Characterize Framework for Seismicity and Structural Deformation at Yucca Mountain, Nevada Rev 00, ICN 00

ANL-CRW-GS-000003

April 2000 

1. PURPOSE 
The purpose of this Analyses and Models Report (AMR) is to summarize the probabilistic 
seismic hazard analysis (PSHA) for the Yucca Mountain site such that it can be used in preparing 
the Disruptive Events WE) Process Model Report (CRWMS M&O 2000a). The PSHA, 
Probabilistic Seismic Hazard Analyses for Fault Displacement and Vibratory Ground Motion at 
Yucca Mountain, Nevada (Civilian Radioactive Waste Management System [CRWMS] 
Management and Operating Contractor w&0] 1998a), was a 4-year multidisciplinary project 
that assessed both ground motion and fault displacement hazards. The DE process model report 
is one of a group of documents summarizing models and data that will form the technical basis 
for the total system performance assessment (TSPA) supporting the Site Recommendation. The 
DE process model report will describe analyses of seismic and igneous events and their effects 
for use in the TSPA for Site Recommendation. In addition to supporting the DE process model 
report directly, this AMR also furnishes indirect support to: 
Analyses addressing the effects of ground motion and fault displacement for the 
postclosure period 
An analysis of seismic-related features, events, and processes (FEPs) to determine 
whether they should be included in the TSPA for Site Recommendation 
An evaluation of the extent to which the U.S. Nuclear Regulatory Commission's (NRC) 
subissues and acceptance criteria associated with the Seismicity and Structural 
Deformation and other key technical issues have been addressed (NRC 1999). 
Results of the PSHA also support development of seismic inputs for preclosure design. 
Seismic hazards potentially affecting the Yucca Mountain site consist of vibratory ground 
motion and fault displacement. Consideration of these hazards in TSPA depends on their 
likelihood of occurrence and their effects on engineered items and the natural system. 
Likelihood of occurrence is addressed in this AMR. Analyses to assess ground motion effects 
are being carried out in support of Engineered Barrier System, Waste Package, and Waste Form 
process model reports. Fault displacement effects are addressed in the analyses Fault 
Displacement Eflects on Transport in the Unsaturated Zone (CRWMS M&O 2000b) and Eflects 
of Fault Displacement on Emplacement Drifts (CRWMS M&O 2000c), which support the DE 
process model report. Results on likelihood of occurrence and effects will then form part of the 
basis for an analysis, Disruptive Events FEPs (CRWMS M&O 2000d), which will determine 
whether seismic-related FEPs need to be included in TSPA for Site Recommendation. 
Therefore, one purpose of this AMR is to summarize the PSHA results such that they can be 
used in these subsequent analyses to evaluate effects of seismic hazard and their impact on 
performance. 
For postclosure, the seismic hazard results are being used to evaluate whether future ground 
motions or fault displacements contribute to any repository events that occur with a probability 
greater than 1 in 10,000 in 10,000 years, and that have significant effects on overall performance. 
Consistent with U.S. Department of Energy (DOE) interim guidance (Dyer 1999, Section 63.2), 
for the purpose of postclosure performance assessment, an event in this regard is considered in 
this report to be the failure of a structure, system, or component (SSC) to perform its fbnctional 
goal. A seismic event then is the failure of an SSC to perform its intended fbnctional goal under 
ground shaking or fault displacement loading during the postclosure period of interest. 
Although simplified analyses are used to support TSPA for Site Recommendation, ultimately 
analyses to determine and describe seismic ground motion events for input to performance 
assessment will involve the development of fragility curves (frequency of failure as a function of 
ground motion level) for critical SSCs. Depending on final design choices, such SSCs might 
include emplacement drifts, drip shields, and waste packages. The hazard results can be used to 
develop a suite of ground motion time histories for different magnitude earthquakes that can be 
used in analyses to develop the fragility curves. The hazard curves then can be convolved with 
the fragility curves to determine a probability distribution for the frequency of failure of the SSC 
to perform its fbnctional goal. Convolution involves multiplication of the hazard and fragility 
curves and integrating over an appropriate range of ground motion levels to describe the 
probability of unacceptable performance. For SSCs designed to NRC seismic design 
requirements, as will be the case for the Yucca Mountain facility (YMP 1997a), integration to 
about 1.5 to 3 times the seismic design ground motion level appropriately captures the 
probability of unacceptable performance (Kennedy and Ravindra 1984). These analyses will 
support updated evaluations of seismic-related FEPs for inclusion or exclusion in TSPA. If FEPs 
are included, the analyses will also provide the basis for how they are treated. Thus, the ground 
motion hazard curves summarized in this AMR provide the basis for postclosure analyses. 
Ground motion hazard results he also being used to develop preclosure seismic design inputs for 
the potential geologic repository at Yucca Mountain. The ground motion hazard results form the 
basis for identifLing controlling design earthquakes and controlling ground motion spectra 
appropriate for the proposed Geologic Repository Operations Area (Dyer 1999). The locationspecific 
inputs for seismic design of specific SSCs are developed from the controlling design 
ground motions by taking into account the effects of near-surface soil and rock. The inputs are 
then used in analyses to design SSCs that accommodate the ground motion such that safety and 
waste isolation fbnctions are preserved to the extent that the health and safety of the public is 
maintained. Although supported by this AMR, preclosure seismic issues are not part of the 
scope of the DE process model report. Rather, these issues are addressed in a series of three 
topical reports (see Section 6.1 for firther discussion of these reports). 
Fault displacement hazard curves are also being used for postclosure and preclosure analyses. 
For postclosure performance assessment, the fault displacement hazard curves can be used in a 
fashion similar to that for ground motion to identify repository events for input to FEP evaluation 
and postclosure performance assessment. The fault displacement hazard curves thus provide 
input to response analyses of the engineered barrier system, waste package system, and natural 
system in response to fault displacement. Convolving the responses of these repository 
components and the natural system with the fault displacement hazard curves describes event 
frequencies for input to the performance assessment. For preclosure seismic design, the fault 
displacement hazard curves will be used as a basis for determining in which portions of the 
repository waste emplacement area the probability of fault displacement is so low that it does not 
need to be considered in design. Also the fault displacement hazard results are being used as 
input to analyses to determine appropriate setback distances of SSCs from primary faults in order 
April 2000 

to provide reasonable assurance that they will maintain thCir intended waste isolation and 
containment functions. For any safety-related SSCs that cannot be located such that they avoid 
significant faults, the hazard curves will serve as a basis to determine the level of fault 
displacement that must be accommodated in preclosure engineering design. 
A find purpose of this AMR is to summarize how tectonic models for the Yucca Mountain site 
were considered and evaluated in the PSHA. The PSHA employed an expert elicitation process 
to evaluate the extensive database of relevant information pertaining to the characterization of 
seismic sources, fault displacement, and ground motion at Yucca Mountain. The experts were 
provided with available information on tectonic models proposed for the Yucca Mountain 
vicinity. They used that information in weighting the likelihood of different models applying to 
the site. Thus, for seismic hazard -assessment, no single model is selected for Yucca Mountain 
Project use, but rather uncertainty in our understanding of the tectonic framework for the site is 
quantitatively assessed as part of the hazard analysis. This AMR provides a summary of those 
tectonic model assessments for use in the DE process model report and in performance 
assessment. 
To accomplish the above purposes, this AMR has the following objectives as outlined in 
Characterize Framework for Seismicity and Structural Deformation at Yucca Mountain, Nevada 
(Development Plan) (CRWMS M&O 1999a): 
Summarizing the PSHA process and the use of experts to define inputs and 
characterize uncertainties for seismic hazard computation . 
e Summarizing the conceptual framework for seismicity and structural 
deformation at Yucca Mountain based on the interpretations of the PSHA 
experts and other availabIe information (with emphasis on how uncertainty 
. in tectonic models and other relevant input parameters was incorporated in 
the hazard results through the PSHA process) 
e Summarizing vibratory ground motion and fault displacement .hazard results 
at Yucca Mountain. 
As a synthesis of the PSHA, this AMR has no limitations except those implicit in the PSHA; 
these are discussed in Section 6.1.5. 
2. QUALITY ASSURANCE 
Development of this AMK was evaluated in accordance with QAP-2-0, Conduct of Activities, 
and was determined to be quality affecting and subject to Quality Assurance Requirements and 
Description (QARD) (DOE 2000). This is documented in activity evaluations for Work 
Packages 14016105M5 (CRWMS M&O 1999b) and 1401213DMl (Wemheuer 1999). 
Accordingly, this AMK was developed in accordance with AP-3.10Q, Analyses and Models. 
Other applicable DOE Office of Civilian Radioactive Waste Management Administrative 
Procedures are identified in the Development Plan (CRWMS M&O 1999a). In accordance with 
QAP-2-3, ClassiJication of Permanent Items, there are no permanent items directly associated 
with this AMR. 
ANLCRW-GS-000003 REV DO 11 of 89 
\ ~ ~ ~ ~ ~ ~ ~ ~ ~ \ ~ - ~ ~ ~ ~ ~ E C T S \ W C C A M R J \ A M R U ~ - ~ C ~ ~ ) ~ ~ ~ ~ ~ I ~ L W C WlB100 
April 2000 

3. COMPU~ER SOFTWARE AND MODEL USAGE 
No software was used to directly support information reported in this AMR. Nonqualified 
software (e.g., Microsoft Word, Version 97; Aldus Freehand, Version 8) was used to perform 
support activities, such as document and figure preparation, but output from this software was 
not used in quality affecting work. Thus, this software is exempt from qualification requirements 
of AP-SLlQ, Soware Management, Rev. 2, ICN 4. Refer to Section 6.2 and Attachment I1 for 
discussion of software used for PSHA calculations. 
4. INPUTS 
4.1 DATA AND PARAMETERS 
This AMR contains two basic types of input data that all came from the PSHA (CRWMS M&O 
1998a). These include the experts' interpretations and the results for the fault displacement 
hazard assessment (Table I), and the experts' interpretations and results for the ground motion 
hazard assessment (Table 2). For the ground motion assessment, the experts' interpretations 
included both the seismic source characterization and the ground motion attenuation 
characterization (Table 2). The experts' interpretations are based on an extensive database 
(Appendix B of CRWMS M&O 1998a). Both the experts' interpretations and the hazard results 
as described in the PSHA are qualified by virtue of the expert elicitation process. All of these 
inputs are discussed further in Section 6, including explanation of terms and parameters. The Q 
status of the input data is provided in the Document Input Reference System. 
4.2 CRITERIA 
This AMR complies with Part 63.2 DOE interim guidance (Dyer 1999). Subparts of the interim 
guidance that apply to this analysis are those pertaining to the characterization of the Yucca 
Mountain site (Subpart B, Section IS), the compilation of information regarding geology of the 
site in support of the License Application (Subpart B, Section 21 (c) (1) (ii)), and the definition 
of geologic parameters and conceptual models used in performance assessment (Subpart E, 
Section 114 (a)). 
At this time, criteria in the form of specific System Description Documents have not been 
identified that apply to this AMR. The PSHA Project was conducted following the guidance 
provided in Methodology to Assess Fault Displacement and Vibratory Ground Motion Hazards 
at Yucca Mountain, Nevada (YMP 1997b) and the process was generally consistent with 
NUREGICR 6372 (Budnitz et al. 1997) and NUREG 1563 (Kotra et al. 1996). This PSHA 
approach has been accepted in principle by the NRC (Bell 1996). 
4.3 CODES AND STANDARDS 
No specific formally established codes or standards have been identified that apply to this AMR 
or the PSHA for Yucca Mountain. 
ANLXRW-GS-000003 REV 00 12 of 89 
X:\rwCfMROlECmWCCAMfMAMR~-rrvahamOOrrvahamOO~WC Wlm 
April 2000 

Table 1. lnput Data Used from 
the PSHA Fault Displacement Hazard Assessment 
Note that these inputs (the seismic source characterization and the ground motion attenuation characterization) 
are linked together in the same logic tree data files submitted to the Automated Technical Data 
Tracking System. 
5. ASSUMPTIONS 
Description I Data Tracking Number 
Fault Dis~lacement Characterization I M00004MWDRIFM3.002 
for Nine erno on strati on Points I 
Fault Dis~lacement Hazard Results 1 M00004MWDRIFM3.002 I for Nine emo on strati on Points I I 
Table 2. Input Data Used from 
the PSHA Ground Motion Hazard Assessment 
1 I Data Tracking Number I 
Description I 
Experts' lnterpretatlons Feeding into the PSHA I 1 
zonesy I 
Ground Motion Attenuation Characterization (in- I M00004MWDRIFM3.002 
~abulations: - 
Seismic Source Characterization (includes 
tectonic models. fault sources, and areal source 
cludes median ground motions and uncertainhes 
for normal and strike-slip earthquakes)' 
PSHA Ground Motion Hazard Results: 
Peak Ground Accelerations (PGAs) 
M00004MW DRI FM3.002 
I (including mean and fract;'le values for I M00004MWDRIFM3.002 I 
horizontal and vertical motions) 
Peak Ground Velocities (PGVs) 
(includina mean and fractile values for 
As the analysis for this AMR consists of the translation, summary, and documentation of the 
PSHA Project, no assumptions were made in this summary. Key assumptions were made, 
however, in the PSHA process and they are summarized in Section 6.4. 
M00004MWDRIFM3.002 
horizonti and vertical motions) 
Spectral Accelerations (SAs) 
(including mean and fractile values for 
horizontal and vertical motions) 
The analysis for this AMR is the translation, summary, and documentation of the PSHA Project. 
There were no models developed for this AMR. The following sections first briefly describe the 
necessary background information on the PSHA Project, computer software, description of input, 
assumptions, methodology, and finally results for calculating both the ground motion and fault 
displacement hazard assessments in the PSHA Project. Sensitivity analyses for the PSHA are 
also discussed in this section. Substantiation of models in the PSHA was carried out by experts 
through the expert elicitation and review process during the project. 
M00004MWDRIFM3.002 
April 2000 

6.1 BACKGROUND FOR THE PSHA PROJECT 
Yucca Mountain is located about 160 lun northwest of Las Vegas, in the southern Great Basin 
portion of the Basin and Range province. The region is tectonically active at a low to moderate 
strain rate (CRWMS M&O 1998b, Section 12.3; Savage et al. 1999) and is characterized by the 
presence of abundant late-Quaternary faults and a moderate level of historical seismicity (Figure 
I), with the occurrence of relatively infrequent earthquakes up to about moment magnitude (M,) 
7.5. 
The Nuclear Waste Policy Act of 1982, as amended in 1987, assigns to the DOE the 
responsibility of evaluating Yucca Mountain as a potential geologic repository to site the 
nation's first permanent disposal facility for spent nuclear fuel and high-level radioactive waste. 
As part of the seismic performance aspect of this effort, the U.S. Geological Survey (USGS) and 
the CRWMS M&O jointly performed the PSHA Project. The PSHA Project was initiated in 
August 1994, was on hiatus from October 1995 to September 1996, resumed in October 1996, 
and concluded in June 1998 with the issuance of the PSHA report (CRWMS M&O 1998a). 
The overall approach that the DOE has undertaken to address potential seismic hazards at Yucca 
Mountain is documented in three topical reports: Methodology to Assess Fault Displacement and 
Vibratory Ground Motion Hazards at Yucca Mountain (Topical Report I ) (YMP 1997b) and 
Preclosure Seismic Design Methodology for a Geologic Repository at Yucca Mountain (Topical 
Report 11) (YMP 1997a). A planned third seismic topical report will document 'the results of 
both the PSHA Project and the Seismic Design Project. The methodology adopted and used in 
the PSHA Project is described in Topical Report I. This methodology is generally consistent 
with state-of-the-practice guidance provided by the Senior Seismic H ~ a r d Analysis Committee 
(Budnitz et al. 1997). The methodology and acceptance criteria used by the DOE to determine 
the preclosure seismic design of repository SSCs is described in Topical Report II. 
6.1.1 . Objectives 
The objective of the PSHA was to provide ground shaking and fault displacement hazard results 
for both preclosure (100 years) design determination and postclosure (10,000 years or more) 
performance assessment. The governing guidance (Dyer 1999) specifies consideration of two 
categories of preclosure events in the seismic design of the repository SSCs and radiological 
safety. Category-1 events are expected to occur one or more times during the preclosure 
operational period of the facility. Design for these events is required to provide for protection of 
worker safety and for seismic design for ground shaking, with the target hazard established at 
annual exceedance probability (YMP 1997a). Design for Category-2 events is required to 
provide for radiological safety protection of the public during the preclosure period. Groundshaking 
seismic design parameters for these events will be based on hazard at an annual 
exceedance probability of 10" (YMP 1997a). As experience with the design of engineered 
structures for fault displacement is limited, corresponding target hazard levels for determining 
fault displacement preclosure designs are and 10" for Category-1 and Category-2 events, 
respectively (YMP 1997a). Although criteria are defined for fault displacement design, the 
primary approach will be to avoid faults capable of significant movement in laying out a 
repository. For additional discussion of how the PSHA Project relates to ongoing preclosure and 
ANLCRW-GS-000003 REV 00 140f89 
\ \ D A K ~ L ~ - W C ~ M R O J U ~ ~ W C C A M M \ A M R U ~ - I C ~ ~ ~ \ ~ ~ ~ ~ ~ ~ ~ C X . D O C 04118100 
April 2000 

postclosure seismic design efforts, see CRWMS M&O (1998a, Section 1.2) and Topical Report 
11 (YMP 1997a). 
For postclosure, the objective of the PSHA was to provide hazard results for evaluating whether 
future ground motions or fault displacements contribute to any repository events that occur with 
a probability greater than 1 in 10,000 in 10,000 years, and that have significant effects on overall 
performance. Note that an event as applied here to postclosure assessment does not refer to an 
earthquake or ground motion event. Instead, an event is the failure of an SSC to perform its 
functional goal (Dyer 1999, Section 63.2). 
5.1.2 Overview 
As shown on Figure 2, the main activities comprising the PSHA process were (1) multiple-expert 
evaluation and characterization of seismic sources, including the characterization of potential 
fault displacement; (2) multiple-expert evaluation and characterization of vibratory ground 
motion attenuation, including earthquake source, wave propagation path, and rock site effects; 
and (3) computation of hazard results for both fault displacement and vibratory ground motion. 
The experts provided alternative evaluations to characterize uncertainties in their interpretations. 
Based on these alternative interpretations, hazards were calculated and expressed as the annual 
probability at which levels of ground motion or fault displacement will be exceeded. 
The fault displacement hazard was evaluated at nine locations within the Yucca Mountain site 
area (Figure 3). These locations were selected to span the range of known faulting conditions 
within the area of the proposed repository and the associated surface facilities, based on various 
surface (e.g. Day et al. 1998) and subsurface studies (e.g. Beason et al. 1996). Faulting 
conditions ranged from primary block-bounding faults to unfaulted rock, and included sites on 
secondary faults, and on fractures that were assigned displacement histories . representing 
displacement conditions encountered in the Exploratory Studies Facility (ESF).. The specific 
conditions at the nine sites are described in Section 6.3.4. The vibratory ground motion was 
evaluated at a "reference rock outcrop" located near the center of the proposed repository (Figure 
3). The reference rock outcrop is defined as free-field ground surface, at the elevation of the 
proposed repository, 300 m below the repository ground surface at Point A on Figure 4. The 
basis of selection and specific properties of this reference site are discussed further in 
Section 6.3.3.1.1. 
The assessment of seismic hazards at Yucca Mountain relied upon the results of scientific 
investigations carried out over the past 20 years. Building upon earlier investigations of the 
Nevada Test Site region, studies of the Yucca Mountain site have included (1) evaluations of 
faults within about 100 krn for evidence of Quaternary activity; (2) detailed paleoseismic faulttrenching 
studies of active faults near Yucca Mountain to determine the history and 
characteristics of past earthquakes; (3) monitoring of contemporary seismicity; (4) compilation 
of a catalog of historical and instrumentally recorded earthquakes in the Yucca Mountain region; 
(5) development of ground motion attenuation relationships for extensional tectonic regimes, 
which includes the Yucca Mountain region; (6) investigation of local site attenuation 
characteristics; (7) numerical modeling of ground motion from scenario earthquakes; (8) 
evaluation of the tectonic stresses from hydrofracture measurements and earthquake focal 
mechanisms; (9) collection and analysis of geophysical data to assess tectonic models and 
ANLCRW-GS-000003 REV 00 15 of 89 
\UIAK~~~&~~~~\~'UE~~\PROIECTS\WCCAMM\AMRU~~-~~~~~~~)~~CX.DOC 04l18100 
April 2000 

identify subsurface faults; and (10) collection and analysis of geodetic data to measure ongoing 
crustal deformation. Results of many of these studies are summarized in Whitney (1996). This 
extensive database, in addition to the numerous studies performed by nonproject scientists and 
the already existing literature and information, formed the basis for the Yucca Mountain seismic 
hazards analyses. For a complete bibliography of material supplied to the PSHA experts, see 
Appendix B of CRWMS M&O (1998a). 
The method to calculate ground-shaking hazard at a site is well established in the literature 
(Cornell 1968; McGuire 1978, 1995). Basic inputs required to perform a ground-shaking hazard 
calculation at a site are (1) an interpretation of seismic sources that contribute to the site hazard, 
from which conditional probability distributions of distance of earthquakes from the site can be 
obtained; (2) an interpretation of earthquake recurrence for each source, including the mean 
annual rate of occurrence and magnitude distribution of earthquakes; and (3) an evaluation of 
ground-shaking attenuation for the site region, including the mean and standard deviation of 
ground-shaking amplitude as a function of magnitude and distance. These inputs constitute an 
interpretation of the seismotectonic environment of the site. $Given the input evaluations, the 
hazard calculation method integrates over all values of the variables and obtains an estimate of 
the mean probability of exceedance of any ground-shaking amplitude at the site. A plot of these 
results is the well-known seismic hazard curve. The hazard curve quantifies the randomness or 
aleatory uncertainty of the earthquake occurrence and ground-shaking attenuation. The 
calculation method can thus be thought of as an aleatory seismic hazard model. 
111 addition to the aleatory uncertainty of the seismic hazard, however, is epistemic uncertainty 
about the seismotectonic environment of a site. Epistemic uncertainty is due to scientific 
uncertainty about earthquake processes and ground-shaking attenuation and the incompleteness 
of available data for evaluating these processes. Significant advances in development of 
methodology to quantify epistemic uncertainty in seismic hazard have been made in the past 20 
years (EPRI [Electric Power Research Institute] 1986, Volume 1; Budnitz et al. 1997). Thesc. . . . 
advances involve the development of alternative interpretations of the seismotectonic 
~nvironment of a site -by multiple experts and the structured characterization. of epistemic 
uncertainty. Evaluations by multiple experts are made within a structured expert elicitation 
process designed to minimize uncertainty due to uneven or incomplete knowledge and 
understanding (Budnitz et al. 1997). The weighted alternative interpretations are expressed by 
use of logic trees (EPRI 1986, Volume 1). Each pathway through the logic tree represents a 
weighted interpretation of the seismotectonic environment of the site for which an aleatory 
seismic hazard curve is computed. The result of computing the hazard for all pathways is a 
distribution of hazard curves representing the full aleatory and epistemic uncertainty in the 
hazard at a site. For further discussion of aleatory and epistemic uncertainty, see Section 6.5.2. 
Elements of this methodology as applied in the PSHA for the proposed Yucca Mountain facility 
are shown on Figure 2. Epistemic uncertainty was evaluated by six teams of three earth science 
experts, who characterized seismic sources in the Yucca Mountain site region (within a distance 
of about 100 km) and fault displacement potential at the nine demonstration points, and by seven 
ground motion (GM) experts, who characterized ground motion attenuation in the site region 
(see next section for additional discussion of experts and project personnel). Details on the 
criteria and process for selecting PSHA experts are provided in Section 2.3 of CRWMS M&O 
(1998a). 
April 2000 

Interpretations for hazard assessment were coordinated and facilitated through a series of 
workshops. Each workshop was designed to accomplish a specific step in the elicitation process 
and to ensure that the relevant data were being appropriately considered and integrated. An 
important goal in the elicitation process was to reduce variability in interpretations that is due to 
a lack of common understanding of the available data and probabilistic models that are used in 
the analysis. The integrity of the seismic hazard results rests principally on the scientific quality 
and thoroughness of interpretations of the seismotectonic environment input to the hazard 
calculation. It is, therefore, important that the methodology should not constrain the experts' 
input interpretations. To satisfy this important requirement, the methodology was modified to 
accommodate interpretations specific to the Yucca Mountain site as required. These 
modifications were incorporated into the computer code FRISK88 (FRISK 88 V2.0, 10139-2.0- 
00) (Section 6.2) that was used to compute the ground-shaking hazard at the Yucca Mountain 
site. In addition, the code was modified to compute fault displacement hazard using multiple 
interpretations of fault displacement potential as input. The final PSHA results were presented 
as mean, median, and fractile hazard curves representing the total uncertainty (epistemic and 
aleatory) in input interpretations. 
6.13 Project Organization 
The major components and personnel of the PSHA Project organization are shown on Figure 5 
i and Table 3. Four technical teams were formed to plan, organize, and lead the technical 
workshops, facilitate the experts interpretations, and perform hazard calculations: (1) Seismic i Source and Fault Displacement (SSJD) Facilitation, (2) GM Facilitation, (3) Data Management, 
and (4) PSHA Calculations. A Review Panel was formed to provide technical review and 
I guidance to the project. Members of the Review Panel were selected to provide expertise in . 
PSHA methodology and the required input evaluations. The Review Panel provided ongoing 
review throughout the performance of the PSIIA. Panel members attended all workshops, made 
.informal comments during the workshops, and made formal recommendations following each 
workshop. This participatory review allowed the project to make adjustments and take 
I corrective actions throughout the performance of the work. The Panel also reviewed the draft 
final report and made formal recommendations. 
Table 3. SSFD and GM Experts 
-- SSFD Expert Teams 
Team AAR: 
Walter J. Arabasz 
R. Ernie Anderson 
- Alan R. Ramelli 
1 earn ASM: 
Jon P. Ake 
D. Burton Slemmons 
James McCalpin 
Team DFS: 
Diane I. Doser 
Christopher J. Fridrich 
Frank H. (Bert) Swan 
University of Utah 
US. Geological Survey 
Nevada Bureau of Mines & Geology 1 US. Bureau of Reclamation 
Consultant 
GEO-HAZ ConsuWng, Inc. --I University of Texas, El Paso 
U.S. Geological Survey 
Geomatrix Consultants, Inc. 
April 2000 

