ML13325A098

APS Response to Second Request for Additional Information (RAI) Regarding Relief Request 51

ML13325A098
Person / Time
Site:	Palo Verde
Issue date:	11/20/2013
From:	Cadogan J J Arizona Public Service Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
102-06799-JJC/RKR/DCE
Download: ML13325A098 (11)

Text

6%A/- 10 CFR 50.55a John J. Cadogan, Jr Vice President, Nuclear Engineering r aps Palo Verde Nuclear Generating Station P.O. Box 52034 Phoenix, AZ 85072 Mail Station 7602 Tel 623 393 4083 102-06799-JJC/RKR/DCE November 20, 2013 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001

References:

1. Arizona Public Service Company (APS) letter number 102-06794, American Society of Mechanical Engineers (ASME) Code,Section XI, Request for Approval of an Alternative to Flaw Removal and Characterization

-Relief Request 51, dated November 8, 2013 2. APS letter number 102-06797, Response to Request for Additional Information

-American Society of Mechanical Engineers (ASME) Code,Section XI, Request for Approval of an Alternative to Flaw Removal and Characterization

-Relief Request 51, dated November 18, 2013

Subject:

Palo Verde Nuclear Generating Station (PVNGS)Unit 3 Docket No. 50-530 APS Response to Second Request for Additional Information (RAI) Regarding Relief Request 51 Pursuant to 10 CFR 50.55a(a)(3)(i), Arizona Public Service Company (APS)requested the Nuclear Regulatory Commission (NRC) approve Relief Request 51 (Reference

1) and responded to a request for additional information (Reference 2).By email dated November 20, 2013, the NRC staff provided a second RAI to request clarification of some of the responses provided in Reference

2. The enclosure to this letter contains the APS response to the second NRC RAI.No commitments are being made to the NRC by this letter.A ierr-ber.

' '. ihe STARS fSt r. av ind Rescu c<,ý xr.rC-.) A.- .[ian~ce Ca-.]. * ( CI L ..ay Di:ab' Canyon -PalI- ',-'erde

• South Texas

• o.I f C reek A ATTN: Document Control Desk U.S. Nuclear Regulatory Commission APS Response to Second Request for Additional Information (RAI) Regarding Relief Request 51 Page 2 Should you need further Information regarding this relief request, please contact Robert K. Roehler, Licensing Section Leader at (623) 393-5241.Sincerely, JJC/RKR/DE~s

Enclosure:

APS Response to the Second Request for Additional Information

-Relief Request 51 cc: M. L. Dapas J. K. Rankin M. A. Brown NRC Region IV Regional Administrator NRC NRR Project Manager for PVNGS NRC Senior Resident Inspector for PVNGS Enclosure APS Response to the Second Request for Additional Information

-Relief Request 51 Enclosure APS Response to the Second RAI -Relief Request 51 Introduction Pursuant to 10 CFR 50.55a(a)(3)(i)

Arizona Public Service Company (APS) requested the Nuclear Regulatory Commission (NRC) approve Relief Request 51, by letter number 102-06794, dated November 8, 2013 [Agencywide Documents Access and Management System (ADAMS) Accession No. ML13317A070].

APS proposed an alternative to the ASME Code requirements of Section Xl related to axial flaw indications identified in a Unit 3 reactor vessel bottom mounted instrument (BMI) nozzle.Specifically, APS proposed a half-nozzle repair and a flaw evaluation as alternatives to the requirements for flaw removal of IWA-4421 and flaw characterization of IWA-3300.By email dated November 15, 2013, the NRC staff provided a request for additional information (RAI). The'APS responses to the NRC RAI items were provided in APS letter number 102-06797, Response to Request for Additional Information

-American Society of Mechanical Engineers (ASME) Code, Section Xl, Request for Approval of an Alternative to Flaw Removal and Characterization

-Relief Request 51, dated November 18, 2013 [ADAMS Accession No. ML13323A763].

Subsequently, by email dated November 20, 2013, the NRC staff requested clarification of some of the RAI responses.

