sign in sign up
<<
Home , Chagrin Shale, Conasauga Formation, Reedsville Formation, Rome Formation

Example for Discussion Regarding Level of Detail Only

EXAMPLE SOIL DESCRIPTION REPORT—SECTIONS 2.3.1 AND 2.3.2 OF SITE HAZARD AND SCREENING REPORT

2.3 Site Response Evaluation

Following the guidance contained in Seismic Enclosure 1 of the 3/12/2012 50.54(f) Request for Information and in the SPID (CEUS-SSC, 2013a) for nuclear power plant sites that are not sited on hard rock (defined as 2.83 km/sec), a site response analysis was performed for SITE.

2.3.1 Description of Subsurface Material

The SITE NPP site consists of about 25 ft of lacustrine sandy silty soils overlying about 75 ft of glacial drift till. The shallow soils overly about 6,000 ft of firm to hard Paleozoic sedimentary rocks below which lies Basement. Table 1 shows the stratigraphic column and unit thicknesses (REFERENCE) based on well logs in the vicinity of the site.

Example for Discussion Regarding Level of Detail Only

TABLE 2.3.1-1 (REFERENCE) BEDROCK AND UNIT THICKNESSES

TOP BOTTOM TOP BOTTOM EL (ft) EL (ft) LITHOLOGY DEPTH DEPTH (ft) (ft)

Pleistocene Lacustrine deposits: very fine sandy, clayey silt 625 594 and silty 0 31 594 565 Pleistocene: Glacial Drift 31 60 . : gray silty to clayey 565 -135 shale with sand shale laminae 60 760 Devonian . Heron Shale: black to brown shale -135 -660 with silty and sandy laminae 760 1285 Devonian Delaware and Columbus formations: hard, dense, -660 -970 cherty , or a dolomitic limestone 1285 1595 Devonian Oriskany Sandstone: fine-to medium-grained -970 -980 sandstone 1595 1605 -980 -1030 L. Devonian to U. Helderberg Limestone 1605 1655 U. Silurian Bass Island Group: argillaceous, dolomitic -1030 -1130 limestone, and calcareous dolomite 1655 1755 U. Silurian Salina Group: interbedded evaporite and -1130 -1830 carbonate rocks 1755 2455 -1830 -2080 M. Silurian Lockport Group: dolomite 2455 2705 -2080 -2110 M. Silurian Rochester “Packer” Shale 2705 2735 -2110 -2290 M. Silurian Clinton Group: dolomite, limestone, and shale 2735 2915 -2290 -2305 M. Silurian Medina Formation: sandstone 2915 2930 Upper Ordivician Queenstown Formation: shale, siltstone, -2305 -2505 and sandstone 2930 3130 Middle to Upper : fine- -2505 -3945 grained shale, , and dolomites 3130 4570 -3945 -4435 M. Ordivician Trenton Limestone and Dolomite 4570 5060 Middle Ordivician Chazy Formation (Black River/Gull River/ -4435 -4615 Glenwood): limestone 5060 5240 -4615 -4715 L. Ordivician Copper Ridge Formation: dolomite 5240 5340 U. : limestone and -4715 -4930 5340 5555 sandstone

Example for Discussion Regarding Level of Detail Only

TABLE 2.3.1-1 (REFERENCE) BEDROCK STRATIGRAPHY AND UNIT THICKNESSES (CONTINUED) TOP BOTTOM TOP BOTTOM EL (ft) EL (ft) LITHOLOGY DEPTH DEPTH (ft) (ft) -4930 -4970 M. Cambrian : dolomite 5555 5595 -4970 -5160 M. Cambrian Shady formation: dolomite 5595 5785 -5160 -5300 M. Cambrian Mt. Simon Formation: sandstone 5785 5925 Precambrian regionally-metamorphosed schists, gneisses, -5300 marbles, and calc-silicate granulites 5925

The following description of the Paleozoic sequence is taken directly from REFERENCE:

“Bedrock directly beneath the Site belongs to the Upper Devonian Ohio Shale Formation, which has been broken down into numerous member units. Because the Site sits on the northwestern flank of the Appalachian geosyncline, the rocks dip gently to the south at a gradient of approximately 20 to 40 ft per mile. The members of the Ohio Shale are, from oldest to youngest, the Plum Brook, Huron, Chagrin, Cleveland, and members.