6.1.4 Quality Assurance 
-- 
SSFD Expert Teams 
Team RYA: 
Albert M. Rogers 
James C. Yount 
Larry W. Anderson 
Team SBK: 
Kenneth D. Smith 
Ronald Bruhn 
Peter L. Knuepfer 
Team SDO: 
Robert B. Smith 
Craig dePolo 
Dennis W. O'Leary 
OM Experts 
John G. Anderson 
David M. Boore 
Kenneth W. Campbell 
Arthur F. McGarr 
Walter J. Silva 
Paul G. Somerville 
Marianne C. Walck 
Note: Teams are named by using the first letter 
The PSHA Project was performed under the USGS Quality Assurance (QA) Program developed 
during that time (August 1994 to June 1998) for the Yucca Mountain Project. This included 
YMP-USGS-QMP-3.16, Rev 0, Scientijk Expert Elicitation (USGS 1996), and a latter 
modification (Rev 0-M1; USGS 1998). The key elements of the program applicable to PSHA 
were personnel qualifications and training, scientific expert elicitation, software controls, records 
management, and data management. Records were submitted to the Records Processing Center 
as per YMP-USGS-QMP-3.16. Personnel qualifications files consisting of position descriptions, 
resumes, and verification statements were collected for PSHA Project members including the 
Affiliation 
GeoRisk Associates, Inc. 
U.S. Geological Survey 
US. Bureau of Reclamation 
University of Nevada, Reno 
University of Utah 
Binghamton University 
University of Utah 
Nevada Bureau of Mines & Geology 
U.S. Geological Survey 
Affiliation 
University of Nevada, Reno 
U.S. Geological Survey 
EQE International Inc. 
U.S. Geological Survey 
Pacific Engineering & Analysis 
URS Greiner Woodward Clyde 
Sandia National Laboratoties 
of each member's last name. 
Management Team, Review Panel, and technical teams. Training iiexpert elicitation and in the 
applicable procedures was provided via workshops and reading assignments. 
At the time that the PSHA was performed, the QARD did not specify requirements applicable to 
scientific expert elicitation. However, the USGS developed YMP-USGS-QMP-3.16, which did 
include appropriate requirements for scientific expert elicitation. Revision 8 of the QARD (DOE 
1998) became effective June 5, 1998 at the end of the PSHA project and it included requirements 
for scientific expert elicitation in Appendix C. These requirements were based on 
NUREG-1563, Branch Technical Position on the Use of Expert Elicitation in the High-Level 
Radioactive Waste Program (Kotra et al. 1996), and implementation of the PSHA Project was 
generally consistent with NUREG-1563. One potential difference in the PSHA project was the 
approach to documenting changes in the experts' interpretations prior to finalizing the results. 
The QARD and the NUREG require the experts to document the reasons for any modifications 
to the& interpretations. within-the struct&d expert elicitation process implemented for the 
PSHA Project, this NUREG requirement was considered to be implicitly met by the workshop 
summaries (CRWMS M&O [1998a], Appendices C and D, workshop summaries). The 
summaries contain descriptions of preliminary evaluations by experts. During the PSHA project, 
April 2000 

additional specific requirements to justify evolving evaluations were considered by the PSHA 
Management Team to have the unacceptable consequence of anchoring and biasing the experts' 
evaluations. During a QA audit of the USGS, DOE'S QA Office compared the USGS procedure, 
the PSHA Project Plan, and implementation of the NUREG guidance to the then-draft QARD 
requirements (DOE 1997). The audit team accepted this position and justification by the PSHA 
Management Team on explicitly documenting changes to the experts' evaluations. 
6.1.5 Limitations 
The PSHA is based on the information and data available at the time of the evaluations (June 
1998). The geology and seismology of Yucca Mountain have been well-studied and the PSHA 
experts were provided an extensive and comprehensive information base fiom which to derive 
their interpretations. As part of their evaluations, the experts provided not only their best 
estimates of seismic source and ground motion parameters but also possible ranges in these 
parameters and their associated uncertainties as allowed by the available data. Thus, these 
interpretations should capture the fill range of models and uncertainty in their evaluations 
considering the extensive available data. As data uncertainty was specifically considered by the 
experts, any new data are not expected to significantly impact the experts' interpretations. 
Additionally, a procedure is currently in place, AP-AC.lQ, Expert Elicitations, by which new 
data that might have significant relevance to the PSHA will be evaluated and its potential impact 
assessed. 
The ground motion hazard has been computed for a location at the approximate center of the site 
area on a reference rock outcrop where a kappa of 0.0186 sec and shear-wave velocity of 1,900 
mlsec was assumed based on limited site-specific data (Sections 6.3.3.1.1. and 6.4). Thus, the 
hazard results are strictly only valid for this reference site condition. An analysis is ongoing to 
develop preliminary seismic design ground motions for the repository, the top of the tuff above 
the repository, and the Waste Handling Building (CRWMS M&O 2000e). The control point 
hazard is generally applicable for any location within the area of the proposed repository, with 
this site condition, although small differences in the hazard are expected near the edges of the 
proposed repository area. 
6.2 PSHA COMPUTER SOFTWARE 
Within the PSHA process, software QA requirements were applicable only to the computer 
codes used for calculating the ground shaking and fault displacement hazards, as per YMPUSGS-
QMP 3.16 (USGS 1996). Any software used by the experts in developing their 
interpretations was considered part of the expert elicitation process and was thus exempted fiom 
QARD software requirements. 
Following the experts' evaluations, the calculations performed as part of the PSHA Project were 
executed using a modified version of FRISK88, a software package, developed by Risk 
Engineering that is accessible through Yucca Mountain Configuration Management (CM). The 
appropriate software configuration identifiers are shown in Table 4. All of the software used for 
seismic hazard cal~ulations was originally documented and verified in compliance with YMPUSGS-
QMP 3.03, Software (USGS 1997). The fill life cycle plan activities and documentation 
included completion of the following: 
ANL-CRW-GS-000003 REV 00 19 of89 
X:\x\x~wRoIEmYucCAMM\AMRUmrm00\amr00m00\amr00taDOC OU19/00 
April 2000 

Software identification form 
Software CM form 
a Requirements specification 
Validation plan 
6 Design description 
User documentation 
a Software validation report 
a Review and verification documentation 
a Documentation for operations and maintenance activities 
Table 4. Software Used in the PSHA Project Calculations 
DPREP (code) 1 1 .O 1 ESP0026.01 1 10141-1 .0-00 
Computer Code or 
Subroutine 
PREP88 (code) 
POST88 (code) 
MRE88 (code) 
The software was appropriate for the application and was used only within the range of 
validation. Recently, the qualification status of all of the computer codes has been reverified 
under AP-SI.lQ, Sofhvare Management, Rev. 1, ICN 0. The verification of the two subroutines, 
MEAN and CMB-FRAC, can be found within Toro (1998). Attachment IJ contains further 
description and explanation of the software used in the PSHA calculations. 
Version 
1 .O 
1 .O 
1 .O 
DRlSK (code) 
FRISK88 (code) 
MEAN (subroutine) 
CMB-FRAC (subroutine) 
63 PSHAINPUTS 
There are three basic types of input developed by the experts for the PSHA: (I) seismic source 
characterization for the ground motion hazard assessment, (2) ground motion attenuation 
characterization, and (3) fault displacement characterization. There is overlap between the 
seismic source characterization for the ground motion assessment and the fault displacement 
characterization; these are discussed separately below for clarity. 
USGS Tracking 
Number 
ESP001 9.01 
ESP0020.01 
ESP0021 .O1 
1 .O 
2.0 
1 .O 
1 .O 
6.3.1 Tectonic Setting and Quaternary Faults at Yucca Mountain 
CM Software 
Tracking Number or 
Reference 
10138-1.0-00 
10136-1 .O-00 
101 40-1 .O-00 
The Quaternary stratigraphy and tectonic setting of Yucca Mountain provides the framework 
necessary for characterizing seismic sources for both the ground motion and fault displacement 
hazard assessments. Therefore, the following section briefly describes the tectonic setting, with 
emphasis on the Quaternary aspects, to provide the needed context for understanding the experts' 
seismic source characterization. A more detailed discussion of the tectonic setting, stratigraphic 
framework, and Quaternary paleoseismicity is included in Whitney (1996) and Section 12.3 of 
the Yucca Mountain Site Description Report (CRWMS M&O 1998b). 
ESP0025.01 
ESP001 8.01 
ESP5.42 
- ESP5.43 
April 2000 
b 10137-1 .0-00 
101 39-2.0-00 
Tor0 (1 998) 
Tor0 (1 998) 

Yucca Mountain is within the Southern Great Basin of the Basin and Range tectonic province. 
Tectonically, the Basin and Range is experiencing extensional strain at a low to moderate rate, 
with !ow to moderate historical seismicity (Figure l), and it has a thin crust. Yucca Mountain is 
located on the south flank of a large Miocene caldera complex. It is considered to be an erosional 
remnant of a 11.4 to 14.0 million-year-old volcanic apron (Fridrich et al. 1999). Structurally, the 
mountain is dominated by subparallel north-trending and east-dipping fault blocks. The blocks of 
ash-flow tuffs are bounded by typical Basin and Range, high-angle, generally west-dipping, 
normal faults formed by rapid east-west extension during the waning phases of Miocene 
volcanism. Secondary intrablock faults are common. 
Although Basin and Range tectonic structure defines the structural pattern of Yucca Mountain 
blccks, the whole proposed repository area lies within the Walker Lane, a 100-km-wide , 
structural belt along the western edge of the Basin and Range province. The Walker Lane is 
characterized by long, northwest-striking and shorter, north-to-northeast-striking, strike-slip 
faults that accommodate much of the early extension in this region. The peak-phase of tectonism 
took place 12.7 to 11.6 million years ago (middle Miocene); and the region has since 
experienced declining strain rates. The current pattern of Quaternary deformation mimics the 
middle Miocene activity, however, at substantially lower rates (Fridrich et al. 1999). 
Within a 100-krn radius of Yucca Mountain, more than 100 Quaternary faults were identified as 
potential seismic sources (Figure 6). With the exception of the Death Valley-Furnace Creek-Fish 
Lake Valley fault system, these faults are interpreted to have low slip rates (SRs) (generally less 
than 1 rnrntyr). 
I 
The faults closest to Yucca Mountain are the most important to vibratory ground motion and 
fault displacement hazards (Figure 6). Within 10 krn of the proposed repository 8 of 14 mapped 
faults show evidence of multiple surface-rupturing earthquakes during the Quaternary. These 
faults are characterized by trace lengths shorter than 26 km, SRs of 0.001 to 0.05 mmlyr, and 
average recurrence intervals of 20,000 to 100,000 years (e-g. Whitney 1996). Several faults are 
spaced only a few krn apart and may merge at depth. Pdeoevent data modeled from all trench 
studies suggest that distributed faulting may have been common at Yucca Mountain (Pezzopane 
et al. 1994). 
6.3.2 Seismic Source Characterization for Ground Motion Assessment 
The objective of seismic source characterization for the ground-shaking PSHA was to identify 
and characterize the seismic sources capable of producing earthquakes significant to groundshaking 
hazard at the site. Evaluations were conducted following the structured elicitation 
process that was adopted for the project, which included information assimilation and 
interpretation workshops and individual team elicitations. The process was facilitated by the 
SSFD Facilitation Team. The elicitation process included a total of six workshops and a 1-day 
elicitation meeting with each team (Figure 2). Each SSFD expert team evaluated seismic sources 
for ground motion and fault displacement hazard computation. The evaluations included 
alternative interpretations, each weighted to express the teams' uncertainty. 
Two basic types of seismic sources were evaluated and characterized by the SSFD experts: fault 
specific sources and areal seismic source zones. Both local faults (defined here as .within about 
ANL-CRW-GS-000003 REV 00 21 of 89 
\ ~ A K ~ ~ ~ ~ ~ ~ ~ ~ ~ \ ~ - W C ~ W R O I E C ~ Y U O C A M T M A M R ~ - ~ C ~ ( ~ ~ \ ~ ~ ~ ~ ~ ~ I C L W C 04/18/00 
April 2000 

10 km) and regional faults (to a distance of about 100 km) were evaluated. Areal source zones 
were defined to represent zones of distributed seismicity not apparently associated with known 
specific faults, and were also used by some teams to characterize known structures that were not 
explicitly included as fault-specific seismic sources. 
Detailed descriptions of each expert team's seismic source characterization for the ground 
motion hazard assessment can be found in Appendix E of CRWMS M&O (1998a), and 
summaries of the evaluations can be found in Section 4.3 of CRWMS M&O (1998a). Table 5 is 
from Section 4.3 of CRWMS M&O (1998a) and it summarizes the key components of each 
team's seismic source characterization model, including issues regarding tectonic models and 
potential seismic sources (areal seismic source zones, regional faults, and local faults). Although 
tectonic models are not seismic sources per se in the PSHA, they are included in Table 5 because 
their evaluation was integral to development of seismic source characterization models. 
Tectonic models provide the framework that can help define or constrain some seismic source 
parameters, such as maximum seismogenic depths, fault dips, rupture models, and probabilities 
of activity. Thus, uncertainty in tectonic models was an integral part of seismic source 
characterization and this uncertainty is fully captured in the hazard results. The following 
sections discuss the overall treatment of the three main types of seismic sources. 
6.3.2.1 Imal Fault Specific Seismic Sources 
An important part of the evaluations by the SSFD experts focused on characterizing the local 
fault-specific seismic sources due to their proximity to the site (figure 6). The local Yucca 
Mountain faults can be subdivided into three categories: (1) north-striking block-bo~mding faults, 
(2) northwest-striking faults, and (3) intrablock faults. The close spacing between faults, their 
anastornosing pattern, and their relatively short lengths suggest that the local faults may be 
structurally interconnected either along strike or at depth and, thus, may rupture either partially 
or fu!ly together. 
The local faults were characterized in terms of their rupture behavior, probability of activity, 
locations, rupture lengths, sense of slip, fault dips, maximum seismogenic depths, maximum 
magnitude (M,,), and rate of activity. Their geometric characterization depended on the 
experts' evaluations of the tectonic models. Parameters for the most significant local faults are 
shown in Table 6, and include the block-bounding Paintbrush Canyon, Bow Ridge, Stagecoach 
Road, and Solitario Canyon faults (Figure 6). 
The parameters in Table 6 (also Table 7) generally show the range of preferred values interpreted 
by the expert teams. Note that because the expert teams varied considerably in their fault 
characterizations, particularly with regard to interpretations of independent seismic sources and 
linked or combined fault sources, not all teams characterized the faults individually as listed in 
Table 6. Approaches used to evaluate the M, for faults were based on empirical relationships 
between magnitude and surface-rupture length (SRL), rupture area (RA), and/or maximumdisplacement 
(MD) and average displacement (AD). M,, values ranged from Mw 5.7 to 6.8 for 
some of the linked systems. Earthquake recurrence rates for the faults were described using 
either recurrence intervals and/or SRs with most teams using the latter due to the lack of 
ANL-CRW-GS-D00003 REV 00 22 of 89 
\ \ O A K ! ~ ~ ~ ~ ~ Y ~ ~ ~ - ~ ~ M P R ~ ~ E C T S \ W C C A M T M A M R \ A ~ ~ - ~ C ~ - ~ ~ ~ . W C W181W) 
April 2000 

Table 5. Summary of Seismic Source Characterizations for Ground Motion Hazard Assessment a able 4-1 of CRWMS M&O 1998a) 
Issue 
TECTONIC MODE1 
Overall Approach 
Planar Block- 
Faulting Models 
AAR Team I ASM Team 1 DFS Team I I SBK Team 1 RYA Team SM) Team 
Viable models based on 
observations and 
inferred processes for 
the Crater Flat structural 
domain, with simple 
shear model given full 
weight (1 .O). 
Superposed NW-SE 
dextral shear manifested 
as specific structures 
(tectonic models A, 6, & 
C) (0.5) or not (tectonic 
model D) (0.5). 
Regional faults are 
modeled as independent 
and linked (for selected 
faults) planar faults to 
maximum seismogenic 
depth. 
Local faults include 
linked and coalesced 
models; planar faults to 
maximum seismgenic - 
depth, to depth of local 
detachment, or in some 
cases to a depth 
constrained by allowable 
aspect ratio or by 
intersection with a 
higher-order fault. 
The source model 
incorporates various 
aspds of planar block fault 
(preferred), detachment, 
iateral shear, and volcanictectonic 
models. 
Regional faults are modeled 
as independent planar faults 
to maximum seismogenic 
depth. 
Local faults-the preferred 
model Is that the faults are 
planar b a depth controlled 
by the brittleductile 
transition and the Bare 
Mountain fault: treated as 
independent and coalescing 
faults that merge at dep?. 
structural models are presented provides a unified 
characterization of local seismic, geologic, and 
faults: geophysical data. 
domino model (0.8) Alternative tectonic and 
Iolanar fault): structural models are 
detachment'(0.2) I considered primarily in the 
nncludes hv~othetical characterization of local 
hdden stril&lip fault of 
either local or regional 
extent ). 
faults. A coalescing fault 
model best fits the Yucca 
Mountain area. 
to maximum seismogenlc 
depth. 
I 
Local faults-include 
models of independent 
(0.95) and distributed (0.05) 
fault behavior; alternative 
structural models (dominoplanar 
and detachmentlistric) 
used to constrain 
downdip geometry and 
extent. 
Regional faults are modeled 
as lnde~endent ~lanar faults 
Independent planar faults to 
maximum seismogenic 
depth. 
Bare Mountain and regional 
faults are modeled as 
Local faults--planar to listric 
(1 to 3 coalescing systems). 
Preferred model: 
oblique rift-planar faults. 
Threedimensional 
strain accommodated 
on planar, strike-slip, 
normal, and oblique-slip 
faults. Rock Valley and 
Highway 95 faults act as 
accommodation zones 
in the rift. 
Regional faults are 
modeled as independent 
planar faults to 
maximum seismogenic 
depth. 
Local faults-Yucca 
Mountain faults are part 
of a half-graben, with 
Bare Mountain as the 
master fault, 
predominantly normal 
slip with a left-lateral 
component. 
Alternative tectonic and 
structural models are 
considered in the 
characterization of local 
faults. Preferred model for 
Crater Flat - Yucca Mountain 
k a half-graben formed within 
a larger rift that opens and 
deepens to the north. 
Deformation history and 
structure are associated with 
carapace effect, clockwise 
vertical axis rotation, basaltic 
volcanism, age and behavior 
of Bare Mountain fault. 
Regional faults are modeled 
as independent planar faults 
to maximum seismogenic 
depth. 
Local faults: 
half-graben model 
(1) end member-all Yucca 
Mountain faults are 
seismogenic, continuous 
planar faults to maximum 
seismogenic depth. 
(2) carapace effect--only 
major Mock-bounding faults 
are throuah-the-crust 
seismogckic faults; other 
intrablock faults are confined 
to the carapace (i.e., are 
aseismic) or link to faults 
having different attitudes and 
aspect ratios below the 
unconformity. 
ANLCRW-GS-000003 REV 00 
X:\r~s\PROJECTS\YUCCAMTMAMR\Am-mvOO\TABLESR00.DOC Ul&PO - 
April 2000 

Table 5 (Continued) 
Issue 
Shear Models 
(buried strike-slip 
faults or fault 
systems) 
Detachment Models 
AAR Team 
Included three 
alternatives: 
Model A - Throughgoing 
regional dextral shear 
zone (0.05); 
Model B - right-stepping 
dextral shear zone that 
produces a pull-apart 
basin WITHOUT an 
underlying cross-basin 
fault (0.6); and 
Model C - right-stepping 
dextral shear zone that 
produces a pull-apart 
basin WITH an 
underlying cross-basin 
fault (0.35). 
Regional detachment 
not viable (0.0), but 
hypothesized local 
detachments included, 
with weights dependent 
on the type of dextral 
shear structures 
assumed to be present. 
Local detachments not 
included as specific 
seismic sources; 
detachments affect only 
downdip fault extent for 
local fault sources. 
Depths induded for local 
detachments range from 
3 km to the maximum 
thickness of the 
seismogenk crust, with 
3 to 10 km preferred. 
ASM Team 
Model 1 -Continuous, long 
(240-kml strikesb fault 
zone as proposed'by 
Schweikert considered. 
Regional (60-km-long) 
sbike-slip fault given low 
weight. 
Model 2 - Shorter (25-km), 
more complex or 
segmented zone. 
Assessment of existence of 
buried strikeslip fault 
condiiional on whether or 
not detachment exists; 
assessment of the 
seismogenic potential of the 
buried strike-slip fault is 
conditional on the depth of 
the detachment (shallow- 
0.8, moderate-0.6, deep 
0.0). 
Detachment Model (0.1 5): 
Hypothesized detachment 
affects down-dip geometry 
and extent of local fault 
sources; seismogenic 
detachment Is included as 
possible fault source with 
very low probability (see 
below). 
DFS Team 
Model allows for component 
of northwest-directed rightlateral 
strikeslip strain. 
HypoWtical hidden strikeslip 
fault source (probability 
of activity [P J = 0.05) is 
included in detachment 
model. 
Two postulated strikeslip 
fault sources are lncluded: 
regional strike-slip fault 
(0.5) 
local strikeslip fault (0.5) 
Detachment Model (0.2): 
Hypothesized detachment 
chiefly affects down-dip 
aeometn, and extent of local 
{auk sokes; seismogenic 
detachment Is included as 
possible fault source with 
very low probability (see 
below). 
ANLCRW-GS-000003 REV 00 
X\rrc(s\PAOJECTS\WCCAMTWR\Amr-revOO\TABLE5RW00M>C 4/18/00 
Page 24 of 89 
buried source covered by 
background source). 
Detachments are not 
explicitly modeled. 
Possibility that local faults 
truncate down dip in a 
detachment or zone of 
decoupling Is included in 
coalescing fault model. 
SBK Team I SDO Team 
A buried reaional shear I Three sources of dextral 
zone modeiis given low 
weight (0.01); no 
evidence for a buried 
strike-slip fault trending 
northwest across Crater 
Flat that would result in 
a earthquake larger than 
the maximum assigned 
to the host source zone. 
detachment affects only I (modeled as an Independent 
shear were evaluated to 
account for vertical axis 
rotation at Yucca Mountain: 
(1) distributed shear 
(restricted to Crater Flat 
basin; basin Is a discrete 
domain controlled by local 
bounding faults); (2) extemal 
transcurrent strike-slip fault 
(passes through the basin, 
totally hidden); and (3) 
extemal strike-slip fault 
enters basin from southeast 
(manifested at Yucca 
Mountain by the N25"W 
striking %ingeline")nd 
terminates In Crater Flat. 
Only (1) and (3) are credible 
modifications to the basic 
model. . 
Hypothesized 
the down-dip extent of - source) was thoroughly 
local fault sources. I considered but could not be 
substantiated bv the available 
A seismogenic detachment 
April 2000 

Table 5 (Continued) 
Issue I AAR Team 
Volcanic-Tectonic I The ~ossibilitv of 
Models ("ash event") simultaneou~rupture on 
subparallel Yucca 
Mountain faults as 
postulated for the "ash 
evenr is included in 
coalesced fault models 
for local faults. 
-- 
ASM ~e&n 
The ~ssibility that some 
surface rupturing 
eatthquakes in Crater Fiat 
are accompanied by dike 
injection (e.g., the 70-ka 
'ash evenr) is included in 
simultaneous rupture 
models for local faults. 
DFS Team I RYA Team 
The possibility of I The coalescing fault model 
simultaneous-rupture on used to model-local faults 
subparallel Yucca Mountain (see below) would explain 
faults as postulated for the the apparent sychroneity of 
'ash event' is included in faulting on Yucca Mountain 
the distributed faulting faults (is., the 70 ka 'ash 
model for local faults. event"). 
Thickness of Dmaxl 12 (0.1) 12 (0.6) 12 km 
15 14 15 km 
(0.2) 
Seismogenic Crust 11 km (0.185) (0.6) 
16 
(0.3) 
17 20 km 
(0.7) 
15 km (0.63) (0.3) (0.1 1 (0.1) 
Zones-- 
Recurrence 
Four scenarios: 
Scenario I w13 zones 
(0.3), Scenario II w/2 
zones (0.3), Scenario Ill 
w/3 zones (0.3), and 
Scenario IV wll zone 
(0.1). 
For all scenarios, a host 
zone (within 20-km 
radius) is defined only 
for assigning a lower 
Meat for separate 
recurrence estimate. 
Truncated exponential 
recurrence rnodel (1 .O) 
300-km radius catalog 
Version 7 (1 .O) 
Adjustment made for 
underground nuclear 
explosions in relevant 
source zones. 
Two source zones within 
100-km radius of site. A 
local zone (within 50-km 
radius) is induded that is 
defined solely for assigning 
a lower M-. 
Truncated exponential 
recurrence rnodel (1 .O) 
300-km radius catalog 
Version 7 10.7) 
Version 5 (0.3j 
Adjustment made for 
underground nuclear 
expiosions. 
Model A (0.2) 
One zone 
Model B (0.8) 
Three zones 
Both models include a local 
zone that Is defined for 
constraining Mm, in the 
area of the detailed site 
characterization studies. 
Truncated exponential 
recurrence model (1 .O) 
300-km radius catalog 
Version 7 10.5) 
Version 5 io.5j 
Three primary source zones 
within 100 km of site; 
two alternative 
configurations to model 
Zone A (local Yucca 
Mountain region) and Zone 
B (the zone surrounding 
Zone A). 
SBK Team I SDO Team 
Explicitly models a ( Distributed fault models 
simultaneous rupture involve simultaneous rupture 
event (triggered by I of local faults that are parallel 
volcanic event: see to each other. Such models 
Local Fault ~odei) would account for volcanism 
and tectonic faulting as a 
coupled process. 
Model A (0.7) 
3 zones 
Model B (0.3) 
4 zones 
Both models include a 
local zone that is 
defined solely for 
assigning a lower M,. 
Truncated exponential Truncated exponential 
recurrence model (1 .O) I recurrence model (1 .O) 
100-km radius catalog 100-krn radius catalog 
Version 5 (0.5) Version 7 10.3 to 0.6) 
Version 7 (0.5j version 5 (0.4 to 0.7j 
Weights vary depending 
on source zone. 
In relevant zones, 
adjustments made for 
underground nuclear 
explosions weighted 
(0.4) versus no 
adjustment (0.6). 
Eight source zones within a 
300-km radius of the site 
were considered initially, but 
only 3 remained given a filter 
of radius 400 km. 
Truncated exponential 
recurrence model (1 .O) 
300-km radius catalog 
Version 5 (0.6) 
Version 7 (0.2j 
Version 8 (0.2) 
ANLCRW-GS-000003 REV 00 Page 25 of 89 April 2000 

