- The NRC ESSI Simulator Program, Current status
- N. . Tafazzoli ; F. Pisano ; J.A Abbel ; B. Kamrani ; C.G. Jeong ; B Aldridge ; R. Roche ; A. Kammerer ; B.. Jeremic
- Book Title / Journal: 22nd Conference on Structural Mechanics in Reactor Technology, San Fancisco California, USA
- Year: 2013
- Soil Dynamics ; Geotechnical Earthquake Engineering
- Description
- In this paper we overview some current modeling and simulation features of the NRC ESSI Simulator Program, a parallel, nonlinear, time domain finite element program developed to solve dynamic problems for the soil/rock – structure interaction of Nuclear Power Plant (NPP) system. The NRC ESSI Program is part of the NRC ESSI Simulator System, a software, hardware and educational system for high fidelity modeling and simulation of dynamic response of NPPs.
PDF |
- Research Information Letter 12-01: Preliminary Deterministic Analysis of Seismic Hazard at Diablo Canyon NPP from Newly Identified ‘Shoreline fault’
- A. Kammerer ; J. Stamatakos ; J McCalpin ; L. Anderson
- Book Title / Journal: U.S. Nuclear Regulatory Commission (NRC)
- Year: 2012 , Series: Research Information Letter 12-01
- Risk & Reliability
PDF |
- Practical Implementation Guidelines for SSHAC Level 3 and 4 Hazard Studies (NUREG-2117, Revision 1)
- A. Kammerer ; J.P. Ake
- Book Title / Journal: Office of Nuclear Regulatory Research
- Year: 2012 , Series: NUREG-2117
- Risk & Reliability
- Description
- 10 CFR 100.23, paragraphs (c) and (d) require that the geological, seismological, and engineering characteristics of a site and its environs be investigated in sufficient scope and detail to permit an adequate evaluation of the Safe Shutdown Earthquake (SSE) Ground Motion for the site. In addition, 10 CFR 100.23, paragraph (d)(1), “Determination of the Safe Shutdown Earthquake Ground Motion,” requires that uncertainty inherent in estimates of the SSE be addressed through an appropriate analysis such as a probabilistic seismic hazard analysis (PSHA). In response to these requirements, in 1997, the U.S. Nuclear Regulatory Commission published NUREG/CR-6372, Recommendations for Probabilistic Seismic Hazard Analysis: Guidance on Uncertainty and the Use of Experts. Written by the Senior Seismic Hazard Analysis Committee (SSHAC), NUREG/CR-6372 provides guidance regarding the manner in which the uncertainties in PSHA should be addressed using expert judgment. In the 15 years since its publication, NUREG/CR-6372 has provided many PSHA studies with the framework and guidance that have come to be known simply as the “SSHAC Guidelines.” The information in this NUREG is based on recent efforts to capture the lessons learned in the PSHA studies that have been undertaken using the SSHAC Guidelines. As a companion to NUREG/CR-6372, this NUREG provides additional practical implementation guidelines consistent with the framework and higher-level guidance of the SSHAC Guidelines.
PDF |
- Tsunami Safety Criteria and Current Site Reviews in the United States
- G. Bagchi ; H. Ahn ; H Jones ; A. Kammerer ; R. Raione ; N. Chokshi
- Book Title / Journal: IAEA International Workshop on External Flooding Hazards at Nuclear Power Plant Sites in Commemoration of the 5 Years of Indian Ocean Tsunami
- Year: 2012
- Other Geotechnical
- Description
- The U.S. Nuclear Regulatory Commission (NRC) has promulgated an alternate licensing framework for early site permits (ESPs), certified reactor designs, and combined construction permits and operating licenses (COLs) as described in 10 Code of Federal Regulations (CFR) Part 52. New applicants have been using the Part 52 framework in submittals since 2003. The reactor site criteria are addressed in 10 CFR Part 100. Guidance for the public on approaches that meet NRC requirements is outlined in NRC regulatory guides. Factors to be considered when selecting the site include physical characteristics of the site including seismology, meteorology, geology, and hydrology. The NRC staff review guidance and acceptance criteria are provided in a document, “Review of Safety Analysis Reports for Nuclear Power Plants, NUREG 0800, Revised March 2007.” Section 2.4 of the staff guidance in NUREG 0800 relates to hydrology and flooding design basis for a nuclear power plant. The objective of this paper is to describe several initiatives undertaken in the U.S. to capture the lessons learned from the 2004 Indian Ocean tsunami; to describe revision of the staff guidance documented in NUREG 0800 Section 2.4.6, “Probable Maximum Tsunami Hazards” and some essential elements from Section 2.4.5, “Probable Maximum Surge and Seiche Flooding;” and to describe efforts related to the revision of the regulatory guide 1.59, “Design Basis Floods for Nuclear Power Plants.” This document also describes the efforts to use the lessons and insights learned from the current site reviews.
