard; Pittore, Massimiliano; Free, Matthew; Fourniadis, Yannis; Villiani, Manuela; Sousa, Luis; Ormukov, Cholponbek; Moldobekov, Bolot; Takeuchi, Ko

2017-04-01

As part of a seismic risk study sponsored by the World Bank, a revised seismic hazard map for the Kyrgyz Republic has been produced, using the OpenQuake-engine developed by the Global Earthquake Model Foundation (GEM). In this project, an earthquake catalogue spanning a period from 250 BCE to 2014 was compiled and processed through spatial and temporal declustering tools. The territory of the Kyrgyz Republic was divided into 31 area sources defined based on local seismicity, including a total area covering 200 km from the border. The results are presented in terms of Peak Ground Acceleration (PGA). In addition, macroseismic intensity estimates, making use of recent intensity prediction equations, were also provided, given that this measure is still widely used in Central Asia. In order to accommodate the associated epistemic uncertainty, three ground motion prediction equations were used in a logic tree structure. A set of representative earthquake scenarios were further identified based on historical data and the nature of the considered faults. The resulting hazard map, as expected, follows the country's seismicity, with the highest levels of hazard in the northeast, south and southwest of the country, with an elevated part around the centre. When considering PGA, the hazard is slightly greater for major urban centres than in previous works (e.g., Abdrakhmatov et al., 2003), although the macroseismic intensity estimates are less than previous studies, e.g., Ulomov (1999). For the scenario assessments, the examples that most affect the urban centres assessed are the Issyk Ata fault (in particular for Bishkek), the Chilik and Kemin faults (in particular Balykchy and Karakol), the Ferghana Valley fault system (in particular Osh, Jalah-Abad and Uzgen), the Oinik Djar fault (Naryn) and the central and western Talas-Ferghanafaukt (Talas). Finally, while site effects (in particular, those dependent on the upper-most geological structure) have an obvious effect on the

Seismic risk mitigation in deep level South African mines by state of the art underground monitoring - Joint South African and Japanese study

Science.gov (United States)

Milev, A.; Durrheim, R.; Nakatani, M.; Yabe, Y.; Ogasawara, H.; Naoi, M.

2012-04-01

Two underground sites in a deep level gold mine in South Africa were instrumented by the Council for Scientific and Industrial Research (CSIR) with tilt meters and seismic monitors. One of the sites was also instrumented by JApanese-German Underground Acoustic emission Research in South Africa (JAGUARS) with a small network, approximately 40m span, of eight Acoustic Emission (AE) sensors. The rate of tilt, defined as quasi-static deformations, and the seismic ground motion, defined as dynamic deformations, were analysed in order to understand the rock mass behavior around deep level mining. In addition the high frequency AE events recorded at hypocentral distances of about 50m located at 3300m below the surface were analysed. A good correspondence between the dynamic and quasi-static deformations was found. The rate of coseismic and aseismic tilt, as well as seismicity recorded by the mine seismic network, are approximately constant until the daily blasting time, which takes place from about 19:30 until shortly before 21:00. During the blasting time and the subsequent seismic events the coseismic and aseismic tilt shows a rapid increase.Much of the quasi-static deformation, however, occurs independently of the seismic events and was described as 'slow' or aseismic events. During the monitoring period a seismic event with MW 2.2 occurred in the vicinity of the instrumented site. This event was recorded by both the CSIR integrated monitoring system and JAGUARS acoustic emotion network. The tilt changes associated with this event showed a well pronounced after-tilt. The aftershock activities were also well recorded by the acoustic emission and the mine seismic networks. More than 21,000 AE aftershocks were located in the first 150 hours after the main event. Using the distribution of the AE events the position of the fault in the source area was successfully delineated. The distribution of the AE events following the main shock was related to after tilt in order to

Overview of seismic margin insights gained from seismic PRA results

International Nuclear Information System (INIS)

Kennedy, R.P.; Sues, R.H.; Campbell, R.D.

