ML13051A199

San Onofre, Unit 2, Enclosure 6, LTR-SGDA-12-36, Rev. 3, Flow-Induced Vibration and Tube Wear Analysis of the San Onofre Nuclear Generating Station Unit 2 Replacement Steam Generators Supporting Restart. Page 228 of 415 Through End

ML13051A199
Person / Time
Site:	San Onofre
Issue date:	02/15/2013
From:	Bell B A, Cullen W K, Hall J M, Langford P J, Norman T L, Pournaras T J, Prabhu P J, Thakkar J G Westinghouse
To:	Office of Nuclear Reactor Regulation
References
TAC ME9727 1814-AA086-M0238, Rev 0, LTR-SGDA-12-36, Rev 3
Download: ML13051A199 (204)

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{{#Wiki_filter:Page 227 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 20136.0 Critical Tubes6.1 MethodA review of the available eddy current data was performed for SG 2E088 and SG 2E089 lookingat tube wear indications primarily in the U-bend region of the SG. The review determined thatalmost 600 tubes had indications of tube wear in SG 2E088, and approximately 800 tubes werefound with SG tube wear in the U-bend region of SG 2E089. The range of wear that wasreported varied from approximately 4% through-wall (TW) to over 30%TW. Clearly all tubes withwear in Unit 2 do not need to be evaluated individually, since the type of wear was, in general,very similar. Since the wear was determined to be similar, the tubes were placed in three groupsof tubes having similar wear depths. For the purposes of this analysis, it was determined thatreasonable groupings of tubes would include tubes with indications of wear in the U-bend asindicated below:Group 1 -Tubes with >20%TW tube wearGroup 2 -Tubes with 10% to 19%TW tube wearGroup 3 -Tubes with 0% to 9%TW tube wearFigures 6-1 and 6-2 contain plots of the SG cross section in the general region of interest witheach of the above general regions identified. It should be noted that there are some 'outliers'corresponding to the three groups defined above that are not included in the associated region.It was not possible to include every tube with a given wear depth in a relatively small regionwithout also including additional tubes that have significantly reduced or no indicated level ofwear. This could result in plugging additional unaffected tubes should a pluggingrecommendation become necessary. As a result, it was determined that the analysis wouldfocus on limiting tubes having the largest amounts of tube wear on an individual basis.Since tubes currently having significant wear would be expected to continue to have the largestamounts of additional wear in future operation, these tubes were selected for further analysis.The selection process included a review and sort of tubes looking at maximum eddy currentindicated wear depth. The tubes were grouped into the three categories of tube wear asdescribed above. The majority of the emphasis was placed on looking at tubes with >20% wearsince it is expected that these tubes will continue to have the largest amounts of wear in futureoperation. The acceptance criteria for plugged tubes and active tubes are different since aplugged tube can withstand significantly more wear before exceeding criteria. As a result, whenlooking at plugged tubes, only tubes with wear >20% were considered since these tubes wouldbe expected to have the largest amounts of future tube wear in the plugged tube population.Tubes that have a large amount of wear will continue to be the basis for the limiting tubes basedon the assumption that the wear at the AVB support location will be small at reduced powerlevels. If the wear is small, the support conditions between the AVB and the tube are notexpected to change so the tubes with small amounts of wear will continue to have small amountsof wear. The wear analysis presented in Section 7 shows that the wear at reduced power levelsis less than what would be expected at 100% power. Therefore, it can be concluded that thetubes with large amounts of wear after operation at 100% power will continue to have the limitingAVB support conditions at reduced power operation.The tube eddy current data were also reviewed to determine the appropriate anti-vibration bar(AVB) support case for use in the FIV analysis. The potential cases are described in Table 4-1.The eddy current test (ECT) data were used to determine the tube support condition likely to be1814-AA086-M0238, REV. 0Page 228 of 415 Page 228 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013present during the prior cycle of operation. In general, the primary FIV analysis case of interestwas defined by determining the largest number of consecutive AVB locations that showedindications of tube wear. Ineffective AVB support locations were defined as locations where AVBwear was reported. If there were more than one group of consecutive AVB wear locations on asingle tube, the location with the highest wear values was chosen to be representative of theprimary FIV tube support condition. These kinds of tubes, i.e., with more than one group ofsequential AVB wear locations, were also selectively considered for further analysis. This wasperformed by considering an additional analysis case where the wear groupings on both sides ofan 'effective AVB' were assumed to be indicative of ineffective AVBs, including the AVB site thatwas apparently effective. This resulted in some analysis cases with many missing AVBsupports.6.2 Tube GroupsThe eddy current data and the AVB support case determination for SG 2E088 are shown in thefollowing tables:Table 6-1 Tubes with >20% wear -Active TubesTable 6-2 Tubes with 10% to 19% wear -Active TubesTable 6-3 Tubes with >20% wear -Plugged TubesThe eddy current data and the AVB support case determination for SG 2E089 are shown in thefollowing tables:Table 6-4 Tubes with >20% wear -Active TubesTable 6-5 Tubes with 10% to 19% wear -Active TubesTable 6-6 Tubes with >20% wear -Plugged TubesThese tables were then used to select tubes for further analysis using the wear model. This isdiscussed in Section 6.3.1814-AA086-M0238, REV. 0Page 229 of 415 Page 229 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Table 6-1AVB Case Determination for Active Tubes with >20% Wear at Power LevelSteam Generator 2E088AVB SG 2E088 Active Tubes with > 20% WearAVBsRow Col B01 B02 803 B04 B05 B06 B07 B08 B09 B10 B11 B12 Missing Case88 96 17 21 2 19133 87 9 19 20 13 6 2 18112 96 17 20 13 17 2 17132 96 18 23 11 3 29120 90 23 16 7 3 28117 83 14 17 10 24 7 3 31118 86 23 12 13 14 6 3 31116 96 23 18 15 7 3 31105 81 22 12 8 3 28125 91 9 22 10 3 28134 84 10 11 21 15 8 3 28118 82 8 21 10 3 2998 90 8 8 11 20 7 3 2797 87 11 25 23 16 4 3897 91 14 12 22 19 4 38108 94 22 15 10 13 4 38131 91 8 22 17 8 4 38108 88 12 9 22 12 4 38125 95 9 10 18 22 10 4 37113 95 10 14 12 9 21 4 39127 93 6 6 23 10 8 5 48128 92 8 22 20 11 12 14 5 4597 93 10 11 23 19 11 5 47124 96 13 22 14 14 9 5 4796 92 14 21 16 18 9 5 47101 95 21 11 11 10 12 5 47116 82 14 8 17 20 14 5 4793 89 14 12 11 20 11 5 471814-AA086-M0238, REV. 0 Page 230 of 415 Page 230 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Table 6-2AVB Case Determination for Active Tubes with 10% -19% Wear at Power LevelSteam Generator 2E088AVB SG 2E088 Active Tubes with 10>19%% WearRow Col B01 B02 B03 B04 B05 B06 B07 B08 B09 810 B11 812 Miss CaseI I Missing133136129126127123113109110138137124102100133130117114118117113112103971281181291141291261141049593988790979193879888959482948992959494879710081959090898491988294959 1211 78 8 106 136 127 1113 67 711 613 6 516 8 86 13 87 12 89 13 1412 7 1312 98 166 139 913 197 1911 188 136 814 101912 789 71112 91012 13615 131212 911 713 9 714 15 11121168151391269102222222223333333333333333344444446 9 6 155 13 14 1010 7 11 148 6 106 8 99 10 117 15 5191010107581814-AA086-M0238, REV. 0Page 231 of 415 Page 231 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Table 6-2 (Continued)AVB Case Determination for Active Tubes with 10% -19% Wear at Power LevelSteam Generator 2E088122 96 5 11 15 6 4 38112 82 9 6 9 12 4 38109 97 6 9 5 12 4 38105 99 15 17 9 17 4 38103 97 6 10 5 7 4 38101 85 12 7 12 14 4 3895 85 9 14 13 19 4 3898 88 11 10 7 7 4 3894 88 12 7 7 7 4 3889 87 10 14 10 8 74 38124 84 8 11 8 6 10 4 39123 99 6 7 12 5 4 39135 93 5 8 10 5 6 4 4099 89 7 10 12 5 4 4093 97 9 17 10 9 4 40103 95 7 8 11 6 6 5 45130 86 6 15 7 7 13 5 46118 84 9 16 15 9 9 5 46112 94 6 16 19 11 14 5 4694 86 7 14 6 8 8 5 4696 88 9 14 17 18 15 11 5 46120 96 10 12 15 13 12 5 4799 95 10 5 8 5 5 5 4796 86 8 9 11 15 13 5 4796 84 11 13 11 11 6 5 4789 93 12 9 8 11 10 5 47128 84 7 6 10 4 5 5 481814-AA086-M0238, REV. 0Page 232 of 415 Page 232 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Table 6-3AVB Case Determination for Plugged Tubes with >20% Wear at Power LevelSteam Generator 2E088AVB SG 2E088 Plugged Tubes with > 20% WearAVBsRow Col B01 B02 803 B04 B05 B06 B07 B08 B09 B10 Bll B12 Missing Case108 92 23 17 17 2 17133 91 8 12 35 29 2 18124 88 10 20 5 2 18109 91 23 7 13 9 3 28107 91 22 9 8 7 3 28101 91 16 8 21 3 28104 88 10 20 17 17 16 3 28114 90 7 8 15 13 22 8 3 30103 91 7 25 11 9 10 4 37111 91 26 20 17 23 4 38110 90 12 17 25 5 4 38110 88 5 9 20 15 4 38116 86 11 6 29 28 13 12 5 46112 86 19 13 24 20 13 14 5 46105 87 9 11 20 12 11 5 46117 93 14 27 12 12 9 5 47117 91 17 16 21 12 7 5 47115 85 6 19 27 13 7 11 5 48113 87 22 22 14 18 11 S 48119 89 16 21 5 13 11 5 5 48123 89 14 13 15 20 7 5 48114 86 13 8 11 21 17 8 15 6 53101 87 11 15 20 7 21 24 6 5497 89 7 18 11 14 23 16 6 54129 93 8 13 15 11 21 9 6 54111 87 5 5 6 10 21 9 6 54105 89 6 10 10 15 20 20 6 54112 88 15 16 23 17 35 10 6 55124 92 19 25 7 9 14 9 6 55112 92 18 24 11 18 10 9 6 55108 90 21 12 7 11 18 13 6 55104 92 7 18 19 12 20 12 6 551814-AA086-M0238, REV. 0Page 233 of 415 Page 233 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Table 6-3 (Continued)AVB Case Determination for Plugged Tubes with >20% Wear at Power LevelSteam Generator 2E088128 94 6 10 7 13 10 32 25 7 60116 92 9 11 24 18 18 16 16 7 60102 92 7 12 24 15 7 18 8 7 60113 91 8 13 26 16 13 9 11 7 61118 92 8 20 13 8 14 11 8 7 61105 85 9 20 13 8 13 8 6 7 61103 89 8 20 12 15 6 18 13 8 7 62120 92 7 11 14 11 32 25 11 10 8 6697 85 7 11 21 14 9 21 25 7 8 6699 93 7 9 5 7 5 14 21 12 8 671814-AA086-M0238, REV. 0Page 234 of 415 Page 234 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Table 6-4AVB Case Determination for Active Tubes with >20% Wear at Power LevelSteam Generator 2E089AVB SG 2E089 Active Tubes with > 20% WearAVBsRow Col B1 B2 B3 B4 B5 B6 87 B8 B9 B10 B11 B12 Missing Case131 91 8 21 6 2 17113 71 14 21 2 18121 95 20 14 5 2 18119 95 7 20 12 3 28129 93 is 22 6 3 2891 73 10 8 22 3 29105 77 7 21 15 3 29106 78 6 26 23 13 3 29119 77 6 14 21 3 29126 90 5 7 12 21 14 4 36121 91 12 15 28 23 4 37124 86 5 9 21 12 4 37123 83 13 12 23 12 10 4 38124 88 10 23 14 6 4 38125 89 8 22 18 6 4 38119 89 5 6 17 28 5 5 4688 78 9 9 7 22 10 5 4793 77 5 7 16 20 22 5 47100 76 13 21 11 14 12 5 47109 75 6 7 8 21 13 5 47112 96 21 9 5 14 17 5 471814-AA086-M0238, REV. 0Page 235 of 415 Page 235 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Table 6-5AVB Case Determination for Active Tubes with 10% -19% Wear at Power LevelSteam Generator 2E089AVB SG 2E089 Active Tubes with 10% -19% WearRow Column B1 B2 B3 B4 B5 86 B7 B8 B9 B1O Bil B12 Miss CaseR C m Missing9912258698o9811111411412066818384858687888888898990909090919192929395961019590162163769495789894162777774717283748488718778848890758778887171929513141311101111161214141111111111111111111111111111111111111814-AA086-M0238, REV. 0Page 236 of 415 Page 236 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Table 6-5 (Continued)AVB Case Determination for Active Tubes with 10% -19% Wear at Power LevelSteam Generator 2E089103 79 12 1 6111 101 13 1 6113 71 14 1 6113 95 11 14 1 6114 70 11 1 6115 101 11 1 6116 96 14 12 1 6116 102 10 1 6117 71 10 1 6117 99 13 1 6119 89 17 1 6120 80 10 1 6120 86 15 11 1 6122 80 11 1 6122 128 10 1 6124 80 12 1 6125 91 10 1 6127 81 10 1 6129 93 15 1 6130 88 11 1 677 71 10 1 786 86 10 1 788 82 13 11 1 789 75 11 1 792 76 10 1 793 77 16 1 795 79 11 1 798 70 15 1 7100 70 12 1 7102 74 11 1 7103 71 11 1 7104 74 10 1 7104 98 11 1 7106 74 10 1 7106 92 10 1 7106 96 16 1 71814-AA086-M0238, REV. 0Page 237 of 415 Page 237 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Table 6-5 (Continued)AVB Case Determination for Active Tubes with 10% -19% Wear at Power LevelSteam Generator 2E089107 71 13 1 7108 74 10 1 7108 94 11 1 7108 96 10 1 7110 94 14 1 7111 71 17 1 7113 79 10 1 7115 79 15 1 7119 77 14 1 7120 102 11 1 7121 79 11 1 7121 95 14 1 7122 98 13 1 7123 89 19 1 7123 93 13 1 7125 87 16 1 7125 89 18 1 7126 82 14 1 7126 94 10 1 7127 89 13 1 7128 92 11 1 7130 82 17 1 7133 87 14 11 1 728 4 7 11 1 845 7 11 1 863 163 11 1 874 70 10 1 882 80 10 1 883 71 10 1 885 77 11 12 1 885 83 15 1 886 76 10 1 886 78 10 1 887 71 11 1 888 70 10 1 889 73 12 1 889 81 15 1 81814-AA086-M0238, REV. 0Page 238 of 415 Page 238 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Table 6-5 (Continued)AVB Case Determination for Active Tubes with 10% -19% Wear at Power LevelSteam Generator 2E08990919192939393959697979798999910010210210410410510910911011011111111111211211311711711811911912070718994737579917871739172697574961187696776993709673939968969393101786999741 81 81 81 81 81 81 81 81 81 81 81 81 81 81 81 81 81 81 81 81 81 81 81 81 81 81 81 81 81 81 81 81 81 81 81 81 8101814-AA086-M0238, REV. 0Page 239 of 415 Page 239 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Table 6-5 (Continued)AVB Case Determination for Active Tubes with 10% -19% Wear at Power LevelSteam Generator 2E08912012112212313113213588899696103103109117120121125126127131981211231248690911101111131211231251278492921011007579947578797490737575739675819095897693859084809192919791839591887012141710111210101310111014141013101312131015141216121 