Table 5 (Continued) 
AAR Team 
For Scenarios I - 111: . - - - .~ . - 
Uniform (1 -0). 
For Scenario IV: 
h-5 km (0.25) 
h = 10 km (0.5) 
h = 20 km (0.25) 
Excluding Host Zone 
6.6 10.3) 
Host Zone (within 20 
km) 
6.0 (0.3) 
6.3 
6.6 
(0.4) 
(0.3) 
19 regional fault 
sources; includes faults 
with Pa of <1 .O; includes 
two possibly linked fault 
systems: Death Valley 
with Furnace Creek 
(0.8), and Arnargosa 
River with Pahrump 
(0.1); also indudes five 
faults considered as 
segmented (ma. 
rupture length <total 
fault length); included 
range of rupture lengths 
for each source. 
Preferred dips: 
normal 65" 
strike-slip 90" 
ASM Team 
Uniform (1 .O) 
Walker Lane 
6.5 (0.185) 
Basin and Ranae 
Site Region (within 50 km) 
6.0 (0.185) 
6.3 (0.63) 
6.6 (0.185) 
24 regional faults (within 15 
to 100 km of site); all fault 
sources active (1.0); 
considers alternative total 
lengths, generalized 
downdip geometry (strikeslip 
WO, normal 60"). 
DFS Team 
Model A: 
h = 10 km (0.25) 
h=25km (0.6) 
Uniform (0.1 5) 
Model 8: 
h=lOkm (0.22) 
h = 25 km (0.53) 
Uniform (0.25) 
Model A (not including site 
vicinity) 
7.0 (0.2) 
7.3 
7.7 
(0.6) 
(0.2) 
Model B (not includmg site 
vicinity) 
SW Walker Lane 
7.0 . (0.2) 
7.3 
7.7 
(0.6) 
(0.2) 
NE Walker Lane and Bash 
and Range 
7.0 (0.2) 
7.25 (0.6) 
7.5 
Site Vicinitv 
(0.2) 
18 regional fault sources 
(within 100 km of site 
hcinity); all fault sources 
active (1.0); considered 
alternative total lengths, 
generalized downdip 
geometry (strike-slip WO, 
normal-60"). 
Page 26 of 89 
RYA Team 
Uniform (0.4): 
11 regional fault sources 
[within 100 km of site): all 
fault sources active (1 .O); 
Includes possibility (0.1) of 
simultaneous rupture of 
Death Valley and Furnace 
Creek faults; includes 
sltemative rupture lengths 
for 9 faults, generalized 
lowndip geometry (strikeslip 
WO, normal 60"). 
SBK Team 
Uniform (1 .O) 
Excluding Local Zone: 
6.2 (0.2) 
Local Zone 
5.6 (0.2) 
6.0 
6.2 
(0.6) 
(0.2) 
16 regional fault sources 
(within 100 km radius); 
includes faults with Pa < 
1 .O; includes range of 
rupture lengths for each 
source-for long faults 
ranges reflect probable 
rupture segment 
lengths, assigned dips 
based on fault type, with 
preferred values of: 
strikeslip WO, normal 
W", and oblique 70". 
SDO Team 
Uniform (0.51 
Within 100 km 
6.4 t 0.2 
cumulative lognormal 
distribution 
6.2 (0.03) 
6.4 (0.5) 
6.6 (0.97 
Beyond 100 km: 
estimated from a correlation 
af fault length with magnitude 
for longest fault: in Zones 2 
and 3 Ms 7.4 i 0.2 
36 regional fault sources (24 
faults (Pa 1.0), 12 faults (Pa 
< 1.0); two faults generally 
outside 100 km (Panamint 
Valley and Ash Hill fault 
zone) Included; altemative 
total lengths, generalized 
downdip geometry (strikeslip 
WO, normal 60"). 
April 2000 

Table 5 (Continued) 
Issue 
Regional Faults- 
Mmax 
Regional Faults-- 
Recurrence 
Approach 
Local Fault 
Sources 
AAR Team 
SRL (0.4); 
RA (0.2); 
SRL and slmp (0.4) 
SR Approach (0.6); 
Recurrence Interval 
Approach (0.4) - where 
data are available. 
Characteristic (0.7) 
Modified exponential 
(0.3) 
DV -FC 
Characteristic (1 .O) 
b-value 
0.80 (0.3), 1.00 (0.4), 
1.20 (0.3) 
20 individual faults 
included w/ probability of 
being seismic (P[s]) 0.1 
to 1 .o 
Synchronous Behavior 
Approach: 
(1) Faults rupture 
independently or are 
grouped in distributed 
systems by linkages 
along strike or 
coalescence down dip. 
(2) Likelihood of 
coalesced behavior is 
dependent on tectonic 
model (in general, 
coalesced behavior 
strongly favored over 
independent behavior). 
(3) Four coalesced 
models defined with 
from one to four fault 
systems. Assigned 
weights depend on 
ASM Team 
SRL (1 .O) 
SR Approach (0.5) 
Recurrence Interval (0.5) , . 
or Slip Rate (1 .O) 
depending on available 
data. 
Characteristic (0.2) 
Maximum moment (0.8) 
b-value varies from fault to 
fault. 
Planar Fault Block Model- 
5 faults modeled as major 
block-bounding faults 
(seismogenic-1 .O) 
5 faults modeled as minor or 
secondary faults (probability 
of being seismogenic-fault, 
PA ranges from 0.5 to 0.9). 
Simultaneous rupture 
models are based on the 
probability of linkage at 
depth (geometric 
constraints) and temporal 
overlap inferred from 
paleoseismic data. 
DFS Team 
SRL (1 .O) 
Alternative rupthe ' 
segments (SRL) are 
considered resulting in a 
range of Mm, for each fault. 
M, * % unit (with some 
exceptions) 
SR Approach (1 .O) 
Characteristic (0.6) 
Maximum moment (0.3) 
Truncated exponential(0.1) 
b-value varies from fault to 
fault. 
Two Fault Behavioral 
Models: 
Distributed (0.05) 
9 scenarios 
Independent (0.95) 
Two Structural Models: 
Domino model (0.8) 
(high-angle planar faults to 
seismogenic depth except 
where they intersect largerthrow 
fault); existence of 
H95 fault not dependent on 
domino model-considered 
as an Independent source 
with low probability of being 
an active seismogenic 
structure. 
Detachment model (0.2) 
listric geometry 
detachment modeled at 6 
km depth; includes hidden 
strike-slip fault sources. 
RYA Team 
SRL 10.351 
RA io.35j 
MD 
or 
(0.3) 
Rupture Length (RL) (0.5) 
RA (0.5) 
depending on ava~lable data 
Mmw * 0.5 unit 
SR Approach (1 .O) 
Characteristic (0.9) 
Truncated exponential(0.1) 
b-value 
1.07 (0.185) 
1.12 
1.2 
(0.63) 
(0.1 85) 
Mmln = 6.3 
Coalescing Fault Model 
(1 .O) 
Bare Mountain fault, 
independent planar fault to 
seismogenic depths. Yucca 
Mountain faults are 
assumed to coalesce down 
dip at relatively shallow 
depth (2 to 5 km). Windy 
Wash, Sditario Canyon, 
and Paintbrush Canyon 
faults are primary 
independent seismogenic 
faults in threefault system. 
Coalescing Models: 
12 km (0.2) and 15 km (0.7) 
seismogenic depth: 
l-fault system (0.1) 
2-fault system (0.5) 
3-fault system (0.4) 
20 km (0.1) seismogenic 
depth 
l-fault system(0.3) 
SBK Team 
SRL. RA. MD. AD, and 
moment app&ches; 
weighted on a fault 
basis depending on 
available data. 
Mmax t % unit, Mmw + 
% =mu 
SR and Recurrence 
Interval Approaches; 
weights vary from fault 
to fault depending on 
available data. 
Characteristic and 
truncated exponential 
models used. Weights 
vary from fault to fault, 
with characteristic 
behavior favored for 
range-bounding faults, 
and exponential for 
zones with multiple 
distributed traces. 
b-value varies from fault 
to fault. 
Within Crater Flat 
domain, included 11 
individual faults (9 YM, 
BM, and Hwy 95); 
excluded 7 mapped 
faults based on no or 
low rates of Quaternary 
activity(P~ = 0) 
(mcluding Ghost Dance 
and Sundance faults). 
Modellocal 
faults sde Into 
detachment between 5 
km and base of 
seismogenic zone(0.01). 
Model- 
Mock-bounding faults 
coalesce at depth either 
in one or two master 
Faults (0.09) 
Model (end member) - 
4 linked block-bounding 
SDO Team 
RL, MD, RL x MD, SR +RL; 
weighted on a fault-specific 
basis depending on available 
data. 
M ~ x * % unit, Mmax + % = 
mu 
Moment rates (SRs) 
Characteristic (0.7) 
Truncated exponential (0.3) 
b-value varies from fault to 
fault. 
Mmin = 6.2 
Behavior models included: 
(1) single-fault 
(2) linked-fault 
(3) distributed-fault 
Single-fault scenarios - 
6 major local faults 
9 linked-fault scenarios 
8 distributed fault scenarios 
ANLCRW-GS-000003 REV 00 Page 27 of 89 April 2000 

Table 5 (Continued) 
Issue I AAR Team 
I tectonic models, but 
models having three to 
four systems are 
strongly favored. 
(4) For independent fault 
behavior, two cases of 
possibly linked faults are 
generally favored. 
Preferred dip 60". 
Dominantly normal slip 
wl left-lateral 
component. 
Local Faults-M, Subsurface RL (for 
buried structures) or 
SRL (all others) 
SRL + slip 
Moment Equation Y Dierent weights 
assigned depending on 
fault length (c or 2 25 
km), tectonic model, and 
coalesced behavior 
model. 
M-i % unit, 
Mmax+W=mU 
ASM Team 
General weights 
SRL (0.31 
Modified on a fault basis 
depending on available 
data. 
DFS Team 
. , * 0.25 units 
RYA Team 
2-fault system(0.4) 
Sfault system(0.3) 
Planar fault and 
detachmentdecoupled 
model geometries are 
considered part of range of 
behavior for coalesced 
systems. 
RL (0.5) 
RA * 0.5 units 
(0.5) 
SBK Team 
faults (0.4) 
Model (end member) - 
faults behave 
independently 
(0.5) 
All of the above models 
include a simultaneous 
rupture scenario that 
acts as an additional 
source; weights on 
activity vary according to 
rupture model (0.1 on 
independent and linked; 
0.5 on detachment and 
coalescing models). 
SRL, RA, MD, AD, 
Seismic Moment 
inferred from stress 
drop; weights vary 
depending on available 
data. 
SDO Team 
RL (0.206) 
MD (0.104) 
RL x MD (0.207) 
RA (0.207) 
SRL + slip (0.069) 
Seismic Moment (0.207) 
Mma t W unit, 
Mma+W=mU 
ANL-CRW-GS-M)(KXn REV 00 Page 28 of 89 April 2000 

Table 5 (Continued) 
Issue 
Local Faults- 
~ecu&nce lnierviil 
Approach (0.4) - where 
data are available. 
Characteristic (0.7), 
Modified exponential 
(0.3) 
-- 
OTHER SOURCES 
Regional strikeslip fault 
50 to 100 km in length 
Buried Regional 
Dextral Shear Zone 
Seismogenic 
Detachment 
Included w/ P[s] = 1.0 
for Tectonic Model A 
(0.05). 
(modeled as 
independent source) 
No (possibility is 
covered by areal source 
zone). 
ASM Team 
SR Approach (0.5); 
~ecuiknce Interval 
Approach (0.5) 
Characteristic (0.7) 
Truncated Exponential (0.2) 
Maximum moment (0.1) 
Yes; see above. 
MMAX 
Mw 7.1 (0.3) 
60-km rupture 
Mw B.7 (0.7) 
25-km rupture 
SR 
0.1 mmlyr (0.6) 
0.025 mmlyr (0.2) 
0.24 mmlyr (0.2) 
Detachment Model (0.1 5) 
Probabili-seismogenic 
(0.01) 
Depth to detachment 
6 km (0.25) 
(BD6) 1 2- 6 km (0.5) 
60 (0.25) 
BD=brittleductile transition 
Mm'mum magnitude 
7.1 (0.15) 
7.6 
8.0 
(0.7) 
(0.15) 
SR 
0.05 mmlyr (0.6) 
0.013 mmlyr (0.2) 
0.12 mmlyr (0.2) 
Mean Recumnce 
25 kyr (0.15) 
DFS Team 
SR Approach (1 .O) 
Independent behavior- 
Characteristic (0.6) 
Maximum moment(0.3) 
Exponential (0.1) 
Distributed behavior- 
Characteristic (0.6) 
Maximum moment(0.2) 
Exponential (0.2) 
Includes a hypothetical 
strike-slip fault of regional or 
local extent, with low 
probability (0.05) that it is a 
seismogenic source. 
Local strike-slip fault (0.5) 
30-km length. 
Regional strike-slip fault 
(0.5) 
200-km length. 
Yes (Paintbrush Canyon 
!Stagecoach fault in the 
detachment model (0.2) is 
modeled as a shallowdipping, 
seismogenic source 
t h ~ t extends beneath the 
Crater Flat Basin). 
RYA Team 
SR Approach (0.7) 
Recurrence Interval 
Approach (0.3) 
Characteristic and 
truncated exponentialweights 
vary depending on 
coalescing model used. 
Not included as fault source; 
possible buried strike-slip 
fault judged incapable of 
producing earthquakes 
larger than the maximum 
background earthquake or 
any other source included in 
the source model. 
Possibility of a seismic 
detachment is excluded. 
SBK Team 
SR ADDroach 
Recurrence Interval 
Approach (used where 
data are available, but 
given lower weight, 0.2 
to 0.3) 
Both characteristic and 
truncated exponential 
models used (weight 
varies depending on 
fault model) 
-- - 
Not included as fault 
source; possibility is 
covered by seismic 
source zone. 
No (shallow and deeper 
detachments as active 
seismogenic structures 
are given no weight). 
Hypothesized 
detachments affect only 
d m d i p fault extent of 
Yucca Mountain faults; 
depth is dependent on 
Bare Mountain fault. 
SDO Team 
Moment Rate (0.33) 
Average Recurrence interval 
(0.33) 
intekeismic Recurrence 
Interval (0.33) 
Characteristic (0.7) 
Truncated exponential (0.3) 
Yes; see above. 
Fault Length 
20 km (minimum) 
27 km (preferred) 
120 km (maximum) 
SR 
0.001 (minimum) 
0.005 (preferred) 
0.02 (maximum) 
A seismogenic detachment 
(modeled as an independent 
source) was thoroughly 
considered but could not be 
substantiated by the available 
evidence. 
ANLCRW-GS-000003 REV 00 Page 29 of 89 April 2000 

Table 5 (Continued) 
Issue 
Volcanic Source 
Zone (basaltic) 
Gravity Fault 
Cross-Basin Fault 
Highway 95 or 
Carrara Fault 
AAR Team 
No (possibility is 
covered by areal source 
zone). 
Considered distinct from 
Ash Meadows fault, 
which is included as a 
regional fault; accounted 
for in assessment of 
M, for background 
source zones >20 km 
from site. 
lncluded wl P[s] = 1 in 
Tectonic Model C (0.35) 
Included wl: P[s] = 0.5 
for Tectonic Model A 
P[s] = 0.8 for Tectonic 
Models B & C. 
ASM Team 
75 kvr 10.7) 
No (maximum magnitudes 
for volcanic-related 
earthquakes are less than 
M, for fault and 
background seismic zones, 
and recurrence rate for 
volcanic eruptive events is 
estimated to be insignificant 
compared to seismicity 
rates). 
Not discussed. Ash 
Meadows fault is included 
as regional fault source 
(probability of activity 1.0). 
Includes local buried strikeslip 
fault with low probability 
(see above); preferred 
length (25-km) (0.7) based 
on down-on-east segments 
along the west side of 
Crater Flat. 
Carrara fault characterized 
as active (PA = 0.85) 
regional fault source. 
DFS Team 
No (possibility is covered by 
seismic source zones). 
AmargosalGravity (Ash 
Meadows) fault is lncluded 
as regional fault source 
(probability of activity 1.0). 
A local hidden strike-slip 
fault Is included with a low 
probability (PA = 0.05) in the 
detachment model for local 
faults. 
Included with low probability 
(PA = 0.1) as a hypothetical 
regional source. 
Yes (0.7) 
Spatial location (basaltic 
cones in site vicinity). 
Preferred return qriods 
2~10~and2x10 
M,,, = 5.5. 
Not discussed. Ash 
Meadows fault included as 
regional fault. 
- 
SDO Team RYA Team 
Not explicitly included in 
SSC model; see comment 
above regarding buried 
strike-sli~ faults. 
SBK Team 
lncluded as potential 
northern extension of 
the Ash Meadows fault 
(0.1). 
No (possibility is 
covered by seismic 
source zones). 
Recurrenc+2 to 3 volcanic 
events per Ma 
Maximum magnitude 
distribution for volcanic 
events: 
6.0 i 0.2 (0.1) 
5.8 i 0.4 (0.6) 
5.5 i 0.3 (0.3) 
Defines two volcanic sources 
with probabilities of 0.25 and 
0.7. 
Characterized as a regional 
fault source, probability of 
activity (0.9). 
characterizdas a buried 
strike-slip fault. 
Not included. Based on evidence lor 
distributed dextral faulting, 
the hingeline-pahrump- 
Stewart Vallev fault is 
I fault source). 
I 
ANL-CRW-GS-000003 REV 00 
X:\rwcfs\PROJECTS\WCCANITN\AMRVhv-rev00\TABLESRW.OOC 4/18/00 
Page 30 of 89 
Highway 95 fault assigned a 
probability of 0.2 (regional 
Not included. 
April 2000 
Included as independent 
fault source (PA = 0.4). 

recurrence interval information. Preferred SRs ranged from about 0.001 mdyr (Crater Flat 
faults) to 0.05 mmlyr (Stagecoach Road fault). Some of the linked faults were assigned slightly 
higher SRs. Four recurrence models were used depending on the teams' evaluations: 
characteristic, truncated exponential, modified truncated exponential, and maximum moment. 
Based on available displacement per event data, the characteristic recurrence model was favored 
by most teams for local fault sources. 
In the characterization of local faults, alternative faulting behavior and structural models were 
evaluated by the SSFD expert teams to capture the range of complex rupture patterns and fault 
interactions. Based on extensive discussion and consideration of available geologic and 
geophysical data, a planar-fault block model was preferred by most teams; along-strike linkages 
or down-dip coalescence were interpreted by all teams. Simultaneous rupture of multiple faults 
was also included in all of the teams' interpretations. Five teams gave weight to detachment 
models with low probabilities to constrain the extent and geometry of the local faults, while 
others included the detachment itself as being seismogenic (Table 5). 
Table 6. Fault Parameters of Significant kocal Faults 
Considered by SSFD Experts 
Notes: ' Only significant and potentially independent fault sources are included here; see Appendix E of CRWMS M&O 
(1 998a) for complete discussion of all local fault sources including multiple fault rupture scenarios. * Range of preferred values interpreted by the expert teams 
Approximate shortest distance to repository 
4 LL = Left-lateral strike-slip; N = Normal slip 
6.3.2.2 Regional Fault Specific Seismic Sources 
Regional faults are those faults within about 100 krn of Yucca Mountain that were interpreted as 
capable of generating earthquakes of Mw 5 or greater based primarily on fault length and 
histories of multiple Quaternary surface-rupturing earthquakes (Figure 6). These faults were 
evaluated and characterized by all SSFD expert teams using approaches similar to those used for 
characterizing local faults. However; overall characterizations of regional sources are less 
sensitive to and less dependent on alternative tectonic models. Paleoseismic data from Piety 
(1996) were used by all the teams to identify and characterize potential regional faults. Other 
sources, such as Anderson, Bucknam et al. (1995), Anderson, Crone et al. (1995), Keefer and 
Pezzopane (1996), McKague et al. (1996), and Pezzopane (1996) were also used by some of the 
teams. Some faults with probabilities of activity of only 0.1 and SRs less than 0.001 mdyr were 
characterized by the experts. Some of the faults that McKague et al. (1996) considered active 
ANL-CRW-GS-000003 REV 00 31 of 89 
\ X I A K ~ ~ ~ ~ ~ ~ Y I : ~ ~ ~ C W R O I U J I S \ Y U C C A ~ R \ A ~ - T C ~ O O Q ~ ~ O O ~ ~ X . W C 041181M) 
April 2000 

were not included as specific fault sources explicitly by the experts because of their short length, 
distance from Yucca Mountain, and evidence that many of these faults either have no significant 
Quaternary displacement or are much shorter than previously thought. However, these faults 
were implicitly considered by the experts as part of the areal source zones in their models. 
The number of regional faults interpreted to be fault-specific seismic sources by the expert teams 
ranged from 11 to 36, reflecting the range of interpretations regarding regional fault activity. The 
specific seismic parameters of the most significant regional faults considered by most of the 
experts are shown in Table 7, whereas general parameters are described in Table 5 (under 
Regional Fault Sources). All teams modeled the regional faults as planar faults to maximum 
seismogenic depths primarily with dips depending on the style of faulting (preferred values of 
90" for strike-slip faults, and generally 60" or 65" for normal-slip faults). The selection of 
maximum seismogenic depths relied on observations of contemporary seismicity including some 
of the better-studied large surface-faulting earthquakes in the Basin and Range province (e.g. 
1983 Borah Peak earthquake). Alternative fault lengths were included to express uncertainty in 
their mapped lengths. 
Of the regional faults, the most significant were the Furnace Creek and Death Valley faults 
because of their high SRs (2.5 to 8 d y r ) and potential to generate large M, of about Mw 7.5, 
despite their relatively long distances to the Yucca Mountain site & 50 lun) (Figure 6). 
Table 7. Fau!t Parameters of significant ~egional Faults 
Considered by SSFD Experts 
April 2000 
West ~pecterxnge 
Amargosa River 
Yucca Lake 
Eleana Range 
Yucca Fault 
Keane Wonder 
Furnace Creek 
West Springs 
Mountains 
, Death Valley 
Belted Range 
Kawich Range 
Pahrump 
West Pintwater Range 
Source: CRWMS M&O 1 W8a, Appendix E 
votes: 
Range of preferred values interpreted by the expert teams * Approximate shortest distance to repository 
LL Left-lateral strike-slip, RL Right-lateral strike-slip, N Normal slip 
8-19 
12-24.8 
13-19 
11-15 
25-32 
23-27 
-- 1051 18 
29-52 
45-71 
21-50 
24-84 
35-65 
37-82 
33 
34 
36 
37 
40 
43 
50 
53 
55 
55 
57 
68 
76 
N 
N-RL 
N-RL 
N 
RL-N 
N 
RL 
N 
N-RL 
N 
N 
RL-N 
N 
0.004-0.01 
0.01 -0.05 
0.005-0.2 
0.00024-0.2 
0.02-0.2 
0.005 
4.0-8.0 
0.02-0.09 
2.5-5.0 
0.01-0.1 
0.001-0.03 
0.005-0.07 
0.008-0.2 
1 .O 
1 .O 
0.5-1.0 , 
1 .O 
1 .o 
0.6-0.8 
1 .O 
1 .O 
110 
1 .O 
1 .O 
1 .O 
1 .O 

