ML15139A020
| ML15139A020 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 05/11/2015 |
| From: | Sartain M D 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 COMPANYRICHMOND, VIRGINIA 23261May 11, 2015U.S. Nuclear Regulatory Commission Attention:
Document Control DeskWashington, DC 20555Serial No.NL&OS/WDC Docket Nos.License Nos.14-273BRO50-338/339 NPF-4/7VIRGINIA ELECTRIC AND POWER COMPANYNORTH ANNA POWER STATION UNITS 1 AND 2MARCH 12, 2012 INFORMATION REQUESTSUPPLEMENT TO RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING FLOODING HAZARD REEVALUATION REPORTBy 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 hazardreevaluation report and seismic hazard and screening report, respectively.
The seismichazard and screening report indicates that the ground motion response spectrum (GMRS)exceeds the safe shutdown earthquake for North Anna. Based on this conclusion, in aMay 14, 2014 letter the NRC requested additional information to complete the review ofthe flooding hazard reevaluation of the North Anna site.As discussed in our June 16, 2014 letter (Serial No.14-273),
a new, detailed seismicevaluation of the North Anna service water reservoir (SWR) was required to providejustification for the seismic capability of the service water impoundment under the updatedseismic hazard to respond to the NRC's RAI. Dominion responded to the NRC's RAI in aletter dated November 13, 2014 (Serial No. 14-273A).
In a clarification call with the NRCon April 16, 2015, Dominion agreed to supplement the information provided in the RAIresponse.
If you have any questions regarding this information, please contact Wanda Craft at(804) 273-4687.
Sincerely, Mark D. SartainVice President
-Nuclear Engineering N" 011.4111JC comlenmqlU
".4 Virginia.
h- ------i~ 01COMMONWEALTH OF VIRGINIACOUNTY OF HENRICO)))The foregoing document was acknowledged before me, in and for the County and Commonwealth aforesaid, today by Mark D. Sartain, who isVice President
-Nuclear Engineering of Virginia Electric and Power Company.
He has affirmed before me that he is duly authorized to executeand file the foregoing document in behalf of that company, and that the statements in the document are true to the best of his knowledge andbelief./,1 Acknowledged before me this /._ day of L , 215.My Commission Expires:
-/ /oNotary Public Serial No. 14-273BDocket Nos. 50-338/339 Page 2 of 2Commitments made in this letter: None
Attachment:
Supplement to Request for Additional Information Regarding Flooding HazardReevaluation Reportcc: U.S. Nuclear Regulatory Commission, Region IIMarquis One Tower245 Peachtree Center Avenue NE, Suite 1200Atlanta, Georgia 30303-1257 Dr. V. Sreenivas, NRC Project Manager -North AnnaU. S. Nuclear Regulatory Commission One White Flint NorthMail Stop 08 G9A11555 Rockville PikeRockville, Maryland 20852-2738 Ms. Karen Cotton-Gross, NRC Project Manager -SurryU. S. Nuclear Regulatory Commission One White Flint NorthMail Stop 08 G9A11555 Rockville PikeRockville, Maryland 20852-2738 Mr. Brian K. HarrisProject ManagerU.S. Nuclear Regulatory Commission One White Flint North, Mail Stop 11 F111555 Rockville PikeRockville, MD 20852-2738 Mr. Victor E. HallProject ManagerU.S. Nuclear Regulatory Commission One White Flint North, Mail Stop 13 H1611555 Rockville PikeRockville, MD 20852-2738 NRC Senior Resident Inspector North Anna Power Station Serial No. 14-273BDocket Nos. 50-338/339 ATTACHMENT SUPPLEMENT TO REQUEST FOR ADDITIONAL INFORMATION REGARDING FLOODING HAZARD REEVALUATION REPORTVIRGINIA ELECTRIC AND POWER COMPANY (DOMINION)
NORTH ANNA POWER STATION UNITS I AND 2 Serial No. 14-273BDocket Nos. 50-338/339 Attachment, Page 1 of 4Supplement to Request for Additional Information Regarding Flooding Hazard Reevaluation ReportNorth Anna Power Station Units I and 2By 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 hazardreevaluation report and seismic hazard and screening report, respectively.
In a May 14,2014 letter the NRC requested additional information to complete the review of theflooding hazard reevaluation of the North Anna site. Dominion responded to the NRC'sRAI in a letter dated November 13, 2014 (Serial No. 14-273A).
