ML15139A020

March 12, 2012, Information Request, Supplement to Response to Request for Additional Information Regarding Flooding Hazard Reevaluation Report

ML15139A020
Person / Time
Site:	North Anna
Issue date:	05/11/2015
From:	Mark D. Sartain Virginia Electric & Power Co (VEPCO)
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
14-273B
Download: ML15139A020 (7)

Text

VIRGINIA ELECTRIC AND POWER COMPANY RICHMOND, VIRGINIA 23261 May 11, 2015 U.S. Nuclear Regulatory Commission Serial No. 14-273B Attention: Document Control Desk NL&OS/WDC RO Washington, DC 20555 Docket Nos. 50-338/339 License Nos. NPF-4/7 VIRGINIA ELECTRIC AND POWER COMPANY NORTH ANNA POWER STATION UNITS 1 AND 2 MARCH 12, 2012 INFORMATION REQUEST SUPPLEMENT TO RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING FLOODING HAZARD REEVALUATION REPORT By letters dated March 11, 2013 (Serial No.13-017) and March 31, 2014 (Serial No.14-133), Virginia Electric and Power Company (Dominion) submitted a flooding hazard reevaluation report and seismic hazard and screening report, respectively. The seismic hazard and screening report indicates that the ground motion response spectrum (GMRS) exceeds the safe shutdown earthquake for North Anna. Based on this conclusion, in a May 14, 2014 letter the NRC requested additional information to complete the review of the flooding hazard reevaluation of the North Anna site.

As discussed in our June 16, 2014 letter (Serial No.14-273), a new, detailed seismic evaluation of the North Anna service water reservoir (SWR) was required to provide justification for the seismic capability of the service water impoundment under the updated seismic hazard to respond to the NRC's RAI. Dominion responded to the NRC's RAI in a letter dated November 13, 2014 (Serial No. 14-273A). In a clarification call with the NRC on April 16, 2015, Dominion agreed to supplement the information provided in the RAI response.

If you have any questions regarding this information, please contact Wanda Craft at (804) 273-4687.

Sincerely, Mark D. Sartain N" 011.4111JC Vice President - Nuclear Engineering comlenmqlU".4 Virginia.

- - - - -- h-- - - - -- i~ 01 COMMONWEALTH OF VIRGINIA )

)

COUNTY OF HENRICO The foregoing document was acknowledged before me, in and for the County and Commonwealth aforesaid, today by Mark D. Sartain, who is Vice President - Nuclear Engineering of Virginia Electric and Power Company. He has affirmed before me that he is duly authorized to execute and file the foregoing document in behalf of that company, and that the statements in the document are true to the best of his knowledge and belief./,1 Acknowledged before me this /._ day of *

• L , 215.

My Commission Expires: -/ /o Notary Public

Serial No. 14-273B Docket Nos. 50-338/339 Page 2 of 2 Commitments made in this letter: None

Attachment:

Supplement to Request for Additional Information Regarding Flooding Hazard Reevaluation Report cc: U.S. Nuclear Regulatory Commission, Region II Marquis One Tower 245 Peachtree Center Avenue NE, Suite 1200 Atlanta, Georgia 30303-1257 Dr. V. Sreenivas, NRC Project Manager - North Anna U. S. Nuclear Regulatory Commission One White Flint North Mail Stop 08 G9A 11555 Rockville Pike Rockville, Maryland 20852-2738 Ms. Karen Cotton-Gross, NRC Project Manager - Surry U. S. Nuclear Regulatory Commission One White Flint North Mail Stop 08 G9A 11555 Rockville Pike Rockville, Maryland 20852-2738 Mr. Brian K. Harris Project Manager U.S. Nuclear Regulatory Commission One White Flint North, Mail Stop 11 F1 11555 Rockville Pike Rockville, MD 20852-2738 Mr. Victor E. Hall Project Manager U.S. Nuclear Regulatory Commission One White Flint North, Mail Stop 13 H16 11555 Rockville Pike Rockville, MD 20852-2738 NRC Senior Resident Inspector North Anna Power Station

Serial No. 14-273B Docket Nos. 50-338/339 ATTACHMENT SUPPLEMENT TO REQUEST FOR ADDITIONAL INFORMATION REGARDING FLOODING HAZARD REEVALUATION REPORT VIRGINIA ELECTRIC AND POWER COMPANY (DOMINION)

NORTH ANNA POWER STATION UNITS I AND 2

Serial No. 14-273B Docket Nos. 50-338/339 Attachment, Page 1 of 4 Supplement to Request for Additional Information Regarding Flooding Hazard Reevaluation Report North Anna Power Station Units I and 2 By letters dated March 11, 2013 (Serial No.13-017) and March 31, 2014 (Serial No.14-133), Virginia Electric and Power Company (Dominion) submitted a flooding hazard reevaluation report and seismic hazard and screening report, respectively. In a May 14, 2014 letter the NRC requested additional information to complete the review of the flooding hazard reevaluation of the North Anna site. Dominion responded to the NRC's RAI in a letter dated November 13, 2014 (Serial No. 14-273A). In a clarification call with the NRC on April 16, 2015, Dominion agreed to supplement the information provided in the RAI response. This attachment provides the supplemental information.