1986-01-01

This paper presents the findings of a study conducted under NRC and EPRI sponsorship in which published seismic PRAs were reviewed in order to gain insight to the seismic margins inherent in existing nuclear plants. The approach taken was to examine the fragilities of those components which have been found to be dominant contributors to seismic risk at plants in low-to-moderate seismic regions (SSE levels between 0.12g and 0.25g). It is concluded that there is significant margin inherent in the capacity of most critical components above the plant design basis. For ground motions less than about 0.3g, the predominant sources of seismic risk are loss of offsite power coupled with random failure of the emergency diesels, non-recoverable circuit breaker trip due to relay chatter, unanchored equipment, unreinforced non-load bearing block walls, vertical water storage tanks, systems interactions and possibly soil liquefaction. Recommendations as to which components should be reviewed in seismic margin studies for margin earthquakes less than 0.3g, between 0.3g and 0.5g, and greater than 0.5g, developed by the NRC expert panel on the quantification of seismic margins (based on the review of past PRA data, earthquake experience data, and their own personal experience) are presented

The risks to miners, mines, and the public posed by large seismic events in the gold mining districts of South Africa

CSIR Research Space (South Africa)

Durrheim, RJ

2006-10-01

Full Text Available are incorporating the risks of seismicity in their disaster management plans, and Johannesburg is urged to do likewise. Some buildings are considered vulnerable to damage by large seismic events, posing safety and financial risks....

A Wide Area Risk Assessment Framework for Underwater Military Munitions Response

Science.gov (United States)

Holland, K. T.; Calantoni, J.

2017-12-01

Our objective was to develop a prototype statistical framework supporting Wide Area Assessment and Remedial Investigation decisions relating to the risk of unexploded ordnance and other military munitions concentrated in underwater environments. Decision making involving underwater munitions is inherently complex due to the high degree of uncertainty in the environmental conditions that force munitions responses (burial, decay, migration, etc.) and associated risks to the public. The prototype framework provides a consistent approach to accurately delineating contaminated areas at underwater munitions sites through the estimation of most probable concentrations. We adapted existing deterministic models and environmental data services for use within statistical modules that allowed the estimation of munition concentration given historic site information and environmental attributes. Ultimately this risk surface can be used to evaluate costs associated with various remediation approaches (e.g. removal, monitoring, etc.). Unfortunately, evaluation of the assessment framework was limited due to the lack of enduser data services from munition site managers. Of the 450 U.S. sites identified as having potential contamination with underwater munitions, assessment of available munitions information (including historic firing or disposal records, and recent ground-truth munitions samples) indicated very limited information in the databases. Example data types include the most probable munition types, approximate firing / disposal dates and locations, and any supportive munition survey or sampling results. However the overall technical goal to integrate trained statistical belief networks with detailed geophysical knowledge of sites, of sensors and of the underwater environment was demonstrated and should allow probabilistic estimates of the most likely outcomes and tradeoffs while managing uncertainty associated with military munitions response.

Seismic Risk of the Base Isolation System Protected by the Hard Stop

International Nuclear Information System (INIS)

Kim, Jung Han; Choi, In-Kil; Kim, Min Kyu

2015-01-01

The concept of base isolation is to permit the deformation of isolator for absorbing seismic input wave from the ground. In a nuclear power plant design, allowable shear deformation of isolators should be enough to absorb the displacement response by extended design basis (EDB) ground motions. However isolators cannot resist over its displacement capacity. So, the clearance of hard stop (CHS) needs to be set between the response of base isolation system excited by the EDB ground motion and the displacement capacity of isolators. The isolation system must survive with high confidence in any seismic accident because it is a non-redundant system. Therefore, the CHS should be determined carefully based on the failure risk of base isolation system considering the uncertainties of earthquake responses and isolator capacities. In this research, the fragility curve of isolation system and its failure risk were estimated. The procedure to calculate the acceleration based fragility curve of the isolation system was developed. The fragility curve and failure risk for example case was estimated and its result was compared with different isolator capacities

Seismic Risk of the Base Isolation System Protected by the Hard Stop

Energy Technology Data Exchange (ETDEWEB)

Kim, Jung Han; Choi, In-Kil; Kim, Min Kyu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2015-10-15