In a clarification call withthe NRC on April 16, 2015, Dominion agreed to supplement the information provided inthe 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 NCEERand 1998 NCEER/NSF Workshops on Evaluation of Liquefaction Resistance of Soils, Journal ofGeotechnical and Geoenvironmental Engineering, 127(10),
October 2001, pp. 817-833.
Serial No. 14-273BDocket Nos. 50-338/339 Attachment, Page 2 of 4Table 1: Liquefaction Analysis Based on Best Estimate Shear Wave VelocityMoment Magnitude:
7.10; Peak Ground Acceleration (PGA) (g): 0.28; Depth of Groundwater Table (ft): 0.0; Magnitude Scaling Factor (MSF): 1.174MEASURED SHEAR WAVE STRATIGRAPHY CORRECTED SHEAR CYCLIC RESISTANCE CYCLIC FACTOR FACTORVELOCITY INFORMATION OVERBURDEN STRESS WAVE VELOCITY RATIO STRESS OF OFRATIORATIO SAFETY SAFETYShear (Age (AgeWave Fines Unit K C r Factor Factor-Elevation Depth Velocity, Content Weight u CFO cr0 Vr V.1 VS1* CRR7.5 (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 6.5312.5 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 6.6307.5 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 6.7302.5 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 6.7297.5 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 6.8292.5 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 6.9287.5 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 7.1282.5 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 7.2277.5 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 7.3272.5 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 7.4267.5 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 7.6262.5 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 7.8257.5 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 8.1252.5 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 8.4247.5 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 8.8242.5 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 9.0237.5 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. 14-273BDocket Nos. 50-338/339 Attachment, Page 3 of 4Clarification 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, isprovided 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 forsaprolite, Zone III, Zone Ill-IV, and Zone IV materials are 125 pcf, 150 pcf, 163 pcf, and164 pcf, respectively.
Table 2: Shear Wave Velocity Information Top Elevation Top Depth Thickness vs Thickness RangeStratum [ft] [ft] [ft] BE [fps] Log-SD [ft]Saprolite-1 315 0 5 472 0.35Saprolite-2 310 5 5 690 0.35Saprolite-3 305 10 5 755 0.35Saprolite-4 300 15 5 787 0.35Saprolite-5 295 20 5 814 0.35Saprolite-6 290 25 5 838 0.35Saprolite-7 285 30 5 860 0.35Saprolite-8 280 35 5 880 0.35Saprolite-9 275 40 5 898 0.35 60-100Saprolite-10 270 45 5 915 0.35Saprolite-1 1 265 50 5 931 0.35Saprolite-12 260 55 5 946 0.35Saprolite-13 255 60 5 960 0.35Saprolite-14 250 65 5 973 0.35Saprolite-15 245 70 5 986 0.35Saprolite-16 240 75 5 998 0.35Saprolite-17 235 80 5 1009 0.35Zoneill 230 85 6 4251 0.31 3-9Zonelll IV- 224 91 19 5449 0.2 12-26Zonelli IV-2 205 110 35 5177 0.41 23-47ZoneIV 170 145 35 8800 0.1 23-47Bedrock-1 135 180 10 9200 0 NABedrock-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. 14-273BDocket Nos. 50-338/339 Attachment, Page 4 of 4Table 3: Saprolite Shear Modulus and Damping Information Strain [%] G/Go Sigma D [%] Sigma0.0001 1 0.004 1.3 0.1870.0003 1 0.008 1.3 0.1960.001 0.99 0.018 1.6 0.2190.003 0.94 0.038 2.4 0.2500.01 0.79 0.079 4.4 0.2550.03 0.57 0.133 8.2 0.2020.1 0.32 0.195 14.3 0.1170.3 0.15 0.234 20.6 0.0601 0.05 0.255 27.9 0.022Note 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 [%] Sigma0.0001 1 0.010 0.6 0.6000.0003 1 0.011 0.6 0.6000.001 1 0.013 0.6 0.6000.003 1 0.045 0.6 0.6000.01 1 0.072 0.6 0.6000.03 0.98 0.108 0.6 0.6000.1 0.87 0.140 2.7 0.4000.3 0.63 0.150 8.2 0.3001 0.33 0.150 17 0.300Note 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 areprovided in Table 5 below.Table 5: Factor of Safe Determined for Seismic Slope Stability Using Seed MethodFactor of SafetyApproach kh k, Undrained Downstream Upstream Acceptable Seed 0.15 -0.08 1.528 1.323 1.11 0.15 +0.08 1.569 1.515 1.1