The possibility that dextral (rcr,) shear is being accommodated in the Yucca Mountain region by 
a buried strike-slip fault was evaluated by all teams. Four teams included a regional buried 
strike-slip fault source with low probability. The other two teams gave zero weight to buried 
strike-slip fault sources. Although they did not preclude the possibility of a buried fault, they 
concluded that this source would be incapable of generating earthquakes larger than those 
associated with their regional source zones. 
6.3.2.3 Areal Seismic Source Zones 
For areal seismic source zones, the experts defined source boundaries based on seismotectonic 
province considerations, including the distribution of historical seismicity (Figure 1) and 
assessed Mmx and recurrence. Some teams included alternative areal zone interpretations within 
100 krn of the site and defined zones beyond 100 krn to completely express uncertainty in the 
seismic source interpretations. Several teams defined a background areal source zone 
representing the area near Yucca Mountain where detailed fault investigations have been 
conducted and, thus, where the mapping of faults is more complete. Table 5 summarizes key 
elements of the various models developed by each team for areal seismic source zones. An 
example map of part of one team's interpretations is shown on Figure 7. It shows the boundaries 
of various areal seismic source zones considered as one of four possible alternatives included in 
their characterization. 
Mmx distributions for the areal seismic source zofies represent uncertainty in the largest 
background earthquake in the region (associated with the minimum threshold for surface 
faulting) and/or the estimated M, for a geologic structure that was not explicitly included as a 
fault-specific seismic source. Earthquake recurrence Tor the areal seismic source zones was 
derived from the historical seismicity record. Four alternative historical earthquake catalogues 
wcre evaluated for completeness and dependent events (CRWMS M&O 1998a, Appendix G). 
Known fault-related earthquakes were removed and undergrourid nuclear explosions and other 
forms of blasting and dependent events (e.g., foreshocks and aftershocks) were deleted using 
declustering algorithms (e-g., Youngs et al. 1987). Experts were required to consider the . 
reservoir-induced seismicity associated with Lake Mead and aftershocks induced by nuclear 
explosions at the Nevada Test Site (Figure 1). Based primarily on their analyses of the historical 
seismicity catalog, all teams used the truncated exponential recurrence model to estimate 
earthquake recurrence rates within the areal seismic source zones (TableS). Alternative 
interpretations of the background seismicity included (1) uniform smoothing of seismicity 
, (uniformly distributed in space) and (2) nonuniform smoothing using different smoothing 
distances to account for an interpreted degree of spatial stationarity. The latter interpretation used 
the technique similar to that reported by Frankel (1995). 
Seismicity related to volcanic processes, particularly basaltic volcanoes and dike-injection, was 
explicitly modeled in volcanic source zones by only two teams. Volcanic-related earthquakes 
were not modeled as a separate source by the other teams, who considered the low magnitude 
and frequency of volcanic-related seismicity accounted for by the areal source zones. 
April 2000 

6.3.2.4 Combined Regional Recurrence 
Earthquake recurrence (including both recurrence models and assigned rates of activity) is one of 
the most significant elements of seismic source characterization for PSHA because it greatly 
influences what contributes most to the hazard. Therefore, recurrence curves were one of the 
many aspects of the models examined by the experts during the feedback process for 
reasonableness and consistency. Figure 8 compares the aggregate (all teams combined) 
earthquake recurrence curves for all sources within 100 km of Yucca Mountain with each team's 
mean recurrence distributions (see Table 3 for team abbreviations). The range in uncertainty in 
the estimation of regional seismicity rates is generally less than an order of magnitude. At 
smaller magnitudes, the range reflects the differences in the teams characterization of the 
regional source seismic zones. The overprediction of the observed rate of Mw 4 to 5 earthquakes 
within 100 krn of the site reflects the teams' general assessment that larger regions are needed to 
characterize the seismicity rates. At larger magnitudes, the assessments from the individual 
teams lie within the uncertainty in the occurrence rates of earthquakes based on the historical 
record. 
6.3.3 Ground Motion Attenuation Characterization 
The physical characteristics of strong ground motion that potentially contribute to damage are 
amplitude, frequency, and duration. In general, larger-magnitude earthquakes generate largeramplitude 
motions for longer time periods, which in turn cause greater damage. Additionally, 
larger-magnitude events generally cause. larger long period motions. However, predicting strong 
ground motions is complex because &und motion characteristics depend on other factors in 
addition to earthquake magnitude. These can be grouped into source, path, and site factors. 
Source factors not only include earthquake size, but also encompass type of faulting (normal, 
strike-slip, or reverse), and other dynamic properties of the fault rupture as it breaks through the 
earth. Path factors include the distance, geologic structure, and crustal material properties 
between the earthquake source and site. Finally, site effects include the local conditions such as 
structural geology, types of surficial deposits, depth to the water table, and topography. 
Numerous empirical attenuation relations that estimate ground motion amplitudes have been 
developed from strong motion records of historical earthquakes. The ground motion amplitudes 
can be expressed using a variety of measures, including PGAs, PGVs, and SAs. These different 
measures are used to characterize different frequencies and types of motions. Ground motion is 
most often measured in terms of PGA, which is typically expressed in units of "g," a percent of 
standard gravity (9.8 m/s2). PGAs characterize high frequency ground motions (defined as 100 
Hz for the Yucca Mountain PSI-IA), whereas PGVs (usually measured in cdsec) characterize 
lower frequency or longer period motions. SAs are used to measure the frequency dependence 
of the response of structures to ground motions and are calculated for a variety of frequencies 
(0.3, 0.5, 1, 2, 5, 10, and 20 Hz for the Yucca Mountain PSHA). The attenuation relations for 
estimating ground motions incorporate the effects of the more significant factors such as 
magnitude, distance, faulting mechanism, crustal attenuation, and type of deposits at the site. 
Unfortunately, strong motion data are limited for the conditions directly applicable to Yucca 
Mountain, presenting many challenges to the GM experts that are discussed further below. 
ANL-CRW-GS-000003 REV 00 34 of 89 
\ \ ( I A K ~ L ~ ~ ~ ~ V ~ ~ \ ~ ~ ~ ~ S W R D ~ C ~ Y U C C ~ R \ A ~ - I C ~ O O \ ~ ~ M ~ ~ X . D O C 01118100 
April 2000 

Due to differences in seismicity rates, stress regimes, and attenuation parameters, strong motion 
, data from the Basin and Range province, even when combined with the very limited data from i analog tectonic environments, are insufficient to adequately constrain empirical attenuation 
models. Consequently, a key issue with respect to characterizing ground motion attenuation in 
the Yucca Mountain region was the applicability of western U.S. attenuation models that are 
based on relatively large data sets, to the Basin and Range province. Most empirical attenuation 
relat~ons in the western U.S. are based on recordings from California strike-slip and reverse-slip 
I earthquakes. Due to the sparse strong motion data recorded from normal faulting earthquakes, 
separate style-of-faulting factors typically have not been estimated for normal dip-slip faulting. 
Instead, the normal faulting data are usually grouped with strike-slip faulting data. Preliminary 
analyses of the few normal faulting strong ground motion recordings have been found to not be 
statistically different from those predicted for strike-slip faulting in previous evaluations 
(Westaway and Smith 1989). However, subsequent studies of an expanded dataset indicate that 
various differences exist between records from extensional and compressional regimes (e.g., 
Spudich et al. 1996). 
In their evaluations, the GM experts considered the possibility that significant differences may 
exist in the seismic source, regional crustal path, and shallow site properties for Yucca Mountain 
as compared to average source, path, and site properties represented in the western U.S. strong 
motion data set. An issue that the GM experts addressed was whether, or to what degree, any 
1 such differences affect median ground motion estimates or variability in ground motions 
expected at Yucca Mountain compared to those predicted by western U. S. empirical ground 
motion models based primarily on California data. 
6.3.3.1 Specific Ground Motion Issues 
In addition to the general issue of evaluating the applicability of empirical strong motion models 
based largely on strong motion data recorded in California, several specific issues were identified 
by the GM experts and prioritized as to importance for further study. Most arose from a lack of 
detailed information or from a need to further evaluate an available data set. A discussion of 
three key issues, site response, stress drops for normal faulting earthquakes and numerical 
simulations, follows. For a more complete discussion of all issues considered by the GM experts 
see Appendix F of CRWMS M&O (1998a). 
6.3.3.1.1 Site Response 
. The ground motion hazard assessment was for a site located on "typical1' emplacement-level tuff 
at Yucca Mountain (near Point 8 on Figure 3). To develop ground motions for this site condition, 
the GM experts required detailed information on the shear-wave velocity and nonlinear 
properties of the shallow tuff at Yucca Mountain (primarily the top 50 m). A preliminary 
velocity profile for the shallow tuff had been estimated as part of a scenario earthquake modeling 
project (Schneider et al. 1996), but this velocity profile was not we11 constrained. The available 
laboratory testing studies to determine the nonlinear properties were not adequate to meet the 
experts' needs. Thus, the GM experts requested that additional studies to evaluate the shear-wave 
velocity and nonlinear properties of the shallow tuff be conducted. Although limited additional 
studies were performed, they did not adequately define the site properties to the extent required 
for site-specific application. Therefore, it was decided to define a reference site condition by 
ANLCRW-GS-000003 REV 00 35 of 89 
\\OAKlLutrives\r-wcfMRO~WCCA~\Amr-1~va)hm00~~x.WC 0411M)O 
April 2000 

removing the top 300 m from the shear-wave velocity profile used in the scenario earthquake 
modeling project. This site condition was called the reference rock outcrop (represented by Point 
A on Figure 4). The mean shear-wave velocity for the reference rock at a 300-m depth is 1,900 
mlsec. 
The parameter kappa is a measure of the near-surface attenuation of seismic waves. Analyses of 
California sites yield kappa values of approximately 0.04. In order to accurately predict highfrequency 
ground motions at Yucca Mountain, a local estimate of kappa must be obtained. To 
I define the appropriate kappa beneath the reference rock outcrop, kappa was determined for the 
upper 300 m and subtracted from the average kappa at the surface. The average kappa for sites at 
I the surface at Yucca Mountain was previously estimated to be 0.02 sec based on studies by Su et 
I - al. (1996). Laboratory studies of the low-strain damping of the tuff in the top 300 m (Stokoe et 
I al. 1998) revealed very low values with an equivalent kappa of 0.0014 sec in the top 300 m. 
I Therefore, subtracting 0.0014 sec from 0.02 sec resulted in a median kappa of 0.0186 sec for the 
reference rock outcrop (CRWMS M&O 1998a, Section 5). It is expected that kappa will vary 
over the site area due to variations in rock properties and this variability was accounted for by 
the GM experts in their estimates of uncertainty in their ground motion attenuation relationships. 
The reference rock outcrop provided a better defined reference site condition for the experts to 
estimate their ground motions. With the change of the reference site condition from the surface 
, of the tuff (represented by Point C on Figure 4) to the reference rock outcrop (represented by 
Point A), the nonlinear properties of the tuff were not needed for the development of ground 
motions in this study. However, nonlinearity of the tuff is discussed in Section 5.7 of CRWMS 
M&O (1998a) and will be addressed in future computations of the seismic design ground 
motions for the repository. 
6.3.3.1.2 Stress.Drops for Normal Faulting Earthquakes 
Spudich et al. (1996) found lower ground motions for earthquakes in extensional regimes than 
for earthquakes in transpressional regimes. Since their analysis was based on residuals from 
attenuation relations, it was not clear whether this difference was due to earthquake source, path, 
or local site effects. The GM experts requested computations of stress drops for the Spudich et al. 
(1996) data set to compare with stress drops for California earthquakes to help determine the 
causes of the ground motion differences. 
Median stress drops for extensional tectonic environments were computed using the normalfaulting 
earthquakes in the Spudich et a1:(1996) worldwide data set. The stress drops were found 
to be consistently lower than those for California earthquakes (Becker and Abrahamson 1997). 
To adjust for this difference in stress drop, ground motion scale factors were developed. See 
CRWMS M&O (1998a), Sections 5.3.1 and 5.4.1, for further discussion of the stress drop 
analysis. 
6.3.3.1.3 Numerical Simulations 
Numerical simulations of ground motions at Yucca Mountain were available for the earthquakes 
considered in the scenario earthquake modeling project (Schneider et al. 1996). The experts, 
however, were required to estimate the ground motions for a much larger range of magnitudes 
ANLCRW-GS-000003 REV 00 36 of 89 
\V)AK~~~~~~~S\I~VF~SWRQIEC~S\WOCAMTMAMRU~-IC~~~\~~~~~~CZDOC 04/18/00 
April 2000 

and distances than was considered in that study. Therefore, the GM experts requested that 
I numerical simulations be generated for the full set of events (point estimates) that were 
considered for the PSHA. Three preferred methodologies were identified by the experts from the 
six included in the scenario earthquake modeling project. The procedures by: (1) Zeng and 
Anderson; (2) Silva; and (3) Somerville were selected based on their perceived superior 
modeling ability as evidenced by comparisons included in the scenario earthquake modeling 
project (Schneider et al. 1996). Ground motions for the required point estimates were then 
! generated for the reference rock outcrop. 
6.33.2 Ground Motion Experts' Evaluations 
Ground motion evaluations were performed using an expert elicitation process similar to that 
used for seismic source and fault displacement characterization. The evaluations developed by 
each expert are described in Appendix F of CRWMS M&O (1998a). The elicitation process was 
. facilitated by the GM Facilitation Team and included three workshops, two working meetings, 
and a lday elicitation meeting with each GM expert (Figure 2). 
The seven GM experts estimated median ground motion, aleatory variability, and epistemic 
uncertainties for a matrix of earthquake magnitudes, source-to-site distances, and faulting styles 
(normal- and strike-slip) and for a suite of spectral frequencies (CRWMS M&O 1998a, 
Sextion 5). The ground motions were defined at the reference rock outcrop. These estimates were 
based on empirical and numerical simulation-based models and combinations of conversion 
factors. The experts classified proponent models as empirical attenuation relations, hybrid 
empirical, point-source numerical simulation, finite-fault numerical simulations, and blast 
models. A complete list of the models is shown in Table 8, and the models are described in 
Section 5 of CRWMS M&O (1998a). 
As discussed above, a fundamental issue that the experts evaluated is whether ground motions at 
Yucca Mountain differ significantly from the motions represented by the data set that forms the 
basis for western U.S. empirical models and, if they differ, by how much. Differences could be 
caused by source, path, or site effects. The region- and site-specific aspects of the ground motion 
could be directly incorporated as input for the numerical simulations, but for the empirically 
based models, proponent conversion factors were developed to account for these differences. 
Suites of conversion factors were obtained using the results of (1) numerical finite-fault 
simulations, (2) stochastic point-source simulations, and (3) empirical attenuation relations. The 
conversion factors included corrections for: 
e Source -- western U.S. sources to Yucca Mountain extensional sources 
a Crust -- western U.S. crust to Yucca Mountain crust 
Site -- Yucca Mountain surface to reference rock outcrop 
Due to the large number of estimates required, the experts used numerical weighting of 
proponent model estimates to develop their initial estimates. The procedure applied two levels of 
weights. The models were first separated into classes or types as shown in Table 8. Weights 
were then assigned based on the expert's evaluation of the applicability of each class. Then for 
each range of magnitude, distance, and fault type, weights were assigned to the models, within 
each class, based on the expert's evaluation of the strengths and weaknesses of each model in 
ANLCRW-GS-000003 REV 00 37 of 89 
lXIAKlLdr*cs\rcards\PRQlECmYUCCAMTMAMRUntr-~~-~x.WC 04/181W) 
April 2000 

Table 8. Proponent Ground Motion Models Used by Each Expert 
l~pudich et al. (1996) (Rock) 1 yes 
Model Class 
impirical 
- 
Hybrid Empirical 
Finite Fault Simulation 
Proponent Models In Class 
Abrahamson and Silva (1 997) 
Boore et al. (1 997) (Vs model) 
Campbell (1 997) (Soft Rock) 
ldriss (University of California, Davis, written 
commur;lication, 1997) (Rock, Stiff Soil) 
(PSHA) 
Joyner and Boore (1988) (Rock) 
McGarr (1 984) (Rock) 
Sadigh et at. (1997) (Rock) 
Sabetta and Pugliese (1996) (Rock) 
Anderson 
Yes 
Yes 
Yes 
Yes 
No 
No 
Yes 
Yes 
Campbell (PSHA) 
Silva Case A (PSHA) 
Silva Case B (PSHA) 
Somerville (PSHA) 
Zeng and Anderson Case A (PSHA) 
Zeng and Anderson Case B (PSHA) 
No 
Yes 
No 
Yes 
Yes 
Yes 
Point Source Random 
Vibration Theory 
Note: 
Blast 
1 These empirical models are incorporated in the Hybrid Empirical model. 
PSHA = CRW MS M&O (1 998a). 
Zeng and Anderson Case C (PSHA) 
Silva (PsHAl 2 
Boom Campbell McGarr Silva Somervllle Walck 
Yes yes' Yes Yes Yes Yes 
Yes yes1 Yes Yes No Yes 
Yes yes' ' Yes Yes Yes Yes 
Yes yes' Yes No Yes Yes 
Yes 
Yes 
Bennett Model 2 (1995 Scenario Study) 
(PSHA) 
No No No No Yes Yes No 
April 2000 

terms of its applicability to Yucca Mountain. In general, each expert varied the class and model 
weights on a case-by-case basis to reflect hislher assessment of the applicability of each model. 
For example, an expert may have downweighted or eliminated an empirical model outside the 
magnitude range represented by the data on which the empirical model was based. The resulting 
matrix of point estimates consisted of 51 combinations of parameters that were considered to 
adequately define attenuation for the seismic sources addressed by the SSFD expert teams. The 
matrix covered a range of conditions, including: Mw 5.0 to 8.0, distances from 1 to 160 krn, and 
strike-slip and normal-slip faulting (for both the hanging wall and footwall). The range of 
frequencies, for which ground motion was evaluated, was selected to span the range of interest 
for the pmposed Yucca Mountain SSCs: 0.3,0.5, 1,2, 5, 10, and 20 Hz in addition to PGA and 
PGV. The GM experts also evaluated two special cases: multiple parallel fault rupture and a 
shallow detachment fault because the SSFD experts had included these caes in their seismic 
source characterizations. Scaling rules were developed to apply to their models in order to 
represent these seisnlic sources (CRWMS M&O 1998a). 
The experts used logic trees to characterize uncertainty in their ground motion evaluations. In a 
typical logic tree, alternative models make up the branches of the tree. A model consists of both 
the median ground motion and the aleatory variability (standard deviation). The expert-toexpert 
differences in the median ground motions and in the standard deviations of the alternative 
models constitute the epistemic uncertainty. Each GM expert evaluated the alternative models 
individually and developed hisher own composite model for their best estimates of the median 
and standard deviation for a given earthquake magnitude and source-site geometry (distance). In 
addition, each quantified the epistemic uncertainty associated with their estimates of the median 
and standard deviation. Thus, the expert's ground motion estimates consisted of four values: 
median, aleatory standard deviation, epistemic uncertainty about the median, and epistemic 
uncertainty in the aleatory variability. By providing hisfher estimates of the epistemic 
uncertainty, each expert provided the effects of hidher own logic trees on the ground motion 
attenuation. Thus, the use of seven experts provided alternative logic trees, not just alternative 
ground motion models. 
Each GM expert's point estimates of the ground motion were regressed by the GM Facilitation 
Team to develop Yucca Mountain attenuation equations for use in the hazard calculations. Each 
GM expert defined the distance measure used in the regression analyses for hidher point 
estimates. Each expert evaluated whether the footwall and hanging wall point estimates were 
regressed together, as a single normal faulting attenuation equation, or separately, fielding 
separate models for sites on the hanging wall and footwall. In addition, the experts evaluated the 
degree of magnitude saturation at close distances. 
As an example, the median PGA attenuation for the hanging wall of a M, 6.5 normal faulting 
earthquake is shown on Figure 9a and the epistemic uncertainty about the median is shown on 
Figure 9b. The total epistemic uncertainty for the median ground motion is a combination of the 
range of the expert's estimates of the median (range on Figure 9a) and the uncertainty associated 
with each expert's estimate (Figure 9b). Note that if the median ground motion estimates are very 
similar, it does not mean that no epistemic uncertainty exists; that would be the case only if the 
epistemic uncertainty was zero. Similar plots for the best estimate of the standard deviation and 
epistemic uncertainty in the standard deviation are shown on Figures 9c and 9d. Consensus on 
the median values occurs when the expert's estimates of the median and standard deviation are 
ANL-CRW-Cis-3 REV 00 39 of 89 
\ \ O A K ~ ~ ~ ~ ~ ~ V ~ ~ ~ ~ S W R O I M J I S \ Y U C C ~ R U \ ~ - I ~ ~ - ~ L D O C 04/18100 
April 2000 

within each epistemic uncertainty of the others. Significant differences occur when the experts' 
median estimates differ by more than the epistemic uncertainty. 
63.4 Fault Displacement Characterization 
The SSFD expert teams developed original approaches and methodologies to characterize fault 
displacement potential for input to the fault displacement hazard assessment (CRWMS M&O 
1998a). The approaches were based primarily on empirical observations of faulting 
characteristics at Yucca Mountain and in the Basin and Range province during past earthquakes 
(both historic and prehistoric). Empirical data were fit. by statistical methods to quantify faulting 
parameters and their variability. These results were then used by the teams to develop their 
approaches and characterize the fault displacement potential at the nine demonstration sites, 
including the uncertainty. 
Approaches to characterizing fault displacement potential were developed to be applicable to any 
Iocation within the proposed repository area. To demonstrate the application of these evaluations 
and to provide an estimate of the fault displacement hazard, nine demonstration points were 
selected (see Figure 3) for fault displacement hazard characterization. Selected points represent 
the expected range of fault displacement hazard conditions within the site area in terms of the 
types of features that may be encountered and include: potentially seismogenic block-bunding 
faults with greater than 50 m of cumulative offset, north- and northwest-striking mapped 
intrablock faults that have a few to tens of meters of cumulative displacement, and additional 
features observed within the ESF that are likely to be encountered within the proposed repository 
block. These features range from small faults uncorrelated with a mapped surface feature to 
intact rock. The selected points are (Figure 3): 
Point 1 -- A location on the Bow Ridge fault where it crosses the ESF. The Bow Ridge fault is a 
block-bounding fault that has been characterized by the SSFD expert teams as being a potentially 
seismogenic fault and/or to be part of a seismogenic fault system. 
Point 2 -- A location on the block-bounding Solitario Canyon fault, which has been 
characterized by the expert teams as one of the longer seismogenic faults withiil the Yucca 
Mountain site vicinity. 
Point 3 -- location on the Drill Hole Wash fault where it crosses the ESF. The'Drill Hole 
Wash fault is one of the longer of the northwest-striking faults within the Yucca Mountain site 
vicinity. 
Point 4 -- A location on the Ghost Dance fault, which is one of the longer north-south intrablock 
faults within the site area. 
Point 5 -- A location on the Sundance fault within the proposed repository footprint west of the 
ESF. The Sundance fault is an intermediate length, northwest-trending intrablock fault. 
Point 6 -- A location on a small fault mapped in bedrock on the west side of Dune Wash. This 
point represents a location on one of the many small north-south-striking intrablock faults 
mapped at the surface of Yucca Mountain. 
ANLCRW-GS-000003 REV 00 40 of 89 
\ W ) A K ~ L ~ ~ ~ ~ ~ - ~ ~ ~ W R O ~ E C T S \ W C C ~ M R ~ - ~ ~ ~ ~ \ ~ ~ ~ ~ ) ~ I C X . D O C WlsXK) 
April 2000 

Point 7 -- A location approximately 100 m east of Solitario Canyon at the edge of the proposed 
repository footprint. Any one of four hypothetical conditions were assumed to exist at this 
location. The conditions represent features that were encountered within the ESF but are not 
directly correlated with specific features observed at the surface: 
(a) A small fault having 2 m of cumulative displacement 
(b) A shear having 10 cm of cumulative displacement 
(c) A fracture having no measurable cumulative displacement 
(d) Intact rock 
Point 8 -- A location within the proposed repository footprint midway between the Solitario 
Canyon and Ghost Dance faults. The same four hypothetical conditions were assumed to exist 
here as at Point 7. 
Point 9 -- A location in Midway Valley east of the Bow Ridge fault on an observed fracture 
having no measurable displacement in Quaternary alluvium. 
The potential for fault displacement was categorized as either principal or distributed faulting, 
both of which are potential hazards to SSCs. Principal faulting occurs along a main plane {or 
planes) that is the locus for release of seismic energy. Where the principal fault rupture extends 
to the surface, it may be represented by displacement along a single narrow trace or over a zone 
that is a few. to many meters wide. Distributed faulting is rupture that occurs on faults in'thevicinity 
of the principal rupture in response to the principal displacement. Distributed faulting is 
spatially discontinuous and may occur over a distance of several tens of meters to many 
kilometers from the principal rupture. A fault that can produce principal rupture may also 
undergo distributed faulting in response to principal rupture on other faults. 
The basic formulation of the probabilistic hazard model for fault displacement is analogous to 
that for computing ground-shaking hazard (compare Sections 6.5.1. and 6.6.1). The hazard can 
be represented probabilistically by a displacement hazard curve that is analogous to a ground 
motion hazard curve. The curve depicts annual occurrence of fault displacement values (i.e., the 
annual frequency of exceeding a specified amount of displacement). Thus, the hazard curve is a 
plot of the frequency of exceeding fault displacement value d, designated by v(d). This frequency 
can be computed using the expression: 
where ADE is the frequency of displacement events at a point of interest, and P(D > d) is the 
conditional probability that the displacement D in a single event will exceed value d. 
Several approaches were developed by the SSFD expert teams to characterize RDE and P(D > d). 
Approaches to characterize RDE can be divided into two categories: the displacement approach 
and the earthquake approach. The displacement approach provides an estimate of the frequency 
of displacement events directly from feature-specific or point-specific observed displacements. 
The earthquake approach relates the frequency of displacement events to the frequency of 
earthquakes generated by the seismic source using the seismic source characterization input to 
the ground motion hazard assessment. 
April 2000 

