ML14189A562
| ML14189A562 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 07/09/2014 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Balazik M, NRR/JLD, 415-2856 | |
| References | |
| Download: ML14189A562 (34) | |
Text
Near-Term Near Term Task Force Recommendation 2.1 Seismic Hazard Evaluation D C Cook D.C.
July 9, 2014
References for Meeting
- Licensee Presentation Slides - ML14190A185
- NRC Presentation Slides -ML14189A562
- Public Meeting Agenda - ML14182A182
- Meeting Feedback Form (request from mfb@nrc.gov)
- May 9, 2014, NRC letter regarding Seismic Screening and Prioritization Results for central and eastern US Licensees (ML14111A147)
- May 21, 2014, NRC memo providing preliminary staff ground motion response spectra for central and eastern Licensees (ML14136A126)
- Meeting Summary to be issued within 30-day
Meeting Introduction
Purpose:
support information exchange and begin dialog to have common understanding of the causes of the primary differences between the preliminary NRC and licensee seismic hazard results B k
Background:
d NRC and d lilicensee seismic i i h hazard d require i
resolution to support a final seismic screening decision and to support related follow-on submittals Outcomes:
- Begin NRC and licensee resolution to support regulatory decisions and development of seismic risk evaluations evaluations, as appropriate
- Establish resolution path, including timelines and identification of potential information needs
Look-ahead:
Potential Next Steps
- NRC will consider the meeting information
- Potential paths:
- Licensee submits supplemental information based on public meeting dialog
- NRC staff issues a request q for information
- Licensee sends a revision or supplement to the seismic hazard report
- NRC completes screening review and issues the final screening determination l tt letter
DC Cook NTTF R2.1 Seismic Hazard Christie Hale Zuhan Xi and Cliff Munson July 9, 2014
6 Primary Issues
- Basis for the 6 profile approach
- 3 of the 6 profiles (P1, P2, P3) infer ref. rock velocities for sedimentary rock layers
- Basis for not including beach sands in velocity profiles fil ((control t l point) i t)
- Approach for calculating kappa and its application to the site response analysis
- NRC unable to replicate licensees GMRS perhaps due to differences in standard deviation of log normally distributed Amp Factor as a function of input rock motion
DC Cook Location Point Beach Palisades DC Cook Braidwood 8
DC Cook FSAR Figure Dune Sand Beach Deposits Lake Deposits 140 ft Glacial Till Bedrock Shale 9
DC Cook Geology DC Cook FSAR Section 2.3:
Site geology a simple sequence of deposits consisting of a surface deposit of dune sand which overlies older beach sand which in turn is underlain by glacial lake clays, glacial till and shale bedrock Regional geology bedrock bedrock consists of a mixed sequence of sedimentary strata including shale, limestone, sandstone, and dolomite. The strata range in age from Cambrian to Pennsylvanian. This sequence is underlain by a basement complex of Precambrian igneous and metamorphic rocks.
rocks Bedrock formations in the vicinity of the site include shale and sandstones of Devonian and Mississippian age.
The Precambrian basement is estimated to occur at a depth of 3,500 feet.
Elev
[ft] Control Point Dune Sand (excavated)
Containment
+608 (Plant Grade)
+583 (Foundation)
Beach Sand Dense beach sands Ground water
+558 (top of clays)
Lake deposits, clayey Gl i l Lake Glacial L k Clays Cl sediments, Lacustrine Clay and Silt
+468 Glacial Till Outwash moraine
+446 Paleozoic Limestone, esto e, Dolomite, o o te, Bedrock? Sedimentary Rocks Shale, Sandstone
-2904 Igneous and metamorphic Crystalline Basement rocks 11
Control Point El Elev Thi k Thickness Vs S Source
[ft] [ft] [ft/s]
Containment 590 Wisconsin paper (dense sands)