The Ohio Shale beneath the Site is composed of the Upper Devonian Chagrin Shale and Huron Shale members as the stratigraphicly higher members have been eroded away from this location. These members extend to depths on the order of 1,250 ft below the ground surface.

The Chagrin Shale member is composed of dark-gray to medium-gray silty or clayey shale occasionally containing light gray sandy shale laminae and is approximately 700 ft thick below the Site. The underlying Heron Shale is a black to dark brown shale with lesser amounts of thinly bedded light gray silty and sandy laminae than the Chagrin Shale and is estimated to be about 525 ft thick below the Site. It is not clear from well log data that the Plum Brook shale is present or not at the bottom of the Ohio Shale below the Site, as it may have been eroded prior to Heron shale deposition.

The remainder of the deeper stratigraphy is based upon analysis of formation tops and bottoms from deep well logs obtained from the Ohio Geological Survey in combination with information from the FSAR. The units and thickness down to the Lower Silurian were obtained from deep wells that are located within 2.5 miles of the Site; while the units and thicknesses below the Lower Silurian are interpreted from deeper wells located about 3 to 4 miles to the southeast of the Site down to Precambrian Basement. Due to the close proximity to the Site of these deep wells, the unit lithologies and thicknesses can be assumed to be very similar to those below the Site.”

2.3.2 Development of Base Case Profiles and Nonlinear Material Properties

Example for Discussion Regarding Level of Detail Only

Table 2.3.2-1 (REFERENCE) shows the recommended shear-wave velocities and unit weights along with elevations and corresponding stratigraphy. From Table 2.3.2-1 the SSE control point is at elevation 560.9 ft within the Devonian Chagrin Shale at a best-estimate shear-wave velocity of 4,472 ft/s and a range of 4,266 ft/s to 5,229 ft/s. The shallow Chagrin Shale shear- wave velocities reflect the only measured shear-wave velocities below the SSE Control Point and appear to be based on laboratory testing for shear moduli (REFERENCE).

Example for Discussion Regarding Level of Detail Only

TABLE 2.3.2-1 (REFERENCE) SUMMARY OF GEOTECHNICAL PROFILE DATA FOR GRMS

ELEVATION LAYER (ft) NO. SOIL/ROCK DESCRIPTION γtotal (pcf) Vs (ft/s) μ 620 Plant Grade (Ground Surface EL 620)

(622) 122 827 A 624 to 612I 1a Lacustrine Deposits (110-145)H (675-955)E, J 0.33 (615) 613 to 624 Ground Water EL

122 827 A 612 to 605 1b Lacustrine Deposits (110-145)H (675-955)E,J 0.49

129 827 A 605 to 594 1c Lacustrine Deposits (110-145)H (675-955)E, J 0.47

(594) 132 899 A 597 to 586 2a Glacial Drift-Upper Till (110-145)H (773-1009)E, J 0.44 1785 (586) 141 E, J 2b Glacial Lower Till (1671-1901) 0.44A 589 to 565 (100-170)H 560.9 GMRS EL -SSE Control Point Nuclear Island Foundation Level 4472 (565) 152 E, J 3a Devonian Chagrin Shale (4266-5229) 0.36A 572 to 556 (88-188)H 556 to 510 3b Devonian Chagrin Shale 152 5273 0.32 531 FIRS EL – Emergency Service Water Pump House Foundation EL 510 to 392 3c Devonian Chagrin Shale 152 5203 0.30 392 to -135 4a Devonian Heron Shale 152 5203 0.30 -135 to -470 4b Devonian Heron Shale 152 6187 0.28 510 to 392 3c Devonian Chagrin Shale 152 5203 0.30 392 to -135 4a Devonian Heron Shale 152 5203 0.30 -135 to -470 4b Devonian Heron Shale 152 6187 0.28 -660 5a Devonian D&C Limestone 168 6187 0.28 -709 5b 168 10540 0.30 -970 6 Devonian Oriskany Sandstone 157 10540 0.30