PDF |
- 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 |
- Developing & Implementing a Real-Time Earthquake Notification System for Nuclear Power Plant Sites Using the USGS Shakecast System
- A. Kammerer ; A.R. Godoy ; S. Stowall ; J.P. Ake ; A Altinoyollar ; N. Bekiri ; D.J. Wald ; K. Lin
- Book Title / Journal: Transactions Structural Mechanics in Reactor Technology (SMiRT) Conference, New Delhi, India
- Year: 2011
- Soil Dynamics ; Geotechnical Earthquake Engineering
- Description
- When an earthquake occurs near a nuclear power plant (NPP), specific information is quickly needed to support accurate real-time situational awareness, assessment of the potential impact to the installation, informed decision making, and effective communication with key stakeholders. To address this important need, the International Atomic Energy Agency (IAEA) and the United States Nuclear Regulatory Commission (NRC), in collaboration with the United States Geological Survey (USGS), are developing and implementing a custom ShakeCast system for post-earthquake real-time notification of ground shaking at NPP sites. The custom system, called Nuclear ShakeCast, is being developed to meet the unique informational needs of the global nuclear community. The project is currently focused on developing and implementing the Nuclear ShakeCast system within the IAEA and NRC. However, the software will be freely available to the international nuclear community once developed. Nuclear ShakeCast has the potential to incorporate observations, estimates of hazard levels, and plant fragility and license information into real-time automated comparisons of estimated ground motions against plantspecific shut-down criteria and basic NPP damage estimations. The earthquake shaking data used by the ShakeCast system is in the form of a ShakeMap, a map that displays earthquake shaking parameters spatially. If an earthquake occurs and is of sufficient size to trigger automatic creation of a new ShakeMap, the ShakeCast software retrieves the map and automatically begins a series of calculations based on protocols and databases specified a priori by the user. The system then sends an automated notification containing the information needed by key personnel in the response organization. The report includes basic information about the earthquake, the estimated levels of ground shaking calculated for those nuclear installation sites located in the affected region, and NPP design information important in the NPPs licensing basis. All this information–-supported by existing operating international seismological networks—is essential for a quick effective communication and decision making. Depending on the responding organization, communication may be with the effected utilities and NPPs, the regulatory body, the media, the public, and governmental organizations. Rapid and automated information is particularly important because affected organizations are busy dealing with the consequences and disruption caused by the earthquake.
PDF |
- Geotechnical Quick Report on the Affected Region of the 23 August 2011 M5.8 Central Virginia Earthquake near Mineral, Virginia
- C. Benson ; M. Chapman ; M Eddy ; R. Green ; A. Kammerer ; S. Lasley ; C Lazarte ; S Nikolaou ; B. Tanyu ; M.. Tuttle
- Book Title / Journal: GEER Association Report No. GEER-026
- Year: 2011
- Soil Dynamics ; Geotechnical Earthquake Engineering
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
- 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 |
- 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 |
- Overview of the U.S. Nuclear Regulatory Commission Collaborative Research Program to Assess Tsunami Hazard for Nuclear Power Plants on the Atlantic and Gulf Coasts
- A. Kammerer ; U.S. Ten Brink ; V. Titov
- Book Title / Journal: Proceedings of the 14th World Conference on Earthquake Engineering, Beijing, China
- Year: 2008
- Soil Dynamics ; Geotechnical Earthquake Engineering
- Description
- In response to the 2004 Indian Ocean Tsunami, the United States Nuclear Regulatory Commission (US NRC) initiated a long-term research program to improve understanding of tsunami hazard levels for nuclear facilities in the United States. For this effort, the US NRC organized a collaborative research program with the United States Geological Survey (USGS) and the National Oceanic and Atmospheric Administration (NOAA) with a goal of assessing tsunami hazard on the Atlantic and Gulf Coasts of the United States. Necessarily, the US NRC research program includes both seismic- and landslide-based tsunamigenic sources in both the near and the far fields. The inclusion of tsunamigenic landslides, an important category of sources that impact tsunami hazard levels for the Atlantic and Gulf Coasts is a key difference between this program and most other tsunami hazard assessment programs. The initial phase of this work consisted of collection, interpretation, and analysis of available offshore data, with significant effort focused on characterizing offshore near-field landslides and analyzing their tsunamigenic potential and properties. In the next phase of research, additional field investigations will be conducted in key locations of interest and additional analysis will be undertaken. Simultaneously, the MOST tsunami generation and propagation model used by NOAA will first be enhanced to include landslide-based initiation mechanisms and then will be used to investigate the impact of the tsunamigenic sources identified and characterized by the USGS. The potential for probabilistic tsunami hazard assessment will also be explore in the final phases of the program.
