- Advances on Seismic Hazard Assessment for Nuclear Facilities in the Central and Eastern United States
- A. Kammerer ; J.P. Ake ; C.G. Munson
- Book Title / Journal: Transactions Structural Mechanics in Reactor Technology (SMiRT) Conference, New Delhi, India
- Year: 2011
- Risk & Reliability
- Description
- The United States Nuclear Regulatory Commission (NRC) is currently sponsoring three key projects in the
area of probabilistic seismic hazard analysis (PSHA) for the central and eastern United States (CEUS). These projects will provide both new guidance describing the methods to be used for PSHA model development and actual updated seismic hazard assessment input models for the CEUS. These three projects, taken together, will result in an advanced regional PSHA model for critical facilities in the CEUS. They will also provide guidance, a welldocumented case study, and a significant number of useful research products, for undertaking PSHA in the US and globally, particularly in low-to-moderate seismicity regions. The first project is the nearly complete NRC Development Project for Practical Procedures for Implementing the Senior Seismic Hazard Analysis Committee (SSHAC) Guidelines and Updating Existing PSHAs. This research program will provide new implementation guidance to complement the original SSHAC guidelines (which are more formally known as NUREG/CR-6372 [1]). The new guidance will be documented in a new NUREG-series report currently in publication [2]. The NUREG provides guidance on the process used to develop Seismic Source Characterization (SSC) and Ground Motion Characterization (GMC) models. The second project, also nearly complete, is the Central and Eastern United States Seismic Source Characterization (CEUS SSC) for Nuclear Facilities Project. The CEUS SSC project will develop an advanced regional SSC model for approximately half of the United States. Lastly, the Next Generation Attenuation Relationships for Central and Eastern North America (NGA-East) Project will produce a suite of ground motion prediction equations that will form the basis for a new GMC model for low-to-moderate seismicity regions. Both the CEUS SSC project and the NGA-East project are being conducted as SSHAC Level 3 studies utilizing the original and new guidance.
PDF |
- Development of Implementation Guidance for SSHAC Level 3 & 4 Assessments used in Probabilistic Seismic Hazard Analyses for Nuclear Facilities
- A. Kammerer ; J.J. Bommer ; K.J. Coppersmith ; J.P. Ake
- Book Title / Journal: Transactions Structural Mechanics in Reactor Technology (SMiRT) Conference, New Delhi, India
- Year: 2011
- Risk & Reliability
- Description
- Seismic risk analysis for nuclear facilities requires probabilistic characterization of both the earthquake loading and the fragility of structures, systems and components, including consideration of the important contributors to uncertainty. The seismic hazard is determined through a probabilistic seismic hazard analysis (PSHA), which requires demonstration that the analyses have identified, quantified and incorporated both aleatory and epistemic uncertainties. The explicit characterization of uncertainty contributes to regulatory assurance by reducing the likelihood of unforeseen circumstances that have not been considered in the safety evaluation. Aleatory (random) variability in both the degree and timing of future seismicity and the ground shaking generated by specific earthquakes is accounted for through an integration process within PSHA. However, the associated epistemic (modeling or interpretation) uncertainty requires expert judgment and the use of logic trees. For critical facilities such as nuclear power plants (NPPs), the judgments of multiple experts are required to capture the complete distribution of technically defensible interpretations of the available Earth science data. The guidelines developed by the Senior Seismic Hazard Analysis Committee (SSHAC) as described in NUREG/CR-6372 provide a structured framework for conducting multiple expert assessments. Following 15 years of experience in applying the SSHAC guidelines for hazard studies for critical facilities, the US Nuclear Regulatory Commission (NRC) conducted a study of the lessons learned from practice. These lessons have now been distilled into a new US NRC NUREG-series report that provides additional practical guidance on implementing the SSHAC assessment process. The NUREG focuses primarily on the higher levels of SSHAC process (Levels 3 and 4), which are the most complex but provide a higher degree of regulatory assurance. The new NUREG gives clear guidance on the requirements for such studies, particularly SSHAC Level 3, which received relatively little attention in the original SSHAC guidelines (where the emphasis was on Level 4 studies). This NUREG also corrects the misperception that the most significant increase in complexity and likelihood of regulatory assurance occurs between Levels 3 and 4. The actual increase occurs between Levels 2 and 3. Indeed, for new nuclear sites the NRC makes no distinction between Level 3 and 4 studies, both of which are viewed as appropriate processes for conducting new PSHA studies.