Clarification Item 1:

Provide a tabulation of the results of the Vs-based correlations from Youd, et al (2001) with a best estimate Vs profile with the age factor of 2 removed (i.e., with age factor=1).

Dominion Response:

The results of the shear wave velocity (Vs) based correlations from Youd, et al (2001) with a best estimate Vs profile with the age factor of 2 removed (i.e., with age factor=l) are presented in Table 1.

Reference:

Youd et al. (2001). Liquefaction Resistance of Soils: Summary Report from the 1996 NCEER and 1998 NCEER/NSF Workshops on Evaluation of Liquefaction Resistance of Soils, Journal of Geotechnical and Geoenvironmental Engineering, 127(10), October 2001, pp. 817-833.

Serial No. 14-273B Docket Nos. 50-338/339 Attachment, Page 2 of 4 Table 1: Liquefaction Analysis Based on Best Estimate Shear Wave Velocity Moment Magnitude: 7.10; Peak Ground Acceleration (PGA) (g): 0.28; Depth of Groundwater Table (ft): 0.0; Magnitude Scaling Factor (MSF): 1.174 MEASURED SHEAR WAVE STRATIGRAPHY CORRECTED SHEAR CYCLIC RESISTANCE CYCLIC FACTOR FACTOR VELOCITY INFORMATION OVERBURDEN STRESS WAVE VELOCITY RATIO STRESS RATIO OF OF RATIO SAFETY SAFETY Shear (Age (Age Wave Fines Unit K C r Factor Factor-Elevation Depth Velocity, Content Weight u CFO cr0 Vr V.1 VS CRR 7. 5 1* (Dr60%)CRR rd CSR 2) 1)

VS (ft) (ft) (ft/sec) (%) (pcf) (psf) (mlsec) 317.5 2.50 472.0 29 125.0 156.0 312.5 156.5 143.9 275.9 200.0 2.00 1.00 2.35 0.99 0.36 13.0 6.5 312.5 7.50 690.0 29 125.0 468.0 937.5 469.5 210.3 306.4 200.0 2.00 1.00 2.35 0.98 0.36 13.2 6.6 307.5 12.50 755.0 29 125.0 780.0 1562.5 782.5 230.1 295.1 200.0 2.00 1.00 2.35 0.97 0.35 13.3 6.7 302.5 17.50 787.0 29 125.0 1092.0 2187.5 1095.5 239.9 282.8 200.0 2.00 1.00 2.35 0.96 0.35 13.5 6.7 297.5 22.50 814.0 29 125.0 1404.0 2812.5 1408.5 248.1 274.7 200.0 2.00 1.00 2.35 0.95 0.34 13.6 6.8 292.5 27.50 838.0 29 125.0 1716.0 3437.5 1721.5 255.4 268.9 200.0 2.00 1.00 2.35 0.94 0.34 13.8 6.9 287.5 32.50 860.0 29 125.0 2028.0 4062.5 2034.5 262.1 264.7 200.0 2.00 1.00 2.35 0.91 0.33 14.2 7.1 282.5 37.50 880.0 29 125.0 2340.0 4687.5 2347.5 268.2 261.4 200.0 2.00 0.97 2.28 0.87 0.32 14.4 7.2 277.5 42.50 898.0 29 125.0 2652.0 5312.5 2660.5 273.7 258.5 200.0 2.00 0.93 2.19 0.83 0.30 14.6 7.3 272.5 47.50 915.0 29 125.0 2964.0 5937.5 2973.5 278.9 256.2 200.0 2.00 0.90 2.12 0.79 0.29 14.8 7.4 267.5 52.50 931.0 29 125.0 3276.0 6562.5 3286.5 283.8 254.2 200.0 2.00 0.88 2.06 0.75 0.27 15.2 7.6 262.5 57.50 946.0 29 125.0 3588.0 7187.5 3599.5 288.3 252.5 200.0 2.00 0.85 2.00 0.71 0.26 15.6 7.8 257.5 62.50 960.0 29 125.0 3900.0 7812.5 3912.5 292.6 250.9 200.0 2.00 0.83 1.95 0.67 0.24 16.2 8.1 252.5 67.50 973.0 29 125.0 4212.0 8437.5 4225.5 296.6 249.5 200.0 2.00 0.81 1.91 0.62 0.23 16.8 8.4 247.5 72.50 986.0 29 125.0 4524.0 9062.5 4538.5 300.5 248.3 200.0 2.00 0.80 1.87 0.58 0.21 17.6 8.8 242.5 77.50 998.0 29 125.0 4836.0 9687.5 4851.5 304.2 247.2 200.0 2.00 0.78 1.83 0.56 0.20 18.0 9.0 237.5 82.50 1009.0 29 125.0 5148.0 10312.5 5164.5 307.5 246.1 200.0 2.00 0.77 1.80 0.56 0.20 17.7 8.8

