ML061920330
| ML061920330 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 04/14/2006 |
| From: | Southern Nuclear Operating Co |
| To: | Office of Nuclear Reactor Regulation |
| araguas C, NRR/DNRL/NAPB,415-3637 | |
| References | |
| Download: ML061920330 (57) | |
Text
1 Vogtle Early Site Permit Seismic Activities NRC Public Meeting April 14, 2006
2 Meeting Objectives
- Inform the NRC
- Obtain NRC feedback
Agenda NRC/SNC Introductions and Opening Remarks 9:00 Jose Clemente Bechtel Corporation Geophysical and Geotechnical Investigations 10:00 Scott Lindvall William Lettis & Associates Geological and Seismological Investigations 9:40 Don Moore SNC Consulting Engineer Ground Motion Program Overview 9:20 Tom McCallum SNC ESP Technical PM ESP Site Location and Description 9:10
Agenda (continued)
Robin McGuire Risk Engineering, Inc Summary of Seismic Hazard for Vogtle Site 10:20 Robin McGuire Risk Engineering, Inc Determination of SSE Ground Motion 10:40 Adjourn 12:00 Opportunity for Public Comment 11:50 NRC and SNC Discussion 11:30 Don Moore SNC Consulting Engineer Plans for AP1000 and Vogtle Site Assessment 11:10
ESP Site Location and Description Tom McCallum ESP Technical Project Manager Southern Nuclear Operating Company
Site Prep First Concrete Fuel Load 11/14 Southern Company Plan COL ESP Prep Begins File ESP 8/06 COL Prep Begins File COLA COL Approval ESP Approval
- Two Units at VEGP Site
- Westinghouse AP-1000 Technology
- Decision to construct pending Commercial Operation Unit 3 - 5/15 Unit 4 - 5/16 Site Work Procurement (Long Lead Items) 2005 2010 2015 2006 2007 2008 2009 2011 2012 2013 2014 ESP 66
7 Plant Vogtle
8 North Unit 3 Containment 8
Power Block Switchyard Intake Structure Cooling Towers Savannah River Existing VEGP Site 9
Switchyard Construction Laydown Area Haul Route Intake Structure Discharge Line Unit 3 Unit 4 Construction Entrance Batch Plant Expanded Barge Slip ISFSI (shared)
Expanded PA Cooling Towers Access Road and Intake Line 10
Ground Motion Program Overview Don Moore Consulting Engineer Southern Nuclear Operating Company
Seismic Program Overview Southern Nuclear Overall Project Management William Lettis
& Associates Geological and Seismological Tasks Risk Engineering PSHA &
Development of SSE Bechtel San Francisco Site Transfer Functions Bechtel Project Mgt and Geotechnical Tasks Ground Motion Review and Advisory Panel Seismic Program Organization 12 12
Ground Motion Review and Advisory Panel Reasons for Formation:
- Seismic hazard considerations are significant
- Approach to developing SSE is being updated
- Seismic ground motion issues are complex and require multi-disciplined effort
- Review by outside experts to ensure defensible approach Seismic Program Overview 13 13
Panel Members Area of Expertise Member Site response to seismic input at rock Dr. Robert Youngs Probabilistic Seismic Hazard Analysis (PSHA)
Dr. Carl Stepp Seismic ground motion for design Dr. Robert P. Kennedy Southeastern US seismicity Dr. Martin Chapman Seismic Program Overview Ground Motion Review and Advisory Panel 14 14
- Two panel meetings have been held to review tasks and comment
- Provided ongoing review and comment on specific tasks, e.g., Charleston Update Activities Ground Motion Review and Advisory Panel Seismic Program Overview 15 15
Other Outside Assistance
- Provided technical staff support for seismic survey and other tasks
- Provided significant amount of data from SRS geotechnical investigations Savannah River Site Seismic Program Overview 16 16
August 2006 Submit ESP application COLA June 2006 May 2006 April 2006 Complete Complete Schedule Interactions with Westinghouse on AP1000 Site-specific SSE Activity Soil/rock profile development and site transfer function development Rock hazard characterization Update of EPRI-SOG per RG 1.165 including update of Charleston Source Geological, seismological, and geotechnical investigations for ESP Seismic Program Status 17 17
Scott Lindvall William Lettis & Associates, Inc William Lettis & Associates, Inc.