81 81 81 81 81 81 81 91 91 91 91 91 91 91 91 91 91 91 91 91 91 102 162 162 162 172 172 172 172 172 172 172 172 172 172 182 181011 1110 15 1315 11 14 1311 1015 1411 1010 13 11 1110 1115 12 1012 1513 12 1210 1010 17 12 1613 1110 101814-AA086-M0238, REV. 0Page 240 of 415 Page 240 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Table 6-5 (Continued)AVB Case Determination for Active Tubes with 10% -19% Wear at Power LevelSteam Generator 2E08995 75 10 10 2 1896 76 11 11 2 1899 73 15 11 2 18101 71 18 12 2 18103 91 15 18 2 18106 70 12 12 2 18107 97 12 14 2 18108 72 11 12 2 18108 80 10 14 2 18112 72 11 11 2 18112 92 10 12 2 18113 77 17 14 2 18115 71 16 18 2 18117 95 10 18 2 18118 80 12 13 2 18119 79 13 11 2 18119 91 17 15 2 18122 88 15 10 2 18124 82 12 14 2 18126 80 12 13 2 18126 92 16 19 2 18130 94 13 13 2 1887 77 10 16 2 1988 76 11 14 2 1989 77 12 14 2 1990 76 13 16 2 1994 76 12 11 2 1996 72 10 11 2 1997 77 16 12 2 1998 90 10 15 14 2 1999 77 17 12 2 19101 77 14 13 10 2 19102 70 19 10 2 19103 77 13 16 2 19107 75 10 12 2 19107 77 19 17 2 19107 79 18 19 12 2 191814-AA086-M0238, REV. 0 Page 241 of 415 Page 241 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Table 6-5 (Continued)AVB Case Determination for Active Tubes with 10% -19% Wear at Power LevelSteam Generator 2E08910911212212913313313487949510210310310512612913513812599110118130889198106123124129951041231081187776929589958675787376819779788393908371100948480777880798491778o8776921512 101015 1115 1314 1013 1515 1311 1010 1918 1115 1215 1311 1314 1213 1111 1213 1014 1412 1214 16121111191919191919192020202020202020202020212828282829292929292929303038393916 11 1917 19 1010 10 1111 16 1811 11 1813 11 1211 10 1411 12 1712 15 1312 13 1414 14 1111 16 1013 17 1310 18 1011 10 14 1210 14 19 1114 16 17 11131814-AA086-M0238, REV. 0Page 242 of 415 Page 242 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Table 6-6AVB Case Determination for Plugged Tubes with >20% Wear at Power LevelSteam Generator 2E089AVB SG 2E089 Plugged Tubes with > 20% WearRow Col B01 B02 B03 B04 B05 B06 B07 B08 B09 BlO Bl1 812 AVBs Missing Case121 83 6 24 9 8 2 16115 91 19 22 22 3 2897 79 5 7 12 22 4 38118 88 10 14 21 16 7 4 38110 80 11 23 12 8 11 5 39117 89 9 13 17 26 9 5 46114 92 6 11 13 24 18 5 46131 89 6 23 11 7 16 5 47112 90 9 21 16 11 5 7 5 46109 87 6 8 14 15 22 7 5 47108 90 8 6 12 27 21 6 6 53120 82 5 14 16 16 16 22 6 53118 82 6 8 17 20 10 19 6 53106 82 8 6 13 18 20 11 6 53103 83 6 15 20 24 20 12 6 54120 84 7 12 12 16 23 9 6 54115 87 7 22 14 15 6 9 6 54110 88 8 8 14 16 22 8 6 54121 89 8 15 22 10 13 13 6 54104 84 5 14 19 21 12 9 6 54103 87 5 14 14 21 9 96 54117 81 6 16 12 19 29 10 6 55122 84 5 21 6 16 13 8 6 55106 88 8 18 21 9 8 11 6 55100 82 20 9 10 18 7 8 6 55100 88 5 14 10 15 22 9 7 6 55115 83 5 8 6 9 5 21 6 6 55134 90 S 11 9 13 6 18 26 10 6 56114 88 7 23 19 24 21 17 8 6 56115 85 9 8 9 15 22 16 5 7 59102 82 6 6 19 15 17 21 10 7 601814-AA086-M0238, REV. 0 Page 243 of 415 Page 243 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Table 6-6 (Continued)AVB Case Determination for Plugged Tubes with >20% Wear at Power LevelSteam Generator 2E08999 85102 88117 85122 82106 84105 83104 8698 86123 9198 88112 84100 84976 876S685511 149 201312 1811 2012 2510 1018 2311 138 159 105 914 15 2015 15 1715 20 1815 27 616 12 1117 14 2223 15 185 6 159 16 615 20 1911 16 2717 20 1912724 9 58 1127 1510 817 1111 1422 1814 713 12 1114 12 57778888888886060626666666666666667671814-AA086-M0238, REV. 0Page 244 of 415 Page 244 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 20136.3 Enveloping TubesThe figures for the bounding box used to select critical tubes are shown in Figures 6-1 and 6-2for the 2E088 and 2E089 steam generators, respectively. Originally this method was going to beused to identify the initial groupings of tubes. However, after some initial work, this method wasdetermined to include too many tubes that are not showing indications of tube wear and wouldresult in excessive tube plugging if this criterion was used to select the tube groups.Using the eddy current data and the missing AVB cases determined in Section 6.2, an alternateselection of limiting tubes was used. The limiting tubes were chosen based on the number ofmissing AVB supports, the location of those AVB supports, and the severity of tube wear at theAVB locations. The tubes determined to be the most limiting are listed in Table 6-7. Thesetubes include the base case determined in Section 6.2 as well as extra alternate cases toconsider based on gaps in sequential AVB tube wear.In general the tubes were selected to find:1) Limiting active tube in SG 2E0882) Limiting active tube in SG 2E0893) Limiting plugged tube in SG 2E0884) Limiting plugged tube in SG 2E089In addition, the following was also performed:1) Confirm limiting tubes were indeed limiting based on tube excitation ratios and wearcriteria,2) Address tubes with tube-to-tube wear,3) Consider effects of additional missing AVBs beyond what is indicated by ECT.Results of the evaluation of these tubes can be found in subsequent sections of this report. Itshould be noted that the expected trends, meaning tubes with higher tube excitation ratios havehigher wear, were generally confirmed in these analyses. This confirms the enveloping tubeshave been addressed.1814-AA086-M0238, REV. 0Page 245 of 415 Page 245 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Table 6-7Limiting Tubes Determined for AVB Wear ConsiderationsNumber NumberTube SG Tube Tube ECT ECT FASTVIB ] FASTVIBIMissing MissingR/C No Status Description Value w/Uncertainty Case Case.[jAVB AVBR97C87 88 Active Limiting Active Tube in SG 88 25 27.4 38 4 46 5R119C89 89 Active Limiting Active Tube in SG 89 (1/2) 28 30.5 46 5 54 628 30.4 37 4 45 5R121C91 89 Active Limiting Active Tube in SG 89 (2/2) x 30.4 x x 46 5x 30.4 x x 53 6R131C91 89 Active Less limiting active tube 21 23.6 17 2 38 4R129C93 89 Active Less limiting active tube 22 24.6 28 3 46 5R126C90 89 Active Less limiting active tube 21 23.6 45 5 60 7R112C88 88 Stab Limiting Plugged Tube in SG 88 35 37.2 47 5 55 6R133C91 88 Stab Limiting Plugged Tube in SG 88 35 37.2 38 2 45 5R114C90 88 Stab Limiting Plugged Tube in SG 88 22 24.5 48 3 60 7R111C91 88 Stab Limiting Plugged Tube in SG 88 26 28.4 38 4 x xR116C86 88 Stab Limiting Plugged Tube in SG 88 29 31.3 46 5 61 7R117C93 88 Stab Limiting Plugged Tube in SG 88 27 29.4 47 5 x xR115C85 88 Stab Limiting Plugged Tube in SG 88 27 29.4 48 5 61 5R114C86 88 Stab Limiting Plugged Tube in SG 88 21 23.5 53 6 66 8R128C94 88 Stab Limiting Plugged Tube in SG 88 32 34.3 60 7 x xR120C92 88 Stab Limiting Plugged Tube in SG 88 32 34.3 66 8 x xR121C83 89 Stab Limiting Plugged Tube in SG 89 24 26.4 16 2 46 4R117C89 89 Stab Limiting Plugged Tube in SG 89 26 28.4 46 5 x xR108C90 89 Stab Limiting Plugged Tube in SG 89 27 29.4 53 6 x xR117C81 89 Stab Limiting Plugged Tube in SG 89 29 31.3 55 6 x xR134C90 89 Stab Limiting Plugged Tube in SG 89 26 28.4 56 6 67 8R114C88 89 Stab Limiting Plugged Tube in SG 89 24 26.4 56 6 67 8R117C85 89 Stab Limiting Plugged Tube in SG 89 24 26.4 62 7 74 10R122C82 89 Stab Limiting Plugged Tube in SG 89 27 29.4 66 8 x xR112C84 89 Stab Limiting Plugged Tube in SG 89 27 29.4 67 8 x xR113C81 89 Stab Tube with Tube-to-Tube Wear (1/2) 16 18.6 28 318 20.5 38 4 55 6R11lC81 89 Stab Tube with Tube-to-Tube Wear (2/2)x 20.5 x x 67 8Additional Check Cases21 23.5 18 2 28 3R113C71 89 Active Low SR & High Wear -Check Cases x x x 29 3x x x 38 4R121C95 89 Active Low SR & High Wear -Check Cases 20 22.5 45 5 39 41814-AA086-M0238, REV. 0Page 246 of 415 Page 246 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013toCUC?4cm,0N0o00SMONFigure 6-1Bounding Box for SG 2E0881814-AA086-M0238, REV. 0Page 247 of 415 Page 247 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013I................ ......... ......................................C130)iVIVgl0....................... .... ....................I ..: : :..................... ......... .. ...............................................................xolE 40000--S.w = wIITIIiI..........,..0 ..'..00 .,,°*° ..0...00o. 00.. ., *0.,.....................,.... ..... .......*..............., ., ............i iI.---------------.... .......iatK............0Ln+---------------------------------------.... .... .......LA0CA-40N-40-4-4M08Figure 6-2Bounding Box for SG 2E0891814-AA086-M0238, REV. 0Page 248 of 415 Page 248 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 20137.0 Wear Analysis7.1 General MethodologyTube and support interaction leading to rapid wear in the U-bend region is a complex, highlynonlinear process involving impact dynamics, friction, boundary conditions and forcing functionsthat change with time during the process. Rather than attempt to calculate and benchmark thenonlinear calculations, Westinghouse performed baseline tests that incorporated the nonlinearinteraction for a range of tube and AVB support conditions and measured enveloping workratesthat could be scaled to other conditions using forcing functions that are obtained from results oflinear vibration analyses. Tube wear is then calculated as a function of time following Archardwear theory using the equationV = K(WR)(t)where V is the calculated wear volume, K is the appropriate tube wear coefficient, WR is theworkrate, and t is time. The same equation is used to determine the corresponding AVB wearvolume using an appropriate wear coefficient for the AVB as relative tube and AVB wear volumesare apportioned for conformal interaction. These calculations require three inputs:1. Specific wear coefficients for the tube and AVB,2. The normal force/sliding motion workrate, and3. The depth-volume relationship at the interface.Each is discussed in the context of testing, design bases, and application to SONGS operatingexperience in the following section.7.2 Wear Considerations -Fluidelastic Tube Excitation versus TurbulenceThe methodology that is applied in this evaluation treats the mechanism that was found to be thecause of moderate wear in the U-bend region of conventional Westinghouse Model 51 andModel F steam generators before the development of advanced tube/AVB support configurationsin the mid 1980s as described in Reference 7-1. This mechanism has been variously referred toas "fluidelastic vibration in the support inactive mode," "double-span behavior," "fluidelasticrattling within loose supports," and "amplitude limited fluidelastic vibration." Its characteristics arefundamentally different in many respects from those of random flow turbulence that is alwayspresent in steam generators. Given the evolving state of knowledge and analytical capabilities atthe time as typified by References 7-2 through 7-5, Westinghouse developed a semi-empiricalmethodology to use as a design tool in treating the fundamental characteristics observed intesting.A brief overview of the mechanism is provided in order to facilitate understanding the supportingWestinghouse tests described in Section 7.2.1, details of semi-empirical workrate formulationdescribed in Section 7.2.2, Westinghouse experience with its application in Section 7.2.3, andhow it is applied to the SONGS evaluation in Section 7.2.4. When Westinghouse experiencedmoderate tube wear in the U-bend region of conventional steam generators as described inReference 7-1, the understanding of the gap-limited fluidelastic vibration mechanism was in itsinfancy. S. S. Chen et al (References 7-2 and 7-3) provided some of the first descriptions, notingamong other things that:1. "To facilitate manufacture and to allow for thermal expansion of the tubes, smallclearances are used between tubes and tube supports. When the clearance is relatively1814-AA086-M0238, REV. 0Page 249 of 415 Page 249 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013large, the tube may rattle inside some of the support clearances with small-amplitudeoscillations. This type of mode, in which some supports do not provide effective support,is called tube-support-plate (TSP)-inactive mode."2. "...the natural frequencies of the TSP-inactive modes are lower than those of the 'TSP-active modes,' in which the support plates provide 'knife-edge' type support."3. "Tube displacements associated with the instability of a TSP-inactive mode are small;however, impacts of the tube against TSPs may result in significnt damage in a relativelyshort time."4. "In addition, tube response is intrinsically nonlinear, with the dominance of the TSP-inactive or TSP-active modes depending on the magnitudes of different systemparameters. In general, such a system is difficult to model; only a full-scale test canprovide all the necessary characteristics."5. "In the region in which the TSP-inactive mode is unstable, tube displacement close to thebaffle plate varies very little with the flow velocity."6. "When the tube is offset to one side, the tube does not impact with the other transducer.However, there are double impacts against one of the transducers during each cycle ofvibration."7. "For a given flow velocity, the tube displacement and impact force depend on diametral3gap. For larger gaps, tube motion is more steady and the impact force is larger."8. "Fluidelastic instability associated with a TSP-inactive mode for loosely held tubes hasbeen demonstrated in laboratory tests and observed in a few heat exchangers. It issuspected to be one of the main causes of tube failures in some operating steamgenerators and heat exchangers."There are many other papers dealing with this mechanism that were published during the timewhen Westinghouse was resolving the moderate AVB wear in