Example for Discussion Regarding Level of Detail Only

TABLE 2.3.2-1 (REFERENCE) SUMMARY OF GEOTECHNICAL PROFILE DATA FOR GRMS (CONTINUED) ELEVATION LAYER SOIL/ROCK DESCRIPTION γtotal (pcf) Vs (ft/s) μ (ft) NO. -980 7 Dev-Sil Helderberg Limestone 168 10540 0.30 -1030 8 Silurian Limestone Dolomite 168 10540 0.30 -1130 9a Silurian Salina Carbonate 150 10540 0.30 Rocks -1193 9b 150 8577 0.26 -1455 9c 150 7152 0.30 -1830 10a Silurian Lockport Group 170 11784 0.30 -2015 10b 170 7979 0.30 -2080 11 Silurian 157 7979 0.30 Silurian Dolomite, Limestone, -2110 12 Shale 170 7979 0.30 -2290 13 Silurian Medina Sandstone 157 7979 0.30 -2305 14 Ordivician Queenstown Shale- 157 7979 0.30

Notes: A. Cross hole test B. Down hole test C. Lab sonic test D. Refraction test E. Back-calculation from stiffness parameters adopted in FSAR (Note f) F. Design parameters adopted in FSAR G. Cyclic torsion test H. In-situ test results I. From this elevation down, soil parameters are estimates from sonic velocities of deep wells except unit weight. Unit weights are typical values from literature. Coefficient of variation (COV) = 10 percent for seismic wave velocities. Poisson’s ratio and Gmax are calculated by following formula: 2 2 ν = ([Vp/Vs] – 2) / (2[Vp/Vs] – 2) 2 Gmax = ρ Vs J. Recommended variability (it is based on the variability of shear modulus) K. Recommended variability L. Table 2.5-61 of the FSAR

For the deeper sedimentary rocks, shear-wave velocities and stratigraphy were based on available well log data within several (up to seven) miles of the site. Shear-wave velocities were determined from sonic logs using literature based compression-to-shear-wave velocity ratios which accommodate differences in geology (limestone and dolomite, anhydrites, and salts),

Example for Discussion Regarding Level of Detail Only porosity, and density. Based on the available sonic logs, estimates of shear-wave velocities with geology specific attributes were provided to a depth of about 3,000 ft (elevation -2,305 ft, Table 2.3.2-1).

From Table 2.3.2-1, with the SSE at an elevation of 560.9 ft, the depth below the SSE to Precambrian Basement is about 5,861 ft (1,786m). Table 2.3.2-1 shows a nearly 500 ft (148m) thick layer with shear-wave velocities exceeding the hard rock reference velocity of 9,285 ft/s (2.83 km/s) at a depth below the SSE of about 1,270 ft (387m). Below this thick hard rock section, shear-wave velocities drop generally to about 8,000 ft/s (2,438m/s) to the maximum depth (below the SSE) characterized with dynamic material properties, about 2,870 ft (874m). To accommodate a range in potential depths to hard rock below the elevation of the SSE, two depths were assumed: 1) shallow, 1,270 ft (387m) to the hard rock zone and 2) deep, 5,861 ft (1,786m) to Precambrian Basement (Table 2.3.1-1). For the deep profile, the deepest shear- wave velocity of about 8,000 ft/s (2,438m/s) was assumed to continue below the maximum depth characterized in Table 2.3.2-1, 2,866 ft (874m).