Geological and Seismological Investigations
19 19 Evaluation of Tectonic Features within 25 miles Evaluation of Tectonic Features within 25 miles
- Literature review
- Contact local researchers
- Air photo interpretation
- Aerial reconnaissance
- Field reconnaissance
- Review of seismicity
- Seismic reflection profiles at Vogtle
- Literature review
- Contact local researchers
- Air photo interpretation
- Aerial reconnaissance
- Field reconnaissance
- Review of seismicity
- Seismic reflection profiles at Vogtle
20 20 Site Vicinity Tectonic Features and Seismicity (25-mile radius)
Site Vicinity Tectonic Features and Seismicity (25-mile radius)
21 21
- None of the Site Vicinity (25 miles) or Site Area (5 miles) Tectonic Features are Capable Tectonic Sources
- Non-tectonic deformation and related features mitigated by removal of strata overlying Blue Bluff marl
- None of the Site Vicinity (25 miles) or Site Area (5 miles) Tectonic Features are Capable Tectonic Sources
- Non-tectonic deformation and related features mitigated by removal of strata overlying Blue Bluff marl Summary of Geological and Seismological Investigations Summary of Geological and Seismological Investigations
22 22 Pen Branch Fault Pen Branch Fault
- Triassic Basin normal fault that separates Paleozoic crystalline basement from Triassic basin sediments
- Reactivated as a SE-side-up reverse fault in Cenozoic
- Youngest deformed unit is late Eocene
- Non-capable PBF associated with similar, non-capable faults of the Atlantic Coastal Plain that exhibit a lack of post-Miocene activity
- No geomorphic expression in Pleistocene Savannah River terraces or older landscape
- Triassic Basin normal fault that separates Paleozoic crystalline basement from Triassic basin sediments
- Reactivated as a SE-side-up reverse fault in Cenozoic
- Youngest deformed unit is late Eocene
- Non-capable PBF associated with similar, non-capable faults of the Atlantic Coastal Plain that exhibit a lack of post-Miocene activity
- No geomorphic expression in Pleistocene Savannah River terraces or older landscape
23 23 Reasons for Seismic Reflection Survey Reasons for Seismic Reflection Survey Vogtle ESP geologic investigation indicated the location of the Pen Branch fault and basin boundary could be close to the ESP site The PBF is non-capable, but separates rocks of different velocities Seismic survey was performed to determine:
- 1. If PBF is close to the site, and
- 2. The geometry of the Dunbarton Basin boundary to help constrain velocity profile Vogtle ESP geologic investigation indicated the location of the Pen Branch fault and basin boundary could be close to the ESP site The PBF is non-capable, but separates rocks of different velocities Seismic survey was performed to determine:
- 1. If PBF is close to the site, and
- 2. The geometry of the Dunbarton Basin boundary to help constrain velocity profile
24 24 Seismic Reflection Profiles
25 25 Structure Contours of top of Blue Bluff Marl from Drawing AX6DD377 Pen Branch Fault Vertical Projection from Top of Basement 45 Triassic Basin Rock Crystalline Basement Rock Location of Pen Branch fault at top of basement in seismic profile 25
26 26 NW Section through Site NW Section through Site Triassic Basin Rock Crystalline Basement Rock Coastal Plain Sediments Fault Tip B-1003