The concept of base isolation is to permit the deformation of isolator for absorbing seismic input wave from the ground. In a nuclear power plant design, allowable shear deformation of isolators should be enough to absorb the displacement response by extended design basis (EDB) ground motions. However isolators cannot resist over its displacement capacity. So, the clearance of hard stop (CHS) needs to be set between the response of base isolation system excited by the EDB ground motion and the displacement capacity of isolators. The isolation system must survive with high confidence in any seismic accident because it is a non-redundant system. Therefore, the CHS should be determined carefully based on the failure risk of base isolation system considering the uncertainties of earthquake responses and isolator capacities. In this research, the fragility curve of isolation system and its failure risk were estimated. The procedure to calculate the acceleration based fragility curve of the isolation system was developed. The fragility curve and failure risk for example case was estimated and its result was compared with different isolator capacities.

How to eliminate non-damaging earthquakes from the results of a probabilistic seismic hazard analysis (PSHA)-A comprehensive procedure with site-specific application

International Nuclear Information System (INIS)

Kluegel, Jens-Uwe

2009-01-01

The results of probabilistic seismic hazard analyses are frequently presented in terms of uniform hazard spectra or hazard curves with spectral accelerations as the output parameter. The calculation process is based on the evaluation of the probability of exceedance of specified acceleration levels without consideration of the damaging effects of the causative earthquakes. The same applies to the empirical attenuation equations for spectral accelerations used in PSHA models. This makes interpreting and using the results in engineering or risk applications difficult. Uniform hazard spectra and the associated hazard curves may contain a significant amount of contributions of weak, low-energy earthquakes not able to damage the seismically designed structures of nuclear power plants. For the development of realistic engineering designs and for realistic seismic probabilistic risk assessments (seismic PRA) it is necessary to remove the contribution of non-damaging earthquakes from the results of a PSHA. A detailed procedure for the elimination of non-damaging earthquakes based on the CAV (Cumulative Absolute Velocity)-filtering approach was developed and applied to the results of the large-scale PEGASOS probabilistic seismic hazard study for the site of the Goesgen nuclear power plant. The procedure considers the full scope of epistemic uncertainty and aleatory variability present in the PEGASOS study. It involves the development of a set of empirical correlations for CAV and the subsequent development of a composite distribution for the probability of exceedance of the damaging threshold of 0.16 gs. Additionally, a method was developed to measure the difference in the damaging effects of earthquakes of different strengths by the ratio of a power function of ARIAS-intensity or, in the ideal case, by the ratio of the square roots of the associated strong motion durations. The procedure was applied for the update of the Goesgen seismic PRA and for the confirmation of a

SEISMIC RISK CARTOGRAPHIC VISUALIZATION FOR CRISIS MANAGEMENT

Directory of Open Access Journals (Sweden)

Nina I. Frolova

2014-01-01

Full Text Available Earthquake loss estimations before future events and following strong earthquakesin emergency mode and their corresponding visualization are extremely important for properdecision on preventive measures and effective response in order to save lives and properties. The paper addresses the methodological issues of seismic risk and vulnerability assessment, mapping with GIS technology application. Requirements for simulation models,databases used at different levels, as well as ways of visualizations oriented for EmergencyManagement Agencies, as well federal and local authorities are discussed. Examples ofmapping at the different levels: global, country, region and urban one are given and theinfluence of input data uncertainties on the reliability of loss computations is analyzed.

Shear wave profiles from surface wave inversion: the impact of uncertainty on seismic site response analysis

International Nuclear Information System (INIS)

Boaga, J; Vignoli, G; Cassiani, G

2011-01-01

Inversion is a critical step in all geophysical techniques, and is generally fraught with ill-posedness. In the case of seismic surface wave studies, the inverse problem can lead to different equivalent subsoil models and consequently to different local seismic response analyses. This can have a large impact on an earthquake engineering design. In this paper, we discuss the consequences of non-uniqueness of surface wave inversion on seismic responses, with both numerical and experimental data. Our goal is to evaluate the consequences on common seismic response analysis in the case of different impedance contrast conditions. We verify the implications of inversion uncertainty, and consequently of data information content, on realistic local site responses. A stochastic process is used to generate a set of 1D shear wave velocity profiles from several specific subsurface models. All these profiles are characterized as being equivalent, i.e. their responses, in terms of a dispersion curve, are compatible with the uncertainty in the same surface wave data. The generated 1D shear velocity models are then subjected to a conventional one-dimensional seismic ground response analysis using a realistic input motion. While recent analyses claim that the consequences of surface wave inversion uncertainties are very limited, our test points out that a relationship exists between inversion confidence and seismic responses in different subsoils. In the case of regular and relatively smooth increase of shear wave velocities with depth, as is usual in sedimentary plains, our results show that the choice of a specific model among equivalent solutions strongly influences the seismic response. On the other hand, when the shallow subsoil is characterized by a strong impedance contrast (thus revealing a characteristic soil resonance period), as is common in the presence of a shallow bedrock, equivalent solutions provide practically the same seismic amplification, especially in the