conventional steam generatorsand developing advanced designs as summarized in Reference 7-1. Bouecke (Reference 7-4)concluded that fluidelastic rattling within a relatively loose tube/support strip was the mechanismthat led to wear in an operating steam generator. Fricker (Reference 7-5) noted that nonlinearanalysis which deals with impacting and sliding was one approach to evaluating consequencesof this mechanism, and further, that numerical results indicated a linear relationship betweenclearance and impact force for a given level of negative damping. However, he also noted thatthe approach was rather cumbersome requiring small time steps to obtain the required accuracyand numerical stability, while long time histories are required. Perhaps more importantly forWestinghouse development of a practical design tool, he noted that the cumbersome "analysishas to be repeated for each change in the boundary conditions, (e.g. clearances)."Given this environment and the need for a practical design tool that could be used to optimizeadvanced AVB support systems for the U-bend region, Westinghouse developed a semi-empirical methodology that incorporated the complex, nonlinear characteristics of gap-limitedfluidelastic tube excitation from full-size baseline tests that could be scaled to other loadingconditions using results of linear analyses. All the characteristics described in the extractedsummary descriptions from others were confirmed in Westinghouse testing. Sections 7.2.13 This is the spelling in the published paper.1814-AA086-M0238, REV. 0Page 250 of 415 Page 250 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013through 7.2.4 describe that development in more detail and how it is applied for the currentevaluation of SONGS operating experience.7.2.1 Westinghouse Test ProgramsExtensive flow-induced vibration testing and evaluation to support steam generator design wereperformed using a broad array of consistent methods for much of four decades at theWestinghouse Research Laboratories (now Science and Technology Center). References 7-6through 7-8 illustrate the kinds of idealized tests used in characterizing mechanisms of interestand development of analytical models to evaluate them in more complex steam generatorconfigurations. Subsequently, a variety of tests on segmented portions of full-size steamgenerators, scale-model tests in air and prototypic steam environments, and instrumentationprograms for initial operation of newer models of steam generators served to confirm and refineanalytical models. Early testing supported SG design with tubes arranged in square arraypatterns, but new tests were conducted for triangular arrays with the same pitch-to-diameter ratioin the 1980s in the same test rigs to develop consistent models for evaluation of bothconfigurations. Only those tests pertinent to the methodology applied in evaluation of SONGSflow-induced vibration and wear potential are described in this report.Figure 7-1 shows the idealized triangular arrangements that were tested first in the same watertunnel that had been used two decades earlier for square pitch configurations. Figure 7-2provides a context and reference for discussion of tube vibration response characteristics andflow-induced vibration (FIV) mechanisms using sample results that were obtained from one ofthose tests. The tube response data on Figure 7-2 includes vortex shedding contributions in theidealized water test that may exist around the periphery of the steam generator inlet regions, butthey are not a concern in the two-phase, highly turbulent flow in the U-bend region of interest tothis evaluation. The narrow band tube response to random flow turbulence typically varies asvelocity raised to about the second power4 and is illustrated by the red line on Figure 7-2.However, there is a critical velocity above which fluidelastic tube excitation initiates and tuberesponse is so extreme that it must be avoided altogether in design (see Section 7.2.2 for morediscussion of Westinghouse design bases). For illustration purposes, the black line onFigure 7-2 varies with velocity to the tenth power, and it envelopes the tube response in thesample shown.The FIV mechanisms of interest to U-bend tube response are fluidelastic excitation and flowturbulence with the same characteristic trends as shown in Figure 7-3. However, the parametersthat determine initiation and response must be obtained from more representative tests becausetube stiffnesses are different for out-of-plane (OP) and in-plane (IP) directions in the U-bendregion. They also vary to a lesser extent with tube radius, so the U-bend region is much lesshomogeneous than the straight leg region in terms of tube stiffness and frequency responsecharacteristics. Figure 7-4 is a schematic of the quarter-scale U-bend model with a paralleltriangular array pattern that was tested in the same wind tunnel as earlier quarter-scale modelsfor square-pitch configurations to obtain parameters for evaluating U-bend tubes. Tests wereperformed first with no AVBs present and then for six other configurations representing differentnumbers of AVB supports with increasing frequency response. Test results included thefollowing relative to initiation of fluidelastic tube excitation with no AVBs in the model:4 The specific exponent applicable to FIV analyses in Section 4.0 and to the trend line on this plotusing the same correlation is [ ]a,c,e.1814-AA086-M0238, REV. 0Page 251 of 415 Page 251 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 20131. Vibration amplitudes were small until a critical velocity was exceeded. Amplitudesincreased rapidly with increasing flow after that.2. Large amplitudes were caused by fluidelastic vibration and they were in the OP directiononly.3. The triangular-pitch arrangement was [ ]be as the square-pitcharrangement with the same pitch/diameter ratio5 when tested without AVBs.4. Not all the tubes responded equally to the fluidelastic excitation. This was also true forthe earlier square array tests, but [ ]b,e in thetriangular array tests.Additional tests were performed with all but one of the tubes having sixincluded the following:AVBs pinned. Results1. [2.3.]Pebe]b.e4.]b,eA piezoelectric force gauge and a non-contacting fiber-optic vibration displacement transducerwere installed to measure tube response characteristics of the same tube for two different AVBsupport configurations. During these tests, front and back locations of AVB surfaces werecontrolled by micrometer extensions to determine6 the effects of gap magnitude and symmetryon both impact forces and displacements. Results included the following:1.2.[[be3.4.b,ebe56IbeIb,e1814-AA086-M0238, REV. 0Page 252 of 415 Page 252 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 20135.]b,e6.]b,eFigure 7-5 illustrates the basic characteristics of results from these quarter-scale tests thatinclude both turbulence and fluidelastic excitation mechanisms when U-bend tubing interactswith AVBs across large gaps. Portions of data plots recorded to the same scales for flows up toabout twice the tube excitation threshold during the U-bend tests have been copied and pastedabove the schematic illustration of the two mechanisms originally shown on Figures 7-2 and 7-3.As flow velocity increases up to the point of fluidelastic instability, the displacements fromturbulence are small and insufficient to interact with the AVB even sporadically. For narrow bandrandom turbulence response, the peak amplitudes follow []ac.e. For the illustrated conditionsthere will be either zero or negligible turbulence interaction with the AVB across the clearance up[]b,eThe observed almost instantaneous change from a benign to a significant tube/AVB interactionlong before random flow turbulence causes any interaction by itself, as illustrated on Figure 7-5using actual U-bend flow response characteristics, is the reason why FEI and not turbulence isconsidered the mechanism to be avoided or controlled. Not all tubes will respond this way fromfluidelastic excitation, but it is possible anywhere that AVB gaps are large enough to create atube span that is long enough to become unstable if the AVB did not exist. What to call themechanism can be debated, but the dominant tube vibration results from energy extracted fromfluidelastic excitation and not random flow pressure fluctuations. This data is sufficient to explainwhy FEI causes tube wear, but not to explain how because the consequential workrates areneeded for wear calculations using the Archard type equation described in Section 7.1.Following tests on both the square-pitch and triangular-pitch small-scale U-bend configurations,two series of wind tunnel experiments were conducted on cantilever tubes designed to simulate theresponse of curved U-bend tubes as described generally in Reference 7-1. A 7-row by 5-columnarray of full-size tubes mounted in such a way that orthogonal stiffnesses differed to match U-bendresponse as shown on Figure 7-6 provided two kinds of information. Basic fit-up effects on tuberesponse to both fluidelastic and turbulent excitation were determined first. []b.e Both the thresholdtube excitation constant and turbulent tube response correlations were consistent with thosederived from the scale-model U-bend tests. Then the test rig was modified to refine basicfluidelastic driving force correlations for use in properly controlling mechanical shaker tests of full-size steam generator U-bends.1814-AA086-M0238, REV. 0Page 253 of 415 Page 253 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Mechanical excitation tests followed on full-size 0.688 inch OD x 0.040 inch average wall thicknessU-bends configured as shown on Figure 7-7 to characterize the wear producing forces and motionsat the tube/AVB intersections. These tests are also described generally in Reference 7-1 and indepth in Reference 7-8. Two different size tubes with up to either 4 or 6 AVB intersections wereevaluated. Each had a full-length straight leg span supported at a top plate with simulatedbroached flat contact lands. All tests were performed with tubes filled with water and pressurizedto 1200 psi. Parametric tests covered a range of fit-up conditions subject to simulated out-of-planefluidelastic excitation, in-plane turbulence, and out-of-plane turbulence. Initial tests with four AVBintersections (simulating two sets of AVB's) first confirmed the fundamental conclusion that out-of-plane fluidelastic vibration within tube/AVB gaps was the likely explanation for wear which hadbeen observed in some operating steam generators. Subsequent tests with six AVB intersectionssimulated the excitation forces and fit-up conditions characteristic of advanced designconfigurations. Wear producing forces and motions were determined and recorded in the form ofworkrates that could be used for wear calculations. These workrates were verified by independenttesting on the same full-size tube using a simulated negative damping feedback loop as explainedin Reference 7-9 in addition to the original effective sinusoidal force simulation described inReference 7-8.Several overall conclusions from the test programs are important to subsequent discussion:1. The tests described in this section for triangular array configurations are most applicableto the evaluation of the SONGS steam generators. However, the methodology anddesign bases were originally developed for square pitch configurations based on earliertests. The limiting amplitude limited fluidelastic vibration mechanism leading to tube/AVBwear that is illustrated by large displacements and impact forces before significantturbulence interaction on Figure 7-5 affects a larger percentage of tubes in square pitchconfigurations.2. Displacements, impact forces, and workrates derived for wear calculations from theselaboratory tests are more modulated in steam generators with complex geometry andvariations in two-phase flow. This implies they are conservative for the range of testedconfigurations for the design purposes for which they were intended, but in that sensemay overpredict wear in steam generators.3. On the other hand, the range of tested tube/AVB support conditions tested for designpurposes does not cover the apparent range of support conditions implied from the ECTwear indications described in Section 5.1. In this sense, the test and design bases mayunderpredict the extreme wear in the SONGS steam generators.These factors are addressed more fully in Section 7.2.4.7.2.2 Westinghouse Design Basis7.2.2.1 Wear CoefficientsDetermination of appropriate wear coefficients is based on both extensive testing withinWestinghouse and correlation of results from licensees and external sources. Specific wearcoefficients for the Alloy 690 tubes (Kt) and 405 Stainless Steel (SS) TSP/AVBs (Ka) were derivedfrom all available impact/sliding wear test data. The median value of the wear coefficient for tubingwhen interacting with 405 SS from the raw test data was [ ]b.e. However, threeadditional factors are considered in establishing a calculation reference:1814-AA086-M0238, REV. 0Page 254 of 415 Page 254 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 20131. Raw data is typically based on extrapolating wear rates linearly from time zero throughconditions defined at the end of a wear test. This is typically conservative by factors of from2 to 4 depending on the material couple, test specimen surface conditions, environment,and test duration. In addition to an inherent minimum run-in effect, Figure 7-8 shows howinitial surface roughness can significantly increase the wear coefficient during initialoperation prior to achieving