PDF |
- Preliminary Results of the U.S. N.R.C. Collaborative Research Program to Assess Tsunami Hazard for Nuclear Power Plants on the Atlantic and Gulf Coasts
- A. Kammerer ; U.S Ten Brink ; D.C. Twichell ; E.L. Geist ; J. Chaytor ; J Locat ; H.J. Lee ; B.J. Buczkowski ; M. Sansoucy
- Book Title / Journal: Proceedings of the 14th World Conference on Earthquake Engineering, Beijing, China
- Year: 2008
- Soil Dynamics ; Geotechnical Earthquake Engineering
- Description
- In response to the 2004 Indian Ocean Tsunami, the United States Nuclear Regulatory Commission (US NRC) initiated a long-term research program to improve understanding of tsunami hazard levels for nuclear facilities in the United States. For this effort, the US NRC organized a collaborative research program with the United States Geological Survey (USGS) and other key researchers for the purpose of assessing tsunami hazard on the Atlantic and Gulf Coasts of the United States. The initial phase of this work consisted principally of collection, interpretation, and analysis of available offshore data and information. Necessarily, the US NRC research program includes both seismic- and landslide-based tsunamigenic sources in both the near and the far fields. The inclusion of tsunamigenic landslides, an important category of sources that impact tsunami hazard levels for the Atlantic and Gulf Coasts over the long time periods of interest to the US NRC, is a key difference between this program and most other tsunami hazard assessment programs. Although only a few years old, this program is already producing results that both support current US NRC activities and look toward the long-term goal of probabilistic tsunami hazard assessment. This paper provides a summary of results from several areas of current research. An overview of the broader US NRC research program is provided in a companion paper in this conference.
PDF |
- USNRC Research & Regulatory Guidance for Soil-Structure Interaction
- H. Graves ; A. Kammerer ; V. Thomas
- Book Title / Journal: 4th U.S. - Japan Workshop on Soil-Strucutre Interaction, Tsukuba, Japan
- Year: 2007
- Soil Dynamics ; Geotechnical Earthquake Engineering
- Description
- Over the last three years, the U. S. Nuclear Regulatory Commission (NRC) has focused attention on soilstructure-interaction (SSI) issues in order to better understand emerging issues and to update its regulatory guidance in regards to SSI. NRC’s recent work is in advance of possible construction of new nuclear power plants (NPP) in the United States. Some conceptual designs for new NPP, also called advanced reactors, have proposed certain safety related NPP structures that will be partially or completely embedded below grade. In addition to this and other design features, some siting analyses for new NPP have used a performance-based method to determine the safe shutdown earthquake (SSE) ground motion. The performance-based method uses a target annual probability [e.g., 10-5 /year for the onset of significant inelastic deformation of systems, structures, and components] for the maximum acceptable facility damage from an earthquake. This paper presents some of the key areas that have been the focus of NRC activity over the last three years, namely: 1) the development of computational tools; 2) an assessment of deeply embedded structures and; 3) exploration of emerging issues; for example, performance-based methods and inclusion of seismic ground motion incoherency into SSI analyses.
PDF |
- Shear Strain Development in Liquefiable Soil Under Bi-directional Loading Conditions
- A. Kammerer ; J. Wu ; M. Riemer ; J Pestana ; R. Seed
- Book Title / Journal: 13th World Conference on Earthquake Enigineering, Vancouver, Canada
- Year: 2004
- Soil Dynamics ; Geotechnical Earthquake Engineering
- Description
- A comprehensive testing database composed of modeling-quality multi-directional cyclic simple shear testing on medium to high relative density, fully-saturated samples of Monterey 0/30 sand has recently been developed. This testing program incorporated a variety of multi-directional stress paths, including a large number of stress paths never before examined. Results from these tests have proven useful for enhancing current understanding of liquefaction behavior by allowing for a more complete theory to emerge. This new 3-dimensional theory greatly expands current understanding of liquefaction behavior and elucidates some areas in which current theory—which has been based principally on uni-directional laboratory testing—can be misleading or unconservative. Of particular interest are the topics of pore pressure generation and softening, the relationship between pore pressure and strain capacity, and the dilational lock-up in medium density sands that acts to limit large free-flow type deformations. Insight has also been gained on the complex effects caused by an initial static shear stress such as would be imposed by sloping ground conditions or the presence of a structure.
PDF |
- A new Multi-diractional Direct Simple Shear Testing Database
- A. Kammerer ; J. Wu ; M. Riemer ; J Pestana ; R. Seed
- Book Title / Journal: 13th World Conference on Earthquake Enigineering, Vancouver, Canada
- Year: 2004
- Soil Dynamics ; Geotechnical Earthquake Engineering
- Description
- This paper presents the development of a comprehensive modeling-quality cyclic simple shear testing database composed of tests performed on fully-saturated samples of Monterey 0/30 sand. This newly developed database is composed of two series. The first consists of a comprehensive series of unidirectional tests incorporating a variety of relative densities and confining pressures. The second series consists of tests performed under a variety of multi-directional stress paths, including a number of stress paths never before examined in the laboratory. The bi-directional series is focused on soils that exhibit dilatant behavior (i.e. medium to high-density soils). The database is designed such that the unidirectional series serves as a comprehensive baseline against which to compare the results of the multidirectional series. Together, they represent an unmatched resource for both the development and calibration of 3-dimensional constitutive models and understanding the behavior of liquefiable soils under both uni-directional and multi-directional loading.
PDF |