PDF |
- Implementation Guidance for SSHAC Level 3 & 4 Processes
- K.J. Coppersmith ; J.J. Bommer ; A. Kammerer ; J.P. Ake
- Book Title / Journal: 10th International Probabilistic Safety Assessment & Management Conference
- Year: 2010
- Risk & Reliability
- Keywords: PSHA ; Epistemic uncertainty ; SSHAC
- Description
- Risk analysis for critical facilities requires a probabilistic assessment of the hazards that could affect the installation. The complexity of the processes that generate geological hazards such as seismic ground shaking and volcanic events is such that there is inevitably large uncertainty associated in the hazard assessment. This uncertainty is reflected in the range of legitimate technical interpretations made by informed technical experts based on the available data. Procedures to develop multiple expert assessments for seismic hazards in a structured process have been established in the SSHAC (Senior Seismic Hazard Analysis Committee) guidelines. The objective of the present paper is to capture and clarify the insights gained from performing a number of detailed assessments using the SSHAC approach over the past 10-15 years. Unlike classical expert elicitation, which attempts to extract information from independent experts, the SSHAC process encourages interaction amongst experts and fosters learning by the experts throughout the process, with the ultimate objective of capturing the full community distribution of technical interpretations. The SSHAC guidelines, written largely in abstract, have now been implemented in practice several times. In these studies valuable lessons have been learned, which are now being distilled into a new U.S. Nuclear Regulatory Commission NUREG-series report to provide practical guidance on implementing SSHAC processes for hazard assessments. A key lesson from these studies is that higher level SSHAC processes (Levels 3 and 4) which specify the use of a Participatory Peer Review Panel (PPRP), provide a higher degree of regulatory assurance and stability for the initial development of hazard models for safety-critical installations. Also, significant technically-informed participation by project sponsors and regulators throughout the process enhances the likelihood of regulatory acceptance.
PDF |
- Active Risk Management for Construction in Natural and Built Environments
- W.A. Marr
- Book Title / Journal: Geocomp Resources: Technical Papers
- Year: 2009
- Risk & Reliability
- Keywords: Risk Management ; Construction
PDF |
- Critical assessment of existing physical vulnerability estimation approaches for debris flows
- S. Sterlacchini ; J. Blahut ; S.O. Akbas
- Book Title / Journal: International Conference : Landslide Processes - From Geomophologic Mapping to Dynamic Modelling in Strassbourg France
- Year: 2009 , Series: Chapter 3: Landslide modeling - Methods for hazard and risk quantification
- Landslides ; Slope Stability ; Risk & Reliability
- Keywords: vulnerability functions
- Abstract
- An empirical vulnerability function is developed based on the data obtained from the 13 July 2008 debris flow in the village of Selvetta located in Italian Alps, (Valtellina, Lombardy Region). The obtained function is conpared to those reported in the literature. Large differences in the estimated vulnerabilities resulting from the use of different methods suggest that there is a need for further studies with additional data, to construct vulnerability functions that can be used with a higher confidence level.