This enclosure contains the APS response to the second NRC RAI.NRC RAI-1 Your response to RAI-2 dated November 18, 2013, stated that, "The maximum faulted condition, Loss of Secondary Pressure [LSP] stresses, derived in Attachment 1 to this enclosure, occur at about 118 seconds into the transient (at the maximum through-wall temperature gradient) when the cold leg temperature is 344 0 F and the pressure is less than 300 psia. It is therefore conservative to add the maximum thermal stresses for this transient to the SS [steady state] pressure stresses." Please confirm that by adding the stresses under the SS condition to the stresses under the LSP condition for the SS +LSP condition, you basically assumed that the pressure will be at 2235 psig at any time during the LSP and this is the source of conservatism that you mentioned above in the quote. Please clarify whether there is any other conservatism in the stresses under the SS + LSP condition.

APS Response Yes, the stresses from SS conditions with a pressure equal to 2235 pounds per square inch absolute (psia) and a temperature equal to 565 degrees Fahrenheit (OF) were added to the LSP transient.

There are no other conservatisms regarding applied loads considered in the SS + LSP condition.

I Enclosure APS Response to the Second RAI -Relief Request 51 NRC RAI-2 Reference 7 of Attachment 2 to Relief Request 51 dated November 8, 2013, was provided as part of your response to RAI-4 dated November 18, 2013. However, it is not clear which stresses in Reference 7 were used in this application.

Please indicate the Table number in Reference 7 from which the stresses were used to calculate the stress coefficients under the SS condition in Table 6-1 of Attachment 2 to Relief Request 51.APS Response The values were obtained from Table 5-3a, zero degree nozzle nodes, from weld top to weld bottom at a corresponding axial height of 1.11 inches to 2.89 inches, respectively.

For axial heights 3.14 inches and 3.35 inches, the head nodes 81310 and 81410 are used and the stresses obtained from the supplemental data provided by Dominion Engineering, Inc. (Attachment 1 -Supplemental Data Table from PVB-OA).NRC RAI-3 Your response to RAI-5 dated November 18, 2013, stated that, "The parameters used to calculate the CD [cooldown]

condition used the same total stresses as defined for the SS condition above and included a cooldown transient of 100°F/hour." Considering that the stresses under the CD condition in Table 4-3 of Attachment 2 to Relief Request 51 are much less than the stresses under the SS condition, the NRC staff still thinks that the CD condition are for thermal stresses only. Please confirm that by adding the stresses under the SS condition to the stresses under the CD condition for the SS + CD condition, you basically assumed that the pressure will be at 2235 psig at any time during CD and this is one source of extra conservatism.

Please clarify whether there is any other conservatism in the stresses under the SS + CD condition.

APS Response Yes, the stresses from SS conditions with a pressure equal to 2235 psia and a temperature equal to 565 OF were added to the CD transient.

There are no other conservatisms regarding applied loads considered in the SS + CD condition.

NRC RAI-4 Your response to RAI-6 dated November 18, 2013, indicated that the J-R curve based on NUREG-0744, Volume 2, Revision 1, "Resolution of the Task A-1 1 Reactor Vessel Materials Toughness Safety Issue," is significantly different from that based on Regulatory Guide (RG) 1.161, "Evaluation of Reactor Pressure Vessels with Charpy Upper-Shelf Energy Less Than 50 FT-LB." As a result, you used the safety factors associated with RG 1.161 to perform the elastic plastic fracture mechanics (EPFM)analysis.

The required safety factors for detected flaws (ASME Code) are different from 2 Enclosure APS Response to the Second RAI -Relief Request 51 those for postulated flaws (RG 1.161). To avoid identifying the causes for the significant difference between the J-R curves based on the two sources, which may be time consuming, please take out the extra conservatism associated with the stresses under the SS + CD condition (RAI-3) and perform the EPFM analysis using the safety factors for detected flaws.APS Response An EPFM evaluation for the SS + CD condition was performed removing the 2235 psia pressure stress component for SS conditions and replacing it with 800 psia, which corresponds to the time of the maximum through-wall temperature gradient.

This flaw evaluation was done using the J-R curve model presented in Regulatory Guide (RG)1.161, Evaluation of Reactor Pressure Vessels with Charpy Upper-Shelf Energy Less Than 50 Ft-Lb, 1995. In addition, for the J-T based flaw stability analysis, the applied safety factors of 3.0 for primary and 1.5 for secondary (residual plus thermal) were used replacing the RG 1.161 safety factors of 1.5 and 1.0 respectively.