conformal wear between the tube and AVB such that thecoefficient is determined solely by the internal structure of the two materials. Correlation ofthe data from an early EPRI program (Reference 7-12) intended to characterize steadystate effects in prototypic SG environments with Alloy 600 tubing and 405 SS supportsyielded a median value of 69 (1012 in2/lb). More recent tests (Reference 7-12) withAlloy 690 tubing and 405 SS supports indicate an obtained value only two percent differentfor average wear coefficients for Alloy 690 than for Alloy 600 tubing. The significant wearobserved in the SONGS steam generators may not allow any normal surface films andoxides to develop such that higher coefficients would apply. Early tests sponsored byWestinghouse in which all surface oxides were removed during testing produced tube wearcoefficients that were [ ]b,e higher than the EPRI value intended for long-term lowlevel wear in prototypic environments.2. Following theory described by Rabinowicz (References 7-13 and 7-14), relative hardness ofthe tube and AVB (from chemistry and structure: not cold work) is an important factor indetermining relative wear effects. The harder of two materials generally wears less andhas a lower wear coefficient: a factor of three difference is common. This effect is part ofthe typical variability in wear coefficients of 16 (+/- 4 times). Apparent differences betweensome groups of data are consistent with relative AVB/tube hardness trends. []b e This indicates that actualtubing wear coefficients for similar AVBs could be expected to be higher than nominal. Theprocessing history and materials properties associated with the SONGS tubes and AVBs isnot known.3. Wear tests are necessarily more severe than service conditions in order to obtain results inreasonable test durations. Wear coefficients typically vary little with load over a broadrange of loading. However, classical wear theory indicates there is a load below whichburnishing or polishing will occur, but wear particles will not form. Loads measured duringshaker tests intended to conservatively simulate nominal operating conditions in advanceddesign configurations are about the same as this threshold. Thus, it is likely that the weartests with loads more than two orders of magnitude higher may be very conservativerelative to expected service conditions for advanced configurations with tight tube/AVB fit-up. On the other hand, for the specific SONGS evaluation with short-term wear, this factoris moot.Based on these considerations, a design value of]b,e1814-AA086-M0238, REV. 0Page 255 of 415 Page 255 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013On the other hand, nothing other than nominal drawing specifications is known about the actualstructure of the materials, the initial surface conditions, or the effect of severe wear interfering withdevelopment of prototypic surface oxides and films. Therefore, it is considered possible that anumber up to three or four times higher could be possible for the wear observed during the firstoperating cycle of the SONGS steam generators.The average ratio of AVB material wear coefficient to tubing wear coefficient in the originalimpact/sliding test data was 2.1. However, this data included much softer AVBs. Relatively harderAVBs that wear slower in the early stages are especially limiting if the AVB is not perfectly alignedwith the tube. Therefore, the AVB specific wear coefficient is typically considered to be the sameas the tubing for reference calculations, but is varied from 0.01 times (negligible AVB wear) up totwo times (more AVB wear than tube wear) in normal design calculations. Section 7.2.4 explainsthe approach taken for this evaluation.7.2.2.2 WorkratesWorkrates are scaled from baseline mechanical shaker test trends using inputs from qualifiedthermal-hydraulic and FIV analyses such as ATHOS/VGUB and FASTVIB as described inSections 3.1 and 4.2 for the SONGS RSGs. As noted in Section 7.2.1, vibration tests wereoriginally conducted to simulate tube/AVB interaction that occurred in earlier model steamgenerators that experienced moderate tube/AVB wear in less than seven years as described inReference 7-8. Wear producing forces and motions from these tests were assimilated in terms ofworkrate for use in calculating tube wear depth (Reference 7-10). The product of the normal forceand sliding motion during contact was numerically summed as a time integral to approximate theworkrate parameter used to quantify test results.Two mechanical shakers were used to excite the tube. Instrumentation used to measure forcesand displacements at the tube/AVB intersections included conventional force and displacementgauges in addition to light sensors that measured the small in-plane relative displacementsduring impact. Out-of-plane sinusoidal drive force simulated fluidelastic excitation, and randomforces in both out-of-plane and in-plane directions simulated turbulence. Various combinationsof tube/AVB clearances, force levels, tube/AVB contact impedance, and tube/AVB interfacefriction were tested.Initial tests simulated conditions representative of previous steam generator models to see ifworkrates consistent with field experience would result for expected operating conditions.Workrate trends and characteristics that were originally obtained using equivalent sinusoidalexcitation were also confirmed by additional simulated negative damping tests using the same testrig (Reference 7-9). After confirming the resulting workrates, which could explain the observedwear progression trends for conventional designs, additional tests were performed as a benchmarkfor advanced designs with shorter spans, better controlled tube/AVB interfaces, triangular pitchconfigurations, and AVBs with lower tubing wear coefficients. Shaker tests for the triangularconfiguration were done using a negative damping simulation since the reference design at thattime had staggered AVBs that intersected the tube at different locations on each side of the tube.Evaluating any other geometry, including tube row and AVB location, and any other flow field,requires adjustment of experimentally determined workrates using parameters appropriate to theconfiguration of interest. In this case, workrates for the SONGS steam generators weredetermined using scaling factors derived from analyses in Sections 3.3 and 4.3. This is done usingan equation that is a function of tube frequency, secondary fluid density, effective velocity of the1814-AA086-M0238, REV. 0Page 256 of 415 Page 256 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013fluid for the limiting vibration mode, fluidelastic tube excitation ratio, effective tube span length, andtube/AVB clearance as described in Reference 7-8. The form of this semi-empirical equation forpredicting workrates uses an analytical expression of the fluidelastic excitation force,F, = CfPoDU,2 { )- UC L.enthat is consistent with measured wind tunnel test results, taken together with experimental trendsdetermined in the baseline U-bend shaker tests. Overall results of the test program were providedin the form of workrate coefficients, Wr, for use in an equation of the formWR = WJf DF.where F, is the appropriate fluidelastic force calculated from the previous equation that is a functionof cross flow excitation. Values for the parameters are obtained from linear vibration analysesusing FASTVIB and the extracted ATHOS properties that have been interpolated using VGUB forthe tube as explained in Sections 3.1 and 4.2.Figure 7-9 shows schematically how workrates that are proportional to the fluidelastic excitationforce expression would convert increasing fluidelastic excitation into workrates that can be used inArchard's equation to calculate tube and AVB wear volume. Figure 7-9 is simply a normalizedrepresentation that uses the parameters obtained from ATHOS and FASTVIB to scale theconsequences of increasing the amplitude limited fluidelastic tube excitation ratio on the workrateafter impacting begins up to the point where turbulence effects could modulate the tube/AVBinteraction forces and displacements. Note that the sharply increasing trend with increasing flowwould start at a higher or lower value depending upon the available clearance.This semi-empirical formulation was developed to envelope workrates using interactionscharacterizing the tube/AVB interactions at up to three ineffective supports. Figure 7-10 illustratesthe typical logic diagram followed during design analyses. Figure 7-11 shows the basiccharacteristics of the measured workrate trends from U-bend shaker tests as described more fullyin Reference 7-10. The methodology uses the workrate trend ACDE on Figure 7-11 as thedominant characteristic of the limiting wear from amplitude limited fluidelastic excitation. Ittherefore captures the effects of increasing flow rates and increasing gaps due to wear on theexcitation and impact forces, but it does not explicitly calculate what is happening at the effectiveintersections on each end of a long span that would be unstable if the supports with large gapswere actually not present. For nominal tube/AVB gaps, the adjacent effective intersections mayindeed have higher initial workrates that could lead to gaps and longer spans as shown on the leftside of Figure 7-11. Thus, when performing normal design calculations, a range of potentialsupport conditions must be evaluated separately. However, as wear progresses for any givensupport configuration, the workrate at the large gap becomes limiting after some point illustrated byD on Figure 7-11. This methodology therefore does not explicitly calculate details of modalinteractions and detailed physics of the process for the entire tube, but it does follow the dominanttrend for the mechanism that can lead to rapid wear in tubes with ineffective supports from largegaps that allow amplitude limited fluidelastic rattling within the clearances. The semi-empiricalmethodology takes workrates that include all nonlinear interactions present in the shaker tests,scales them to levels appropriate to the design being evaluated using results of thermal-hydraulic1814-AA086-M0238, REV. 0Page 257 of 415 Page 257 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013and linear FIV analyses, and preserves the mode shape for the unstable frequency as wearprogresses.For fundamental modes resulting from multiple consecutive gaps, wear progresses at the firstsupport with tube/AVB interaction, depending upon the mode shape and the existing gaps, tointeraction with successive supports as the tube amplitudes fill the gap as it grows from wear atboth the tube and the support. If more ineffective locations with gaps are involved in aconfiguration being evaluated, the first three to interact depending upon the gaps and relativemode shapes can be evaluated. The total workrate that is available to wear the interacting sites(WR) is determined by scaling the characteristic workrate trend from shaker tests (Wr) using theexcitation force (F,) apportioned to the various intersections to preserve the fundamental modeshape. Sharing among the different intersections depends upon whether one, two, or threeintersections are wearing at the same time as illustrated on the right side of Figure 7-11. Thisprocess is sensitive to the mode shape and the gaps at the three intersections such that wearbegins, pauses, or stops at any given location to preserve the dominant mode shape.One additional factor has a significant effect on the depth of wear at an intersection. If the tube isoff-centered more than []b.e and relative workrates were confirmed during the shaker tests to beabout twice as high for single-sided interaction on one side of a tube as for splitting the availableenergy to wear both sides of the tube at the same intersection. Current coding allows either choicefor all sites, but all intersections in the configuration being evaluated must be either single- ordouble-sided.7.2.2.3 Depth- Volume RelationshipDepth-volume relationships are calculated based on tube and matching support geometricrelationships (Reference 7-15). Figure 7-12 illustrates those applicable to 0.750-inch diametertubing (Reference 7-16B through 7-16D) and 0.59-inch wide AVBs (Reference 7-16H) for variousdegrees of twist. Note that there is almost an order of magnitude difference in the depth of thecombined tube and AVB wear that results from the volume removed from wear required to reachthe dashed line that represents 40% through-wall (TW) for the 0 to 4 degree range illustrated onFigure 7-12. The factor is even higher for smaller wear depths, e.g., about 25 at 10%TW. Therelative factor for the tube alone depends upon the size of the corner radius and the relative tubeand AVB wear coefficients in addition to the unknown degree of actual twist.7.2.3 Operational History of "Plant B"Figure 7-13 shows the general arrangement of the tube bundle support structure, and Table 7-1provides a summary comparison of design features for the Westinghouse steam generators thatare most comparable to the SONGS steam generators evaluated in this document. The SONGStube bundles have a maximum radius that is about 3 percent larger with a smaller pitch/diameterratio, but Plant B has about 9 percent more, with smaller and more flexible tubes. The straightleg tube support structures are similar with broached trifoil 405 SS support plates having flat tubecontact lands and similar clearances to constrain tube motion. The SONGS plates are thicker,but the range of contacting support land lengths can actually be smaller for the thicker plates dueto the tolerances on shaping the holes. Both