PDF |
- Landslide investigation: from morphodynamic mapping to hazard assessement. A case-study in the Romanian Subcarpathians: Muscel catchment
- M. Micu ; D. Balteanu
- Book Title / Journal: International Conference : Landslide Processes - From Geomophologic Mapping to Dynamic Modelling in Strassbourg France
- Year: 2009 , Series: Chapter 3: Landslide modeling - Methods for hazard and risk quantification
- Landslides ; Slope Stability ; Risk & Reliability
- Keywords: risk assessment ; hazard assessment
PDF |
- Landslide risk modelling: an experience in northern Spain
- A. Cendrero ; J.R. Diaz ; A Gonzalez-Diez ; J. Remondo ; J Bonachea
- Book Title / Journal: International Conference : Landslide Processes - From Geomophologic Mapping to Dynamic Modelling in Strassbourg France
- Year: 2009 , Series: Chapter 3: Landslide modeling - Methods for hazard and risk quantification
- Landslides ; Slope Stability ; Risk & Reliability
- Keywords: risk assessment ; risk modeling
PDF |
- Evaluation of landslide susceptibility using multivariate statistical methods: a case study in the Prahova subcarpathians, Romania
- I. Savulescu ; B. Mihai ; I Sandric ; Z. Chitu
- Book Title / Journal: International Conference : Landslide Processes - From Geomophologic Mapping to Dynamic Modelling in Strassbourg France
- Year: 2009 , Series: Chapter 3: Landslide modeling - Methods for hazard and risk quantification
- Landslides ; Slope Stability ; Risk & Reliability
- Keywords: landslide susceptibility ; statistical methods
PDF |
- Evaluation of the susceptibility to failure of rocky slopes based on the SMR index
- O. Mavrouli ; J. Corominas
- Book Title / Journal: International Conference : Landslide Processes - From Geomophologic Mapping to Dynamic Modelling in Strassbourg France
- Year: 2009 , Series: Chapter 3: Landslide modeling - Methods for hazard and risk quantification
- Landslides ; Slope Stability ; Risk & Reliability
- Keywords: SMR index ; Rocky slopes
PDF |
- A soil and groundwater remediation program using risk analysis as a design tool
- R.C.M. Nobre ; M.M.M. Nobre
- 17th International Conference on Soil Mechanics and Geotechnical Engineering (Alexandria)
- Year: 2009
- Remediation Technology ; Risk & Reliability
PDF |
- Identifying and mitigating ground risk on large Water Industry Asset Management Programmes in the UK
- Malcolm Eddleston ; Elaine Holme
- 17th International Conference on Soil Mechanics and Geotechnical Engineering (Alexandria)
- Year: 2009
- Risk & Reliability
PDF |
- Research Information Letter 09-001: Preliminary Deterministic Analysis of Seismic Hazard at Diablo Canyon Nuclear Power Plant from Newly Identified "Shoreline Fault"
- A. Kammerer
- Book Title / Journal: US Nuclear Regulatory Commission (NRC)
- Year: 2009 , Series: Regulatory Guide (RG)1.100
- Risk & Reliability
- Description
- On November 14, 2008, the Pacific Gas & Electric (PG&E) Company informed the U.S. Nuclear
Regulatory Commission (NRC) that it had identified a zone of seismicity that may indicate a
previously unknown fault located offshore of the Diablo Canyon Nuclear Power Plant (DCNPP).
The licensee identified the potential fault as a result of a collaborative research program
between PG&E and the U.S. Geologic Survey (USGS)—the PG&E-USGS Cooperative
Research and Development Agreement (CRADA). This program, which focused on increasing
the understanding of tectonics in the region of the DCNPP, included both new geophysical field
studies and the application of advanced seismological techniques to small-magnitude recorded
earthquakes. Shortly after PG&E notified the NRC, it provided the Agency with sets of initial
scientific information related to the hypothesized fault (ML090690193, ML090690218), which
PG&E informally named the “Shoreline Fault.” In discussion with the NRC staff, the licensee
described its preliminary assessment that the hazard potential of the Shoreline Fault is bounded
by the current review ground motion spectrum for the facility.
Based on the initial information provided by PG&E and the USGS, NRC staff undertook a
preliminary review of possible implications of the potential Shoreline Fault to the DCNPP to
determine if an immediate safety concern existed for the facility. The purpose of this letter is to
expand on the Staff’s preliminary review with a more thorough discussion of the data, the
parameters used, and the basis for the Staff’s initial conclusions. The data used in this review
is summarized throughout the text, and analysis results are provided.
PDF |
- Report of TC32: Engineering Practice of Risk Assessment and Management
- F. Nadim
- 17th International Conference on Soil Mechanics and Geotechnical Engineering (Alexandria)
- Year: 2009
- Risk & Reliability
PDF |
- Geotechnical problems in urban terrains
- O. Makovetsky
- IAEG2006 Paper number 449
- Year: 2006
- Risk & Reliability
PDF |
- Administrative report: TC32 – Engineering practice of risk assessment and management
- Farrokh Nadim
- 16th International Conference on Soil Mechanics and Geotechnical Engineering (Osaka)
- Year: 2005
- Risk & Reliability
PDF |