For principal faulting, the conditional probability of exceedance, P(D > d), contains two-parts: 
the variability of slip from event to event, and the variability of slip along strike during a single 
event. The teams developed several approaches for characterizing the distribution of slip at a 
location given a principal faulting event. 
6.3.4.1 Team Approaches and Characterizations of Fault Displacement Potential 
The approaches and characterization of fault displacement potential at the nine demonstration 
points are described in detail in Appendix E of CRWMS M&O (1998a), for each team. Table 9 
is from Section 4.3.2.1 of CRWMS M&O (1998a) and it summarizes key points of the fault 
displacement characterizations, for each team. The following section provides a general 
discussion of some of these key points. For more detail see also Section 4.3.2.1 of CRWMS 
M&O (1998a). 
In aggregate, the six SSFD expert teams slightly preferred the displacement approach (aggregate 
weight - 0.6) over the earthquake approach for characterizing fault displacement potential at 
sites subject to principal faulting and at sites subject to only distributed faulting. For 
characterizing principal faults, four of the teams used only one approach (Table 9). Three teams 
used only one approach for characterizing displacement potential on distributed faults. 
1 . Principal faulting hazard was assessed for sites located on faults that the SSFD expert teams 
I identified as being seismogenic. In the displacement approach, the preferred method for 1 
1 estimating tiDE used SR divided by the AD per event. The expert teams used a number of 
1 approaches to evaluate P(D>d), based on empirical distributions derived from Yucca Mountain 
trenching data. These distributions were normalized by various parameters, including the 
expected MD in the maximum event, the AD estimated from displacement data, and the AD and 
MD estimated from the length of the fault. i 
To characterize & for assessing displacement hazard on principal faults using the earthquake 
approach, the teams used the frequency of earthquakes they had evaluated for the ground motion 
hazard assessment and multiplied it by the conditional probability that an earthquake produces 
I surface rupture at the site of interest. The along-strike intersection probability was computed 
using the rupture length estimated from the magnitude of an event randomly located along the 
fault length. Most teams used an empirical model based on historical ruptures to compute the 
probability of surface rupture. The preferred approach to assess P(D>d) was to define a 
distribution for the MD based either on the magnitude or the rupture length of the earthquake. 
This distribution was convolved with a distribution for the ratio of the displacement to the MD to 
compute P(D>d). 
The preferred approach to characterize RDE on features subject to only distributed faulting used 
SR divided by the AD per event (displacement approach). The SRs were derived using the 
cumulative displacement and slip history on the fault or feature. The teams used approaches for 
evaluating P(D>d) similar to those used in the displacement approach. The empirical 
distributions were combined with a scaling relationship, used to estimate the AD per event, to 
obtain P(D>d). 
ANLCRW-GS-000003 REV 00 42 of 89 
\ \ O A K ~ ~ ~ ~ ~ ~ ~ ~ ~ \ ~ ~ I Y E ~ I \ P R ~ ~ E C ~ S \ W C C ~ U ~ ~ - ~ ~ ~ I ~ O O ~ ~ ~ W18100 
April 2000 

Table 9. Summary of SSFD Expert Team Fault Displacement Hazard Characterizations (Table 4-3 of CRWMS M&O 1998) 
. . 
Principal Faulting based on 
Can Occur P(C) I probability fault Is I I on probability fault is based on 
seismogenic I probability fault is 
Frequency of 
Displacement 
Events 
SR 
Displacement Appm8ch for Principal Faulting 
Probability That I Evaluate P(C) I NA I Evaluate P(C) based I Evaluate P(C) I 
I 
RYA Team 
Displacement 
approach [l .O] 
Issue 
PRINCIPAL 
FAULTING 
APPROACH 
AD Per Event, 5 E 
ASM Team 
Earthquake 
approach 
[l-o] 
AAR Team 
Displacement 
approach [0.67]; 
Earthquake 
approach t0.331 
Conditional 
Probability of 
Exceedance, P(D>d) 
DFS team 
Displacement 
approach [l .O] 
SBK Team 
Displacement 
approach (0.85-0.91 
Earthquake 
approach [0.1-0.151 
seismogenic 
SR [l .O] 
SDO Team 
Earthquake approach 
[l .O] 
Quaternary slip 
rates used in SSC 
model 
- 
D E d.83 MD'- 
( M P from: 
fault length [0.3]; 
Dam [0.3]; and, 
paleoseismicity 
data [0.4]) 
S R ~ D E [OS]; 
Recurrence intervals 
(RI) [O.S] 
Paleoseismic data 
[0.7l; 
Uniform post-Tiva 
Canyon [0.1]; 
Uniform post-Rainier 
Mesa [0.1]; 
Decreasing slip rate 
model [O.l] 
Paleoseismic data 
SRx Rl[0.5] 
seismogenic 
SR (0.21; 
~ e c u rrence 
intervals [0.8] 
Quaternary slip 
rates used in SSC 
Paleoseismic data 
.OI 
Distribution for I D/MP[o.s] 
Distribution for 
D / M P [l .O] 
SR (0.81; 
Recurrence intervals 
10.21 
Quaternary 
~aleoseismic data 
I 
Paleoseismic data I NA 
N A 
P.81; 
From ADRL [0.1]; 
From MDRL [0.1]; 
DMDF~LJ - 
correlated with D E 
Distribution for D/AD 
[1 .01 
Distribution for 
D/AD [0.5]; 
Can Occur, P(C) 
Frequency of 
Earthquakes on 
Principal Faulting 
Source 
-- Earthquake Approach for Principai Fauitlnq 
ANL-CRWGS-000003 REV 00 
X : ~ ~ ~ I I \ P R O I E C ~ W C C ~ U ~ - ~ T A B L E ~ R ~ ~ ~ D O C UIMI) 
GM assessment 
Earthquake 
frequency from 
source model for 
GM assessment 
43 of 89 April 2000 
N A NA P(C) = P(S) from 
source model for 
Probability That 
Principal Faulting 
GM assessment 
Earthquake 
frequency from 
source model for 
GM assessment 
P(C) = P(S) from 
source model for GM 
P(C) = P(S) from 
source model for 
P(C) = P(S) from 
source model for GM 
N A N A 
assessment 
Earthquake 
frequency from 
source model for GM 
assessment 
assessment 
Earthquake 
frequency from 
source model for GM 
assessment 

Table 9 (Continued) 
ue 
I Probabilitv of 
I Surface du~ture 
7 Probability of 
rupture depth with 
rupture width 
based on 
RUhspect ratio; 
RL specified by 
magnitude- RL 
~ 5 1 ; 
magnitude-rupture 
area [0.51 
Maximum 
displacement per 
event, MD, from 
SRL [0.33]; 
M, [0.33]; and 
RLD (0.341; 
D/MD from 
Wheeler data [I .O] 
32 rea at Basin 
earthquakes [0.5]; 
105 Worldwide 
earthquakes [0.5] 
MD from Mw [ I .O] 
DM0 from 
Wheeler data [I .O] 
DFS team 
N A 
RYA Team 
V A 
SBK Team 
Empirical model 
32 Great Basin 
sarthquakes [ I .O] 
MD from Mw [ I .O] 
D M from 
Wheeler data [0.5]; 
fractal model [0.5] 
SDO Team 
Em~irical models 
32 breat Basin 
earthquakes [0.5]; 
47 Northern Basin 
and Range 
earthquakes [0.5] 
AD and distribution 
for D/AD 10.51; 
(~~from;: - 
Mw [0.21; 
RL [0.4]; and 
Paleoseismlc data 
[0.41) 
MD and distribution 
for D M (0.51; 
(MD from*: 
Mw [0.21; 
RL [0.4]; and 
Paleoseismic data 
[0.41;) 
D/MD from: 
Wheeler data [0.8], 
fractal model r0.2) 
' for maU-M use 
only Mw 
Ramelli curve, also 
was used for Solitario 
Canyon fauk 
ANLCRWGS-000003 REV 00 
X : \ r w c f r \ P R O I E C I S \ ~ U m - m a h T A B L E 9 R 0 0 . D O C UIMW) 
April 2000 

Table 9 (Continued) 
- issue 
DISTRIBUTED 
FAULTING 
APPROACH 
Probability of 
Occurrence P(C) 
Frequency of 
Earthquakeson 
Seismic Sources 
Probability of Slip 
Per Event, 
PflliplEvent on 1) 
AAR Team 
Displacement 
approach (0.67; 
Earthquake 
approach [0.33] 
If capable of 
principal faulting 
P(C) = P(S) 
Otherwise, P(C) 
based on sliptendency 
Earthquake 
frequency from 
SSC model 
Logistic regression 
of historical faulting 
data [I .O] 
ASM Team 
Earthquake 
approach [I .O] 
Eaffbqual 
Function of the 
category and 
orientation of 
feature, cos(strike 
azimuth) 
Earthquake 
frequency from 
SSC model 
Probabili a 
function of rand 
hanging wallfootwall 
location; 
preferred model 
[0.6]; upper-bound 
model [0.4] 
DFS team 
Displacement 
approach [ I .O] 
Approach for DisMbc 
- 
RYA Team 
Displacement 
approach [ I .O] 
SBK Team 
Displacement 
approach [0.8]; 
Earthquake 
approach [0.2] 
SDO Team 
On Principal Faults- 
Earthquake approach 
[1 .OI; 
Other Sites- 
Displacement 
approach [0.3, 
Earthquake approach 
10.71 
Earthquake 
frequency from SSC 
mobel - I model 
P(t?) based on 
slip tendency [0.5]; 
Relative orientation 
[0.51 
F(event) based on 
logistic regression, of 
historical surface 
faulting data [OS], 
peak velocity (0.51 
P(8) based on 
relative orientation 
11 .OI 
/=(event) based on 
logistic regression of 
historical surface 
faulting data [I .O] 
ANLCRW-OS-000003 REV 00 
X : \ * ~ ~ ~ ~ W R O J E C ~ ~ U ~ - F ~ ~ O ~ A T A B I ~ ~ R W . W C U1M)O 
April 2000 

Table 9 (Continued) 
Issue 
Conditional 
Probability of 
Exceedance, P(D>d) 
Frequency of 
Distributed Faulting 
Events 
AAR Team I ASM Team 
For site of principal I RF times principal 
faulting 
use principal 
faulting-distribution 
times a reduction 
factor (RF) [I .O] 
For other sites- 
Distribution of 
Dl MDmd"; 
( M F from: 
Evaluate P(C) 
based on 
orientation. 
faulting distribution; 
(RFfrom: 
Displacement 
potential [0.7], 
Relative 
cumulative 
displacement 
tO.31) 
DFS team RYA Team SBK Team 
N A N A D/Dm [I .O] 
I I 
- 
N A I Evaluate P(C) based Evaluate P(C) 
on orientation, 
location, and P(S) 
Slip rate [I .O] 
Uniform post 11.6 
Ma [0.1], 
Uniform post 3.7 
Ma [0.3], and 
3.26 x 10" Dm 
0.83MD"= from AD Per Event, D E Length fO.51, 
I 
Conditional I Distribution for 
Probability of DAUF [I .O] 
Exceedance, P(D>d) 
ANLCRW-GS-000003 REV 00 
N A SRIDE [0.5], and 
Recurrence intervals 
(Rlj [0.5] 
Uniform post-Tiva 
Canyon [0.33], 
Uniform post-Rainier 
Mesa [0.33], and 
Decreasing slip rate 
model [0.34] 
NA Direct estimate [0.5] 
SR'RI [0.5] 
N A I Distribution for D/AD 
based on 
orientation, 
location, and P(S) 
Slip rate [I .O] 
SDO Team 
Distribution for D/MD 
on principal rupture 
as a function of 
distance from ruDture 
10.81, 
Distribution for DAUD 
on principal rupture 
times function of 
relative Darn [0.2] 
P(C)=l .O Based on slip 
tendency [I .O] I 
D-112.7 [0.1], 
0.02 DfunJ1.6 
[0.6], and 
0.2 DfunJ3.7 [0.3] 
Fault length [0.5] 
Dm [0.51 
Distribution for 
D/AD [0.5] 
Distribution for 
~h.10"" [0.5] 
(with MF = 
AW0.83) 
April 2000 
Slip rate [I -01 Slip rate [ I .O] 
Geologic history 0.02 Ddl.6Ma 
[0.75] tO.31; 
(with: DanrJ12.5 [0.1], 0.006 Dnnrll.6Ma 
0.2 Dd11.6 [0.3], [0.4]; 
and 0.8 D-x 0.002 Dd1.6Ma 
0.2110.9 [0.6]) 
Ratio of cumulative 
P.31 
slip to that of blockboundin~
l faults and 
their sliprates l0.251 1 
D- f 1 -01 I Based on Dm and - - I AAR scaling 
relationship [0.5]; 
I SBK distribu%on[0.5] 
Distribution for 1 For AAR scaling 
distribution for 
DAUD-, 
for SBK scaling 
distribution for Dl&,,, 

The characterizations of distributed faulting potential using the earthquake approach had the 
largest uncertainties. The basic evaluation of the frequency of earthquakes was derived from the 
seismic source characterization for ground motion hazard assessment defined by each team. The 
probability that an earthquake causes slip at the point of interest was assessed in a variety of 
ways. The preferred approach utilized a logistic regression model based on analyses of the 
pattern of historical ruptures (CRWMS M&O 1998a, Section 4.3.2). The widest variations in 
approaches were those for assessing the distribution for displacement per event on the distributed 
ruptures. 
The characterizations of distributed faulting potential using the earthquake approach had the 
largest uncertainties. The basic evaluation of the frequency of earthquakes was derived from the 
seismic source characterization for ground motion hazard assessment defined by each team. The 
probability that an earthquake causes slip at the point of interest was assessed in a variety of 
ways. The preferred approach utilized a logistic regression model based on analyses of the 
pattern of historical ruptures (CRWMS M&O 1998a, Section 4.3.2). The widest variations in 
approaches were those for assessing the distribution for displacement per event on the distributed 
ruptures. 
6.4 PSHA ASSU11IPTIONS 
Assumptions made in the PSHA process are briefly summarized below. Assumptions made by 
the experts in their evaluations are described in detail in Appendices E and F in CRWMS M&O 
(1998a). 
6.4.1 Expert Elicitation 
A primary objective of the PSHA was that the evaluations of the experts captured and expressed 
the range of interpretations and uncertainty of the informed technical community (CRWMS 
M&O 1998a, Section 2). The selection of the experts and the elicitation as camed out in the 
PSHA Project follows the guidelines set forth in NUREGICR-6372 (Budnitz et al. 1997). We 
assume that this process and the manner in which it was applied allows for this objective to be 
accomplished. 
6.4.2 Model of Randomness 
The assumption that the behavior of the earth is generally Poissonian or random is the underlying 
assumption in all probabilistic hazard analyses. In other words, all earthquakes are considered as 
independent events with regard to size, time, and location. Although there may be cases where 
sufficient data and information exists to depart from this assumption, the Poissonian model is 
generally an effective representation of nature and represents a compromise between the 
complexity of natural processes, availability of information, and the sensitivity of results of 
engineering relevance (Budnitz et a]. 1997). 
6.43 Kappa 
As discussed in Section 6.3.3.1 .l, a median kappa value of 0.0186 sec was assumed appropriate 
for the reference rock outcrop whose shear wave velocity was 1,900 mlsec. This value was the 
April 2000 

best estimate for the site area baied on the available data. If ongoing investigations indicate that 
the median value is different than 0.0186 sec, the hazard results may be adjusted accordingly. . 
6.4.4 Threshold of Damage 
The PSHA was computed by integrating recurrence curves for earthquakes of MW 5.0 and 
greater. It is established practice that smaller earthquakes produce no damage to well-engineered 
structures regardless of the ground motions they generate (e.g., McCann and Reed 1990). 
6.4.5 Seismic Sources 
Two key simplifying assumptions are made in the modeling of seismic sources. First, faults are 
represented by segmented planar features and rupture is typically considered to occur anywhere 
along the fault with equal likelihood. Secondly, for areal seismic source zones, it is commonly 
assumed that the occurrence of earthquakes is uniform in space and time (i.e., there is equal 
likelihood of occurrence of events at all locations within the zone). Four of the six expert teams 
did incorporate to some degree, no nun if om^ spatial occurrence based on the historical earthquake 
catalog and a nonuniform spatial density function (Table 5). 
6.4.6 Ground Motion Attenuation 
A simplifying assumption in the development of ground motion attenuation relations that is 
commonly made and was made by the experts is that the ground motions are a function of only 
magnitude, distance, faulting style, and location in the hanging wall or footwall (Joyner and 
Boore 1988; p. 49-58). Other dependencies (such as directivity and stress drop) have been 
mapped into estimates of the epistemic uncertainties, which are captured in the hazard results. 
6.5 PSMA GROUND MOTION HA7ARD ASSESSMENT 
6.5.1 Methodology 
The methodology to calculate the probabilistic ground motion hazard at a site is well established 
in peer-reviewed literature (Cornell 1968, 197 1; McGuire 1978, 1995). This section provides an 
overview of the approach. For further details about the implementation of the methodology as 
applied to the Yucca Mountain site, see Section 7.2 of CRWMS M&O (1998a). Calculation of 
the hazard requires specification of the following three inputs: 
The geometry of a seismic source (e.g., source i) relative to the site, and a relationship 
between rupture size, R(i), and magnitude, M(i), determine the conditional probability 
distribution of distance r from the earthquake rupture to the site (with a given magnitude, 
M): fR,olMfi)(rlm). The types of sources are faults and areal source zones. 
The mean annual rate of occurrence Vi and magnitude distribution fM(ifm) of 
earthquakes occurring on each source i. This characterization includes the M, that a 
seismic source can produce. The Mw scale is used in all the hazard calculations. 
0 An attenuation relation for the estimation of ground motion amplitude (A) at the site as a 
function of earthquake magnitude (m) and distance (r), G~lm,r (a*). This 
April 2000 

characterization includes both an equation for the median amplitude and a standard 
deviation a that describes the site-to-site and event-to-event scatter in ground motion 
amplitude observations for the same magnitude and distance. 
These inputs are illustrated on Figure 10, Parts a through c. Figure 10 shows the geometry of a 
seismic source and the distance distribution for a given value of magnitude. The distribution of 
magnitude fMfi)(m) for an areal source is typically specified as the doubly truncated exponential 
distribution. Seismicity for a source with the exponential magnitude distribution is completely 
specified by the minimum magnitude m, and parameters a and b. Parameter a is a measure of 
seismic activity, b is a measure of relative frequency of large versus small events, and log[vi 
fMfi)(m)] is proportional to -bm for m 5 rn-. Except for truncation effects near Mmx, this is the 
well-known Gutenberg-Richter relation (Youngs and Coppersmith 1985). The distribution of 
magnitude fM(,)(m) for a fault is specified by either an exponential distribution, a characteristic 
distribution (Youngs and Coppersmith 1985; Figure lob of this document), or a maximummoment 
distribution (Wesnousky et al. 1983). The rate information for these three distribution 
shapes may be specified, respectively, as the rate vi, the rate of large earthquakes (magnitude 
greater than Mmx - !4), or the SR (for faults only). 
The ground motion is modeled by an attenuation function, as illustrated on Figure 10c. The 
ground motion amplitudes (A) can be for a variety of different parameters, including PGAs, 
PGVs, and SAs (see Section 6.3.3 for explanation and discussion of parameters evaluated in the 
PSHA). 
Attenuation functions are usually of the'form ln[~]' = flM,R) + E, whem A is ground motion 
amplitude, M is magnitude, R is distance, and E is a random variable (with mean zero and 
standard deviation a ) that represents scatter in ln[A] for the same magnitude and distance. The 
attenuation function is used to calculate G+,,.(a*) = P[A > a*lm,r]: the probability that the 
ground motion amplitude A is larger than a*, for a given M and R. The seismic hazard over all 
sources is calculated as a summation: 
in which v(aL) is the annual rate of earthquakes that produce amplitudes A > a* at the site, and 
the summation is performed over all seismic sources i. The integration on magnitude in Equation 
6-2 considers only earthquakes with magnitudes greater than a minimum magnitude m,, typically 
taken as Mw 5. Smaller earthquakes are assumed to produce no damage to engineered structures, 
regardless of the ground motion amplitudes they generate. Thus, both v and fM(O(m) are only 
specified for magnitudes greater than m,, although smaller magnitudes are considered in the 
determination of the rate and magnitude distribution. 
Equation 6-2 is formulated using the assumption that earthquakes (most particularly, successive 
earthquakes) are independent in size and location. In all seismic hazard applications, primary 
interest is focused on computing probabilities for the occurrence of high (rare) ground motions 
(as a result, the probability of two or more exceedances in 1 year is negligible). Thus, the 
ANLCRW-GS-000003 REV 00 49 of 89 
\ V ~ A K ~ ~ ~ ~ ~ ~ V ~ ~ \ ~ ~ W C ~ ~ \ P R ~ S \ W C C A M M U M R U ~ ~ - I C ~ ~ ~ ~ ~ O O ~ I C L D O C 04ILB100 
April 2000 

quantity on the right side of Equation 6-1, which is the annual rate of earthquakes with amplitude 
A > a*, is a very good approximation to the probability of exceeding amplitude a* in 1 year. 
The calculation of hazard from all sources is performed for multiple values of a*. The result is a 
hazard curve, which gives the annual probability of exceedance as a function of a*. This 
calculation is performed for multiple measures of ground motion amplitude (i.e., PGA and SA at 
multiple frequencies). 
6.5.2 Treatment of Uncertainty 
The most recent PSHA studies distinguish between two types of uncertainty, namely epistemic 
and aleatory. Aleatory uncertainty (sometimes called randomness) is probabilistic variability 
that results from natural physical processes. The size, location, and time of the next earthquake 
on a fault and the details of the ground motion are examples of quantities considered aleatory. In 
c u m t practice, these quantities cannot be predicted, even with the collection of additional data. 
Thus, the aleatory component of uncertainty is irreducible. The second category of uncertainty is 
epistemic (sometimes called simply uncertainty), which results from imperfect knowledge about 
earthquakes and their effects. An example of epistemic uncertainty is the shape of the magnitude 
distribution for a given seismic source. In principle, this uncertainty can be reduced with 
advances in knowledge and the collection of additional data. 
These two types of uncertainty are treated differently in advanced PSHA studies. Integration is 
carried out over aleatory uncertainties to get a single hazard curve (see Equation 6-2), whereas 
epistemic unccrtainties are expressed by incorporating multiple assumptions, hypotheses, 
models, or parameter values. These multiple interpretations are propagated through the analysis, 
rssulting in a suite of hazard curves and their associated weights. Results are presented as cwves 
showing statistical summaries (e.g., mean, median, fractiles) of the exceedance probability for 
each ground motion amplitude. The mean and median hazard curves convey the central. 
tendency of the calculated exceedance probabilities. The separation among fractile curves 
conveys the net effect of epistemic uncertainty about the source characteristics and ground 
motion prediction on the calculated exceedance probability. 
Epistemic uncertainties are associated with each of the three inputs to the seismic hazard 
evaluation. .fie seismogenic potential of faults and other geologic features is uncertain, as a 
result of (I) uncertainty about the tectonic regime operating in the region and (2) incomplete 
knowledge of these geological features. The geometry of these geologic features is also 
uncertain. Uncertainty in the rate of seismicity is generally divided into uncertainty in M-, 
uncertainty in the type of magnitude distribution, uncertainty in the rate parameter (i.e., activity 
rate, rate of large events, or SR), and uncertainty in b or other shape parameters of the magnitude 
distribution fMtifm). Finally, the attenuation functions are uncertain, which arises from 
uncertainty about the dynamic characteristics (source, path, and site effects) of earthquake 
ground motions in the Yucca Mountain vicinity. This uncertainty is large because few strong 
motions have been recorded in the region. Uncertainties in seismic source characterization and 
ground motion attenuation relations were quantified by considering inputs from six SSFD expert 
teams and seven GM experts, and by each team's and expert's own assessment of uncertainty. 
ANL-CRW-GS-000003 REV 00 50 of 89 
YQK~~~~~~~~S\~~~~SWRQ~ECTS\WCCAMTN\AMRU~-~~OO\~~M)~~CX.M)(: 04/18EO 
April 2000 

That is, each SSFD expert team formulated multiple alternative interpretations about the 
seismogenic characteristics of potential seismic sources, and assigned weights to these 
hypotheses according to their credibility given the current state of knowledge and the degree they 
are supported by data. Each GM expert applied a similar procedure to alternative interpretations 
about the source, path, and site characteristics affecting ground motions. The development of 
these seismic source and ground motion interpretations was described previously in Section 6.3. 
6.5.3 Ground Motion Hazard Results 
All ground motion hazard results were computed for the reference rock outcrop, which 
corresponds to the proposed waste emplacement depth (represented by Point A on Figure 4). 
Ground motion was computed at this reference location as a control motion to facilitate the 
future determination of seismic design input motions for surface locations (Points C and D) and 
potential waste-emplacement level locations (Point B). 
Ground motion hazard was calculated for PGA, PGV, and SA at 0.3, 0.5, 1, 2, 5, 10, and 20 Hz 
structural fiequencies. The computations were based on equal weighting of the six SSFD expert 
teams' and the seven GM experts' evaluations. Complete data files of the results are located in 
DTN:M00004MWDRIFM3.002. The results are presented here in the form of hazard curves 
showing the mean, median, and 15th and 85th fiactile annual exceedance probability for a given 
ground motion value as shown on Figures 1 1 through 13. The hazard is also expressed as mean, 
median, and 15th and 85th fiactile SA on uniform hazard spectra (Figures 14 and 15) for target 
annual exceedance probabilities of lo4 and 1c3, respectively. These hazard results can be used 
for postclosure to evaluate whether future ground motions contribute to any repository SSCfailure 
events that occur with a probability greater than 1 in 10,000 years in 10,000 years, as 
discussed in Section 1. The uniform hazard spectra show SAs with the same annual exceedence 
probabilities and they can be deaggregated to help develop seismic design inputs. The spectra 
can be deaggregated on magnitude, distance, and ground motion variability, as shown on Figure 
16, to determine controlling earthquakes and provide engineering insights for development of 
design spectra (McGuiie 1995). PGA, PGV, and SA values for the reference rock outcrop are 
summarized in Table 10 for target design basis hazard annual occurrences of 10" and lo4. Note 
that typographical errors in the PGVs shown in Table 7.1 of CRWMS M&O (1998a) have been 
corrected in Table 10. 
Table 10. Mean SA (g), PGA (g), and PGV (cmlsec) Values 
for Reference Rock Outcrop (modified from Table 7.1 of CRWS M&O 1998a) 
April 2000 
Ground Motion 
Parameter 
SA, Frequency (Hz) 
0.3 
0.5 
1 
2 
5 
10 
20 
PGA 
PdV 
Horizontal Vertical 
Annual Exceedance Frequency 
lo3 
0.051 
0.091 
0.162 
0.263 
0.346 
0.355 
0.284 
0.169 
1 S A 
lo4 
0.168 
0.278 
0.471 
0.782 
1.083 
1.160 
0.951 
0.534 
AA 9 
loa 
0.029 
0.046 
0.073 
0.130 
0.200 
0.250 
0.225 
0.112 
7 R 
lo4 
0.105 
0.159 
0.222 
0.406 
0.660 
0.906 
0.853 
0.391 
94 Q 

