A classification of quaternary dating methods
No abstract available.
U.S. Nuclear Regulatory Commission Report↗
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Discussion of proposed rule in Federal Register, 10 CFR Part 60, pertaining to ground-water travel time; an appendix to report by Sandia National Laboratories to U.S. Nuclear Regulatory Commission, assessing the technical criteria for geologic disposal of high-level radioactive waste
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Open-File Report↗
Joint US Geological Survey, US Nuclear Regulatory Commission workshop on research related to low-level radioactive waste disposal, May 4-6, 1993, National Center, Reston, Virginia; Proceedings
This report contains papers presented at the "Joint U.S. Geological Survey (USGS) and U.S. Nuclear Regulatory Commission (NRC) Technical Workshop on Research Related to Low-Level Radioactive Waste (LLW) Disposal" that was held at the USGS National Center Auditorium, Reston, Virginia, May 4-6, 1993. The objective of the workshop was to provide a forum for exchange of information, ideas, and technology in the geosciences dealing with LLW disposal. This workshop was the first joint activity under the Memorandum of Understanding between the USGS and NRC's Office of Nuclear Regulatory Research signed in April 1992. Participants included invited speakers from the USGS, NRC technical contractors (U.S. Department of Energy (DOE) National Laboratories and universities) and NRC staff for presentation of research study results related to LLW disposal. Also in attendance were scientists from the DOE, DOE National Laboratories, the U.S. Environmental Protection Agency, State developmental and regulatory agencies involved in LLW disposal facility siting and licensing, Atomic Energy Canada Limited (AECL), private industry, Agricultural Research Service, universities, USGS and NRC.
Water-Resources Investigations Report↗
Jack Boatwright’s last science
In the months before he passed away, Jack Boatwright asked us to review a manuscript on source properties, specifically stress drop, of earthquakes in northeastern North America (NENA). This manuscript originated in research funded by the U.S. Nuclear Regulatory Commission (NRC), described in his final report to NRC and published as USGS Open-File Report 2018-1073 (Boatwright, 2018). We wish to call attention to Boatwright (2018) for those who may not be aware of what Jack was unable to put into journal publications.
Seismological Research Letters↗
Ground motion and seismic hazard in the central and eastern United States
This report describes work carried out under the U.S. Nuclear Regulatory Commission (NRC) Interagency Agreement to the U.S. Geological Survey (USGS) “Research to Support NRC’s Seismic Hazard Analyses” for Task 3, “Seismic Hazard and Ground Motion Models.” The focus of this work has been on evaluation of the Next Generation Attenuation (NGA)-East groundmotion models (GMMs) with available ground-motion data and evaluation of alternative methods for characterizing epistemic uncertainty for probabilistic seismic hazard analysis (PSHA). When the Interagency Agreement commenced, the USGS’s National Seismic Hazard Model (NSHM) was being updated, and a significant part of the update for the 2018 NSHM included the introduction of new GMMs for the central and eastern United States (CEUS) (Petersen et al., 2020). In addition to the implementation of the then-recently developed NGA-East GMMs (Goulet et al., 2018), the ground-motion characterization for the CEUS in the 2018 NSHM also included a logic-tree branch with weights applied to the updated “adjusted seed” models that were developed as part of the NGA-East process and in updates by the GMM developers. The Statement of Work for Task 3 of the NRC Interagency Agreement to the USGS included the following parts: (1) Describe technically acceptable approaches in combining GMMs for use in PSHA calculations; (2) Evaluate the effect of using different sets of GMMs (NGA-East SSHAC versus NGA-East USGS) on PSHA calculations; (3) Describe the results of the GMM testing against recorded data, and provide a recommendation on the GMMs application for use in the PSHA; (4) Evaluate the impacts of recently updated individual GMMs on the published NGAEast models; and (5) Submit a final Technical Letter Report documenting results of this task. We present results from this work in two sections: (Chapter 1) Updated Central and Eastern United States Ground Motions and Ground-Motion Analyses; and (Chapter 2) Approaches to Combining Ground-Motion Models for Probabilistic Seismic Hazard Analysis in the Central and Eastern United States.