Uncertainty in shear-wave velocity listed in Table 2 for the shallow Chagrin Shale (4,266 ft/s to

5,229 ft/s) was based on laboratory testing and reflects a σln of roughly 0.1. For the deeper materials, with shear-wave velocities based on sonic logs, the recommended COV was 0.11, reflecting a scaling factor of about 1.1, assuming a lognormal distribution. Based on the proximity of the sonic logs to the site, the generally flat lying geologic units, and the geology specific compressional- to- shear-wave velocities, a scale factor of 1.25 for developing upper and lower base-cases was judged to be a more appropriate reflection of epistemic uncertainty at this site. The scale factor of 1.25 reflects a σμln of about 0.2 based on the SPID (EPRI, 2013a) th th 10 and 90 fractiles which implies a 1.28 scale factor on σμ.

Using the shear-wave velocities specified in Table 2.3.2-1 and an assumed 8,000 ft/s for depths exceeding those in Table 2.3.2-1, three base-profiles were developed using the scale factor of 1.25. The specified shear-wave velocities were taken as the mean or best estimate base-case profile (P1) with lower and upper range base-cases profiles P2 and P3 respectively. Profiles P1 and P3, mean and upper range base-cases respectively, extended to shallow hard rock conditions at a depth (below the SSE) of 1,270 ft (387m), randomized ± 380 ft (± 116m). Profile P2, the lower range or softest base-case, was taken to reflect the deepest extent to hard rock and extended to 5,861 ft (1,786m) randomized ± 1,755 ft (± 536m). The base-case profiles (P1, P2, and P3) are shown in Figure 2.3.2-1 and listed in Table 2.3.2-2. The depth randomization reflects ± 30% of the depth and was included to provide a realistic broadening of the fundamental resonance at deep sites rather than reflect actual random variations to basement shear-wave velocities across a footprint.

Figure 2.3.2-1. Shear-wave velocity profiles for SITE NPP site (Deleted from Example because site name could not be removed from the figure)

Example for Discussion Regarding Level of Detail Only

Table 2.3.2-2 Layer thicknesses, depths, and shear-wave velocities (Vs) for 3 profiles, SITE site