6.5.4 Sensitivity Analyses 
Extensive evaluations of the sensitivity of the hazard results to changes in the input parameters 
were performed (CRWMS M&O 1998a, Section 7). These sensitivity analyses indicate that the 
uncertainty in ground motion attenuation was the largest contributor to uncertainty for the 
ground motion hazard. Each GM expert characterized epistemic uncertainty in the median U 
amplitide and the scatter of ground motion about the median amplitude for a set of magnitudedistance 
pairs. These evaluations were used to develop a ground motion attenuation relationship 
for each expert including epistemic uncertainty in the median and the standard deviation of 
motion about the median estimate. Sensitivity analysis shows that the most important ground 
motion contributor to uncertainty in the hazard are the within-expert uncertainties about the 
median ground motion and the standard deviation of motion about the median. 
Figure 17 shows the mean hazard for horizontal PGA by individual SSFD teams and for all 
teams combined. The spread in the curves illustrates the team-to-team episternic uncertainty, 
which can be considered a measure of the earth science community's state of knowledge about 
earthquake processes. This uncertainty is generally less than a factor of 2 and is relatively small, 
reflecting the large common information base used by the experts, and the success of the expert 
elicitation process that minimized differences in knowledge and understanding. 
With respect to the seismic source characterization, the carthqu'ake recurrence approach (use of 
either SRs or recurrence intervals) and recurrence models (e.g., characteristic, exponential or 
maximum moment) were found to contribute the most to uncertainty in the ground motion 
hazard. Mmx has a small effect on uncertainty, especially for 10 Hz motions, because a large 
fraction of the hazard at this frequency comes from more frequent moderate magnitude events at 
near distances. Geometric fault parameters (e.g., rupture lengths, dips, maximum depths) are 
minor contributors to uncertainty. These parameters have a 'moderate effect on the locations of 
earthquakes and on evaluations of M, but do not affect earthquake recurrence. 
Denggregation of the mean hazard for an annual exceedance of lo4 shows that at intermediate 
frequencies (5 to 10 Hz), ground motions are dominated by earthquakes smaller than Mw 6.5 
occurring at distances less than 15 krn (Figure 16a). The sources of these events are the 
Paintbrush Canyon - Stagecoach Road and Solitario Canyon faults (or coalesced fault system 
including these two faults) and the host areal seismic source zone. Dominant events for low 
Frequency ground motions (e.g., 1 to 2 Hz), display a bimodal distribution showing significant 
contributions to the total hazard from large nearby earthquakes, the same three sources 
mentioned above, and from Mw 7 and larger earthquakes beyond distances of 50 km (Figure 
16b). The latter contribution is mainly from the significantly higher recurrence rates of the Death 
Valley and Furnace Creek faults. Multiple-rupture interpretations involving comparable seismic 
moment release on more than one fault (i.e., those requiring modification of the attenuation 
equations) make a small contribution to the total hazard. Buried strike-slip faults, volcanic 
seismicity, and seismogenic detachments contribute negligibly to the total hazard, 
ANL-CRW-GS-000003 REV 00 52 of 89 
\\OAKILulri~~sk f f c M P R Q 1 E C T S \ W C C ~ M R - x . OU18100 
April 2000 

6.6 PSHA FAULT-DISPLACEMENT HAZARD ASSESSMENT 
6.6.1 Methodology 
, This section describes the methodology used to perform the PSHA calcuIations for fault 
displacement at the Yucca Mountain site and the application of this methodology to the 
I demonstration sites within the site area. This presentation uses many of the elements and 
concepts from the ground motion PSHA that were introduced and described in Section 6.5.1. 
I Fault displacement PSHA results in the probability that the tectonically induced fault 
, 
I displacement at a given site will exceed any value. The site of interest may or may not be on an 
active fault. Results are in the form of fault displacement hazard curves, which show annual 1 exceedance probability for values of the displacement. 
I Of the two approaches for fault displacement PSHA described in Section 6.3.4, the earthquake 
zpproach calculates the principal and distributed faulting separately, using different attenuation 
equations, and then adds them to obtain a total displacement hazard curve. The displacement 
approach, on the other hand, considers both principal and distributed faulting but does not 
distinguish between them. 
6.6.1.1 Earthquake Approach 
The evthquake approach explicitly considers earthquake magnitudes and locations as' 
intermediate variables in the calculation of fault displacement and uses the same seismic source 
models (i.e., .source geometries and magnitude-recurrence models, and their. associated 
uncertainties) that are used in the ground motion PSHA. The only substantive ,difference 
between the earthquake approach for fault displacement PSHA and the ground motion analysis 
described in Section 6.5 relates to the attenuation equations. These differences fall into the 
following two categories: 
I) Because both principal and distributed faulting are nonuniformly distributed, there is a 
probability of no displacement at the site under consideration, given the occurrence of tm 
earthquake in the vicinity of the site. Thus, the attenuation equation is written as the 
product of two terms: (1) the probability of nonzero displacement given the occurrence of 
an earthquake of certain characteristics at a given location and (2) the probability that the 
displacement at the site will exceed a value d*, given nonzero displacement. 
2) Both the probability of nonzero displacement and the conditional probability on the 
amount of displacement depend on a number of quantities besides just magnitude and 
distance. These quantities may be grouped into three categories: (1) geometry of the site 
relative to the rupture (particularly the along-rupture location x/L defined on Figure 8-1 of 
CRWMS M&O 1998a), (2) characteristics of the principal fault (e.g., total length, 
cumulative displacement), and (3) characteristics of the feature (fault or fracture, if 
present) where the site is located (e.g., total length, cumulative displacement). 
ANLCRW-GS-00a003 REV 00 53 of 89 
\ ~ A K ~ ~ ~ ~ ~ V ~ ~ \ ~ ~ W C ~ S W R O I E C T S \ W C C ~ R \ A ~ - I C ~ ~ ~ ~ ~ ~ ) ~ Q X . D O C 0411MIO 
April 2000 

The resulting attenuation equations for fault displacement are of the form 
where Go is the attenuation function for fault displacement, represents the location of the 
rupture relative to the site (not just distance), and &rincbal and sip represent characteristics of the 
principal fault and site (all quantities in &rincipd and Zire will be represented by for the sake of 
brevity). Separate attenuation equations are developed for principal and distributed faulting. 
The attenuation equation for principal faulting is used only in conjunction with the fault where 
the site is located, if that fault is active. The attenuation equation for distributed faulting is used 
for all other faults and for the areal source zone containing the site. 
The calculation of fault displacement hazard, considering all seismic soimes and all earthquake 
magnitudes, is performed using a modified version of Equation 6-2, namely 
where i indicates source number, V, is- the rate of earthquakes on source i, f,,(m) is the 
probability density function of magnitude, and fRerMe. (Em)is the probability density function of 
earthquake location (given magnitude). The calculation of fault displacement hazard given by the 
equation above is performed for multiple values of d*. The result is a hazard curve, which gives 
the annual probability of exceedance as a function of d*. 
As in the case of ground motions, the primary interest is focused on computing probabilities for 
large but rare displacements. As a result, the probability of two or more events with D > d* in 
one year is negligible. Thus, the quantity on the right side of Equation 6-4, which is the annual 
rate. of earthquakes with displacement D > d* is a good approximation to the probability of 
exceeding displacement d* in one year. If the quantity of interest is the maximum single-event 
fault displacement during a long time period T, one can use the equation 
P [ Dm, (T) > d*.J = 1 --exp[-v(d*)TJ (Eq. 6-51 
It should be emphasized that these hazard results are applicable to single events. If the quantity 
of interest is the cumulative displacement from more than one earthquake over a long time 
period, which is not the intent in this study, it is necessary to use the theory of compound Poisson 
processes. 
6.6.1.2 Implementation of the Earthquake Approach 
Calculations for the earthquake approach consider all local faults, as well as the host areal source 
zone(s). The regional faults do not contribute to distributed fault displacement because the 
distributed displacement attenuation equations decay rapidly with distance, given the models 
formulated by the SSFD expert teams. 
ANLCRW-GS-000003 REV 00 54 of 89 
\ U I A K l L x d r i v c s \ r v c f s \ P R 0 1 ~ S \ W a : ~ \ h m - ~ v O n P m O O ~ m W C 04118100 
April 2000 

The rate portion of the attehuation equations for principal displacement (i.e., the first term in 
Equation 6-3) consists of a portion that depends on d L (i.e., unity for d L in the interval [0,1], 
zero otherwise), and a magnitude-dependent portion. The magnitude-dependent portion is 
considered a logistic function of magnitude, except by one team that considers the probability 
distribution of hypocentral depth, the magnitude-dependent rupture width, and the downdip 
geometry of the fault. The rate portion of the attenuation equations for fault displacement is a 
logistic function of magnitude and distance, or PGV at the site. The rate portion for distributed 
faulting also includes the probability P[C] that the site is capable of fault displacement. This 
probability represents episternic uncertainty (unless it is exactly zero or unity). 
The distribution portion of the attenuation equations for principal and distributed displacement 
(i.e., the second term in Equation 6-3) is specified as an expression for the scale parameter of the 
distribution (e.g., mean displacement given magnitude, a, etc.), and information about the 
shape and spread of the distribution. For several teams, this expression consists of a product of 
several random terms. For instance, several teams -calculate the principal displacement as the 
product of the MD (taken as lognormal, with a median value that depends on magnitude) times a 
random shape function (which, for a given x/L, takes the form of a beta distribution with 
parameters that depend on x/L). In all these instances, these products are approximated using 
lognormal probability distributions, with medians and coefficients of variation computed using 
the well-known approximations for products of random variables. The accuracy of all these 
approximations was tested by comparing the exact and approximate distribution shapes. 
There are also situations where the distribution portion of the attenuation equation for distributed 
displacement is not a function of the earthquake magnitude or distance, and depends only on 
some characteristic of the site. This approach constitutes a hybrid between the earthquake and 
displacement method, where the occurrence portion of the model considers earthquakes, but the 
distance-distribution portion depends only on the characteristics of the site. 
66.1.3 Displacement Approach 
The displacement approach uses a direct characterization of the occurrence rate of displacement 
events at the site and the probability distribution of displacement per event, without using 
earthquake magnitude and location as intermediate variables. The occurrence rate information 
may be provided as direct values of the occurrence rate h or in the form of a SR divided by an 
average displacement per event. Specification of the probability distribution of displacement per 
event P[D>d* I event] is in the form of a scale parameter (such as the average displacement per 
event &, maximum displacement Dm, or cumulative displacement Dcu,) and information 
about the shape and spread of the distribution. 
Calculation of the fault displacement hazard curve for the displacement approach (under the 
essumption of rare events discussed above) is straightforward, namely: 
April 2000 

6.6.1.4 Implementation of the Displacement Approach 
Although calculation of the hazard curve for this approach does not require integration over 
magnitudes and distances or summation over seismic sources, a logic tree analysis is required 
because the expert teams specified multiple alternatives for the various elements of the model 
and for the characteristics of the site. 
6.6.2 Treatment of Uncertainty 
As with the ground motion PSHA methodology (discussed in Section 6.5.1), the formulations 
given above for the earthquake and displacement approaches for the fault displacement PSHA 
represent the aleatory uncertainty in the natural phenomena of tectonically-induced fault 
displacement. Mathematically, aleatory uncertainty is represented by the rates and probability 
distributions in Equations 6-3, 6-4, and 6-5. Epistemic uncertainty is associated with imperfect 
knowledge about these phenomena. In the earthquake approach, epistemic uncertainty is in the 
seismic source characterization, the attenuation equations, and the characteristics of the site that 
affect fault displacement. In the displacement approach, epistemic uncertainty is in the two 
elements of the model, namely the rate information and the parameters of the displacement per 
event distribution, as well as in the characteristics of the site that affect fault displacement. 
Epistemic uncertainties in seismic source characterization and fault displacement attenuation 
equations are quantified by considering inputs from the six SSFD expert teams, and by each 
team's own assessment of epistemic uncertainty. Each expert team selects an approach for the 
fault displacement PSHA (earthquake, displacement, or a weighted combination of both), then 
formulates multiple alternative interpretations for the fault displacement attenuation equations (if 
using the earthquake approach) or for the rate and the distribution of displacement per event (if 
using the displacement approach). Calculations for the earthquake approach consider cach 
expert team's fault displacenmt attenuation equations in conjunction with that team's source 
characterization. 
6.6.3 Fault Displacement Hazard Results 
Probabilistic fault displacement hazard was calculated at the nine sites within the site area 
proposed for the repository (Figure 3). Two of the sites (7 and 8) have four displacement 
histories specified to represent actual fault and fracture conditions that have been mapped at 
Yucca Mountain. 
All of the teams considered Sites 1 and 2 to be on principal faults. Two teams also considered 
some potential for principal faulting hazard at Site 4 because they interpreted some probability 
that the Ghost Dance fault is seismogenic. One team also made the interpretation that Site 6 in 
Dune Wash lies on the West Dune Wash fault and has some probability of being subject to 
principal faulting hazard. 
The teams varied widely in their assessments of the probability that distributed faulting could 
occur in future earthquakes at Sites 3 through 9, which are away from the block-bounding faults 
and principal faults. These assessments were based on fault orientation, cumulative slip, and 
structural relationships. One team's interpretation was that all features with some evidence of 
cumulative displacement are capable of displacement in future earthquakes. Another team's 
ANL-CRW-GS-000003 REV 00 56 of 89 
\ \ D A K ~ ~ ~ ~ ~ W ~ ~ S W R Q I U ~ T S \ W C C ~ R \ A ~ - ~ ~ I C X . W C W l ~ 
April 2000 

interpretation was that for most of these features, the probability that they are capable of 
displacement in h r e earthquakes is low. All the teams considered that the probability of 
displacement at a point in intact rock resulting fiom a fbture earthquake is either extremely low 
or zero. 
The integrated hazard results provide a representation of fault displacement hazard and its 
uncertainty at the nine sites, based on the interpretations and parameters developed by the SSFD 
expert teams. Complete data files of the results are located in DTN: M00004MWDRIFM3.002. 
Separate results are shown here for each site in the form of summary fault displacement hazard 
curves (Figures 18 through 22). Note that separate curves are not shown for Site 7d and 8d 
because all results are below an annual exceedance probability of 10' @. 8-6 of CRWMS M&0 
1998a). Also note that for some of the sites, the median and/or 15th percentile curves are not 
shown because the values are below the range of the plots (for example, Site 7, Figure 21). 
Additionally, for many of the sites, mean values can actually exceed the 85th percentiles at lower 
probabilities (Figures 18 through 22). This is due to the skewed distributions resulting fiom 
large uncertainties as discussed firther below. Table 11 contains a summary of the mean 
displacement hazard results for the two target preclosure design annual exceedance probabilities, 
lo4 and lo", at the nine sites. 
With the exception of the block-bounding Bow Ridge and Solitario Canyon faults (Sites 1 and 2, 
respectively), the mean displacements are all 0.1 cm or less at a 10" annual exceedance 
probability (Table 11). For the Bow Ridge and Solitario Canyon faults at 1us annual exceedance 
probability, the mean displacements are 7.8 and 32 cm, respectively (Figure 18; Table 11). Thus, 
sites not located on a block-bounding fault (i.e., sites on the intrablock hults, other small faults, 
shear fractures, and intact rock) are assessed to have displacements of 0.1 cm or less for target 
preclosure design hazard annual exceedance probabilities (Figures 19 through 22; Table 11). 
Due to the large uncertainties, extrapolating the displacement hazard curves to lower exceedance 
probabilities for performance assessment may require additional considerations in applying the 
results. The hazard results for the Bow Ridge fault (Figure 18a) suggest 2 and greater than 5 m 
displacements corresponding to 10' median and mean annual exceedance probabilities, 
respectively. The large difference between the mean and median hazard results is a consequence 
of the very large knowledge uncertainty about modeling fault displacement hazard. This large 
uncertainty is hrther highlighted by the fact that the mean hazard curve is above the 85th 
percentile for annual exceedance probabilities below lo-', illustrating that the hazard results are 
driven by large modeling uncertainty at these low annual exceedance probabilities. The 
projected hazard curves at lo4 annual exceedance probabilities for the Solitario Canyon fault 
suggest median and mean displacements of about 3.5q and more than 5 m, respectively. 
Similar to the Bow Ridge fault, the mean displacement hazard curve is larger than the median 
curve for low probabilities. Due to such large uncertainties controlling the mean hazard curve at 
low probabilities (below lo6) it may be appropriate for some applications to use the median 
hazard curve, or some intermediate value between the mean and median, to determine fault 
displacement hazard values at these low annual exceedance probabilities. 
Geologic data for these faults also support using median rather than mean displacement values at 
low exceedance probabilities. Paleoseismic data indicate displacements per event were 80 cm or 
less for the Bow Ridge fault (maximum estimate for the last two to three surface-faulting events 
April 2000 

that occurred within the past 340,000 years), and 140 cm or less for the Solitario Canyon fault 
(maximum estimate for the last four to six events that occurred within the past 200,000 years) 
(CRWMS M&O 1998b, Section 12.3). Even cumulative displacements for these same time 
periods are less than the mean hazard values at exceedance probabilities. The short lengths 
of these faults also suggest that mean displacement values exceed what is physically credible for 
correspondingly small rupture areas. For example, the total end to end length of the local faults 
is less than 33 km. 'Given a maximum surface rupture length of 33 km, empirical relations yield 
expected maximum displacements of 1.3 and 1.5 m for all type and normal slip faults, 
respectively (Wells and Coppersmith 1994). Even at two standard deviations, maximum 
clisplacements based on surface rupture are less than 3 m. 
Table 11. Mean Displacement Hazard at Nine Demonstration Sites 
(Table 8-1 from CRWMS M80 1998a) 
6.6.4 Sensitivity Analyses 
I . 
4 
6 I 3a 7 
7b 
' 7c 
7d ' .- 
8 
88 
8b 
8c 
8d 
9 
Extensive evaluations of the sensitivity of hazard results to evaluated parameters were performed 
(CRWMS M&O 1998a, Section 8). Figure 23 illustrates the team-to-team variation in the mean 
fault displacement hazard for Site 1. The team-to-team uncertainty is significantly larger than is 
found for ground motion hazard. We believe this relatively larger scientific uncertainty 
appropriately reflects the earIy stage of development of the methodology for probabilistic . . assessments of fault displacement hazard. ' . 
A positive correlation between the amount of geologic data available at a site and the uncertainty 
in the calculated fault displacement hazard at that site is observed, as should be expected. For 
sites with significant geologic data, the team-to-team uncertainty is less than 1 order of 
magnitude. For sites with few or no data, the team-to-team uncertainty may span 3 orders of 
magnitude. The larger uncertainty at these sites is considered to be due to data uncertainty (i.e., 
less certain constraints on fault displacement characterization models). 
' Location shown on Figure 3. 
Location 
Bow Ridge fault 
Solitario Canyon fault 
Drill Hols Wash fault 
Ghost Dance fault 
Sundance fault 
Unnamed 100 m east fault of Solitario west of Canyon Dune Wash fault . 
2-m small fault 
1 0-cm shear 
Fracture 
Intact rock 
Between Solitario Canyon and Ghost Dance 
2-m small fault 
10-cm shear 
Fracture 
Intact rock 
Midway Valley 
ANL-CRW-GS-000003 REV 00 58 of 89 
\ U ~ A K ~ ~ ~ ~ ~ ~ ~ + ~ \ ~ ~ W C ~ ~ ~ E C T S \ Y U C C A M I F ~ U M R U I I ~ ~ - I C ~ - ~ C X . W C 04/18100 
April 2000 
- 
Mean Displacement 
lo4 Annual 
Exceedance 
Probability 
4.1 
<0.1 
<0.1 
<O. 1 
cO.1 
c0. 1 
, <0.1 
c0. 1 
cO.1 
cO.1 
cO.1 
<0.1 
<0.1 
<0.1 
4.1 
(cm) 
lw5 Annual 
Exceedance 
Probability- 
7.8 * 
32 
cO.1 
<O. 1 
~ 0 . 1 
cO.1 
4.1 
4.1 
4 . 1 
<0.1 
<0.1 
<0.1 
<O. 1 
<0.1 
0.1 

While the fault displacement h&ard results display large uncertainty, the hazard levels are quite 
low. Sites with the highest fault displacement hazard show uncertainties comparable to those 
obtained in the ground motion PSHA. Sites with low hazard show much higher uncertainties. 
While the fault displacement hazard results overall have significantly greater uncertainty than the 
ground motion hazard results, they are considered robust by virtue of the extensive efforts at 
expert elicitation and feedback, as well as the methodological developments that were 
undertaken as part of this study. 
7. CONCLUSIONS 
The main conclusions for this AMR are the same as those for the PSHA report (CRWMS M&O 
1998a). The earthquake hazards from ground shaking and fault displacement have been 
evaluated for the potential geologic repository at Yucca Mountain (DTN: 
M00004MWDRIFM3.002). PSHA using multiple expert interpretations to capture scientific 
uncertainty have been employed. The resulting level of ground motion hazard, calculated for a 
defined rock condition (Point A on Figure 4), is comparable to moderate tectonically and 
seismically active sites elsewhere in the Basin and Range province such as the Rio Grande rift in 
New Mexico and southern Colorado (Wong and Olig 1998). For example, horizontal PGAs at 
Yucca Mountain with annual exceedance frequencies of and lo4 are 0.169 and 0.534 g, 
respectively (Table 10). The hazard at Yucca Mountain is lower than elsewhere in the Basin and 
Range tectonic province, for example, locations along the Wasatch fault in central Utah. 
The approaches used in the probabilistic fault displacement hazard analysis were developed 
specifically for the Yucca Mountain site and represent the state of the art in this type of hazard 
evaluation. The results indicate that fault displacement hazard is not a seismic design issue for 
the repository, although block-bounding faults should be avoided in the layout of the 
underground facilitates in accordance with YMP (1997a). 
This document may be affected by technical product input information that requires 
confirmation. Any changes to the document that may occur as a result of completing the 
confirmation activities will be reflected in subsequent revisions. The status of the input 
information qu'ality may be confirmed by review of the Document Input Reference Systems 
database. 
April 2000 

8. INPUTS AND REFERENCES 
8.1 DOCUMENTS CITED 
Abrahamson, N.A.; and Silva, W.J. 1997. "Empirical Response Spectral Attenuation Relations 
for Shallow Crustal Earthquakes." Seismological Research Letters, 68, (I), 94-127. El 
Cerrito, CA: Seismological .Society of America. TIC: 240553 
Anderson, RE.; Bucknarn, R.C.; Crone, A.J.; Haller, K.M.; Machette, M.N.; Personius, S.F.; 
Barnhard, T.P.; Cecil, M.J.; and Dart, R.L. 1995. Characterization of Quaternary and 
Suspected Quaternary Faults, Regional Studies, Nevada and California. Open-File Report 
95-599. Denver, CO: U.S. Geological Survey. ACC: MOL. 19960924.0562. 
Anderson, R.E.; Crone, A.J.; Machette, M.N.; Bradley, . L.A.; and Diehl, S.F. 1995. 
Characterization of Quaternary and Suspected Quaternary Faults, Amargosa Area, 
Nevada and Calfornia. Open File Report 95-613. Denver CO: U.S. Geological Survey. 
TIC: 246589. 
Beason, S.C.: Turlington, G. A.; Lung, R.C.; Eatman, G.L.W.; Ryter, D., and Barr, DL 1996. 
Geology of the North Ramp-Station 0+60 to 4+00, Exploratory Studies Facility. Yucca 
Mountain Project, Yucca Mountain, Nevada Denver, Colorado: U.S. Geological Survey. 
ACC: MOL. 19970 lO6.CJ449. 
Becker, A.M.; and Abrahamson, N.A. 1997. "Stress Drops in Normal Faulting Earthquakes." 
Seisnidogical Research Letters, 68, (2), 322. El Cerri to, California: Seismological Society 
of America. TIC: 247049. 
Bell, M.J. 1996. "Issue Resolution Status Report on 'Methodology to Assess Fault Displacement 
and Vibratory Ground Motion Hazard at Yucca Mountain'." Letter to Dr. S. Brocoum 
DOJYYMSCO, July 26, 1996, with enclosure. Washington D.C.: U.S. Nuclear Regulatory 
Commission. ACC: MOV. 199804 17.0079. 
Boore, D.M.; Joyner, W.B.; and Fumal, T.E. 1997. "Equations for Estimating Horizontal 
Response Spectra and Peak Acceleration from Western North American Earthquakes - A 
Summary of Recent Work. Seismological Research Letters, 68, (I), 128-153. El Cerrito, 
CA: Seismological Society of America. TIC: 240882. 
Camybzll, K.W. 1997. "Empirical Near-Source Attenuation Relationships for Horizontal and 
Vertical Components of Peak Ground Acceleration, Peak Ground Velocity, and Pseudo- 
Absolute Acceleration Response Spectra." Seismological Research Letters, 68, (I), 154- 
179. El Cerrito, CA: Seismological Society of America. TIC: 241762. 
Corncil, C.A. 1968. "Engineering Seismic Risk Analysis." Bulletin of the Seismological 
Society of America, 58, (3, 1583-1606. El Cerrito, CA: Seismological Society of America. 
TIC: 237493. 
April 2000 