Seismic fragility analyses

International Nuclear Information System (INIS)

Kostov, Marin

2000-01-01

In the last two decades there is increasing number of probabilistic seismic risk assessments performed. The basic ideas of the procedure for performing a Probabilistic Safety Analysis (PSA) of critical structures (NUREG/CR-2300, 1983) could be used also for normal industrial and residential buildings, dams or other structures. The general formulation of the risk assessment procedure applied in this investigation is presented in Franzini, et al., 1984. The probability of failure of a structure for an expected lifetime (for example 50 years) can be obtained from the annual frequency of failure, β E determined by the relation: β E ∫[d[β(x)]/dx]P(flx)dx. β(x) is the annual frequency of exceedance of load level x (for example, the variable x may be peak ground acceleration), P(fI x) is the conditional probability of structure failure at a given seismic load level x. The problem leads to the assessment of the seismic hazard β(x) and the fragility P(fl x). The seismic hazard curves are obtained by the probabilistic seismic hazard analysis. The fragility curves are obtained after the response of the structure is defined as probabilistic and its capacity and the associated uncertainties are assessed. Finally the fragility curves are combined with the seismic loading to estimate the frequency of failure for each critical scenario. The frequency of failure due to seismic event is presented by the scenario with the highest frequency. The tools usually applied for probabilistic safety analyses of critical structures could relatively easily be adopted to ordinary structures. The key problems are the seismic hazard definitions and the fragility analyses. The fragility could be derived either based on scaling procedures or on the base of generation. Both approaches have been presented in the paper. After the seismic risk (in terms of failure probability) is assessed there are several approaches for risk reduction. Generally the methods could be classified in two groups. The

Second Quarter Hanford Seismic Report for Fiscal Year 2000

International Nuclear Information System (INIS)

Hartshorn, D.C.; Reidel, S.P.; Rohay, A.C.

2000-01-01

Hanford Seismic Monitoring provides an uninterrupted collection of high-quality raw and processed seismic data from the Hanford Seismic Network (HSN) for the US Department of Energy and its contractors. Hanford Seismic Monitoring also locates and identifies sources of seismic activity and monitors changes in the historical pattern of seismic activity at the Hanford Site. The data are compiled, archived, and published for use by the Hanford Site for waste management, Natural Phenomena Hazards assessments, and engineering design and construction. In addition, the seismic monitoring organization works with the Hanford Site Emergency Services Organization to provide assistance in the event of a significant earthquake on the Hanford Site. The HSN and the Eastern Washington Regional Network (EWRN) consist of 42 individual sensor sites and 15 radio relay sites maintained by the Hanford Seismic Monitoring staff. The HSN uses 21 sites and the EWRN uses 36 sites; both networks share 16 sites. The networks have 46 combined data channels because Gable Butte and Frenchman Hills East are three-component sites. The reconfiguration of the telemetry and recording systems was completed during the first quarter. All leased telephone lines have been eliminated and radio telemetry is now used exclusively. For the HSN, there were 506 triggers on two parallel detection and recording systems during the second quarter of fiscal year (FY) 2000. Twenty-seven seismic events were located by the Hanford Seismic Network within the reporting region of 46--47degree N latitude and 119--120degree W longitude; 12 were earthquakes in the Columbia River Basalt Group, 2 were earthquakes in the pre-basalt sediments, 9 were earthquakes in the crystalline basement, and 5 were quarry blasts. Three earthquakes appear to be related to geologic structures, eleven earthquakes occurred in known swarm areas, and seven earthquakes were random occurrences. No earthquakes triggered the Hanford Strong Motion