27 27 Results of Reflection Survey Results of Reflection Survey Non-Capable Pen Branch fault imaged Strikes N34E to N45E and dips 45SE Juxtaposes Triassic basin rocks against higher velocity Paleozoic crystalline rocks to NW Basement rocks vertically separated across fault (SE-side-up) and consistent with separations and sense of slip observed at SRS Triassic basin rock underlies two proposed units Non-Capable Pen Branch fault imaged Strikes N34E to N45E and dips 45SE Juxtaposes Triassic basin rocks against higher velocity Paleozoic crystalline rocks to NW Basement rocks vertically separated across fault (SE-side-up) and consistent with separations and sense of slip observed at SRS Triassic basin rock underlies two proposed units
Jose Clemente Principal Geotechnical Engineer Bechtel Corporation Geophysical and Geotechnical Investigations
29 ESP Subsurface Investigation 12 borings, including 1 to a depth of 1,338 ft (290 ft into rock) 11 CPTs, including 3 seismic CPTs Geophysical testing of 3 boreholes, including:
- Suspension P-S Velocity Logging (p-wave and s-wave velocity measurements)
- Caliper/Natural Gamma Measurements
- Resistivity/Spontaneous Potential Measurements
- Boring Deviation Measurements 15 new ground water observation wells (10 above and 5 below the Blue Bluff Marl)
Laboratory testing
30 General Subsurface Profile Coastal Plain Sediments Q Upper sand stratum-Barnwell Group:
X Depth ranging from 78 to 154 ft-Average of 94 ft X Very loose to very dense Blue Bluff marl stratum - Lisbon Formation:
X Thickness ranging from 63 to 95 ft (3 boreholes)-About 76 ft average thickness X Very hard, slightly sandy, cemented, calcareous silt/clay Q Lower sand strata-Coastal Plain Deposits; X Dense sands X Thickness of 900 ft (at B-1003)
Q Dunbarton Triassic Basin Bedrock (1,049 ft below grade at B-1003)
Q Ground water elevation is 165 ft (55-60 ft below grade)
31 0
200 400 600 800 1000 1200 1400 0
5000 10000 15000 20000 VELOCITY (ft/s)
DEPTH (ft)
Near-Far Receivers, Vs Near-Far Receivers, Vp Coastal Plain Deposits Dunbarton Triassic Basin S-wave and P-wave Velocity Measurements Borehole B-1003 Receiver to Receiver Vs and Vp Analysis Blue Bluff Marl Upper Sands
32 Construction Excavation The upper sands - Barnwell Group:
Q Have highly variable density along the depth and from borehole to borehole Q
A shelly, very porous material was encountered at the bottom of the Barnwell Group/top of Blue Bluff Marl that caused severe drilling fluid losses Q
These soils were completely removed and replaced with compacted granular fill for construction of existing Units 1 and 2.
Q For these reasons, these soils will be removed
33 Preliminary Powerblock Excavation Plan 2125 1725 385 785
34 B-1003 B-1002 B-1004 Triassic Basin Bedrock Paleozoic Crystalline Basement Bedrock Cretaceous-Tertiary Coastal Plain Deposits Marl Grade EL. 220 MSL Cross Section Normal to PBF
35 Summary of Seismic Hazard at Vogtle Risk Engineering, Inc.
Robin K. McGuire NRC Meeting, Rockville April 14, 2006
36 Steps taken to meet RG1.165
- Effect of additional seismicity, 1985 through mid-2005
- Update of EPRI-SOG seismic sources to account for new source information
- Update of EPRI-SOG ground motion models (using EPRI 2004)
37 Replication of EPRI-SOG hazard at Vogtle 1E-6 1E-5 1E-4 1E-3 1E-2 10 100 1000 PGA, cm/s^2 Ann. Freq. Exceedance.
2005 85%
EPRI-SOG 85%
2005 mean EPRI-SOG mean 2005 median EPRI-SOG median
38 Historical Earthquakes
39 Comparison of catalog seismicity for triangular source
.00001
.0001
.001
.01 4.5 5.5 6.5 7.5 magnitude (mb)
Annual freq. of exceed.
Triangular source thru 1984 Triangular source thru 2004
40 Updated Charleston Seismic Source
- Logic Tree -
41 Updated Charleston Seismic Source (UCSS)
42 Seismic hazard from Charleston, 1 Hz 1E-8 1E-7 1E-6 1E-5 1E-4 1E-3 1E-2 0.01 0.1 1.
1 Hz SA, g Annual freq. exceedance A
B BP C
Total
43 Deaggregation of 1Hz, 5E-5 hazard
44 Deaggregation of 10Hz, 5E-5 hazard
45 Mean rock UHS, 2006 results Rock mean UHS, Vogtle 0.1 1.
10.