Cornell, C.A. 1971. "Probabilistic Analysis of Damage to Structures Under Seismic Loads." 
Chapter 27 of Dynamic Waves in Civil Engineering, Howells, D.A., Haigh, I.P., and 
Taylor, C., eds. New York: Wiley Interscience. TIC: 241003. 
CRWMS M&O (Civilian Radioactive Waste Management System, Management and Operating 
Contractor). 1998a. Probabilistic Seismic Hazard Analyses for Fault Displacement and 
Vibratory Ground Motion at Yucca Mountain, Nevada. Milestone SP321M3. Wong, I.G. 
and Stepp, J.C., coordinators. Oakland, California: CRWMS M&O. ACC: 
MOL. 1998 1207.0393. 
CRWMS M&O. 1998b. Yucca Mountain Site Description, B00000000-01717-5700-00019, 
Revision 00. Las Vegas, Nevada: CRWMS M&O. ACC: MOL. 1998 1202.0492. 
CRWMS M&O. 1999a. Characterize Framework for Seismicity and Structural Deformation at 
Yucca Mountain, Nevada. TDP-CRW-GS-000001, Revision 2. Las Vegas, Nevada: 
CRWMS M&O. ACC: MOL. 19991 1 10.0438. 
CRWMS M&O. 1999b. Analysis to Characterize the Framework for Seismicity and Structural 
Deformation at Yucca Mountain, Nevada. Activity Evaluation, July 26, 1999. Las Vegas, 
Nevada: CRWMS M&O. ACC: MOL. 199909 17.0050. 
CRWMS M&O. 2000a. Disruptive Events Process Model Report. TDR-NBS-MD-000002 
REV 00. Las Vegas, Nevada: CRWMS M&O. URN-0230. 
CRWMS M&O. 2000b. Fault Displacement Effects on Transport in the Unsaturated Zone. 
ANL-NBS-HS-000020. Las Vegas, Nevada: CRWMS M&O. URN-0035. 
CRWMS M&O. 2000~. Efects of Fault Displacement on Emplacement Drifrs. ANL-EBS-GE- 
000004 REV 00. Las Vegas, Nevada: CRWMS M&O. ACC: MOL.20000228.0529. 
CRWMS M&O. 2000d. Disruptive' Events FEPS. ANL-WIS-MD-000005 REV 00. Las 
Vegas, Nevada: CRWMS M&O. WRN-0017. 
CRWMS M&O. 2000e. Development of Preliminary Seismic Design Ground Motion Inputs for 
a Geologic Repository at Yucca Mountain, Nevada. ANL-CRW-GS-00001 REV 01. Las 
Vegas, Nevada: CRWMS M&O. URN-0229 
3 
Day, W.C.; Dickerson, R.P.; Potter, C.J.; Sweetkind, D.S.; San Juan, C.A.; Drake I., R.M.; and 
Fridrich, C.J. 1998. Bedrock Geologic Map of the Yucca Mountain Area, Nye County, 
Nevada. Geologic Investigations Series 1-2627. Denver, Colorado: U.S. Geological Survey. 
ACC: MOL. 19981014.0301. 
DOE (U.S. Department of Energy). 1997. Audit Report of United States Geological Survey at 
Denver, Colorado. USGS-ARP-98-01, Washington, D.C.: U.S. Department of Energy, 
Office of Civilian Radioactive Waste Management. ACC: MOL.19980204.0037. 
ANLCRW-GS-000003 REV 00 61 of 89 
\ \ O A K ~ ~ ~ W E ~ S \ P R O I E C I S \ ~ A M T M A M R U ~ ~ - ~ C ~ O O ~ ~ ~ ~ O O ~ ~ X . D O C 04118iW) 
April 2000 

DOE. 1998. Quality Assurance Requirements and Description. DOEIRW-0333P, Revision 8. 
Washington D.C.: U.S. Department of Energy, Office of Civilian Radioactive Waste 
Management. ACC: MOL 19980601.0022. 
DOE 2000. Quality Assurance Requirements and Description. DOE/FtW-00333P, Revision 9. 
Washington D.C.: U.S. Department of Energy, Office of Civilian Radioactive Waste 
Management. ACC: MOL. 1999 1028,0012. 
Dyer, J.R. 1999. "Revised Interim Guidance Pending Issuance of New U.S. Nuclear Regulatory 
Commission (NRC) Regulations (Revision 01, July 22, 1999), for Yucca Mountain, 
Nevada." Letter from Dr. J.R. Dyer (DOEIYMSCO) to Dr. D.R. Wilkins (CRWMS 
M&O), September 3, 1999,OL&RC:SB-1714, with enclosure, "Interim Guidance Pending 
Issuance of New NRC Regulations for Yucca Mountain (Revision 01)". ACC: 
MOL. 19990910.0079. 
EPRI (Electric Power Research Institute). 1986.. Seismic'riazard hlethodology for the Central 
and Eastern United States, Volume 1: Methodology. EPRI NP-4726. Palo Alto, CA: 
Electric power Research Institute. TIC: 222575. -. 
Frankel, A. 1995. "Mapping Seismic Hazard in the Central and Eastern United States. 
Seismological Research Letters, 66, (4), 8-21. El Cerrito, CA: Sesmological Society of 
America. TIC: 2433 18. 
Fridrich, C.J.; Whitney, J.W.; Hudson, M.R.; and Crowe, B.M. 1999. "Space-Time Patterns of 
Lake Cenozoic Extension, Vertical-Axis Rotation, and Volcanism in the Crater Flat Basin, 
Southwest Nevada." Cenozoic Basins of the Death Valley Region, Wright, LA. and 
'I'roxel, B.W., eds. Special Paper 333, p. 197-212. Boulder, Colorado: Geological Society 
of America. TIC: 245358. 
Joynel; W.B. and Boore, D.M. 1988. "Measurement, Characterization, and Prediction of Strong 
Ground Motion." Proceedings, Conference on Earthquake Engineering and Soil 
Dymmics 11: Recent Advances in Ground-Motion Evaluation, Geotechnical 
DivisiodAmerican Society of Civil Engineers, Park City, Utah, June 27-30, J.L. Von Thun, 
ed., p. 43-102. New York, New York: American Society of Civil Engineers.'TIC: 241219. 
Keefer, W.R. and Pezzopane, S.K. 1996. "Quaternary Faults in the Yucca Mountain Region." 
Chapter 3 of Seislnoteclonic Framework and Characterization of Faulting at Yucca 
Mountain, Nevada, Whitney, J.W., ed. Milestone 3GSH100M. Denver, CO: U.S. 
Geological Survey. TIC: 237980. 
Kennedy, R.P. and Ravindra, M.K. 1984. "Seismic Fragilities for Nuclear Power Plant Risk 
Studies." Nuclear Engineering and Design, 79, 47-68. Amsterdam, The Netherlands: 
Elsevier Science Publishers B.V. (North-Holland Physics Publishing Division). TIC: 
243985. 
McCann, M.W., Jr., and Reed, J.W. 1990. "Lower Bound Earthquake Magnitude for 
Probabilistic Seismic Hazard Evaluation. " Nuclear Engineering and Design, 123, 143-153. 
Amsterdam, The Netherlands: Elsevier Science Publishers. TIC: 247150. 
April 2000 

McGarr, A. 1984. "Scaling of Ground Motion Parameters, State of Stress, and Focal Depth." 
Joumal of Geophysical Research, 89, @8), 6969-6979. Washington, D.C.: American 
Geophysical Union. TIC: 222577. 
McGuire, R.K. 1978. FRISK: Computer Program for Seismic Risk Analysis Using Faults as 
Earthquake Sources. Open-File Report 78- 1007. Denver, CO: U. S. Geological Survey. 
ACC: NNA. 19891 107.01 12. 
McGuire, R.K. 1995. "Probabilistic Seismic Hazard Analysis and Design Earthquakes - Closing 
the Loop." Bulletin of the Seismological Sociefy of America, 85, (S), 1275-1284. El 
Cerrito, CA: Seismological Society of America. TIC: 232947. 
McKague, H.L.; Stamatakos, J.A.; and Ferrill, D.A. 1996. Type I Faults in the Yucca Mountain 
Region. CNWRA 96-007, Revision 1. San Antonio, TX: Center for Nuclear Waste 
Regulatory Analyses. TIC: 23206 1. 
NRC (U.S. Nuclear Regulatory Commission). 1999. Ime Resolution S W s Report Key 
Technical Issue: Structural Deformation and Seismicity. Revision 2. Washington, D.C.: 
U.S. Nuclear Regulatory Commission. ACC: MOL. 199912 14.0623. 
Pezzopane, S.K., 1996. "Relevant Earthquake Sources." Chapter 1 1 of Seismotectonic 
Framework and Characterization of Faulting at Yucca Mountain, N e d , Whitney, J. W., 
ed. Milestone 3GSH100M. Denver, CO: U.S. Geological Survey. TIC: 237980. 
Pezzopane, S.K.; Menges, C.M.; and Whitney, J.W. 1994. "Quaternary Paleoseismology and 
Neogene Tectonics at Yucca Mountain, Nevada" Proceedings of the Workshop on 
Paeloseismology, September 18-22, Marshall, Calijomia, Prentice, C.S. Schwartz, D.P., 
and Yeats, R.S., eds., 149-1 52. Open-File Report 94-568. Denver, CO: U.S. Geological 
Survey. ACC: MOL. 19960305.0290. 
Piety, L.A. 1996. Compilation of Known or Suspected Quaternary Faulrs Within 100 km of 
Yucca Mountain, Neva& and Cali$omia. Open File Report 94-1 12. Denver, CO: U.S. 
Geological Survey. ACC: MOL. 1997 1009.0003. 
Sabetta, F. and Pugliese, A. 1996. "Estimation of Response Spectra and Simulation of 
Nonstationary Earthquake Ground Motions." Bulletin of the Seismological Society of 
America, 86, (i), 337-352. El Cerrito, CA: Seismological Society of America. TIC: 
241042. 
Sadigh, K.; Chang, C.-Y.; Egan, J.A.; Makdisi, F.; and Youngs, R.R. 1997. "Attenuation 
Relationships for Shallow Crustal Earthquakes Based on California Strong Motion Data." 
Seismological Research Letters, 68, (I), 1 80- 189. El Cerrito, CA: Seismological Society of 
America. TIC: 243233. 
Savage, J.C.; Svarc, J.L.; and Prescott, W.H. 1999. "Strain Accumulation at Yucca Mountain, 
Nevada, 1983-1998." Journal of Geophysical Research, 104, @8), 17627-1763 1. 
Washington, D.C.: American Geophysical Union. TIC: 245645. 
April 2000 

Schneider, J.F.; Abrahamson, N.A.; and Hanks, T.C. 1996. Ground Motion Modeling of 
Scenario Earthquakes at Yucca Mountain, Final Report for Activity 8.3.1.1 7.3.3. Volume 
1. Denver, CO: U.S. Geological Survey. ACC: MOL. 19980617.0477. 
Spudich, P.; Fletcher, J.B.; Hellweg, M.; Boatwright, J.; Sullivan, C.; Joyner, W.B.; Hanks, T.C.; 
Boore, D.M.; McGarr, A.; Baker, L.M.; and Lindh, A.G. 1996. Earthquake Ground 
Motions in Extensional Tectonic Regimes. Open-File Report 96-292. Menlo Park, CA: 
U.S. Geological Survey. TIC: 245279. 
Stokoe, K.H.; Darendeli, M.B.; and Moulin, B.S. 1998. Laboratory Evaluation of the Dynamic 
Properties of Intact Tu# Specimens jFom the Yucca Mountain Site. Geotechnical 
Engineering Report GR98-1. Austin, TX: University of Texas at Austin. ACC: 
MOL. 19990827.0 153. 
Su, F.; Anderson, J.G.; Brune, J.N.; and Yuehua, Z. 1996. "A Comparison of Direct S-Wave and 
Coda-Wave Site Amplification Determined fi-om Aftershocks of the Little Skull Mountain 
Earthquake." Bulletin of the Seismological Society of America, 86, (4), 1006-1018. El 
Cerrito, CA: Seismological Society of America. TIC: 236585. 
Toro, G. 1998. Probabilistic Seismic Hazard Analysis (PSHA) Soffware Documentation for 
Limited Requirements S o M e Programs MEAN and CMB-FMC, Supporting 
Documentation. ACC: MOL. 19991 104.0337. 
Wells, D.L.; and Coppersmith, K.J. 1994. "New Empirical Relationships Among Magnitude, 
Rupture Length, Rupture Width, Rupture Area, and Surface Displacement." Bulletin of the 
Seismological Society of America, 84, (4), 974- 1002. El Cerrito, CA: Seismological Society 
of America. TIC: 226273. 
Wernheuer, R.F. 1999. ''First Issue of WOO NEPO QAP-2-0 Activity Evaluations." Interofice 
correspondence fi-om RF. Wemheuer (CRWMS M&O) to RA. Morgan (CRWMS M&O), 
October 1, 1999, LV.NEPO.RTPS.TAG. 10199-1 55, with enclosures, Activity Evaluations. 
ACC: MOL. 1999 1028.0 162. 
Wesnousky, S.G.; Scholz, C.H.; Shimazaki, K.; and Matsuda, T. 1983. "Earthquake Frequency 
Distribution and the Mechanics of Faulting." Journal of Geophysical Research, 88, (B 1 l), 
933 1-9340. Washington, D.C. : American Geophysical Union. TIC: 241700. 
Westaway, R.; and Smith, R.B. 1989. "Strong Ground Motion in Normal-Faulting Earthquakes." 
Geophysical Journal, 96, 529-599. New York: Gordan and Breach Science Publishers. 
TIC: 237524. 
Whitney, J.W., ed. 1996. Seismotectonic Framework and Characterization of Faulting at Yucca 
Mountain, Nevadb. Milestone 3GSH100M. Denver, CO: U.S. Geological Survey. ACC: 
MOL. 19970129.O041; MOL. 19970 129,0042; MOL. 19970129.0043; MOL. 19970129.0044; 
MOL. 19970129.OO45; MOL. 19970 129.0046; MOL. 19970129.0047; MOL. 19970129.0048; 
MOL. 19970129.0049; MOL. 19970129.0050; MOL. 19970129.005 1; MOL. 19970129.0052; 
MOL.19970129.0053; MOL. 19970129.0054; MOL.19970129.0055; MOL. 19970129.0056; 
April 2000 

MOL. 19970129.OOS7; MOL. 19970129.0058; MOL. 19970129.0059; MOL. 19970129.0060; 
MOL. 19970129.0061; MOL. 19970129.0062. 
Wong, I.G. and Olig, S.S. 1998. "Seismic Hazards in the Basin and Range Province: 
Perspectives fiom Probabilistic Analyses." In Western States Seismic Policy Council 
Proceedings Volume, ~ a i i n and Range Province Seimic-Hazards Summit, Lund, W.R., 
ed., 1 10-1 27. Miscellaneous Publication 98-2. West Valley, Utah: Utah Geological Survey. 
TIC: 246993. 
Youngs, R.R. and Coppersmith, K.J. 1985. "Implications of Fault Slip Rates and Earthquake 
Recurrence Models to Probabilistic Seismic Hazard Estimates. Bulletin of the 
Seismological Society of America, 75, (4), 939-964. El Cerrito, CA: Seismological Society 
of America. TIC: 237426. 
Youngs, R.R.; Swan, F.H.; Power, MS.; Schwartz, D.P.; and Green, R.K. 1987. "Probabilistic 
Analysis of Earthquake Ground Shaking Hazard Along the Wasatch Front, Utah." Chapter 
M of Assessment of Regional Earthquake Hazards and Risk Along the Wasatch Front, 
Utah, Gori, P.L. and Hays, W.W., eds. Open-File Report 87-585, v.2, p. M1-M110. 
Reston, VA: U.S. Geological Survey. TIC: 245616. 
YMP (Yucca Mountain Project). 1997a. Preclosure Seismic Design Methoclology for a 
Geologic Repository at Yucca Mountain. Topical Report YMPRR-003-NP, Revision 2. 
Las Vegas, NV: DOE/Yucca Mountain Site Characterization Office. ACC: 
MOL.19971009.0412. 
YMP. 1997b. Methodology to Assess Fault Displacement mzd Vibratory Ground Motion 
Hazards at Yucca Mountain. Topical Report YMP/TR-002-NP, Revision 1. Las Vegas, 
NV: DOWucca Mountain Site Characterization Office. ACC: MOL. 1997 10 16.0777. 
8.2 CODES, STANDARDS, REGULATIONS, AND PROCEDURES 
AP3.10Q7 Rev. 2, ICN 0, Analyses and Models. Washington, D.C.: U.S. Department of 
Energy, Ofice of Civilian Radioactive Waste Management. ACC : MOL.200002 17.0246. 
AP-AC-lQ, Rev. 0, ICN 0, Expect Elicitation. Washington, D.C.: U.S. Department of Energy, 
Office of Civilian Radioactive Waste Management. ACC: MOL. 199910 19.0014. 
AP-SI.lQ, Rev. 1, ICN 0, Software Management. Washington, D.C.: U.S. Department of 
Energy, Ofice of Civilian Radioactive Waste Management. ACC: MOL. 19990630.0395. 
AP-SI.lQ, Rev. 2, ICN 4, Software Management. Washington, D.C.: U.S. Department of 
Energy, Ofice of Civilian Radioactive Waste Management. ACC: MOL.20000223.0508. 
Budnitz, RJ.; Apostolakis, G; Boore, D.M.; Cluff, L.S.; Coppersmith, K.J.; Cornell, C.A.; and 
Morris, P.A. 1997. Recommendations for Probabilistic Seismic Hazard Analysis - 
Guidance on Uncertainty and Use of merts. NUREG/CR-6372. Two volumes. 
Washington, D.C. U.S. Nuclear Regulatory Commission. TIC: 235076; 235074. 
ANL-CRW-GS-000003 REV 00 65 of 89 
\WI\-~RIVES\xRIVES\xwc6\PRO~WCCMFMUMRUmr-~OO*x.DOC 04/19/00 
April 2000 

Kotra, J.P.; Lee, M.P; Eisenberg, N.A; and Dewispelare, kR. 1996. Branch Technical 
I Position on the Use of Expert Elicitation in the High-Level Radioactive Wasfe Program. 
NUREG-1563. Washington, DC: U.S. Nuclear Regulatory Commission, TIC: 226832. 
Nuclear Waste Policy Act of 1982. 42 U.S.C. 10101 et seq. 
QAP-2-0, Rev 5, ICN 1, Conduct of Activities. Las Vegas, NV: CRWMS M&O. ACC: 
MOL. 19991 109.0221. 
QAP-2-3, Rev. 10. Ckification ofPermanent Items. Las Vegas, NV: CRWMS M&O. ACC: 
MOL. 199903 16.0006. 
USGS (U.S. Geological Survey). 1996. "Section 16 - Scientific Expert Elicitation." Chapter 3- 
ScientiJic Investigation and Design Control, Management Procedures Mamral. YMPi 
USGS-QMP-3.16, Rev. 0. Denver, Colorado: U.S. Geological Survey. ACC: 
MOL. 19970127.0096. 
USGS. 1997. "Section 3 - Software." Chapter 3 - Scientific Investigation and Design Control, 
Management Procedures Mamral. YMP-USGS-QMP3.03, Rev. 7. Denver, Colorado: U.S. 
Geological Survey. ACC: MOL. 1997121 8.0474. 
USGS. 1998. QMP-3. I6RO, Scientific Expert Elicitation. YMPB Modification to YMPB Quality 
I Management Procedure. QMP 3.16, RO-MI . Denver, Colorado: U. S. Geological Survey. 
ACC: MOL. 19980720.0024. 
8.3 SOURCE DATA, LISTED BY DATA TRACKING NUMBER 
M00004MWDRIFM3.002. Results of the Yucca Mountain Probabilistic Seismic Hazard 
Analysis (PSHA). Submittal date: 4/14/2000. 
ANLCRW-ClS-000003 REV 00 66 of 89 
\~AKl\AKXDRIVES\xRIVES\xw&\PROIECm~R\Amr-rrv0O\muOOOtaDOC 04/19/00 
April 2000 

Source: CRWMS M&0 1998% Appendix G 
Note: Significant earthquakes are shown with the year of ~ccurrmce. 
Figure 1. Historical Seismicity (1 868 to 1996) Showing Mw 3.5 or Modified Mercalli Intensity 111 or 
Greater Events within 300 km of Yucca Mountain 

SEISMIC SOURCE 
GROUND MOTION PROBABILISTIC 
DISPLACEMENT CHARACTERIZATION SEISMIC HAZARD 
CHARACTERIZATION 
Working Meeting #I 
Working Meeting #2 
Ground Motion Hazard Calculations 
Source: CRWMS M&O lW8a 
Note: The expert elicitation process was initiated after workshop #4 for the SSFD experts and after Working Meeting #1 
for the GM experts. 
Figure 2. Probabilistic Seismic Hazard Analyses Project Process for Yucca Mountain 
ANL-CRW-GS-000003 REV 00 April 2000 

Source: CRWMS M&O 1998a, Section 4 
Note: See Figure 6 for regional kcation map. 
Figure 3. Location of Nine Points for Demonstration of Fault Displacement 
Hazard Assessment (1 through 9) and Location of the Site for 
Ground Motion Hazard Assessment ( e at Point 8) 
ANGCRW-GS-000003 REV 00 April 2000 

Point C Point D 
-v-v-v-v 
Tuff 
LEGEND 
Point A - Reference rock outcrop at repository elevation 
Point B - Repository elevation 
Point C - Rock surface 
Point D - Soil surface 
Source: CRWMS M&O 1998a, Section 1 
Note: An of the PSHA ground motion calculations discussed in this AMR 
were done for Point A. Point A is located near Point 8 on Figure 3. 
However. site conditions assumed for Point A do not corres~ond to 
a&al odnditions at Point 8, but were defined for reference bonditions 
(discussed in Section 6.3.3.1.1) to fadlitate future application of results 
io a variety of site conditions. 
Figure 4. Locations of Specified Seismic Design Ground Motion Input 
ANGCRW-GS-000003 REV 00 April 2000 

PROJECT MANAGEMENT 
Carl Stem NRSGWC) 
REVIEW PANEL 
Ivan ~ o n g (URSGWC) 
John Whitney (USGS) 
James Brune (UNR) 
Richard Qulttmeyer (URSGWC) 
Allln Cornell (Stanford) 
Tom Hanks (USGS) 
Jean Savy (UNL) 
Tim Sullivan (DOE) 
Davld Schwa* (USGS) 
DATA MANAGEMENT 
TEAM 
John Whltney 
Ivan Wong 
SEISMIC SOURCE 
AND FAULT I DISPLACEMENT 
FACIUTATIONTEAM I 
Kevin Coppersmtth 
(Geomatrix) 
Bob Youngs (Geomatrix) 
Susan Ollg 
(URSGWC) 
Roseanne Pennan 
(Geomatrix) 
Slhrlo Penopane 
WGS) 
Peter Morrls (ADA) 
Kathyrn Hansen 
(Geomatrix) 
SEISMIC SOURCE 
AND FAULT 
DISPLACEMENT 
EXPERTS 
(see Table 3) 
GROUND MOTION 
FACILITATION TEAM 
Norm Abrahamson 
(Consultant) 
Ann Becker 
(URSGWC) 
Peter Morris (ADA) 
GROUND MOTION 
EXF'ERTS 
(see Table 3) 
Gabriel Toro 
(Risk Engineering) 
ADA - Applied Decision Analysis 
DOE - U.S. Department of Energy 
UNL - Lawrence Livermore National Laboratory 
UNR - University of Nevada. Reno 
URSGWC - URS Greiner Woodward Clyde 
USGS - U.S. Geological Survey 
Source: CRWMS M&O 1998a. Section 1 
Figure 5. PSHA Project Organization 
ANL-CRW-GS-000003 REV 00 April 2000 

I 
Source: Modified from CRWMS M&O 1998b. section 12.3 
* Yucca 
Movntaln 
Site 
Figure 6. Known or Suspected Quaternary Faults and Potentially Significant Local Faults within 100 km of Yucca Mountain 

Source: CRWMS Ma0 1998a, Sedion 4 
Note: See Section 4 of CRWMS M&O 1998a for the 
complete set of maps for all teams. 
Figure 7. Map Showing One Scenario of an Example Regional Source Zone 
Model Considered by One SSFD Expert Team 
ANL-CRW-GS-000003 REV 00 April 2000 