central and eastern United States↗
Nuclear power reactor sites in the southeastern United States
This report describes nuclear power reactor sites in the southeastern United States. The map indicates the location of all sites as of July 1976 in the conterminous United States, and a later published report will include all sites. The project is one of several in the National Environmental Overview Program of the U.S. Geological Survey which will identify and summarize geologic, hydrologic, and topographic topics associated with future energy, mineral resource, and land use development in the United States. The increasing use of atomic energy creates a need for the dissemination of information about nuclear reactors. Because power plant safety is related, in part, to the geology and seismology of the plant area and surroundings, this study is focused primarily on that relationship. Information about the geology and seismology is summarized from reports prepared by consultants to utility companies and submitted by the companies to the U.S. Nuclear Regulatory Commission (formerly the U.S. Atomic Energy Commission) in support of the application for a construction permit. Coordinates for site locations were established by the author from descriptive information in the reports. The U.S. Geological Survey 7-1/2 minute topographic maps were used in confirming the geographic location of the sites. The coordinates may in some cases represent the planned location rather than the exact actual location.
Open-File Report↗
Implementation of the SSHAC Guidelines for Level 3 and 4 PSHAs - Experience gained from actual applications
In April 1997, after four years of deliberations, the Senior Seismic Hazard Analysis Committee released its report 'Recommendations for Probabilistic Seismic Hazard Analysis: Guidance on Uncertainty and Use of Experts' through the U.S. Nuclear Regulatory Commission as NUREG/CR-6372, hereafter SSHAC (1997). Known informally ever since as the 'SSHAC Guidelines', SSHAC (1997) addresses why and how multiple expert opinions - and the intrinsic uncertainties that attend them - should be used in Probabilistic Seismic Hazard Analyses (PSHA) for critical facilities such as commercial nuclear power plants. Ten years later, in September 2007, the U.S. Geological Survey (USGS) entered into a 13-month agreement with the U.S. Nuclear Regulatory Commission (NRC) titled 'Practical Procedures for Implementation of the SSHAC Guidelines and for Updating PSHAs'. The NRC was interested in understanding and documenting lessons learned from recent PSHAs conducted at the higher SSHAC Levels (3 and 4) and in gaining input from the seismic community for updating PSHAs as new information became available. This study increased in importance in anticipation of new applications for nuclear power facilities at both existing and new sites. The intent of this project was not to replace the SSHAC Guidelines but to supplement them with the experience gained from putting the SSHAC Guidelines to work in practical applications. During the course of this project, we also learned that updating PSHAs for existing nuclear power facilities involves very different issues from the implementation of the SSHAC Guidelines for new facilities. As such, we report our findings and recommendations from this study in two separate documents, this being the first. The SSHAC Guidelines were written without regard to whether the PSHAs to which they would be applied were site-specific or regional in scope. Most of the experience gained to date from high-level SSHAC studies has been for site-specific cases, although three ongoing (as of this writing) studies are regional in scope. Updating existing PSHAs will depend more critically on the differences between site-specific and regional studies, and we will also address these differences in more detail in the companion report. Most of what we report here and in the second report on updating PSHAs emanates from three workshops held by the USGS at their Menlo Park facility: 'Lessons Learned from SSHAC Level 3 and 4 PSHAs' on January 30-31, 2008; 'Updates to Existing PSHAs' on May 6-7, 2008; and 'Draft Recommendations, SSHAC Implementation Guidance' on June 4-5, 2009. These workshops were attended by approximately 40 scientists and engineers familiar with hazard studies for nuclear facilities. This company included four of the authors of SSHAC (1997) and four other experts whose contributions to this document are mentioned in the Acknowledgments section; numerous scientists and engineers who in one role or another have participated in one or more high-level SSHAC PSHAs summarized later in this report; and representatives of the nuclear industry, the consulting world, the regulatory community, and academia with a keen interest and expertise in hazard