Similarly, for the J-integral limited flaw extension of 0.1-inch analysis, the applied safety factors of 1.5 for primary and 1.0 for secondary (residual plus thermal) were used replacing the RG 1.161 safety factors of 1.4 and 1.0, respectively.

These results demonstrate that both EPFM acceptance criteria were met.Reaulatorv Guide 1.161 J-R Curve used with NUREG-0744 Safety Factors Ductile Crack Growth Stability Criterion:

T"app < Tmat At instability:

Tapp = Tmat Safety Factors Kl*p KI*s Kl*(a) ae Kl'(ae) Japp Tapp Stable?Primary Secondary (ksi'in) (ksi'in) (ksi'in) (in.) (ksi/in) (kips/in)1.00 1.00 22.862 91.014 113.876 2.4557 123.942 0.506 1.800 Yes 1.50 1.00 34.293 91.014 125.307 2.5364 138.606 0.633 2.252 Yes 3.00 1.50 68.585 136.522 205.107 3.3144 259.350 2.217 7.884 Yes 5.00 1.00 114.309 91.014 205.323 3.3171 259.726 2.223 7.906 Yes 7.00 1.00 160.032 91.014 251.047 3.9328 345.787 3.941 14.014 No Iterate on safety factor until Tapp = Tmat to determine Jinstability:

2.0878 2.0878 47.730 190.018 237.748 3nstability T1app 3.362 11.956 Tmat 11.956 3.7410 319.384 at Jmat = 2.217 kips/in, Tmat = 23.690 ( Tapp -TM=t = 0.000 Applied J-Integral Criterion:

Japp <JO.1 Jo.1 = Jmat at Aa = 0.1 in.where, Safety Factors Kl*p Primary Secondary (ksi'Jin)Kl*I Kl*(a)(ksiqin) (ksi/in)ae Kl'(ae) Japp Jo. 1 (in.) (ksi'in) (kips/in) (kips/in)OK?1.50 1.00 34.293 91.014 125.307 2.5364 138.606 0.633 1.542 Yes 3 Enclosure APS Response to the Second RAI -Relief Request 51 These results demonstrate that both EPFM acceptance criteria are satisfied using primary/secondary safety factors of 3.0/1.5 for stable flaw extension and 1.5/1.0 for limited flaw extension.

The applied tearing modulus of 7.884 is less than the material tearing modulus of 11.956 at instability and the applied J-integral of 0.633 kips/in is less than the material J-integral of 1.542 kips/in at a flaw extension of 0.1 inch.4 Enclosure APS Response to the Second RAI -Relief Request 51 ATTACHMENT I Supplemental Data Table From PVB-OA Page 1 of 3 Enclosure

-Attachment 1 Supplemental Data Table from PVB-OA PVB-OA results.txt USE MACRO FILE WELDTAB SELECT IN RANGE FOR ITEM=LIVE COMPONENT=

1 TO 82309 STEP 1 3467 ELEMENTS (OF 3467 DEFINED) SELECTED BY ESEL COMMAND.SELECT ALL NODES HAVING ANY ELEMENT IN ELEMENT SET.1 4311 NODES (OF 4311 DEFINED) SELECTED FROM 3467 SELECTED ELEMENTS BY NSLE COMMAND.PRINT S NODAL SOLUTION PER NODE***** ANSYS -ENGINEERING ANALYSIS SYSTEM RELEASE 8.0 ANSYS Mechanical U 00206332 VERSION=HPPA 8000-64 15:04:13 MAY PV BMI(Od,CYC SS,3.001/0.75,0,A)