designs have a first span above the tubesheet that1814-AA086-M0238, REV. 0Page 258 of 415 Page 258 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013is close to the nominal span length for the rest of the straight leg. This is not common forWestinghouse designs, but it tends to make the comparison more consistent.The U-bend tube support structures are similar in many respects, but markedly different in onethat has several ramifications. Both have V-shaped AVBs made of 405 SS with similar tighttube-to-AVB clearances if welded at the nominal TSP pitch spacing. However, the SONGSbundles have a different AVB configuration that has two sets of AVBs on each side of thecenterline and two sets centered in the middle (the conventional way). This design necessitatesan extra orthogonal bridge structure to keep the off-centered sets in place. This extra weight andattachment to the longer AVBs at a 15-column spacing introduces new reactions during rotationsthat are necessary during fabrication as well as added weight on the bundle in the installedRSGs. The Plant B configuration has five sets of AVBs with the bends all centered in the bundle,but alternate columns have staggered insertion depths to reduce the pressure drop for flowthrough the U-bend. The U-bend region of the Plant B steam generators extends beyond the topTSP about six inches more than the SONGS RSGs in spite of the larger maximum radius of theSONGS tubing. This is a consequence of the smaller indexing between tubes in the samecolumn for SONGS with comparable values for the same radial zones included in Table 7-1.This spacing and the tubesheet drilling tolerances at the bottom of the table are discussed furtherin Section 8.2.1.At the time of the last operating cycle that included an ISI inspection of the tubing, Plant B hadoperated for 6 cycles accumulating 8.1 effective full power years (EFPY). Figure 7-14 shows acomparison of the average number of tube/AVB wear indications for the two Plant B steamgenerators compared to the averages for SONGS Units 2 and 3 using data taken fromReference 7-17. Plant B is the only domestic steam generator with advanced U-bend supportsystems that were developed in the 1980s that has significant U-bend wear. However, it is smallwhen compared with the SONGS experience, and Plant B is currently operating for multiple fuelcycles between inspections.a,e7.2.4 Application to SONGS Steam GeneratorsThe semi-empirical wear calculation methodology developed for design as described inSection 7.2.2 and based on testing described in Section 7.2.1, was adapted for characterizingthe SONGS tube wear experience. It includes projecting expectations for future operation atdifferent power levels. The only change to the structure of the coding was to allow continued1814-AA086-M0238, REV. 0Page 259 of 415 Page 259 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013operation from an existing conformal tube/AVB wear geometry developed during an earlier timeperiod with a different excitation level for the new time period. Without this change, the highlynonlinear effects of beginning with a fresh tube and AVB depth-volume relationship as shown onFigure 7-12 would have prevented meaningful extrapolation of continued operation of theexisting steam generators. The other significant change was in the approach to accomplish adifferent objective; i.e., continued operation versus evaluation of a new design.Normal design practice involves definition of ranges of potential parameter variables andtube/AVB geometry configurations and then demonstrating that the maximum tube wearconsequences are less than a design margin. For the SONGS application, the resulting weardistribution after a cycle of operation is known, or can be inferred from existing ECT data, but forany given tube, there are many parameters that resulted in the wear distribution that areunknown. For example, neither the tube nor the AVB wear coefficient is known except over arange of possibilities for the two materials (Alloy 690 TT tubing and 405 SS AVBs). Whether theinferred tube wear distribution has less wear on the AVB, equal wear on the AVB, or more wearon the AVB markedly affects the combination of other parameters that would produce the sametube wear depth distribution. It can be assumed that the tube and AVB surfaces will not havesignificant run-in effects (see Figure 7-8) for the first cycle of operation, but even this assumptioninvolves a potential error of several hundred percent. Most importantly, the tube/AVB geometryis expected to be different than the original design intent, but all that can be inferred with theavailable information is the minimum length of the dominant tube vibration span. In the largestsense, the answer (wear distribution) is known, but the inputs are unknown.Based on the testing and design basis methodology described in Sections 7.2.1 and 7.2.2, thedominant flow-induced vibration mechanism leading to the observed tube/AVB wear in theSONGS steam generators is considered to be amplitude limited fluidelastic vibration withcharacteristics as shown on Figures 7-5 and 7-9. Based on the findings of the SCE root causeevaluation (Reference 7-18), the possibility of in-plane (IP) fluidelastic instability leading to tube-to-tube wear must also be precluded in this overall evaluation. Even though Westinghouse testshave never produced an IP instability for any U-bend configuration, initial calculations inReference 7-19 and in Section 4.3.2 used a very conservative threshold IP instability constant,I ]b.e, equal to the lower bound OP constant, [ ]b.e, to address that objective. Inorder to address concerns about IP instability potential that are not based on such a conservativeassumption, recent tests by Pettigrew et al (Reference 7-20) were reviewed, and the test resultsshown in Figure 7-5 were extended and modified as shown on Figure 7-15.Previously, displacements and impact forces were shown on Figure 7-5 only out to about twicethe OP tube excitation threshold. Figure 7-15 includes the same data that was recorded for thefull range of tests out to more than four times the beginning of OP tube excitation. Significantmodulation of both displacements and stresses occurs after []b,e In tests with all U-bendtubes loosely held during testing, Pettigrew et al (Reference 7-20) obtained IP instability at abouttwice the OP tube excitation threshold with [ ]b,e.Westinghouse tests on triangular pitch U-bends had been tested for flow rates only up to about1.7 times the threshold that first caused tube excitation in the out-of-plane direction.when alltubes were non-supported or loosely constrained as in the cited Pettigrew (Reference 7-20)tests. This is illustrated schematically on Figure 7-15 in the upper left corner. Therefore, it is1814-AA086-M0238, REV. 0Page 260 of 415 Page 260 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013theoretically possible that a bundle with many tubes subject to many loose support conditions inmany adjacent tubes could develop IP instability for flow excitation that exceeds twice the OPthreshold (consistent with the Pettigrew citation and not disproved by the Westinghouse testswith all tubes loosely constrained). For the Westinghouse tests with all tubes loose, the actualthreshold was]b,e. Iftwice the minimum P3op obtained from Westinghouse tests were to be used for Pip (as in theReference 7-20 Pettigrew citation), then the implied in-plane instability constant, P3ip, would be]b.e, a number much larger than the Reference 7-20 value. Since this would likely invitequestions about using a best-estimate Westinghouse value compared to the reported Pettigrewvalue of 7.1, a more conservative value of [ ]be is used in subsequent evaluation ofIP instability for this evaluation as explained in Section 8.1. This value is []b,e still considered a very conservative basisrelative to Westinghouse data.Calculation of tube/AVB wear for SONGS Unit 2, before occurrence of any IP instability asprecluded by explanations in Sections 7.3 and 8.1, follows the semi-empirical methodologyadapted as described earlier in this section to continue from the end of Cycle 16 interfaceconditions. The process can be illustrated by an example tube for which ECT indicates wear atintersections with AVB4 and AVB5. The first step is to adjust the raw ECT indication to cover therange of bobbin coil uncertainty using the equation from Reference 7-21Wi = 0.98ECTi + 2.89where WV is the wear for eddy current indication ECT, at the tube intersection with AVB i. ThenFASTVIB solutions for various cases of postulated missing AVBs as described in Section 4.2 arereviewed to obtain the case with the lowest number of missing AVBs that is unstable in the OPdirection. Values for the reference density, po, modal effective velocity, Uen, tube excitation ratio,ER=UJIUcn, and modal effective length, Len, are then extracted for use in the fluidelastic forcescaling equation defined in Section 7.2.2.2. These values, along with the corresponding modalfrequency for the unstable mode, fn, are then used in the equation to scale the U-bend shakertest reference workrate, Wr, to obtain the workrate, WR, applicable to the SONGS flow excitationand support configuration being evaluated.The semi-empirical wear calculation procedure apportions the overall workrate available for thelimiting vibration amplitude determined by Ce among the interacting AVBs depending upon therelative clearances at each intersection. Figure 7-16 illustrates this example with a postulatedset of initial clearances that could have produced approximately equal wear at AVBs 4 and 5.Following the observed trends for displacements to fill the available clearance as shown onFigure 7-5, amplitude limited vibration occurs with the overall workrate applied at the firstintersection to interact with the dominant unstable mode. Wear progresses at that AVB until theclearance becomes big enough from combined wear at the tube and the AVB to allow thedominant mode to begin impacting at the second AVB. As shown on Figure 7-16 the workratesand wear volumes at AVBs 4 and 5 will be about equal to half the total amount that is possiblefor the configuration being evaluated.If the observed ECT wear indications are not equal, the postulated initial gaps can be changed tomake the site with the highest wear closer than the other and wear longer than the second sitewith all the energy on the first until impacting at the second begins. Wear volumes at each site1814-AA086-M0238, REV. 0Page 261 of 415 Page 261 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013are converted into depths (for both tubes and AVBs) following the selected correlation fordifferent degrees of twist from Figure 7-12. A manual, iterative "tuning" process then apportionsthe available energy to produce the relative wear depths observed from ECT. These depths,which have been tuned to match the observations, could have been obtained with many differentcombinations of wear coefficients, amounts of AVB cross-sectional twist, workrate trends(nominal or maximum to cover individual tests), single-or double-sided interaction choices, andvarious factors of uncertainty on FIV parameters. After achieving wear at both sites consistentwith ECT after Cycle 16, the combination that produced the result can be held constant whileevaluating various excitation levels for subsequent operation using FIV scaling parameters fromFASTVIB calculations based on appropriate part load ATHOS analyses. This is the approachthat has been used to obtain results described in the following Section 7.3.When choosing a set of initial conditions for observed wear at AVBs 4 and 5, it is also possiblethat a different FASTVIB case corresponding to a different span length with more than two AVBshaving ineffective supports. Figure 7-17 shows one such possibility with similar clearances thatcould have existed at AVBs 3, 4, 5, and 6, but the wear during the first cycle did not progressdeep enough to lead to interaction at AVBs 3 and 6. An entirely different set of geometric andmaterial parameters could be used with this case to tune the computed wear at AVBs 4 and 5 tomatch the observed wear. Then, this new combination could also be used to projectexpectations for future operation at different levels of excitation.There is no appropriate way to know what the correct combination of geometric and materialproperties is for various tubes in the SONGS steam generators. Minor differences in theprojections for wear in Cycle 2 have been obtained when making limited comparisons of differentcombinations, but in all cases the differences would not impact a decision about the appropriatechoice of future operating levels as indicated by results in Section 7.3. There is insufficient dataavailable to make statistical arguments about precision. However, this methodology followsdominant trends of the mechanism considered to be the source of the observed tube/AVB wearin the SONGS Unit 2 steam generators. It takes the available energy arising from constrainedamplitude fluidelastic excitation for any support configuration, matches the starting levels of wearfor subsequent operation, and allows rapid evaluation of the relative effects of many variables.As concluded in an earlier evaluation for three specific tasks (Reference 7-19), the geometrictube/AVB interaction conditions must be outside the range of expectations during the designphase, but all tubes above about Row 100 could have significant wear for multiple ineffectiveAVB intersections. The greatest uncertainty in these calculations is considered to be theappropriate geometric parameters to apply. No attempt has been made