analysis. This report is a community-based set of recommendations to NRC for improved practical procedures for implementation of the SSHAC Guidelines. In an early publication specifically addressing the SSHAC Guidelines, Hanks (1997) noted that the SSHAC Guidelines were likely to evolve for some time to come, and this remains true today. While the broad philosophical and theoretical dimensions of the SSHAC Guidelines will not change, much has been learned during the past decade from various applications of the SSHAC Guidelines to real PSHAs in terms of how they are implemented. We anticipate that, in their practical applications, the SSHAC Guidelines will continue to evolve as more experience is gained from future SSHAC applications. Indeed, to the extent that every PSHA has its
Open-File Report↗
Subsurface-water flow and solute transport: federal glossary of selected terms
The purpose of this report is to provide a glossary of selected terms for saturated and unsaturated flow and related processes involved in transport of contaminants in the subsurface. The glossary contains five tables. Table 1 is a list of parameters with associated symbols and units. Tables 2 to 5 are conversion charts. The original manuscript was prepared by Thomas J. Nicholson, U.S. Nuclear Regulatory Commission. It was subsequently examined by the Ground-Water Glossary Working Group and experts within and outside the Federal Government, whose recommendations were accommodated where appropriate in the glossary. It is hoped that the glossary will aid in the communications between soil scientists, hydrologists, and hydrogeologists. The terms defined in the glossary were selected after an extensive survey of glossaries and reports in the areas of (1) ground-water geology, hydraulics, and chemistry, (2) soil-water physics and chemistry, (3) contaminant transport, (4) unsaturated-zone hydrology, (5) chemistry and transport of solutes, and (6) ground-water quality. Some of the definitions have been modified for clarity from a variety of technical sources. Where more than one definition appears for the selected term, the first one was determined by the working group to be the most appropriate general definition, followed by other, more specialized, definitions. Some terms and definitions are not currently in use by all agencies; however, they are included in the glossary because they can be found in the literature. The reader is encouraged to consult with the original source cited for more explanatory comments. Additional regulatory definitions, which are underlined and are taken directly from the Code of Federal Regulations (CFR) and Federal laws (USC), were added following review by the various Federal agencies in May 1986. The definitions and conversion charts are from two principal sources provided herein. The first is the 11Glossary11 compiled by A. I. Johnson in the 1981 report by the American Society of Testing and Materials titled Permeability and Groundwater Contaminant Transport. The second is Manu a 1 40, 11Ground-water Management, 11 produced by the American Society of Civil Engineers in 1985.
Report↗
Introduction: Geomorphic studies of the storm and flood of November 3-5, 1985, in the upper Potomac and Cheat River basins
The heavy rains of November 3-5, 1985, produced record floods and extensive landsliding in the Potomac and Cheat River basins in West Virginia and Virginia (pl. 1). Although rainfall intensity was moderate, the storm covered a very large area and produced record floods for basins in the size range of 1000-10,000 km 2 . In addition, thousands of landslides were triggered on slopes underlain by shale bedrock. The total social cost of the storm amounted to 70 lives lost and an estimated $1.3 billion in damage to homes, businesses, roads, and productive land in West Virginia and Virginia (Federal Emergency Management Agency (FEMA) 1985a, b). These extreme costs were incurred despite the fact that the affected area is sparsely populated. To understand the origins and geomorphic effects of the 1985 storm, studies were undertaken by the U.S. Geological Survey, University of Maryland, West Virginia University, Cornell University, University of Virginia, The Johns Hopkins University, and Carleton College. Personnel were also consulted from the National Weather Service, Nuclear Regulatory Commission, U.S. Army Corps of Engineers, Soil Conservation Service, and Interstate Commission on the Potomac River basin. This cooperative effort serves to document the effects of the storm as an example of an extreme geomorphic event in the central Appalachian Mountains. The following chapters comprise observations and preliminary analyses for some of the observed phenomena. Subsequent publications by the contributors to this volume will expand the scope of this research.