+583 (Foundation) 800 GE study DC Cook 25 Beach Sand 328 to 1640 Stanford paper (dry sands)
+558 (top of clays) 650 to 1800 Wisconsin paper (clays) 750 to 1300 Illinois GS paper (Lacustrine) 90 Glacial Lake Clays 650 to 2600 Stanford paper (sat. Sh & clays) 1360 GE study Palisades Vs 1600 GE study DC Cook Vs 1829 EGC ESP Illinois (Lacustrine)
+468 22 Glacial Till 2780 GE study t d Palisades P li d Vs V
+446 5620 GE study Palisades Vs 1640 to 5905 Stanford paper (Sh & Ss) 3350 Paleozoic P l i 6561 to >9200 Stanford paper (Ls & Do)
Sedimentary Rocks >9200 GE study DC Cook Vs
>9200 Braidwood FSAR Vs
-2904 Crystalline Basement >9200 12
NRC Velocity Profiles uln = 0.35 Vs
[ft/s]
Formation Thick [ft] Lower (10th %) Median Upper (90th %)
Beach Sand 25 511 800 1253 Glacial Lake Clays 90 868 1360 2130 Glacial Till 22 1775 2780 4354 670 3065 4800 9200 670 3321 5200 Paleozoic 670 3576 5600 S di Sedimentary R Rocks k
670 3831 6000 670 4087 6400 Crystalline Basement 9200 9200 13
Shear Wave Velocity, ft/s Shear Wave Velocity, ft/s 0 2000 4000 6000 8000 10000 0 2000 4000 6000 8000 10000 0 0 20 CNP LBC1 CNP BC1 500 40 CNP UBC1 Depth Below Control Point , ft NRC LBC 60 NRC BC NRC UBC 80 1000 Depth Below w Control Poin nt , ft 100 120 1500 140 160 2000 180 200 CNP LBC1 2500 CNP BC1 CNP UBC1 3000 NRC LBC Licensees first 3 profiles NRC BC sedimentary rock = bedrock NRC UBC 3500 14
Shear Wave Velocity, ft/s Shear Wave Velocity, ft/s 0 2000 4000 6000 8000 10000 0 2000 4000 6000 8000 10000 0 0 20 CNP LBC2 CNP BC2 500 40 CNP UBC2 Depth Below Control Point , ft NRC LBC 60 NRC BC NRC UBC 80 1000 Depth Below w Control Poin nt , ft 100 120 1500 140 160 2000 180 200 CNP LBC2 2500 CNP BC2 CNP UBC2 3000 NRC LBC Licensees second 3 profiles NRC BC bedrock beneath sedimentary rock NRC UBC 3500 15
Shear Modulus & Damping Curves
- NRC used EPRI soil and Pennisular Range G/Gmax and hysteretic damping curves for soil layers
- NRC used EPRI Rock curves and Linear with 3%
damping for first 200 ft of sedimentary rock
- Remaining sedimentary rock layers modeled as linear with 1% damping 16
Kappa
- NRC estimated total site kappa values of 24 msec (MBC), 32 msec (LBC), and 8 msec (UBC)
- Applied Campbells Campbell s eqn for 137 ft of soil: 2 2.5 5 msec
- Used Qs of 40 to determine kappa for sedimentary rock layers: 16 msec (MBC) and 24 msec (LBC)
- Added additional 6 msec for reference rock contribution 17
Amplification Functions (kappa = 0.024)
DC Cook NRC Analysis 3.5 3
2.5 Ampliffication 2
PGA = 0.01 1.5 PGA = 0.1 1 PGA = 0.5 05 0.5 0
0.1 1 10 100 Frequency [Hz]
18
3.5 Median AF vs. Rock Motion 3
2.5 0.5 Hz 2 1 Hz H
2.5 Hz 5 Hz 1.5 10 Hz 25 Hz PGA 1
05 0.5 0
0 0.2 0.4 0.6 0.8 1 1.2 1.4 19
Sigma ln(AF) vs. Rock Motion 0.8 0.7 0.6 0.5 Hz 05 0.5 1 Hz H
2.5 Hz 5 Hz 0.4 10 Hz 25 Hz PGA 0.3 0.2 0.1 0
-0.1 0.1 0.3 0.5 0.7 0.9 1.1 1.3 1.5 20
DC Cook 1.2 1
0.8 SA (g) 0.6 04 0.4 0.2 0
0.01 0.1 1 10 100 Frequency (Hz)
Licensee_SSE Licensee GMRS NRC GMRS Updated NRC GMRS 21
DC Cook Submittal
- Whatat aaree the t e bases for o velocities e oc t es as well e as lack ac of o
velocity gradients for both soil and rock layers?
- What is the basis for the highg P-wave velocityy (17,000 fps) for the sedimentary rocks as shown in Table 2.3.1-1?
- What is the basis for assumed Poissons ratio of 0.2 for the sedimentary rock?
- What Wh t iis ththe b basis i ffor considering id i sedimentary di t rock to have reference rock velocity for 3 of the 6 profiles rather than just 1 of 3?
22
Shear Wave Velocity Data (Glacial Lake Clays layer)
Illinois Geologic Survey Report 1300 ft/s 750 ft/s
Shear Wave Velocity Data Bechtel Paper - Shoreline of Lake Michigan in Wisconsin
~ 590 ft/s
~ 650 to 1800 ft/s
DC Cook Submittal
- What is basis for control point such that b h sands beach d are not iincluded l d d iin velocity l i profiles?