0.1 1.
10.
100.
Frequency, Hz Spectral Acceleration, g.
46 Hazard comparison for Vogtle: 2006 results and EPRI-SOG Comparison of mean rock UHS results 0.01 0.1 1.
10.
0.1 1.
10.
100.
Frequency, Hz Spectral acceleration, g.
2006 1E-5 EPRI-SOG 1E-5 2006 1E-4 EPRI-SOG 1E-4
47 Calculation of soil hazard
- Develop soil profile with properties
- Determine soil amplitudes for multiple rock input amplitudes (frequencies from 100 Hz to 0.1 Hz) (1D SHAKE analysis) using M and R from deaggregation (high-and low-frequency spectra)
- Convolve rock hazard with site amplification (including uncertainties in input motion and soil properties) to obtain soil UHS for multiple annual frequencies (NUREG/CR-6728 Approach 2A)
- Develop vertical spectra using V/H ratios (NUREG/CR-6728)
48 Illustrative cross-section at location of new units Triassic Basin Rock Crystalline Basement Rock Coastal Plain Sediments Fault Tip B-1003
49 B-1003: R1-R2 0
500 1000 1500 2000 2500 3000 3500 4000 4500 0
2000 4000 6000 8000 10000 12000 Shear-Wave Velocity (ft/sec)
Depth (ft)
DRB-11 shifted DRB-10 shifted DRB-9 shifted R1-R2: shallow R1-R2: deep 1050 ft 9,200 ft/sec Rock Velocity Picks Slope 0.6 Slope 0.9 Slope 1.3 Bottom of Coastal Plain Shear-wave velocity measurements at Vogtle and SRS
50 Determination of SSE Ground Motion Risk Engineering, Inc.
Robin K. McGuire NRC Meeting, Rockville April 14, 2006
51 Definition of SSE
- SSE is defined here as the site-specific, risk-informed, response spectrum that represents the ground motion that meets regulatory criteria.
- The SSE is a free-field ground motion defined at a specified control point.
- The SSE will subsequently be modified by structure-specific analyses (accounting for foundation size, etc) to define a Design Response Spectrum (DRS)
52 Method for calculating Vogtle SSE
- Risk (performance-goal) based approach is aimed at achieving a Seismic Core Damage Frequency (SCDF) less than a target SCDF goal.
- The target SCDF goal is the industry-proposed value of mean 5E-6/yr (Ref: NEI letter, Heymer to Imbro dated 3/30/06)
- Table 2.2 of NUREG 1742 summarizes existing plant seismic PRA results using EPRI-type hazard curves; overall results:
- Median value 1.2E-5/yr
- Mean value 2.5E-5/yr
- SSE response spectrum will be defined to meet this target goal.
53 Control point for Vogtle ESP SSE
- Per SRP 3.7.1 and 3.7.2: for profiles consisting of one or more thin soil layers overlaying competent material, the control motion should be located at an outcropat the top of the competent material.
- Approximately 90 of existing soil above the Blue Bluff marl unit will be removed and replaced with engineered backfill.
- Therefore, the SSE will be specified at the top of the Blue Bluff marl unit.
Plans for AP1000 / Vogtle Site Assessment Don Moore Consulting Engineer Southern Nuclear Operating Company
55 Plans for AP1000 Assessment Exchange of information started with Westinghouse AP1000 soil site parameters Vogtle site soil conditions Monitor Westinghouse/NRC interactions on soil technical report APP-GW-GLR-015, Extension of Nuclear Island Seismic Analyses to Soil Sites Perform evaluations to demonstrate Vogtle site compatibility with AP1000 design
Summary of Key Points Purpose of seismic survey was to identify rock type/profile below ESP site Using EPRI-SOG seismic hazard model with update of Charleston Seismic Source Using EPRI 2004 ground motion model incorporating EPRI Task G1.3 standard deviation Developing site transfer functions using NUREG/CR-6728 method 2A Developing SSE based on target performance goal of mean 5E-6 SCDF Defining control point of SSE at top of competent material (Blue Bluff Marl)
57 Discussion