Virginia, West Virginia↗
Sizes of the largest possible earthquakes in the central and eastern United States— Summary of a workshop, September 8–9, 2008, Golden, Colorado
Most probabilistic seismic-hazard assessments require an estimate of Mmax, the magnitude (M) of the largest earthquake that is thought possible within a specified area. In seismically active areas such as some plate boundaries, large earthquakes occur frequently enough that Mmax might have been observed directly during the historical period. In less active regions like most of the Central and Eastern United States and adjacent Canada, large earthquakes are much less frequent and generally Mmax must be estimated indirectly. The indirect-estimation methods are many, their results vary widely, and opinions differ as to which methods are valid. This lack of consensus about Mmax estimation increases the uncertainty of hazard assessments for planned nuclear power reactors and increases design and construction costs. Accordingly, the U.S. Geological Survey and the U.S. Nuclear Regulatory Commission held an open workshop on Mmax estimation in the Central and Eastern United States and adjacent Canada. The workshop was held on Monday and Tuesday, September 8 and 9, 2008, at the U.S. Geological Survey offices in Golden, Colorado. Thirty-five people attended. The workshop goals were to reach consensus on one or more of: (1) the relative merits of the various methods of Mmax estimation, (2) which methods are invalid, (3) which methods are promising but not yet ready for use, and (4) what research is needed to reach consensus on the values and relative importance of the individual estimation methods.
Open-File Report↗
Magnitude conversion and earthquake recurrence rate models for the central and eastern United States
Development of Seismic Source Characterization (SSC) models, which is an essential part of Probabilistic Seismic Hazard Analyses (PSHA), can help forecast the temporal and spatial distribution of future damaging earthquakes (𝑀 w ≥ 5) in seismically active regions. Because it is impossible to associate all earthquakes with known faults, seismic source models for PSHA often include sources of diffuse seismicity in which future earthquake scenarios are not localized on mapped faults. These sources of diffuse seismicity are referred to as area source zones, distributed seismicity zones, or just source zones. During the early years of PSHA studies, it was assumed that earthquakes in seismotectonic zones have (1) uniform spatial distribution, (2) Poisson temporal distribution, and (3) exponential magnitude distribution (NRC, 2012). In seismically active regions (e.g., the Western United States), where active faults are readily identified, models of the spatial distribution of earthquakes include both the fault source geometries and the distributed seismicity (background) source zones. Source characterization of active faults is complemented by paleoseismic studies with estimates of earthquake magnitudes, dates of occurrences, and slip rates, which provide important information for PSHA studies. In the Central and Eastern United States (CEUS) very few Quaternary-active faults have the requisite information for use in PSHA (i.e., fault geometry and dimensions, event rates or slip rates, etc.), and we lack knowledge about the causative faults for most observed seismicity in the region. As a result, area source zones are frequently used in site-specific PSHA in the CEUS to represent diffuse seismicity that cannot be associated with faults. However, there are examples of active fault sources in the CEUS, such as the Meers fault, the Cheraw fault, and New Madrid region, where individual faults can be characterized. The source characterization models for background seismicity are based, to a large extent, on an assumption that spatial distribution of historical and recorded seismicity will not change substantially for time periods of interest for PSHA (approximately the next 50-100 years for engineered structures). Furthermore, studies such as those by Kafka (2007, 2009) found a correlation between the locations of small- to moderate-magnitude earthquakes and the locations of large-magnitude earthquakes, indicating that we can, with some level of confidence, use the spatial pattern of smaller earthquakes to forecast the future pattern of damaging earthquakes. Within background seismicity zones, the earthquake rate forecast is developed using spatial smoothing of the small to moderate magnitude events in earthquake catalogs. Different methodologies are used for this purpose and can predict varying distributions of seismicity rates. This in turn affects the results of a seismic hazard analysis. The U.S. Geological Survey (USGS) and Nuclear Regulatory Commission (NRC) use different methods for computing spatially smoothed seismicity rates in the CEUS; the USGS uses kernel-based spatial smoothing methods in developing the National Seismic Hazard Model (NSHM), and the method adopted in