to guess the applicabilityof any of the variables to unknown conditions inside the SONGS steam generators in thefollowing evaluation. Any range of selected variables to be imposed could be evaluated, butsuch an effort would have a different objective and would be beyond the scope of assessingconsequences of operating at different power levels in the near-term future.7.3 Tube Wear Projection ResultsData files for SONGS Unit 2 steam generators SG 2E088 and SG 2E089 that were available atthe beginning of this study (those used for Reference 7-17) were reviewed and sorted to obtaingroups of tubes having maximum wear in three different categories based on bobbin coil ECTresults from the ISI inspection following the first cycle of operation. The three categories were:1814-AA086-M0238, REV. 0Page 262 of 415 Page 262 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 20131. Tubes with 0-9 percent wear,2. Tubes with 10-19 percent wear, and3. Tubes with wear equal to or greater than 20 percent.This ranking was performed for both Unit 2 steam generators separately for both active andplugged tubes. Then each category within each group was further subdivided by matching thenumber of consecutive AVB intersections having wear to the appropriate FASTVIB case7 takenfrom Section 4.3.1 out-of-plane tube excitation ratio results. These subdivisions were thensorted to allow selection of the limiting case with maximum wear for each support condition.Wear calculations were performed for limiting tubes as described in Section 7.3.1 for remainingactive tubes and in Section 7.3.2 for tubes which have already been plugged, but are still in thesteam generators.7.3.1 Active TubesTable 7-2 shows the tubes with indicated wear greater than or equal to 20%TW and ECT bobbincoil data that was used to define limiting tubes. Maximum wear values for each tube are shownin bold font. Tubes that were selected as being limiting have row and column numbers shown inbold font. SG 2E089 was evaluated first. Only one additional tube from the SG 2E088 list hadnot already been enveloped in this preliminary evaluation. The referenced FASTVIB analysiscase is listed in the next to last column with additional cases covering postulated cases toaddress consequences of continuing wear leading to longer effectively unsupported spansshown in the last column. Yellow shaded locations were used to define the postulated additionalcases before starting analyses. Amber shading shows cases added during evaluation. Resultsof additional ECT evaluations done with RPC and +Pt coils that are described in Section 5.1were not available in time to affect choices for limiting cases documented in this preliminaryevaluation. Locations with low level wear based on these additional ECT evaluations as shownon Table 5-2 have been added to Table 7-2 to indicate which have already been covered andhow best to update preliminary analyses for the final report. In most cases, consideration of theadditional shallow wear scars simply moved the configuration to another location in the table thathas already been enveloped.Active tube analyses documented in this preliminary report were done based on the assumptionthat Cycle 16 operation for 22 calendar months was at full power conditions covered by theATHOS analyses in Section 3.2. ECT wear indications were then adjusted to cover uncertaintyin the bobbin coil data, and wear calculation parameters were adjusted to match the targetdistribution as described in Section 7.2.4. Then calculations were made for subsequentoperation at different power levels for an additional 18 months. Results of these extendedcalculations were also extracted after 6 months into the new cycle for use in assessing wearpotential at an interim ISI inspection currently planned to occur within that time. After completionof these analyses, the duration of Cycle 16 was determined to be 627 effective full power days(EFPD) which corresponds to 20.6 effective full power months (EFPM), so these preliminaryresults were re-evaluated for the final report. The effect of this difference was shown to be smallas indicated by final results added to the plots referenced in the following discussion.7 Table 4-1 provides a detailed description of the 79 cases including definition of which AVBs areinactivated for the FASTVIB analysis of each case.1814-AA086-M0238, REV. 0Page 263 of 415 Page 263 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Figure 7-18 shows the results of wear calculations for the first limiting SG 2E089 tube onTable 7-2 in a format that is repeated for several others. The first 22 months on the abscissa arefor Cycle 16 operation. Both the raw ECT values and the higher target values intended to coverthe bobbin coil uncertainty are shown on the plot above the 22 month time. The degree to whichthe wear calculations match the observed wear distribution can be judged from the plot(s).Times after 22 months are for continued operation at various power levels with results tabulatedfor both the planned interim ISI after 6 months and at the end of an additional 18 monthsoperation. Only two AVBs were considered ineffective when defining the reference FASTVIBCase 17 and the tube excitation ratio was close to, but not above, 1.0. The semi-empiricalmethodology treating amplitude limited fluidelastic vibration excitation only applies forconfigurations with tube excitation, so a 1.3 factor was applied to include the potential range ofuncertainty normally considered possible from mass density distribution approximations ordamping uncertainty. This made the Cycle 16 loading produce tube excitation, but all other partload conditions did not. The same R131C91 tube was then evaluated for Case 38 whichassumed that there could have been a gap at AVB7 also such that there were actually 4ineffective AVBs with large gaps with results shown on Figure 7-19. These assumptions changedetails of wear calculations, but do not appreciably change projections beyond the target valuesbecause all the input parameters for both cases have been tuned to produce the same overallenergy or workrate applied over 22 months to reach the same target before extending to furtheroperating times at other load levels.Figure 7-20 shows similar preliminary calculations for a reference Case 28 applied to theR129C93 tube with alternative calculations for Case 46 shown on Figure 7-21. These resultsactually targeted the same wear distribution on Table 7-2, but the target was shifted as if thewear had occurred at AVBs 5 to 7 rather than 6 to 8, so a new reference Case 29 with analternative Case 47 were evaluated for this final report at the same time that the adjustment for20.6 months rather than 22 months in Cycle 16 is made.Figures 7-22 and 7-23 show reference and alternative calculations for R126C90. Figure 7-24shows reference calculations for R121C91, one of the two tubes with 28%TW maximum ECTvalues among the remaining active tubes. Three different alternative Cases 45, 46, and 53 wereevaluated for this tube with a comparison of results for all four cases for the 80% part load levelof excitation shown on Figure 7-25. The maximum projected additional wall loss after 6 monthsof operation at a part load level of 80% does not exceed [ ]a.c.e and variesonly from [ ]a,c,e. Operation at lower part load levels resultsin even less potential. Figure 7-26 shows the reference calculations for R1 19C89, the other tubewith 28%TW maximum ECT indicated wear. Calculations for the alternative Case 54 are notplotted, but projections of potential additional wear are very similar to the reference whenprojected. Table 7-3 provides summary results for these active tubes and the limiting tube forSG 2E088 along with results of plugged tube calculations that are discussed in the nexttwo Sections 7.3.2 and 7.3.3.7.3.2 Plugged TubesWear calculations for further operation of plugged tubes were done after learning that Cycle 16covered 20.6 rather than 22 EFPM, so these analyses used an availability factor built into thecoding to obtain a better match for the starting conditions for Cycle 2 operation (factor of20.6/22 = 0.936). This procedure imposes the same factor on subsequent operation such thatthe maximum length of Cycle 2 that is already covered by preliminary calculations is 0.936 x 18 =1814-AA086-M0238, REV. 0Page 264 of 415 Page 264 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 201316.8 EFPM. For this report, only calculations at 0.936 x 6 = 5.6 EFPM are consistentlydocumented for all cases, but all intermediate calculations at half-month intervals can beextracted from the output. Limiting results were added to each of the tables on the plots for thelocation with highest wear. These analyses were also performed using active tube mass densitydistributions since the FASTVIB analyses described in Section 4.3.3 demonstrated this approachis conservative relative to plugged tubes with stabilizers considering the mass of the stabilizerswith no additional damping contributions.Table 7-3 includes results for both plugged and active tubes. Projections for additional wearpotential are similar except that a few of the plugged tubes could have slightly higher wearpotential as might be expected for those that were preventatively plugged after the first cycle ofoperation. The highest projection of additional wall loss is still not more than 0.0012 inches(1.2 mils).7.3.3 Rl11-113/C81 Tube/AVB Wear ResultsTwo of the preventively plugged tubes had free span indications that were considered topotentially represent the presence of conditions that lead to more severe tube-to-tube wear inUnit 3 steam generators. They have therefore been much more extensively evaluated in manyrespects such as in Sections 5.1, 5.2, 8.1, and 8.2 for this evaluation. Indeed, these two tubesare the only potential connection of Unit 2 experience with all the in-plane instability concernsarising from extensive tube-to-tube wear observed in Unit 3. Both Tubes Ri11C81 andRi 13C81 were preventively plugged because of this concern even though the tube/AVB wearwas not above 20%TW for either tube.Table 7-3 has four sets of calculations for the Ri11C81 tube that envelopes the adjacentR1 13C81 tube with regard to tube/AVB wear. The maximum raw ECT value was 18%TW with atargeted wear depth of 20.5%TW to cover the bobbin coil uncertainty. Continued operation atthe same Cycle 16 loading would produce an increase only to [ ]a'c'eTW for the referenceFASTVIB Case 38 and only to [ ]a'c'eTW using the first mode of alternative Case 67. Theconfiguration evaluated for the reference case has 6 ineffective AVBs and the alternative has 8ineffective AVBs. For tubes with 4 or more ineffective AVBs, more than one OP mode isunstable at the same time. The reference shaker tests that defined the baseline workrate trendsfor scaling using FIV calculated parameters did not include such severe loading: no multiplemodes, and no background simulated turbulence that would be consistent with such highloading. There was no incentive to develop such bases for design, so how to combine multiplemodal effects in wear calculations is not clear. If each mode is treated separately, the first modeis limiting. If both modes are evaluated as for the first and second modes in Case 67 for thistube, two sets of comparable numbers are obtained as shown, but the second mode producesmore wear at AVBS 5, 6, and 7, while the first was at AVBs 6, 7, and 8. Two of the locationstherefore have significant contributions from each mode. Although not shown in the table, if theyare summed and then scaled to match the observed ECT and wear targets, the projected growthis less than shown for either case separately. However, if the effects are summed as wouldseem reasonable, the underlying parameters required to produce the observed wear would besmaller, i.e., much smaller gaps would produce the combined wear. This observation is notgermane to projections, but could be important if using the methodology for other objectives. Forpurposes of this evaluation, the two tubes in SG 2E089 with free span indications have muchless tube/AVB wear potential during subsequent operation than the limiting plugged tubesdiscussed in Section 7.3.2.1814-AA086-M0238, REV. 0Page 265 of 415 Page 265 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 20137.3.4 Potential for Increased Probability of IP Modes after WearIt has been determined that all active tubes would be expected to be stable in the in-planedirection during the next cycle of operation. The analysis considers the current AVB supportconfiguration and various potential future power levels of operation. It must be noted that evenat operation at the 100% power level used in Cycle 16, the remaining active tubes are stable inthe in-plane direction.In order for an in-plane mode to develop during the next cycle of operation it would be necessaryfor at least one of several changes to take place versus the conditions that existed during the firstcycle of operation. These changes include:1. SG operating conditions that would increase the likelihood of IP stability.2. Changes in tube support condition due to tube wear.With respect to the effects of changes in operating condition, it has been shown in Section 4.0that decreasing the power level has a large effect on decreasing both the out-of-plane and the in-plane stability ratio. Power reduction from 100% to 70% power effectively reduces the potentialfor in-plane instability by about half. Since power levels of this magnitude are being consideredfor the next cycle, the potential for a reduction in IP stability ratio is a more likely outcome. Itshould be repeated that the eddy current