-Operating***** POST1 NODAL STRESS LISTING *****25, 2004 CP=8.740 LOAD STEP= 0 TIME= 7004.0 SUBSTEP=0 LOAD CASE= 0 THE FOLLOWING X,Y,Z VALUES ARE IN ELEMENT COORDINATES NODE SX SY SZ SXY 1 1622.3 16457. -576.34 -2661.9 2 2937.2 13974. -3617.6 -2064.9 3 4870.3 13191. -4536.1 -1641.9 4 4326.3 12733. -4470.5 -1695.4 5 2343.2 12575. -3393.2 -2062.2 6 19.788 12457. -2000.3 -2423.1 7 -1732.5 10394. -882.02 -2297.1 8 -2041.9 8657.6 -643.20 -2065.5 9 -1682.8 7289.2 -1406.2 -1765.8 101 -2238.6 1701.4 -749.29 -872.18 102 -2174.4 2469.2 -5364.4 -980.12 103 -2189.7 3271.3 -6712.6 -1126.5 104 -2007.1 3810.6 -6286.8 -1208.0 105 -1419.5 5381.0 -4896.5 -1437.3 106 -928.55 6454.8 -2394.5 -1614.6 107 -802.72 7100.8 -7.0911 -1774.2 108 -1425.3 6576.0 1493.7 -1729.2 109 -2212.8 5111.3 737.50 -1517.8 201 -4914.7 -13785. -5035.8 1776.6 202 -5680.6 -10954. -9118.7 1049.7 203 -7073.4 -8129.1 -10415. 191.71 204 -7314.8 -5627.0 -9249.9 -367.67 205 -6722.7 -3051.3 -6923.4 -774.53 206 -5268.3 505.97 -3630.8 -1216.4 207 -3646.9 4150.2 932.10 -1618.7 208 -2851.0 5567.1 5340.1 -1743.1 209 -1557.6 4627.1 6616.0 -1331.5 301 -5761.0 -22054. -11780. 3348.7 302 -7077.4 -17233. -13289. 2089.4 303 -8813.0 -13228. -13372. 904.45 304 -9556.8 -9557.4 -11162. -14.052 305 -9712.5 -5605.8 -8149.2 -875.73 Page 1 SYZ-238.10 29.576 307.83 620.52 788.01 753.02 528.11 218.45 156.25-70.323 257.03 553.95 812.86 979.32 1001.3 836.27 481.85 274.59 220.58 595.77 890.25 1033.7 1093.9 1131.5 1069.6 819.60 475.70 342.96 683.74 1006.0 1110.2 1107.2 Sxz-455.72 102.91 1482.9 3028.0 3881.2 3831.2 2611.3 1187.0 486.79 455.14 1217.8 2730.0 4017.5 4871.5 5001.9 4260.5 2338.7 1192.4 2005.0 2935.5 4440.3 5188.8 5497.6 5649.5 5391.4 3849.3 2331.1 2342.6 3435.6 5075.3 5661.6 5672.1 Page 2 of 3 Enclosure