Serial No. 14-273B Docket Nos. 50-338/339 Attachment, Page 3 of 4 Clarification Item 2:

Provide a tabulation of shear wave velocity, shear modulus, and damping information for the saprolite material (similar to the tabulation of information submitted in conjunction with the seismic hazard and screening report).

Dominion Response:

Tabulation of shear wave velocity for the subsurface materials, including saprolite, is provided in Table 2. Shear modulus (G) and damping (D) information for the saprolite and Zone III materials is provided in Tables 3 and 4, respectively. The unit weights for saprolite, Zone III, Zone Ill-IV, and Zone IV materials are 125 pcf, 150 pcf, 163 pcf, and 164 pcf, respectively.

Table 2: Shear Wave Velocity Information Top Elevation Top Depth Thickness vs Thickness Range Stratum [ft] [ft] [ft] BE [fps] Log-SD [ft]

Saprolite-1 315 0 5 472 0.35 Saprolite-2 310 5 5 690 0.35 Saprolite-3 305 10 5 755 0.35 Saprolite-4 300 15 5 787 0.35 Saprolite-5 295 20 5 814 0.35 Saprolite-6 290 25 5 838 0.35 Saprolite-7 285 30 5 860 0.35 Saprolite-8 280 35 5 880 0.35 Saprolite-9 275 40 5 898 0.35 60-100 Saprolite-10 270 45 5 915 0.35 Saprolite-1 1 265 50 5 931 0.35 Saprolite-12 260 55 5 946 0.35 Saprolite-13 255 60 5 960 0.35 Saprolite-14 250 65 5 973 0.35 Saprolite-15 245 70 5 986 0.35 Saprolite-16 240 75 5 998 0.35 Saprolite-17 235 80 5 1009 0.35 Zoneill 230 85 6 4251 0.31 3-9 Zonelll IV- 224 91 19 5449 0.2 12-26 Zonelli IV-2 205 110 35 5177 0.41 23-47 ZoneIV 170 145 35 8800 0.1 23-47 Bedrock-1 135 180 10 9200 0 NA Bedrock-2 125 190 0 9200 0 NA

• Strattma Bedrock-I (10 ft thick) is added with the bedrock properties for bedrock depth variation analysis.

Serial No. 14-273B Docket Nos. 50-338/339 Attachment, Page 4 of 4 Table 3: Saprolite Shear Modulus and Damping Information Strain [%] G/Go Sigma D [%] Sigma 0.0001 1 0.004 1.3 0.187 0.0003 1 0.008 1.3 0.196 0.001 0.99 0.018 1.6 0.219 0.003 0.94 0.038 2.4 0.250 0.01 0.79 0.079 4.4 0.255 0.03 0.57 0.133 8.2 0.202 0.1 0.32 0.195 14.3 0.117 0.3 0.15 0.234 20.6 0.060 1 0.05 0.255 27.9 0.022 Note that the damping ratio is limited to 15% for the site response analysis.

Table 4: Zone III Shear Modulus and Damping Information Strain [%] G/Go Sigma D [%] Sigma 0.0001 1 0.010 0.6 0.600 0.0003 1 0.011 0.6 0.600 0.001 1 0.013 0.6 0.600 0.003 1 0.045 0.6 0.600 0.01 1 0.072 0.6 0.600 0.03 0.98 0.108 0.6 0.600 0.1 0.87 0.140 2.7 0.400 0.3 0.63 0.150 8.2 0.300 1 0.33 0.150 17 0.300 Note that the damping ratio is limited to 15% for the site response analysis.

Clarification Item 3:

Provide a summary of the results of the slope stability calculation for the Seed method.

Dominion Response:

The summary of the results of the slope stability calculation for the Seed method are provided in Table 5 below.

Table 5: Factor of Safe Determined for Seismic Slope Stability Using Seed Method Factor of Safety Approach kh k, Undrained Downstream Upstream Acceptable

-0.08 1.528 1.323 1.1 Seed 0.15 1.1 1 0.15 +0.08 1.569 1.515