DC C Cookk FSAR SSection ti 2 2.5.2:
52 Major plant structures are supported on mat foundations installed on the overlying compact sand, recompacted sand, or stiff clay deposits.
The containment areas as well as the remainder of the plant areas were excavated to elevation 588 ft. The dewatering system which consisted of eductor wells was installed around the entire periphery of the general plant site excavation and the ground water level was lowered to the top of the clay stratum, approximately elevation 558'. The containment areas were then excavated to Elevation 583'-4. the dense sand at elevation 583'4" was compacted with a vibratory compactor. The containment structures were constructed on mat foundations founded directly on the dense beach sands.
25
DC Cook Submittal
- What is basis for second sentence in Section 2.3.2.1 as soil layers total about 128 ft?
- The firm soil material over the upper 500 ft was assumed to have behavior
- Total site kappa values for P4, P5, P6 are similar to staffs values; however basis for statement in Section 2.3.2.2 is unclear
- As documented in Reference 14 for shallow, less than about 3000 ft soil/firm rock sites, kappa may be estimated based on the small strain damping contributed by the profile
- Does above statement refer to kappa estimate for P1 P2 &
y P3 only?
26
DC Cook Submittal
- Range for total standard deviations (T or lnAFlx) of ln AF given rock motions are much lower than staffs staff s values shown on Slide 16
- Affects hazard integral probability calculations P(AF>z/xlx)
- Consistent with standard deviations in Table A2-B2 for o spec specificc models, ode s, profiles, p o es, aand d PGA G levels?
e es 27
Median AF vs. Rock Motion 3.5 3
2.5 0.5 Hz 2 1 Hz 2.5 Hz 5 Hz 1.5 10 Hz 25 Hz PGA 1
0.5 0
-0.1 0.1 0.3 0.5 0.7 0.9 1.1 1.3 1.5 28
Sigma ln(AF) vs. Rock Motion 0.8 0.7 0.6 0.5 0.5 Hz 1 Hz 2.5 Hz 0.4 5 Hz 10 Hz 25 Hz 0.3 PGA 0.2 0.1 0
-0.1 0.1 0.3 0.5 0.7 0.9 1.1 1.3 1.5 29
Rock Hazard Verification
- Using Table A-2a A 2a in submittal (lnAFlx l l and lnAFlx) together with NRC rock hazard curves for DC Cook staff calculated control point hazard curves and also UHRS at 10-4 and 10-5 and GMRS
- Results match indicating that NRC and Licensee rock hazard curves are similar 30
Rock Hazard Verification Results Freq. (Hz) 10-4 UHRS (g) 10-5 UHRS (g) GMRS (g) 100 0 171 0.171 0 516 0.516 0 248 0.248 25 0.295 0.958 0.454 10 0.337 0.952 0.464 Licensee 5 0.297 0.869 0.421 2.5 0.185 0.487 0.240 1 0.0866 0.202 0.102 0.5 0.0493 0.110 0.0563 Freq. (Hz) 10-4 UHRS (g) 10-5 UHRS (g) GMRS (g) 100 0.17 0.51 0.25 25 0.28 0.79 0.39 10 0.33 0.93 0.45 NRC 5 0.30 0.86 0.42 2.5 0.19 0.50 0.25 1 0.09 0.20 0.10 0.5 0.06 0.11 0.06 31
NRC Replication of LicenseesLicensee s Models
- Staff calculated site response for DC Cook using licensees velocity models
- 20 layer model for P1, P1 P2, P2 P3
- 62 layer model for P4, P5, P6
- FFor shallow h ll profilefil (P1 (P1, P2 P2, P3) staff t ff used d EPRI Soil and Peninsular curves
- For deeper profile (P4, P5, P6) staff used EPRI rock and Linear with 3% damping for 500 ft 32
DC Cook 1.2 1
0.8 SA (g) 0.6 04 0.4 0.2 0
0.01 0.1 1 10 100 Frequency (Hz)
Licensee_SSE Licensee GMRS Lic. P1-P3 Lic. P4-P6 33
Primary Issues
- Basis for the 6 profile approach
- 3 of the 6 profiles (P1, P2, P3) infer ref. rock velocities for sedimentary rock layers
- Basis for not including beach sands in velocity profiles fil ((control t l point) i t)
- Approach for calculating kappa and its application to the site response analysis
- NRC unable to replicate licensees GMRS perhaps due to differences in standard deviation of log normally distributed Amp Factor as a function of input rock motion