-Attachment 1 Supplemental Data Table from PVB-OA PVB-OA results.txt 81106 17597. 31911. -24553. -2965.8 -1812.5 -9015.9 81107 23449. 45464. -13303. -4617.4 -2292.8 -11540.81108 29958. 53076. -2299.9 -4773.4 -3152.5 -15678.81109 30827. 56779. 12280. -5603.7 -4035.9 -18996.81111 36522. 30210. -3606.7 1887.1 -4273.2 -22326.81112 46142. 32226. -10760. 3176.3 -2945.3 -16041.81113 36744. 40837. -9770.5 -1012.0 1049.8 7241.6 81114 47566. 54405. 14083. -1258.1 4563.0 25429.81115 40519. 46495. 11435. -1092.0 5019.1 28191.81116 57940. 47765. 11012. 2122.4 3276.5 17304.81117 74980. 49608. 10352. 5265.7 916.36 3895.8 81118 65345. 27615. 3149.2 7851.8 652.40 4334.6 81119 46865. 8913.1 -2561.6 7868.5 753.56 4338.7 81120 32189. 13180. -1331.8 3980.4 360.58 1736.4 81121 24770. 14811. -1208.2 2082.1 -5.9303 235.11 81122 21080. 15667. -1779.0 1126.3 -93.294 -533.11 81123 19886. 16590. -1621.9 712.69 -294.81 -724.76 81201 1976.4 14733. -35191. -2631.1 -448.46 -2535.1 81202 3051.3 12886. -36030. -2029.1 -833.62 -4144.3 81203 6829.9 15632. -32602. -1828.8 -1402.4 -7022.6 81204 10782. 20663. -28709. -2075.0 -1881.0 -9476.7 81205 15464. 27482. -23744. -2508.1 -2451.6 -12307.81206 20808. 34950. -15472. -2922.5 -3076.8 -15442.81207 27707. 45992. -3072.8 -3769.2 -3728.7 -18611.81208 33106. 53371. 15477. -4125.4 -4658.6 -23649.81209 29328. 24597. 5742.7 1569.4 -4522.3 -22857.81211 35199. 15338. -20402. 4712.5 -2469.3 -13638.81212 25455. 26224. -30739. -355.54 -1747.6 -8403.6 81213 31130. 47715. -8340.3 -3043.5 413.08 6116.3 81214 28101. 54232. 6116.3 -4223.6 3522.8 23326.81215 39396. 60555. 23612. -3343.3 3900.9 25912.81216 55443. 56919. 17404. 178.98 1821.8 8896.7 81217 70956. 52978. 12048. 3742.7 -431.96 -3695.4 81218 62481. 21398. 686.35 8608.1 919.08 5471.3 81219 43655. 10011. -1171.4 7072.9 1088.8 5700.8 81220 30621. 13299. -824.18 3636.7 299.10 2212.7 81221 23841. 14676. -1122.6 1910.9 16.751 126.56 81222 20627. 15602. -1600.4 1048.5 -154.23 -753.14 81223 19459. 16419. -1511.1 656.19 -358.69 -1037.8 81301 3097.4 18111. -22596. -3160.1 -573.25 -3483.3 81302 3277.3 13216. -26600. -2081.2 -1122.8 -5628.5 81303 6467.3 13047. -24528. -1350.7 -1871.7 -9346.1 81304 9125.1 16729. -20272. -1571.4 -2479.9 -12362.81305 11412. 23669. -14063. -2581.4 -3054.9 -15262.81306 14010. 34276. -5637.0 -4296.0 -3637.6 -18171.81307 14426. 44034. 4313.7 -6162.7 -3830.7 -19311.81308 9184.4 45219. 25352. -7949.8 -3611.6 -17296.81309 -807.55 36848. 40600. -8692.7 -2285.7 -13327.81310 15898. 3862.3 -41681. 2528.6 -1121.8 -8119.2 81311 -3379.0 20437. -38698. -5471.7 -2231.6 -9558.1 81312 9717.0 33295. -25931. -5241.9 -2148.7 -10211.81313 16358. 45540. -16398. -5396.4 -258.70 465.66 81314 27193. 57645. -1491.2 -4754.6 2047.0 13077.81315 36828. 67305. 14572. -4707.1 2564.5 15805.81316 45750. 57204. 21263. -1662.7 1711.5 9578.1 81317 51903. 42032. 7931.2 1559.4 -163.49 787.05 81318 52143. 17339. -1803.5 7283.4 1615.0 6352.1 81319 38843. 10846. -249.45 5970.1 930.26 6867.7 81320 28174. 12894. -867.64 3206.4 258.26 2303.6 81321 23137. 14680. -1089.2 1774.2 -43.567 -9.6570 81322 20031. 15457. -1495.4 949.10 -220.11 -1009.9 81323 19080. 16255. -1420.8 597.15 -410.40 -1293.3 81401 1536.3 21795. -11924. -4275.3 -523.78 -3021.5 Page 65 Page 3 of 3 Enclosure