Profile 1 Profile 2 Profile 3 thickness(ft) depth (ft) Vs(ft/s) thickness(ft) depth (ft) Vs(ft/s) thickness(ft) depth (ft) Vs(ft/s) 0 4472 0 3577 0 5590 4.9 4.9 4472 4.9 4.9 3577 4.9 4.9 5590 5.0 9.9 5273 5.0 9.9 4218 5.0 9.9 6591 5.0 14.9 5273 5.0 14.9 4218 5.0 14.9 6591 5.0 19.9 5273 5.0 19.9 4218 5.0 19.9 6591 5.0 24.9 5273 5.0 24.9 4218 5.0 24.9 6591 5.0 29.9 5273 5.0 29.9 4218 5.0 29.9 6591 5.0 34.9 5273 5.0 34.9 4218 5.0 34.9 6591 5.0 39.9 5273 5.0 39.9 4218 5.0 39.9 6591 5.0 44.9 5273 5.0 44.9 4218 5.0 44.9 6591 5.0 49.9 5273 5.0 49.9 4218 5.0 49.9 6591 1.0 50.9 5273 1.0 50.9 4218 1.0 50.9 6591 5.0 55.9 5203 5.0 55.9 4162 5.0 55.9 6503 5.0 60.9 5203 5.0 60.9 4162 5.0 60.9 6503 5.0 65.9 5203 5.0 65.9 4162 5.0 65.9 6503 5.0 70.9 5203 5.0 70.9 4162 5.0 70.9 6503 5.0 75.9 5203 5.0 75.9 4162 5.0 75.9 6503 5.0 80.9 5203 5.0 80.9 4162 5.0 80.9 6503 10.0 90.9 5203 10.0 90.9 4162 10.0 90.9 6503 10.0 100.9 5203 10.0 100.9 4162 10.0 100.9 6503 10.0 110.9 5203 10.0 110.9 4162 10.0 110.9 6503 10.0 120.9 5203 10.0 120.9 4162 10.0 120.9 6503 10.0 130.9 5203 10.0 130.9 4162 10.0 130.9 6503 20.0 150.9 5203 20.0 150.9 4162 20.0 150.9 6503 20.0 170.9 5203 20.0 170.9 4162 20.0 170.9 6503 20.0 190.9 5203 20.0 190.9 4162 20.0 190.9 6503 20.0 210.9 5203 20.0 210.9 4162 20.0 210.9 6503 20.0 230.9 5203 20.0 230.9 4162 20.0 230.9 6503 20.0 250.9 5203 20.0 250.9 4162 20.0 250.9 6503 20.0 270.9 5203 20.0 270.9 4162 20.0 270.9 6503 20.0 290.9 5203 20.0 290.9 4162 20.0 290.9 6503 20.0 310.9 5203 20.0 310.9 4162 20.0 310.9 6503 20.0 330.9 5203 20.0 330.9 4162 20.0 330.9 6503 20.0 350.9 5203 20.0 350.9 4162 20.0 350.9 6503 20.0 370.9 5203 20.0 370.9 4162 20.0 370.9 6503 20.0 390.9 5203 20.0 390.9 4162 20.0 390.9 6503 20.0 410.9 5203 20.0 410.9 4162 20.0 410.9 6503 20.0 430.9 5203 20.0 430.9 4162 20.0 430.9 6503 20.0 450.9 5203 20.0 450.9 4162 20.0 450.9 6503 20.0 470.9 5203 20.0 470.9 4162 20.0 470.9 6503 20.0 490.9 5203 20.0 490.9 4162 20.0 490.9 6503 9.1 500.0 5203 9.1 500.0 4162 9.1 500.0 6503 39.1 539.1 5203 39.1 539.1 4162 39.1 539.1 6503 39.2 578.3 5203 39.2 578.3 4162 39.2 578.3 6503 39.2 617.5 5203 39.2 617.5 4162 39.2 617.5 6503 39.2 656.7 5203 39.2 656.7 4162 39.2 656.7 6503 39.2 695.9 5203 39.2 695.9 4162 39.2 695.9 6503 33.5 729.4 6187 33.5 729.4 4949 33.5 729.4 7733 33.5 762.9 6187 33.5 762.9 4949 33.5 762.9 7733 33.5 796.4 6187 33.5 796.4 4949 33.5 796.4 7733 33.5 829.9 6187 33.5 829.9 4949 33.5 829.9 7733 33.5 863.4 6187 33.5 863.4 4949 33.5 863.4 7733

Example for Discussion Regarding Level of Detail Only

33.5 896.9 6187 33.5 896.9 4949 33.5 896.9 7733 33.5 930.4 6187 33.5 930.4 4949 33.5 930.4 7733 33.5 963.9 6187 33.5 963.9 4949 33.5 963.9 7733 33.5 997.3 6187 33.5 997.3 4949 33.5 997.3 7733 33.5 1030.8 6187 33.5 1030.8 4949 33.5 1030.8 7733 38.0 1068.8 6187 38.0 1068.8 4949 38.0 1068.8 7733 38.0 1106.8 6187 38.0 1106.8 4949 38.0 1106.8 7733 38.0 1144.8 6187 38.0 1144.8 4949 38.0 1144.8 7733 38.0 1182.8 6187 38.0 1182.8 4949 38.0 1182.8 7733 38.0 1220.8 6187 38.0 1220.8 4949 38.0 1220.8 7733 24.5 1245.3 6187 24.5 1245.3 4949 24.5 1245.3 7733 24.5 1280.0 6187 24.5 1269.8 4949 24.5 1269.8 7733 >1280 9285 1.0 1270.8 8000 >1269.8 9285 459.1 1729.9 8000 459.1 2189.0 8000 459.1 2648.1 8000 459.1 3107.1 8000 459.1 3566.2 8000 459.1 4025.3 8000 459.1 4484.4 8000 459.1 4943.4 8000 459.1 5402.5 8000 >5403 9285