All Sources 
Observed 
- 
5 - 
- - Aggregate Mean 
Aggregate 5th, 95th 
- x RYA - * SBK 
- .005 - 
3.5 4 4.5 5 5.5 6 6.5 7 7.5 8 8.5 
Magnitude 
Source: CRWMS M&O 1998a, Section 4 
Note: See Table 3 for explanation of team abbreviations. 
Figure 8. Predicted Mean, 5th-, and 95th-Percentile Recurrence Rates for All Sources 
Combined Within 100 km of the Site for all SSFD Expert Teams Compared to 
Mean Recurrence Estimates for Individual Teams 
1 
ANL-CRW-GS-000003 REV 00 
I 
I 
April 2000 

i 1-0 100 
Distance (km) 
5 515 6 615 7 7:5 
Moment Magnitude 
Anderson - - - - McGarr -.- Somerville 
--- Boore ................ Silva -..- Walck 
- - - Campbell 
i 10 
Distance (krn) 
100 5 5:5 6 615 7 715 
Moment Magnitude 
Source: CRWMS M&O 199&, Section 6 
Note: a median attenuation of horizontal PGA, @) aleatoty uncertainty of the median values, 
{cl epistemic variability, and (d) epistemic uncertainty in the aleatoty variability. 
Figure 9. PGA Characterization of a Mw 6.5 Normal Faulting Earthquake in the Hanging Wall 
I 
ANL-CRW-GS-000003 REV 00 

a) Seismic source i 
Earthquake locations in space and 
ma nitude-dependent rupture imensions) % 6 lea to a distribution of d~stance 
b) Magnitude distribution and rate of 
occurrence for source i 
Rupture k Site L~autt 
I 
Distance r 
c) Ground-motion attenuation equation 
GA I rn,r(a*) 
mo Magnitude. 
mmax 
d) Probability analysis: A 
annual exceedance probability 
i 
r m 
Amplitude a* 
Source: CRWMS M&O 1998a, Section 7 
Figure 10. Seismic Hazard Computational Model 
ANL-CRW-GS-000003 REV 00 April 2000 

lo-' 
1 o - ~ 
10" 
lo4 
104 
lo-' 
85th ---- 
Mean - 
Median - - 
15th = = = - 
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 
Peak Ground Acceleration (g) 
I I I 1 I 1 I 
85th ---- 
Mean - 
Median - - 
15th ---- 
0.4 0.6 0.8 1 
Spectral Acceleration (g) 
Source: CRWMS Ma0 1998a, Section 7 
Note: All ground motion results are calculated for the reference rock outcrop (Point A on Figure 4). 
Figure 11. Summary Hazard Curves for Horizontal (a) PGA and (b) 1-Hz SA 

I I I I I I 1 1 1 
85th 
Meau - Median - - 15th *==- 
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 
Peak Ground Accelemtion (g) 
Source: CRWMS M&O 1998a, Section 7 
- I I I I I 
85th = m m g 
Meon - Median - - 15th m - = - 
0.4 0.6 0.8 1 
Spectral Acceleration (g) 
Note: All ground motion results are calculated for the reference rock outcrop (Point A on Figure 4). 
Figure 12. Summary Hazard Curves for Vertical (a) PGA and (b) 1 -Hz SA 

I I I I I I I 1 I 
85th - o * * 
Mean - Median - - 15th **.* 
0 50 100 150 200 250 300 350 400 450 500 
Peak Ground Velocity (dsec) 
85th ==.- 
Meal~ - Median - - 15th 
0 50 100 150 200 250 300 350 400 450 500 
Peak Ground Velocity (dsec) 
Source: CRWMS M&O 1998a, Section 7 
Note: All ground motion results are calculated for the reference m k outcrap (Point A on Figure 4). 
Figure 13. Summary Hazard Curves for (a) Horizontal and (b) Vertical PGVs 

L . . * -15th Median . . . -85th 
w 
percentile- Mean --- 
0.01 - r 
1 1 1 1 1 1 I 1 1 1 1 1 1 1 l . I I 1 1 1 
L .. ..15h 
~ e r c e n t ~ ~ e Median .. . .=th M e a n 
Percentile 
0.w - 1 1 1 1 1 1 
I r l l I l l 
I 1 1 1 1 1 1 1 l I I I I I 
Frequency (Hz) 
Source: DTN: M00002MWDRIFM3.001 
Note: All $round motion results are calculated for the reference rock outcrop 
(Pomt A on Figure 4). 
Figure 14. Horizontal (a) and Vertical (b) Uniform Hazard Spectra for lo4 
Annual Exceedance Probability 
ANGCRW-GS-000003 REV 00 April 2000 

. .. .851h M e a n 
p e r c e n t i l e Median Percentile 
Frequency (Hz) 
Source: DM: M00002MWDRIFM3.001 
Note: All ground motion results are calculated for the reference rock outcrop 
pornt A on ~ i u r e 4). 
Figure 15. Horizontal (a) and Vertical (b) Uniform Hazard Spectra for 1 o3 
Annual Exceedance Probability 
ANGCRW-GS-000003 REV 00 April 2000 

Source: CRWMS M&O 1998a, Section 7 
Note: Both plots are for lo4 annual exceedance probability. 
Figure 16. Magnitude-Distance-Epsilon (E) Deaggregation c 
(a) 5 to 10 Hz and (b) 1 to 2 Hz Horizontal SA 
~f Mean Seismic Ham d for 
ANL-CRW-GS-000003 REV 00 p* Y / t 7 l b ~ April 2000 
8~ sf 89 

AAR - 
ASM --- 
DFS - - - RY ..m..m 
SBK - * - 
SDO -- 
Combined -- - I 
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 
Peak Ground Acceleration (g) 
Source: CRWMS M&O 1998a, Section 7 
Note: See Table 3 for explanation of team abbreviations. All ground motion results are calculated for 
the reference outcrop (Point A on Figure 4). 
Figure 17. Mean Hazard Cunres by Team for Horizontal PGA 
ANGCRW-GS-000003 REV 00 April 2000 

85th ---- 
Mean - Median - - 
15th ---- 
Displacement (cm) 
. . . . . . . . I . ' . . ' . " I I . . 
85th ---- 
Mean - 
Median - - 15th -=- 
1 10 100 
Displacement (cm) 
Source: CRWMS M&O 1998a, Section 8 
Note: See Figure 3 for site locations. 
Figure 18. Summary Fault Displacement Hazard Curves for (a) Site 1, Bow Ridge Fault 
and (b) Site 2, Solitado Canyon Fault 

85th - = - = 
Mean - Median - - 
1 10 
Displacement (cm) 
85th - = 0 = 
Mean - Median - - 
0.1 1 10 100 
Displacement (cm) 
Note: The 15th percentile cuwe lies below the range of displacements plotted for both sites. 
Figure 19. Summary Fault Displacement Hazard Curves for (a) Site 3, Drill Hole 
Wash Fault and (b) Site 4, Ghost Dance Fault 

85th 9 - 9 
Mean - Median - I - - . . - . - . a . - 
85th -- 
Mean - Median - 
(4 
85th 
Mean - Median - 
1 10 
Displacement (cm) 
I 10 
Displacement (cm) 
Source: CRWMS Mi30 1998a, Section 8 
Note: The 15th percentile curve lies below the range of displacements plotted for bath sites. 
Figure 20. Summary Fault Displacement Hazard Curves for (a) Site 5, Sundance Fault 
(b) Sie 6, Unnamed Fault West of Dune Wash, and (c) Site 9, Midway Valley 
ANL-CRW-GS-000003 REV 00 m15 %2i1o~ April 2000 
86 of 89 

85th mme 
Mean - Median - = 
IEM - 
0.1 1 10 100 
Displacrment (cm) 
Source: CRWMS 
85th - m - 
Mcan - 
0.1 1 10 100 
Displacement (cm) 
(c) 
Note: The 15th percentile awe lies below the range shown for all conditions and the median lies below the range shown for 
Plots b and c. See Figure 3 for site location. 
1E-03 
1w 
T lW5 
1 M 6 ! 
Figure 21. Summary Fault Displacement Hazard Curves for Site 7, Considering Three Hypothetical 
Conditions: (a) 2 m of Cumulative Displacement, (b) 10 cm of Cumulative Displacement, 
and (c) No Measurable Cumulative Displacement 
- - -----., - - --..-., - - ---.-., - - - 
85th -me 
Mcan - 
- 
- 
*** \ s s s 
ANL-CRW-GS-000003 REV 00 
.--I - . - - . - - - I - - - - - - . - I - - . 
0.1 1 10 I00 
Displacement (cm) 
Mil0 1998a. Section 8 
us8 'r'lnloo ~ p r i l 2000 
87of 89 

I . - - " . . ' I . . " . ' . . I . ' 
85th --- Mean - Median - - 
0.1 1 10 100 
Displacement (cm) 
(b) 
1 0-3 I . . . ...'. I ' - - ""'I - . 
85th --- Mean - 
Displacement (cm) 
10-4 
104 
Source: CRWMS M&O 1998a, Section 8 
Note: The 15th percentile curve lies below the range shown for all conditions and the median lies below the range shown 
for Plots b and c. See Figure 3 for site location. 
85th - - Mean - 
- 
- 
Figure 22. Summary Fault Displacement Hazard Curves for Site 8, Considering Three 
Hypothetical Conditions: (a) 2 m of Cumulative Displacement (b) 10 cm of 
Cumulative Displacement, and (c) No Measurable Cumulative Displacement 
* 
lo-' - . 
1 
1w8 . . . . . . .....I . . . ...-I . . . 
0.1 1 10 100 
Displacement (cm) 
ANL-CRW-GS-000003 REV 00 April 2000 

AAR (displ; 67%) - 
AAR (quake; 33%) - - - 
ASM (quake; 100%) - - - 
DFS (displ; 100%) -= = -= 
RYA (displ; -. - 
SBK (displ; 85%) - - 
SBK (quake; 15%) - - - 
SDO (quake; 100%) - - - - 
1 10 100 
Displacement (cm) 
Source: CRWMS M&O 1998a, Section 8 
Note: See Table 3 for explanation of team abbreviations. 
Figure 23. Mean Fault Displacement Hazard Curves by Team for Site 1, Bow Ridge Fault 
ANL-CRW-GS-000003 REV 00 

ATTACHMENT I 
GLOSSARY 
ANL-CRW-GS-000003 REV 00 1-1 
\ \ D A K ~ ~ ~ ~ & - W ~ ~ I W R O I E C T S \ Y U C C ~ R U ~ ~ - ~ ~ O ~ ~ L D O C 0418100 
April 2000 

GLOSSARY 
Aleatory uncertainty - Refers to randomness in a physical process. This uncertainty cannot be 
reduced with additional data. 
Anastarnosing - Interconnecting parts between any branching system, applied here to faults. 
Annual exceedance probability - The probability that a specified value (such as for .ground 
motions or fault displacement) will be exceeded during 1 year. 
Attenuation - A decrease in seismic-signal amplitude as waves propagate from the seismic 
source. Attenuation is caused by geometric. spreading of seismic-wave energy and by the 
absorption and scattering of seismic energy in different earth materials (termed anelastic 
attenuation). 
Earthquake recurrence model - A model for the rate of occurrence of different size 
earthquakes, usually expressed as a relation between earthquake magnitude and the annual 
frequency of occurrence of earthquakes of that magnitude and larger. Examples include 
exponential, truncated exponential, characteristic, and maximum-magnitude models. 
Deaggregate -To break apart a whole into its constituent parts. 
Dipslip fault - A fault in which the relative displacement is along the direction of dip of the 
fault plane and the largest component of slip is usually vertical; the offset is either normal or 
reverse. 
Distributed faulting - Secondary slip that occurs on faults or fractures in the vicinity of the 
principal rupture in response to the principal displacement. 
Earthquake hazard - Any physical phenomenon associated with an earthquake that may 
produce adverse effects on human activities. These phenomena include surface faulting, ground 
shaking, landslides, liquefaction, tectonic deformation, tsunami, and seiche and their effects on 
land use, man-made structures, and socioeconomic systems. A commonly used restricted 
definition of earthquake hazard is the probability of occurrence or exceedance of a specified 
level of ground shaking in a specified period of time. 
Earthquake (or seismic) source - Geologic structure or feature (such as a fault or volcanic 
feature) that is a potential source for generating earthquakes. 
Epistemic uncertainty - Uncertainty due to a lack of knowledge that can be reduced by 
additional data. 
Epsilon (E) - Ground motion parameter, epsilon, refers to the ground motion residual. 
Footwall - The block of earth below an inclined fault (cf. hanging wall). 
ANL-CRW-GS-000003 REV 00 1-2 
\\OAKl~ufrivesLcvffsWR01ECTS\WCCAMlMAMR\Ana-rrvOhamOO~1cxXDOC W l 1 ~ 
April 2000 

Free-field - Refers to ground motions that are not influenced by manmade structures. 
Frequency (for seismic waves) - Number of cycles occurring in a unit of time. Hertz (Hz), the 
unit of frequency, is equal to the number of cycles per second. 
Ground motion (shaking) - General term referring to the qualitative or quantitative aspects of 
movement of the earth's surface from earthquakes or explosions. Ground motion is produced by 
waves that nre generated by sudden slip on a fault or sudden pressure at the explosive source and 
travel through the earth and along its surface. 
Hanging wall -The block of earth above an inclined fault (cf. footwall). 
Kappa -- A parameter that quantifies the attenuation of ground motions in the near surface (c 1 
to 2 krn depth). 
Left-lateral fault - A strike-slip fault on which the displacement of the far block is to the left 
when viewed from either side. 
Magnitude (M)- A measure of earthquake size, determined by taking the common logarithm 
(base 10) of the largest ground motion recorded by a seismograph and applying a correction for 
the distance to the earthquake. Several scales have been defined, but the most commonly used 
are (1) local magnitude (ML), cornrnonly referred to as "Richter magnitude," (2) surface-wave - 
magnitude (A&), (3) body-wave magnitude (mb), and (4) moment magnitude (Mw); Scales 1-3 
have limited range and applicability and do not satisfactorily measure the size of the largest 
earthquakes. The moment magnitude (Mw) scale, based on the concept of seismic moment, is . 
miformly applicable to all sizes of earthquakes but is more difficult to compute than the other 
tws. In principle, all magnitude scales could he cross calibrated to yield the same value for any 
given earthquake, but this expectation has proven to be only approximately true, thus the need to 
specify the magnitude type as well as its value. 
hlaximum magnitude - The largest magnitude considered rertsonablc for an earthquake source. 
Normal fault - A clip-slip fault in which the rock above the fault plane has moved downward 
relative to the rock below. 
Oblique-slip fault - A fault that combines some strike-slip motion with some dip-slip motion. 
Period - Inverse of frequency, the time interval required for one full cycle of a wave. 
Principal faulting - Slip that occurs along a main fault plane or planes that is (are) the locus for 
release of seismic energy (cf. distributed faulting). 
Recurrence interval - The time span between earthquakes at a particular site. 
April 2000 

Response spectrum - A curve showing the mathematically cbmputed maximum response of a 
set of single damped harmonic oscillators of different natural frequencies to a given input 
ground-acceleration record. 
Right-lateral fault - A strike-slip fault on which the displacement of the far block is to the right 
when viewed from either side. 
Seismic moment - A measure of earthquake size that equals the product of the rupture-plane 
area, the average slip over that plane, and the rigidity (shear modulus) of the rock (cf. 
magnitude). 
Sdsmic source parameters - Parameters that physically define an earthquake source, such as 
earthquake magnitude, location, orientation and geometry of a fault, stress drop, slip direction. 
Shear wave - A seismic wave that involves a shearing motion in a direction perpendicular to the 
direction of propagation. Shear waves are the primary source of damaging ground motions 
within -1 00 krn of an earthquake. 
Slip rate (SR) - The average rate of displacement at a point along a fault as determined from 
geodetic measurements, from offset manmade structures, or from offset geologic features whose 
age can be estinlated. It is measured parallel to the predominant slip direction or estimated from 
the vertical or horizontal separation of geologic markers. Slip rates can be calculated by dividing 
displacement by recurrence intervals (and so slip rates can vary depending on the time period of 
interest). 
Spectrum - In .seismology, a curve showing amplitude and phase as a function* of structural 
frequency or period (plural - spectra). 
Stress drop - The difference between the stress across a fault before and after an earthquake.. A 
parameter in many models of the earthquake source that has a bearing on the level of highfrequency 
shaking that the fault radiates. 
Strikeslip fault - A fault whose relative displacement is purely horizontal. 
Strong motion data - Records of strong ground motions from historical earthquakes; although 
, . strong is not universally or formally defined, it is often taken as accelerations of 0.1 g or larger, 
the threshold of damaging motions for many nonengineered structures. 
Transpressional regime - A region with a mix of compressional (reverse) and strike-slip 
faulting. 
April 2000 

PSHA SOFI'WARE DESCRIPTION 
ANJXRW-GS-000003 REV 00 11- 1 
\ \ O A K ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ - ~ C ~ S W R ~ ~ E C T S \ Y U C C A ~ U ~ ~ ~ - I C ~ O O ~ ~ O O ~ L ~ D O C WIIBIU) 
April 2000 

PSHA SOFIUIARE DESCRIPTION 
The FRISK88 software package used for the PSHA (CRWMS M&O 1998a) calculations 
consists of four programs: PREP88 (version 1.0), FRISK88 (version 2.0), POST88 (version 1.0), 
and MRE88 (version 1.0). Program PREP88 is a preprocessor that prepares input to FRISK88, 
using information about the logic tree, the attenuation equations, and the seismic-source 
parameters and geometry. Typically, PREP88 is run separately for each seismic source. 
Program FRISK88 calculates the seismic hazard curves for each combination of input 
interpretations. FRISK88 also produces deaggregated seismic-hazard results. Program POST88 
computes the total seismic hazard at the site, and sensitivity results, using the logic tree and the 
seismic-hazard curves fiom the various seismic sources. Another postprocessor, MRE88, 
calculates marginal and joint probability distributions and summary statistics of magnitude, 
distance, and ground motion for one or more seismic sources, using the deaggregated results 
produced by FRISK88. Programs DPREP (version 1.0) and DRISK (version 1.0) perform 
operations similar to those of PREP88 and FRISK88 for the calculation of fault displacements 
using the displacement approach. In addition, the combination of results fiom multiple teams 
andlor for multiple frequencies is performed by two small postprocessing utilities, namely 
MEAN and CMB-FRAC. The individual programs and algorithms used in the Yucca Mountain 
PSHA calculations are described firther in the following sections. Note that the overall 
methodologies for the analyses and the terms used in these following sections are described 
further. in Sections 6.3, 6.5, and 6.6. Note also that all input and output files referred to are 
located in DTN: M00004MWDRTFM3.002. 
PREP88 (PREP88 V1.0, 1013 8- 1 .O-00) prepares input files for the FRISK88 program. 
Typically, PREP88 is run separately for each seismic source. The calculations performed by 
PREP88 involve only the generation of all branches of the logic tree (i.e., generate all possible 
combinations of parameter values) and the calculation of the associated probabilities. 
The input to PREP88 consists of three parts, each contained in a separate file, as follows: 
Attenuation Fie ( Contains the parameters of the attenuation-equations, as well as other 
information that is common to all seismic sources. 
Logic-Tree File ( Defines the global parameters or interpretations that affect the 
characteristics of the seismic source (geometry, magnitude-recurrence, maximum magnitude 
k]), the probabilities associated with each parameter or interpretation, and any 
probabilistic dependence among them. 
Source File ( Contains information on how each source characteristic depends on the global 
parameters and interpretations that were specified in the logiotree file. 
The output fiom PREP88 consists of a FRISK88 input file and an echo file. 
ANGCRWOS-000003 REV 00 II-2 
\ ~ A K I \ - X D R I V E S \ ~ ~ ~ C ~ W R ~ Y U C C A M R J U M R U ~ ~ ~ O \ ~ ~ O O ~ ~ ~ M X : W19m0 
April 2000 

Program FRISK88 evaluates the probability that the earthquake ground motion at a site does not 
exceed specified amplitudes. This probability is evaluated by integrating all earthquake 
magnitudes, distances, and ground motion residuals. Typically, this calculation is performed 
separately for each seismic source. Alternative values of source parameters and geometry are 
input to represent their uncertainty. Each alternative parameter is given a weight to represent its 
credibility. FRISK88 can also be used for probabilistic fault-displacement calculations with the 
earthquake approach (see Section 6.3.4 for explanation of the earthquake and displacement 
approaches to assessing fault displacement). 
The calculations performed by FRISK88 consist of numerical integration over three dimensions 
(earthquake magnitude, distance, and ground motion epsilon) as described in Equation 6-2. The 
calculatior~s are performed for multiple values of the parameters that control the shape of the 
three functions in the integrand. Evaluation of the integral is performed by discretizing the range 
of earthquake magnitudes and locations within the seismic source and summing the contributions 
from each combination of magnitude and location. The algorithm does not involve iterative 
procedures, matrix inversion, numerical solution of systems of equations, or any other operation 
sensitive to instability or roundoff problems. 
Input to FRISK88 consists of a file describing the alternatives for the geometry and magnitude 
distribution of the source, and the alternative attenuation equations. For areal sources- with 
spatially varying seismicity, an additional input file contains the spatial distribution of seismicity. 
Output from FRISK88 consists of the following: 
Echo Fie ( Contains a detailed echo of the program input. 
Error File ( Contains error and warning messages. . 
Fractiles Fie ( Contains summary statistics (mean and fractiles) of earthquake hazard 
curves. 
Hazard-Curve File ( Contains each hazard curve (exceedance probability vs. ground motion 
amplitude) that is calculated from each combination of source parameters and geometries, 
together with the weight associated with that curve. 
Cryptic Fie ( Indicates the combination of parameters that correspond to each hazard curve 
in the Hazard-Curve File. 
Magnitude-Distance-Epsilon (MRE -88 V1.0, 10136-1.0-001) Deaggregation File ( 
Contains the.contributions of each MRE combination for one ground motion amplitude. 
(Epsilon is the ground motion residual.) 
DPREP AND DRISK 
Programs DPREP @REP88 V1 .O, 10141-1 .O-00) and DRISK @RISK88 Vl .O, 10137-1.0-00) 
perform operations similar to those performed by PREP88 and FRISK88 for the displacement 
approach to fault displacement (see Section 6.3.4 for explanation of displacement approach). 
ANLCRW-GS-000003 REV 00 11-3 
\W~L\_xdrinskwcfs\PROlECmYUCCAMTN\AMR\Amr-~vaOhrnOOvaOhrnOOtC~DOC 04/181W 
April 2000 

The displacement approach calculates the probability of fault displacement in terms of 
displacement events at the site of interest, without considering earthquake magnitude or location. 
The integrztion in DRISK is performed using well-known approximations for the cumulative 
distribution function of normal, gamma, and exponential random variables. Input and output to 
and from DPREP and DRISK are organized in a similar manner to those of PREP88 and 
FRISK88 (except for the MRE file, which is not generated). The output from DRISK contains 
the total displacement hazard at the site. Running POST88 (POST88 V1.0, 10136-1.0-00) on the 
DRISK output is necessary only for the calculation of sensitivity results. 
Program POST88 calculates the total hazard at the site by adding the hazard from all seismic 
sources. ccrnsidering their uncertainty. The calculations performed by POST88 involve the 
generation of all branches of the global logic tree (i.e., generate all possible combinations of 
panmeter values for all seismic sources), the calculation of the associated probabilities, the 
calculatiorr of total hazard (from dl seismic sources) for each branch of the logic tree, and the 
calculzttion of summary statistics. 
Input to POST88 consists of the following files: 
a Control File ( Contains a list of the seismic sources, their associated file names, and 
instructions on how to simplify their logic trees, if appropriate. It also indicates which 
sensitivity analyses to perform. 
Lcgic-Tree File ( Defines the global parameters or hypotheses that affect the characteristics 
of dl seismic sources (geometry, magnitude-recurrence, Mmx ), the probabilities associated 
with each parameter or hypothesis, and any probabilistic dependence among them. . 
e Hazard Curve and Cryptic Files ( Contains hazard curves for each seismic source. . . 
Output from POST88 consists of an echo file, a fractile file, and files containing sensitivity 
re~ults. 
MRE88 calculates marginal and joint probability distributions and summary statistics of 
magnitude, distance, and ground motion .for one or more seismic sources. The calculations 
performed by MRE88 consist of bookkeeping and the calculation of summary statistics (e.g., 
means, standard deviations). 
Input to MlE88 consists of the following files: 
Control File ( Contains a list of the seismic sources and their associated file names. 
a MRE Deaggregation Files ( Contain deaggregated results for each seismic source. 
ANL-CRW-GS-000003 REV Oa 11-4 
\ ~ A K ~ L ~ ~ ~ ~ v c ~ \ ~ _ w c ~ ~ \ P R O ~ Y V ~ : A M T M A 04/181M) 
April 2000 

Output from -88 consists of a file containing echo of the input, probability distributions of 
magnitude, distance and epsilon (trivariate, bivariate, and univariate), and summary statistics. 
These distributions are also output to separate files to facilitate plotting and tabulation of results. 
6. UTILITY PROGRAMS (MEAN AND CMB-FRAC) 
MEAN adds the mean hazards from multiple fractile files (and optionally normalizes them). It is 
useful for calculating the mean hazard from several sources or teams. Input to MEAN consists 
of a control file listing the names of the fractile files to use, the fractile files specified in the 
control file (fractile files are created by FRISK88, DRISK, and POST88), and an optional 
configuration file indicating the return periods to consider. Output from MEAN consists of a file 
containing a mean hazard curve. 
CNB-ERAC combines the fractile hazard curves calculated for multiple expert inputs and 
cmputes fractiles using either equal or arbitrary weights. Input to CMB-FRAC consists of a 
ccr.'rol file specifying names of the fractile files to use (and optional weights), the fractile files 
spmfied in ;he control file, and an optional configuration file indicating the return periods to 
consiaer. Output from CMB-FRAC consists of a new fractile file containing the calculated 
frficCks. mi a log file. 
ANLCRW-GS-000003 REV 00 11-5 
\\OAKl\~x&ivrsLCwffsWROIECmYUCC~\Am-marrwuoOmarrwuootC~WC 041IM)O 
. , / 
April 2000 
i