the Central and Eastern United States Seismic Source Characterization (CEUS-SSC) project is used when evaluating seismic hazard for nuclear power plant siting. These methods are described and the impact on seismic hazard are evaluated in this Research Information Letter (RIL). Another important input to estimating the rate of distributed seismicity is event magnitudes listed in earthquake catalogs. A substantial source of uncertainty in catalogs is the magnitude assigned to a given earthquake. Numerous different magnitude types exist, with each magnitude type computed in a different way. Therefore, for the sake of consistency, both the CEUS-SSC and the USGS NSHM have attempted to assemble a complete catalog with a uniform magnitude determination. To this end, moment magnitude, 𝑀 w , which is a physics-based measurement, has been adopted as the standard. However, 𝑀 w was not computed routinely until the past few decades. To address this issue, the CEUS-SSC conducted extensive analyses to determine conversion equations from which to take a routinely computed network (e.g., 𝑀 L or 𝑚 bLg ) and convert it into 𝑀 w . Another issue with using 𝑀 w is that it becomes increasingly difficult to compute for earthquakes with 𝑀 less than ~4. This study investigates the effects of moment magnitude estimation and spatial smoothing methods on estimation of the earthquake rate forecast and on seismic hazard. We investigate the validity of the magnitude conversion equations and their associated uncertainties by applying them to a case study for induced earthquakes in southern Kansas and northern Oklahoma, and summarize the use of the decay of the seismic coda to estimate 𝑀 w for small earthquakes (𝑀 w < 4. Furthermore, the study documents a comparison and assessment of background seismicity smoothing methods implemented by the USGS for the NSHM and used by the CEUS-SSC for siting nuclear facilities based on probabilistic seismic hazard estimates from multiple source zones in the CEUS and for multiple sites.
central and eastern United States↗
Application of at-site peak-streamflow frequency analyses for very low annual exceedance probabilities
The U.S. Geological Survey (USGS), in cooperation with the U.S. Nuclear Regulatory Commission, has investigated statistical methods for probabilistic flood hazard assessment to provide guidance on very low annual exceedance probability (AEP) estimation of peak-streamflow frequency and the quantification of corresponding uncertainties using streamgage-specific data. The term “very low AEP” implies exceptionally rare events defined as those having AEPs less than about 0.001 (or 1 × 10 –3 in scientific notation or for brevity 10 –3 ). Such low AEPs are of great interest to those involved with peak-streamflow frequency analyses for critical infrastructure, such as nuclear power plants. Flood frequency analyses at streamgages are most commonly based on annual instantaneous peak streamflow data and a probability distribution fit to these data. The fitted distribution provides a means to extrapolate to very low AEPs. Within the United States, the Pearson type III probability distribution, when fit to the base-10 logarithms of streamflow, is widely used, but other distribution choices exist. The USGS-PeakFQ software, implementing the Pearson type III within the Federal agency guidelines of Bulletin 17B (method of moments) and updates to the expected moments algorithm (EMA), was specially adapted for an “Extended Output” user option to provide estimates at selected AEPs from 10 –3 to 10 –6 . Parameter estimation methods, in addition to product moments and EMA, include L-moments, maximum likelihood, and maximum product of spacings (maximum spacing estimation). This study comprehensively investigates multiple distributions and parameter estimation methods for two USGS streamgages (01400500 Raritan River at Manville, New Jersey, and 01638500 Potomac River at Point of Rocks, Maryland). The results of this study specifically involve the four methods for parameter estimation and up to nine probability distributions, including the generalized extreme value, generalized log-normal, generalized Pareto, and Weibull. Uncertainties in streamflow estimates for corresponding AEP are depicted and quantified as two primary forms: quantile (aleatoric [random sampling] uncertainty) and distribution-choice (epistemic [model] uncertainty). Sampling uncertainties of a given distribution are relatively straightforward to compute from analytical or Monte Carlo-based approaches. Distribution-choice uncertainty stems from choices of potentially applicable probability distributions for which divergence among the choices increases as AEP decreases. Conventional goodness-of-fit statistics, such as Cramér-von Mises, and L-moment ratio diagrams are demonstrated in order to hone distribution choice. The results generally show that distribution choice uncertainty is larger than sampling uncertainty for very low AEP values.
Scientific Investigations Report↗