analysis of tube wear in Unit 2 has not found anyindications of wear that would indicate in-plane instability is occurring in these SGs. Therefore,reducing the power level would further reduce the potential for an event that has not yet beenobserved in prior operation.With respect to tube support conditions, the effects of additional wear on the tubes that couldoccur during the next cycle were also considered. It should be noted that any additional wear atexisting wear sites would not affect the boundary conditions for that tube since the AVB at thatparticular location would already be ineffective. Increased gaps at these locations wouldincrease the rate of wear, but the tube was already unstable in the out-of-plane direction;therefore. that would not change the boundary conditions of that tube. As indicated in the priorsections, any tube wear that has been projected to occur over the next cycle of operation hasbeen calculated to be very small. Calculations indicate that the amount of tube wear that couldoccur would range from [ ]a,c,e for the most limiting tubes at the mostlimiting location. The most limiting location on any give tube is the location with the largest weardepth at the end of the last cycle of operation. Should wear begin to occur at a new locationalong the tube, then a change in the tube boundary condition could potentially occur with thattube. However, the rate of wear at that new location (with no current wear) would be much lessthan what has been calculated at the limiting location. This is a result of how the tubes wearwhile unstable in that the available energy tends to focus at the location with the largest tubegap. Should any wear develop at that new location, the amount of wear would be much lessthan the maximum amount of wear calculated for the next cycle of operation with expected levelsof wear [ ]a,c,e. Gap changes of this magnitude are considered to be so smallas to be negligible as it relates to support of the tube.In conclusion, the potential for in-plane stability to develop over the next cycle of operation is notconsidered credible for several reasons. First, the power level reduction (to 70%) powereffectively reduces the IP stability ratio by about half and that reduces the potential for any IPinstability to develop versus the response during the prior cycle of operation. Also, it has beennoted that the potential for any wear to begin to develop at currently effective AVBs is considered1814-AA086-M0238, REV. 0Page 266 of 415 Page 266 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013to be negligible and will not affect the boundary conditions at those sites. Therefore additional,modes will not become active and result in in-plane instability.7.4 Potential for Wear on AVB Surfaces7.4.1 Tube FIV Induced WearThe methodology used to evaluate maximum tube/AVB wear potential simultaneously calculatesthe conformal wear in both the tube and AVB. Results that have been discussed to this pointhave used input wear coefficients that maximize tube wear and minimize AVB wear. Thereverse could be done, or any other combination of relative wear could be prescribed. In typicaldesign calculations based on experience with Westinghouse AVB material and processinghistory, equal tube and AVB wear coefficients are typically used with a check for variabilityeffects in either direction (up to AVBs having twice the tube wear coefficient). It is not likely thatthe AVBs would wear significantly more than the tubing, and they are significantly thicker thanthe tubing wall thickness, so this is not a major concern for near-term operation.7.4.2 AVB FIV Induced Wear PotentialOn the other hand, there is a potential that AVBs can vibrate and cause tube wear if long,unsupported spans are created inside the bundle. The SCE root cause evaluation(Reference 7-18) concluded there was no indication of AVBs vibrating and causing tube wear.However, there are several instances of AVBs having 15 or more consecutive tubes in a columnwith wear indications. As a result, an additional evaluation including review of all available ECTdata including any RPC evidence was performed. Table 7-4 provides a summary of the resultsfrom that additional review for Column 81 in SG 2E089. There are 20 consecutive tubes in thissame column having wear scars along AVB 7. AVBs 5, 6, 8, and 9 have similar sequences ofmultiple scars on every tube in this column. Reference 7-23 describes two types of gallopinginstability that are possible in bluff structures that are exposed to cross-flow excitation that ismostly parallel to the width of the cross section (such as these AVBs with long spans). Thewidth/thickness aspect ratio of the SONGS AVBs are shown to be inherently stable against theplunge type of galloping instability using quasi-steady evaluation of how the lift and drag forcesvary with the angle of attack of the flow. Evaluation of potential torsional instability using thesame theory is more complex, but review of ECT results in Table 7-4 demonstrates that oppositeedges of the AVBs are not impacting the tubes because the consecutive wear scars arepredominantly flat. Torsional instability would produce multiple hourglass wear scar profiles.Therefore, it is concluded that the AVBs are not likely responding in any kind of aerodynamicallyunstable mode, but they are likely vibrating as a response to flow turbulence and reactions toimpacts from other tubes in the same column due to gap-limited fluidelastic vibration in theregions having many consecutive intersections with significant tube wear. AVB displacementsdue to longer spans in turbulent flow, combined with reactions from simultaneous impacting fromup to 19 other tubes provides additional relative tube/AVB sliding motions during impacting dueto gap-limited fluidelastic excitation that exceeds levels that were included in the baseline shakertests. However, the process of matching the observed wear as a starting point for projectionswould account for this potential by choosing a set of parameters that produced the workratesnecessary to produce the observed wear.1814-AA086-M0238, REV. 0Page 267 of 415 Page 267 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 20137.5 Potential for Additional Tube-to-Tube Wear at Rl11/113C81Eddy current tests indicate that 14% through-wall tube wear has been found8 on both R111C81and R113C81 in SG 2E089 with the wear located between AVB9 and AVB10. Subsequent UTmeasurements indicate that the tube wear was closer to 7% through-wall. Although there is noevidence of in-plane displacements (e.g., no tube wear at an AVB was identified that extendsoutside of the AVB width), a concern has been expressed that this tube wear could have beencaused by tube-to-tube contact from in-plane displacements associated with active in-planefluidelastic instability. Further, there is a concern that additional wear at this location could resultin significant degradation of the tubes during future operation.The following wear indications were reported based on the bobbin data. It should be noted thatshallow AVB wear indications were also reported at B08, B09 and B10 on R113C81 and at B09on Rl11C81 based on a detailed review by Westinghouse of the +Pt data. However, theevaluations described herein are based on the bobbin data.Reported Wear Indications Based on Bobbin DataSG Row Col B12 811 BIO FSc B09 B08 807 806 805 804 B03 B02 B0189 113 81 14 5 5 1689 111 81 7 14 18 13 8 14The tube most likely to become excited by the secondary side flow would be RI 11C81 since thisis the tube with the most sequential ineffective AVB supports. Wear calls have been reported atAVB 5 through 8, which could imply up to four sequential ineffective AVBs. The FASTVIBcomputer code was used to evaluate this case (Case 38) where four AVBs are sequentiallymissing starting at AVB5. An additional case has also been considered to address the possibilitythat significant wear is not occurring at AVB9, but that the AVB is still an ineffective support.Should this be the case, which is consistent with the RPC data, it would be possible that up to sixsequential AVBs would be ineffective for this tube. This would include AVB5 through AVB10.This case (Case 55) was also considered in the FASTVIB analysis. Calculations for a third andfourth case, which considered seven and eight sequential AVBs ineffective (Case 62, 61 and 67)were also performed. The following is a summary of the in-plane excitation ratios calculated forthese cases:8 See Section 5.2 regarding the eddy current resolution of these indications.1814-AA086-M0238, REV. 0Page 268 of 415 Page 268 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Summary of In-Plane Excitation Ratios100% Power 80% Power 70% PowerCase Number of Stability Ratio Stability Ratio Stability Ratio(With Stabilizer) (With Stabilizer)a,c,eCase 38 4 1-- -Case 55 6Case 62 7Case 61 7Case 67 8As can be observed, these tubes are stable in-plane for the 100% power case until it is assumedthat seven AVBs are missing. All cases are stable at reduced power levels. The cases for 70%and 80% power were calculated assuming a cable stabilizer was installed in the tubes.Calculations performed for in-plane instability used Beta values that are consistent with the out-of-plane direction and are considered to be conservative values for use when looking at the in-plane direction. However, if best estimate Betas would be used, the calculated stability ratiowould be less than 1.0 even for the case of 7 or 8 missing AVBs. If a Beta of []a.c:e is used, the largest IP stability ratios for 8 missing AVBs would be approximately]a,c,e. Therefore, missing 2 additional AVBs beyond the 6 indicated by bobbin/RPC wouldindicate the tube with the tube-to-tube wear was stable in-plane during the last cycle. In addition,any motion that would result in wear at the tube-to-tube contact site would also likely be evidenton at least the two nearest AVBs (AVB9 and AVB10). No indications of wear were found outsidethe location immediately below these AVBs (or other AVBs on these tubes), which indicates thatmotion in the in-plane direction at the tube-to-tube wear site also would not be occurring. All theother characteristics of indications for these two tubes are more consistent with proximity issuesthan with IP motion issues.Note that the additional mass of the stabilizer was conservatively included in the calculation, butany additional damping was not included in the calculation based on the damping test resultsfrom MHI (Reference 7-22).The analytical calculation indicating stability in the in-plane direction is supported by eddy currentdata at the AVB/tube contact locations. Since any in-plane motion would also produce wearextending outside the AVB and no such indications were found, it strongly suggests that vibrationof the tube in the in-plane direction is not occurring for this tube. It should be noted that wear isoccurring in the tubes directly under the AVB location, which is not unexpected for the AVBsupport configurations considered possible from the ECT results. Wear outside of AVBs was notcharacterized in the results files for Unit 2. A comparison of the RPC and bobbin wear reportsfor Unit 3 indicates there are many non-reported bobbin indications at AVBs within tube-to-tubewear regions. The tube-to-tube wear (TTW) likely is overpowering the bobbin signal. Acomparison of the Unit 2 and Unit 3 combined bobbin/RPC results suggests there is a detectioncapability difference between the two units, most likely from the TTW overpowering bobbin AVBwear signals. Since there is not significant TTW in Unit 2, the bobbin detection is not affected.1814-AA086-M0238, REV. 0Page 269 of 415 Page 269 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013In conclusion, the Westinghouse review of the Unit 2 wear signals confirmed that no wearextends from the AVBs.The following is a summary of the out-of-plane tube excitation ratios for the cases of interest:Summary of Out-of-Plane Tube Excitation Ratios100% Power 80% Power 70% PowerCase Number of Tube Excitation Tube Excitation Tube ExcitationMissing AVBs Ratio Ratio Ratio(With Stabilizer) (With Stabilizer)Case 38 4Case 55 6Case 67 8From the above, it can be concluded that the tube was most likely excited in the out-of-planedirection and that out-of-plane tube excitation produced tube wear at the indicated AVBs. Shouldthe actual support condition at Ri 13C81 include six or more ineffective AVBs, then it is verylikely that additional wear at the indicated AVB locations will occur even at reduced power levelsas a result of out-of-plane tube excitation.There is no analytical or eddy current evidence to suggest that in-plane instability ordisplacements are occurring at these tubes. The two tubes with TTW in Unit 2 are located in thesame region as the large number of tubes with TTW in Unit 3. This is the only commonality withthe Unit 3 TTW findings that is currently known. Westinghouse is not aware of any assessmentthat concludes the Unit 2 TTW is a result of in-plane instability. However, if another assessmentcan be provided that shows IP instability for the Unit 2 TTW, then Westinghouse could reviewand comment once the data is provided. However, the question remains regarding the possibilityof future wear between these tubes. The following provides a basis to conclude that significantTTW wear will not occur at this location during the next operating cycle.Eddy current results described in Section 5.2 indicate that tubes R111/C81 and R113/C81 arecloser than what is specified in Design Drawing L5-04FU053. When this occurs, it is generallytermed a proximity condition. The nominal gap between the Row 111 