Second Quarter Hanford Seismic Report for Fiscal Year 2000

Energy Technology Data Exchange (ETDEWEB)

DC Hartshorn; SP Reidel; AC Rohay

2000-07-17

Hanford Seismic Monitoring provides an uninterrupted collection of high-quality raw and processed seismic data from the Hanford Seismic Network (HSN) for the US Department of Energy and its contractors. Hanford Seismic Monitoring also locates and identifies sources of seismic activity and monitors changes in the historical pattern of seismic activity at the Hanford Site. The data are compiled, archived, and published for use by the Hanford Site for waste management, Natural Phenomena Hazards assessments, and engineering design and construction. In addition, the seismic monitoring organization works with the Hanford Site Emergency Services Organization to provide assistance in the event of a significant earthquake on the Hanford Site. The HSN and the Eastern Washington Regional Network (EWRN) consist of 42 individual sensor sites and 15 radio relay sites maintained by the Hanford Seismic Monitoring staff. The HSN uses 21 sites and the EWRN uses 36 sites; both networks share 16 sites. The networks have 46 combined data channels because Gable Butte and Frenchman Hills East are three-component sites. The reconfiguration of the telemetry and recording systems was completed during the first quarter. All leased telephone lines have been eliminated and radio telemetry is now used exclusively. For the HSN, there were 506 triggers on two parallel detection and recording systems during the second quarter of fiscal year (FY) 2000. Twenty-seven seismic events were located by the Hanford Seismic Network within the reporting region of 46--47{degree} N latitude and 119--120{degree} W longitude; 12 were earthquakes in the Columbia River Basalt Group, 2 were earthquakes in the pre-basalt sediments, 9 were earthquakes in the crystalline basement, and 5 were quarry blasts. Three earthquakes appear to be related to geologic structures, eleven earthquakes occurred in known swarm areas, and seven earthquakes were random occurrences. No earthquakes triggered the Hanford Strong Motion

First quarter Hanford seismic report for fiscal year 2000

Energy Technology Data Exchange (ETDEWEB)

DC Hartshorn; SP Reidel; AC Rohay

2000-02-23

Hanford Seismic Monitoring provides an uninterrupted collection of high-quality raw and processed seismic data from the Hanford Seismic Network (HSN) for the US Department of Energy and its contractors. Hanford Seismic Monitoring also locates and identifies sources of seismic activity and monitors changes in the historical pattern of seismic activity at the Hanford Site. The data are compiled, archived, and published for use by the Hanford Site for waste management, Natural Phenomena Hazards assessments, and engineering design and construction. In addition, the seismic monitoring organization works with the Hanford Site Emergency Services Organization to provide assistance in the event of a significant earthquake on the Hanford Site. The HSN and the Eastern Washington Regional Network (EWRN) consist of 42 individual sensor sites and 15 radio relay sites maintained by the Hanford Seismic Monitoring staff. The HSN uses 21 sites and the EW uses 36 sites; both networks share 16 sites. The networks have 46 combined data channels because Gable Butte and Frenchman Hills East are three-component sites. The reconfiguration of the telemetry and recording systems was completed during the first quarter. All leased telephone lines have been eliminated and radio telemetry is now used exclusively. For the HSN, there were 311 triggers on two parallel detection and recording systems during the first quarter of fiscal year (FY) 2000. Twelve seismic events were located by the Hanford Seismic Network within the reporting region of 46--47{degree}N latitude and 119--120{degree}W longitude; 2 were earthquakes in the Columbia River Basalt Group, 3 were earthquakes in the pre-basalt sediments, 9 were earthquakes in the crystalline basement, and 1 was a quarry blast. Two earthquakes appear to be related to a major geologic structure, no earthquakes occurred in known swarm areas, and 9 earthquakes were random occurrences. No earthquakes triggered the Hanford Strong Motion Accelerometers

Risk insights from seismic margin reviews

International Nuclear Information System (INIS)

Budnitz, R.J.