-Attachment 1 Supplemental Data Table from PVB-OA 81402 81403 81404 81405 81406 81407 81408 81409 81410 81411 81412 81413 81414 81415 81416 81417 81418 81419 81420 81421 81422 81423 81501 81502 81503 81504 81505 81506 81507 81508 81509 81510 81511 81512 81513 81514 81515 81516 81517 81518 81519 81520 81521 81522 81523 81601 81602 81603 81604 81605 81606 81607 81608 81609 81610 81611 81612 81613 81614 81615 81616 81617 81618 2646.6 4692.7 5448.9 6092.9 5038.3 2951.9 277.89 3745.7-809.56-487.77 106.80 8863.8 18692.24400.30806.35027.33095.27677.25283.21694.19514.18679.1495.8 2598.5 2906.1 1233.3-828.36-1889.3-3142.6-1226.0-1648.0 2523.1 5523.8 4385.0 1931.2 1048.0 495.97-3218.0 4556.1 16909.21261.21547.20291.18834.18245.-207.03 169.54 532.03 158.82-500.20-938.02-154.10 115.01 918.94 1143.7 2110.5 3064.6-788.17-5556.8-8608.7-8186.1-1179.0 9429.9 16689.14265.15530.20927.29263.30789.26202.24197.4O983.32201.35261.40853.44478.48069.47764.36256.7102.7 9525.9 12989.14504.15370.16084.20251.14544.10848.8617.7 8892.2 10120.9234.2 10745.13556.47062.45566.41336.36969.34623.36003.30039.8683.4 4625.6 10505.12961.14494.15253.15909.9746.4 6025.5 4425.1 3383.4 2515.6 1706.0 2089.8 3464.0 6847.5 38556.35320.22772.10194.3964.6 899.45-820.72 414.66 7541.2 PVB-OA results.txt

-16115. -2976.8-15683. -2040.9-12149. -2115.5-7454.8 -3080.2-185.80 -4982.5 4707.9 -5829.8 11358. -4917.9 23859. -3251.7-18919. -9248.4-27479. -7008.9-20992. -7363.6-17100. -6056.1-13204. -4397.7 1007.3 -4219.3 8412.1 -2964.2 1174.7 36.003-1109.9 5363.1 236.43 3685.3-733.66 2564.5-1041.7 1488.6-1414.5 857.16-1349.9 530.80-4278.5 -3856.5-7244.2 -2443.1-7578.5 -1621.0-6051.7 -1527.1-3838.5 -2022.5-1850.9 -2525.8-326.69 -2512.8 5920.7 -2571.5 18201. -3489.2-5506.0 -9135.0-10957. -8174.7-17369. -7516.4-16653. -6481.5-15828. -5801.1-8934.7 -6182.9-2179.2 -5877.2-8528.2 -503.24-1217.0 2540.7 1569.0 2203.7-87.285 1769.5-749.72 1202.9-1269.5 739.94-1253.5 478.75-231.85 -2049.3-2035.8 -1203.6-2765.1 -815.45-2775.3 -666.08-2783.9 -595.99-3237.0 -403.49-1785.8 -347.05 4786.1 -560.86 11093. -1064.1-5184.9 -7605.0-6671.5 -6600.4-11516. -3907.3-14563. -1977.7-13882. -1606.1-13031. -1663.5-11371. -1360.0-10853. -429.88 144.02 239.80 Page 66-1037.1-1841.2-2396.1-2748.7-2694.8-2288.6-988.78 742.21-757.62-1969.8-2917.5-1265.3 345.13 840.82 1788.4 2000.5 2181.7 1048.0 342.60-83.212-235.78-421.57-261.71-596.05-1111.9-1473.6-1532.4-1263.8-704.61-251.73-287.89-572.34-420.36-1363.3-790.56 52.510 351.71 1285.8 1975.1 1573.2 1023.0 330.61-34.498-217.49-404.45-49.744-163.98-338.35-451.37-522.35-479.60-516.25-532.20-270.50 39.925 184.41 294.21 676.48 889.15 836.00 1199.1 842.69 756.33-5251.1-9228.9-11870.-13532.-13333.-11366.-3795.9 289.82-4135.0-8857.3-14274.-6505.2 1910.6 4946.6 11345.10069.8407.0 6782.1 2220.2 4.1405-1103.1-1339.7-1480.1-3001.1-5565.2-7304.7-7537.2-6235.8-3336.7-1769.7-1633.8-717.01-2730.7-6743.2-4088.1 484.45 1807.4 6918.0 9155.3 7625.6 5084.5 2100.6 60.156-998.07-1268.0-414.86-820.78-1669.2-2217.5-2538.5-2329.1-2671.8-2468.4-1897.9 766.78 846.96 1364.5 3845.8 5251.8 4877.7 6756.7 3736.4 3055.7