Example for Discussion Regarding Level of Detail Only

2.3.2.2 Shear Modulus and Damping Curves

No site-specific nonlinear dynamic material properties were determined in the initial siting of the SITE NPP for sedimentary rocks. The rock material over the upper 500 ft (150 m) was assumed to have behavior that could be modeled as either linear or non-linear. To represent this potential for either case in the upper 500 ft of at the SITE NPP site, two sets of shear modulus reduction and hysteretic damping curves were used. Consistent with the SPID (EPRI, 2013a), the EPRI rock curves (M1) were considered to be appropriate to represent the upper range nonlinearity likely in the materials at this site and linear analyses (M2) was assumed to represent an equally plausible alternative rock response across loading level. For the linear analyses, the low strain damping from the EPRI rock curves were used as the constant damping values in the upper 500 ft.

2.3.2.3 Kappa

Base-case kappa estimates were determined using Section B-5.1.3.1 of the SPID (EPRI, 2013a) for a firm CEUS rock site. Kappa for a firm rock site with at least 3,000 ft (1 km) of sedimentary rock may be estimated from the average S-wave velocity over the upper 100 ft

(Vs100) of the subsurface profile while for a site with less than 3,000 ft (1 km) of firm rock, kappa may be estimated with a Qs of 40 below 500 ft combined with the low strain damping from the EPRI rock curves and an additional kappa of 0.006s for the underlying hard rock. For the SITE NPP site, both conditions, greater as well as less than 3,000 ft (1 km) of firm rock, were considered within the uncertainty of available inferences in shear-wave velocity. For profile P1 and P3, with about 1,300 ft of soft rock, the kappa estimates were 0.016s and 0.014s respectively. For the assumed deep profile, P2, kappa based on the average shear-wave velocity over the top 100 ft (below the SSE elevation), 4,154 ft/s (1,266m/s), the relation in the SPID (EPRI, 2013a) results in a kappa estimate of 0.018s. The range of kappa from 0.014s to 0.018s does not reflect a reasonable assessment of epistemic uncertainty. To augment the uncertainty in kappa to a more realistic range and, at the same time, reduce computational demands, a 50% variation to the base-case kappa estimates was added for profiles P1 and P2. For profile P2, the softest profile, the base-case kappa estimate of 0.018s was augmented with 50% increase in kappa to a value of 0.027s, resulting in two sets of analyses for profile P2. Similarly profile P3, the stiffest profile, was augmented with a 50% reduction in kappa, resulting in analyses with low strain kappa values of 0.014s and 0.009s. The suite of kappa estimates and associated weights are listed in Table 2.3.2-3. Weights for the base-case kappa estimates were judged to be the more likely (by 50%) with weights of 0.6 compared to the augmented values with weights of 0.4. This unsymmetric approach significantly reduces computational demands resulting in 6,600 site response analyses (5 combinations of profiles and kappa values, 2 sets of G/Gmax and hysteretic damping curves, 2 source models, 11 loading levels, 30 realizations) compared to 11,800 analyses.

Example for Discussion Regarding Level of Detail Only

Table 2.3.2-3 Kappa Values and Weights Used for Site Response Analyses

Kappa(s) Velocity Profile Lower Range (k2) Base-Case (k1) Upper Range (k2) P1 0.016 P2 0.018 0.027 P3 0.009 0.014

Weights k1 k2 P1 0.4 P2 0.3 0.6 0.4 P3 0.3 0.6 0.4

G/Gmax and Hysteretic Damping Curves M1 0.5 M2 0.5