1990-01-01

This paper discusses the information that has been derived from the three seismic-margin reviews conducted so far, and the information that is potentially available from using the seismic-margin method more generally. There are two different methodologies for conducting seismic margin reviews of nuclear power plants, one developed under NRC sponsorship and one developed under sponsorship of the Electric Power Research Institute. Both methodologies will be covered in this paper. The paper begins with a summary of the steps necessary to complete a margin review, and will then outline the key technical difficulties that need to be addressed. After this introduction, the paper covers the safety and operational insights derived from the three seismic-margin reviews already completed: the NRC-sponsored review at Maine Yankee; the EPRI-sponsored review at Catawba; and the joint EPRI/NRC/utility effort at Hatch. The emphasis is on engineering insights, with attention to the aspects of the reviews that are easiest to perform and that provide the most readily available insights

A New Seismic Hazard Model for Mainland China

Science.gov (United States)

Rong, Y.; Xu, X.; Chen, G.; Cheng, J.; Magistrale, H.; Shen, Z. K.

2017-12-01

We are developing a new seismic hazard model for Mainland China by integrating historical earthquake catalogs, geological faults, geodetic GPS data, and geology maps. To build the model, we construct an Mw-based homogeneous historical earthquake catalog spanning from 780 B.C. to present, create fault models from active fault data, and derive a strain rate model based on the most complete GPS measurements and a new strain derivation algorithm. We divide China and the surrounding regions into about 20 large seismic source zones. For each zone, a tapered Gutenberg-Richter (TGR) magnitude-frequency distribution is used to model the seismic activity rates. The a- and b-values of the TGR distribution are calculated using observed earthquake data, while the corner magnitude is constrained independently using the seismic moment rate inferred from the geodetically-based strain rate model. Small and medium sized earthquakes are distributed within the source zones following the location and magnitude patterns of historical earthquakes. Some of the larger earthquakes are distributed onto active faults, based on their geological characteristics such as slip rate, fault length, down-dip width, and various paleoseismic data. The remaining larger earthquakes are then placed into the background. A new set of magnitude-rupture scaling relationships is developed based on earthquake data from China and vicinity. We evaluate and select appropriate ground motion prediction equations by comparing them with observed ground motion data and performing residual analysis. To implement the modeling workflow, we develop a tool that builds upon the functionalities of GEM's Hazard Modeler's Toolkit. The GEM OpenQuake software is used to calculate seismic hazard at various ground motion periods and various return periods. To account for site amplification, we construct a site condition map based on geology. The resulting new seismic hazard maps can be used for seismic risk analysis and management.

Second Quarter Hanford Seismic Report for Fiscal Year 2008

Energy Technology Data Exchange (ETDEWEB)

Rohay, Alan C.; Sweeney, Mark D.; Hartshorn, Donald C.; Clayton, Ray E.; Devary, Joseph L.

2008-06-26

The Hanford Seismic Assessment Program (HSAP) provides an uninterrupted collection of high-quality raw and processed seismic data from the Hanford Seismic Network for the U.S. Department of Energy and its contractors. The Hanford Seismic Assessment Team locates and identifies sources of seismic activity and monitors changes in the historical pattern of seismic activity at the Hanford Site. The data are compiled, archived, and published for use by the Hanford Site for waste management, natural phenomena hazards assessments, and engineering design and construction. In addition, the seismic monitoring organization works with the Hanford Site Emergency Services Organization to provide assistance in the event of a significant earthquake on the Hanford Site. The Hanford Seismic Network and the Eastern Washington Regional Network consist of 44 individual sensor sites and 15 radio relay sites maintained by the Hanford Seismic Assessment Team. For the Hanford Seismic Network, seven local earthquakes were recorded during the second quarter of fiscal year 2008. The largest event recorded by the network during the second quarter (February 3, 2008 - magnitude 2.3 Mc) was located northeast of Richland in Franklin County at a depth of 22.5 km. With regard to the depth distribution, two earthquakes occurred at shallow depths (less than 4 km, most likely in the Columbia River basalts), three earthquakes at intermediate depths (between 4 and 9 km, most likely in the pre-basalt sediments), and two earthquakes were located at depths greater than 9 km, within the crystalline basement. Geographically, five earthquakes occurred in swarm areas and two earthquakes were classified as random events.