and Row 113 tubes inColumn 81 increases from 0.25 inches in the straight leg to 0.344 inches at the apex of the U-bend. However, the Pre-service Inspection (PSI) eddy current results show a "proximity" callbetween these tubes, and are discussed in more detail in Section 5.2. Based on the eddycurrent results from the PSI, the proximity call indicates the outer diameters (OD) of the twotubes are very close to each other.Figure 7-27 contains a view of how tubes R1 110C81 and Ri 13C81 could have developed a closeproximity condition between AVB 9 and 10. U-bend tubes are thought of as components that areessentially perfect half circles with straight legs attached. However, in practice there is always adegree of flexibility and non-uniformity, especially in tubes with large radius U-bends. TubeR111C81 has a bend radius of 60.77 inches, producing a tube bend diameter that is over10 feet. Tubes of this size are very flexible and it is possible that Tubes Ri 110C81 and Ri 13C81could have contacted as shown in Figure 7-27. As can be observed in the figure, the length ofcontact between the tubes would be expected to be fairly limited. This small proximity length and1814-AA086-M0238, REV. 0Page 270 of 415 Page 270 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013also the recorded wear length are supported by ECT data and are consistent with how the tubesare configured in Figure 7-27. Small deviations in the assembly of the SG could furtherexacerbate this condition. Upper bundle tube proximity potential is discussed in more detail inSection 8.2.As indicated above, calculations show that tubes with out-of-plane tube excitation have little to noin-plane motion during operation. Calculations also show that the tubes are not moving in-planeas a result of in-plane instability. In addition, PSI ECT data indicates the tubes were very closeto each other and as a result were likely either in contact during startup of the plant, closeenough to come into contact when pressurized and heated, or came into contact through in-plane turbulence. Wear could have occurred between the tubes during operation as a result ofthe out-of-plane motion associated with out-of-plane tube excitation. Once Ri11/C81 andR113/C81 wear to the point where there is an in-plane gap between them, tube wear wouldcease. This phenomenon is called 'wear arrest', since the wear stops occurring once the initialinterference is worn away. Additional work regarding how the tube wear could have developed iscontained in Appendix B of this report. This additional work describes a scenario where thetubes were initially very close to each other and then 'skipped' to a new location where tube-to-tube contact is no longer possible.Also, based on the wear calculations in Section 7.4, the wear at the various AVB locations willnot progress through the tube wall. Therefore, Westinghouse concludes that there will not besignificant additional tube-to-tube wear on R111/C81 and R113/C81 during operation of SONGSUnit 2.7.6 SummaryWestinghouse testing and consistent design methodology supports the conclusion that tube/AVBwear that could approach plugging margins within one operational cycle is caused by amplitudelimited fluidelastic tube excitation within larger than expected clearances. Potentialmanufacturing issues that could lead to such unexpected tube/AVB fit-up are discussed inSection 8.2. The amplitude limited fluidelastic mechanism has been demonstrated to exist andproduce workrates that are many times greater than those from flow turbulence in single-phaseair tests, and these characteristics have been used for over two decades to produce boundingwear potential in the design phase. The only domestic steam generators with any tube/AVBwear since adopting this approach is the Plant B experience that was described in Section 7.2.3,and those results were largely attributed to unexpected large scale interactions within the tubebundle associated with fabrication methods and the relatively large amount of stagger in theoutermost AVBs for that design.Pettigrew et al (Reference 7-20) also reported the presence of the amplitude limited fluidelasticmechanism for two-phase air-water tests for low void fractions before turbulence effects are largeenough to disrupt the consistency of the fluidelastic excitation. Air-water tests are somewhatdifferent than a steam environment, and considering the extremely high void fractions present inthe region of most severe wear in the SONGS steam generators (see Figures 7-16 and 7-17 forexample), it is considered to be the most likely explanation for tube/AVB wear in the SONGSsteam generators as explained and supported by calculations in this section. Application of thesemi-empirical methodology to obtain observed wear patterns in the SONGS Unit 2 steamgenerators demonstrates that subsequent operation at any part load levels not exceeding80 percent will not lead to unacceptable tube wear during the next operating cycle before aplanned interim ISI.1814-AA086-M0238, REV. 0Page 271 of 415 Page 271 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 20137.7 References7-1. P. J. Langford, "Design, Assembly, and Inspection of Advanced U-Bend/Anti-VibrationBar Configurations for PWR Steam Generators," Transactions of the ASME Journal ofPressure Vessel Technology, Vol. 111, Nov. 1989, pp. 371-377.7-2. S. S. Chen, J. A. Jendrzejczyk, and M. W. Wambsganns, "Dynamics of Tubes in FluidWith Tube-Baffle Interaction," Symposium on Flow-Induced Vibrations, Vol. 2, presentedat the ASME WAM, Dec. 1984, pp. 285-304.7-3. Y. Cai, S. S. Chen, and S. Chandra, "A Theory for Fluidelastic Instability of Tube-Support-Plate-Inactive Modes," Transactions of the ASME Journal of Pressure VesselTechnology, Vol. 114, May 1992, pp. 139-148.7-4. R. Bouecke, Kraftwerk Union A. G., "Experience with KWU Steam Generators KWUSteam Generator U-Bend Support Concept," in "Part C Additional Information," TopicalReport on Replacement Steam Generators, KWU-UPC-8601-A, transmitted toK. Wichman of USNRC March 23,1988, pp. 70-83.7-5. A.J. Fricker, "Numerical Analysis of the Fluidelastic Vibration of a Steam Generator TubeWith Loose Supports," 1988 International Symposium on Flow-Induced Vibration andNoise, Vol. 5 Flow-Induced Vibration in Heat-Transfer Equipment, Nov. 27 -Dec. 2, 1988,pp. 105-120.7-6. H. J. Connors, "Fluidelastic Vibration of Heat Exchanger Tube Arrays," ASMETransactions Journal of Mechanical Design, Vol. 100, The American Society ofMechanical Engineers, New York, New York, April 1978, pp. 347-353.7-7. H. J. Connors, "Flow-Induced Vibration and Wear of Steam Generator Tubes," NuclearTechnology Vol. 55, Nov. 1981, pp. 311-331.7-8. H. J. Connors and F. A. Kramer, "U-bend Shaker Test Investigation of Tube/AVB WearPotential," Fifth International Conference on Flow-Induced Vibrations, Paper C416/014,IMechE, Brighton, U. K., May, 1991, pp. 57-67.7-9. E. R. France and H. J. Connors, "Simulation of Flow Induced Vibration Characteristics ofa Steam Generator U-tube," Fifth International Conference on Flow-Induced Vibrations,Paper C416/020, IMechE, Brighton, U. K., May, 1991, pp. 33-43.7-10. P. J. Langford and H. J. Connors, "Calculation of Tube/AVB Wear from U-Bend ShakerTest Data," Fifth International Conference on Flow-Induced Vibrations, Paper C416/040,IMechE, Brighton, U. K., May, 1991, pp. 45-55.7-11. P. J. Hofmann and T. Schettler, "PWR Steam Generator Tube Fretting and FatigueWear," EPRI Report NP 6341 prepared by Siemens Kraftwerk Union AG, April, 1989.7-12. Steam Generator Management Program: PWR Steam Generator Tube Wear -Alloy 690/Supports, EPRI, Palo Alto, CA: 2008. 1014991.7-13. E. Rabinowicz, "Wear Coefficients -Metals," Wear Control Handbook, Ed. M. B. Petersonand W. 0. Winer, The American Society of Mechanical Engineers, New York, 1980,pp. 475-506.1814-AA086-M0238, REV. 0Page 272 of 415 Page 272 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 20137-14. E. Rabinowicz, "Adhesive Wear," Friction and Wear of Materials, Wiley, New York, 1965,pp. 125-166.7-15. "Geometry and Mensuration, Ungula of Right Circular Cylinder," Standard Handbook forMechanical Engineers, McGraw-Hill, New York, 6th Ed., p. 2-19.7-16. San Onofre Nuclear Generating Station Units 2 and 3 Replacement Steam GeneratorsMHI Design Drawings:A. L5-04FU001, Rev. 6, "Component and Outline Drawing 1/3".B. L5-04FU051, Rev. 1, "Tube Bundle 1/3".C. L5-04FU052, Rev. 1, "Tube Bundle 2/3".D. L5-04FU053, Rev. 3, "Tube Bundle 3/3".E. L5-04FU107, Rev. 3, "Tube Support Plate Assembly 2/3".F. L5-04FU108, Rev. 3, "Tube Support Plate Assembly 3/3".G. L5-04FU 112, Rev. 1, "Anti-Vibration Bar Assembly 2/9".H. L5-04FU118, Rev. 3, "Anti-Vibration Bar Assembly 8/9".7-17. Westinghouse Report No. SG-SGMP-12-6, "San Onofre SG Tube Wear DegradationComparison," May 2012.7-18. "Root Cause Evaluation: Unit 3 Steam Generator Tube Leak and Tube-to-Tube WearCondition Report: 201836127," Revision 0, May 7, 2012, San Onofre NuclearGenerating Station (SONGS).7-19. Westinghouse Letter LTR-SGDA-12-24, "San Onofre Units 2 and 3 MHI RSG Flow-Induced Vibration Evaluation Customer Correspondence," May 21, 2012.7-20. V.P. Janzen, E.G. Hagberg, M.J. Pettigrew, and C.E. Taylor, "Fluidelastic Instabilityand Work-Rate Measurements of Steam-Generator U-Tubes in Air-Water Cross-Flow," Transactions of the ASME Journal of Pressure Vessel Technology, Vol. 127,February 2005, pp. 84-91.7-21. "Examination Technique Specification Sheet 96004.1," Revision 13, EPRI, April 2010.7-22. "San Onofre Nuclear Generating Station, Units 2 & 3 Replacement Steam GeneratorsDamping Test Results for Stabilizer," Mitsubishi Heavy Industries, L4-04GA581,Revision 1, June 4, 2012.7-23. R. D. Blevins, "Chapter 4 Galloping and Flutter," "Flow-Induced Vibration," KriegerPublishing Company, Malabar, FL, 2nd Ed., p. 104-113.1814-AA086-M0238, REV. 0Page 273 of 415 Page 273 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Table 7-1Feature Comparison of SONGS and Plant B Steam GeneratorsFeature SONGS Plant BNumber of Tubes 9727 10637Tube Material Alloy 690 TT Alloy 690 TTTube Dimensions (in) 0.750 OD x 0.043 t 0.688 OD x 0.040 tTriangular Pitch (in) 1.00 0.95Pitch/Diameter 1.33 1.38Largest Radius, Rmrax (in) 76.27 74.025Number of TSPs 7 8TSP Material 405 SS 405 SSTrifoil Broach Radius (in) 0.381-0.384 0.349-0.353Radial Tube Clearance (in) 0.006-0.009 0.005-0.009TSP Thickness (in) 1.38 (0.2-1.07 land height) 1.125 (0.94-1.08 land height)TSP CL Spacing (in) 42.82 first, 43.66 typical 34.67 first, 35.23 typicalNumber of AVB Sets 6 (2 Each Side, 2 Centered) 5 Centered + StaggeredAVB Material 405 SS 405 SSAVB Dimensions (in) 0.590 W x 0.114 t 0.480 W x 0.133 tNominal* Diametrical Gaps 0.0020 0.0017(in)Average U-bend Span @ Rmax 13 @ -19.4 in 11 @ -23.9 inU-bend Overhang (in) 83 89IP Tube Spacing** at Apex (in) 0.298, 0.344, 0.400 0.442, 0.502, 0.562Alloy 690 Retainer Bars (in) 24 Round (12 ea @ 0.19, 0.41) 20 @ 0.63 W x 0.125 tAlloy 690 Retaining Rings (in) 0.38 Round 0.38 SquareAlloy 690 End Caps (in) 0.38 t x 1.00 W x 1.97 L 0.451 t x 0.860 W x 2.00 LEnd Cap to Ring Welds (in) 0.12 leg 0.19 leg x 0.38-0.63 longOrthogonal Structure 13 Segmented Bridges NoneSG Power Level (MWt) 1729 1522Maximum Steam Quality 0.89 0.75Maximum Void Fraction 0.9955 0.9851Operating Time @ Last ISI Cycle 16 (1.7 EFPY) Cycle 6 (8.1 EFPY)Tubesheet Thickness (in) 27.95 31.56Hole Tolerances (in) 0.756-0.762 (0.769 for 1%) 0.696-0.701Diametrical Expansion (in) 0.006-0.012 (0.019 for 1%) 0.008-0.013*Assuming AVBs are welding at the nominal TSP hole pitch spacing.**For larger tubes in radial zones -41-55, 56-67, and 68-maximum.1814-AA086-M0238, REV. 0Page 274 of 415 Page 274 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Table 7-2Limiting Active Tubes for Wear Greater Than 20% Through-wallSG 2-88 Active Tubes with > 20% WearRow Col 7H BI B2 B3 B4 B5 B6 B7 B8 B9 B10 311 B12 7C #AVBs Case Comment112 96 17 20 13 17 2 17118 86 23 12 13 14 6 2 17133 87 9 19 20 13 6 2 1888 96 17 21 2 19116 96 23 18 15 7 2 20117 83 14 17 10 24 7 2 2098 90 8 8 11 20 7 3 27105 81 22 12 8 3 28120 90 23 16 7 3 28125 91 9 22 10 3 28125 95 9 10 18 22 10 3 28134 84 10 11 21 15 8 3 28118 82 8 21 10 3 29132 96 18 23 11 3 2997 87 11 2S 23 16 4 38 Case4697 91 14 12 22 19 4 38108 88 12 9 22 12 4 38108 94 22 15 10 13 4 38131 91 8 22 17 8 4 38113 95 10 14 12 9 21 4 3993 89 14 12 11 20 11 5 3896 92 14 21 16 18 9 5 3897 93 10 11 23 19 11 5 38101 95 21 11 11 10 12 5 38116 82 14 8 17 20 14 5 38124 96 13 22 14 14 9 5 38128 92 8 22 20 11 12 14 5 45127 93 6 6 23 10 8 5 48 1 1SG 2-89 Active Tubes with > 20% WearRow Col 7H B1 B2 B3 84 B5 B6 B7 B8 B9 B10 B11 B12 7C #AVBs Case Comment131 91 8 21 6 x 2 17 Case 38113 71 14 21 2 18 Cases 28,29, 38,46121 95 20 14 5 2 18 Case 39,47119 95 7 20 12 3 28129 93 x x 15 22 6 3 29 Case4791 73 10 8 22 3 29105 77 7 21 15 3 29106 78 6 26 23 13 3 29119 77 6 14 21 3 29121 91 x x 12 15 28 23 4 37 Cases45,46,53124 86 5 9 21 12 4 37123 83 13 12 23 12 10 4 38124 88 10 23 14 6 4 38125 89 8 22 18 6 4 38126 90 5 7 12 21 21 x 14 x 5 45 Case 60119 89 x x 5 6 17 28 5 x 5 46 Case5488 78 9 9 7 22 10 5 4793 77 5 7 16 20 22 5 47100 76 13 21 11 14 12 5 47109 75 6 7 8 21 13 5 47112 96 21 9 5 14 17 5 47 1x Low level wearfound in +Pt data from WEC review1814-AA086-M0238, REV. 0Page 275 of 415 000co(0CDr%)-40)0C-fPage 275 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Table 7-3Summary of Limiting TubelAVB Wear Calculations with Additional Wall Loss Projections at 80% Part LoadMax Tube/AVB Wear Baseline Calculations @ +6 Months Additional Missing AVB Check -Calculations @ + 6 MonthsTube SG Tube ECl ICTUncert FAS'.flB NoSeq MaxWearDepth@PowerLevel MitsWal FAS'IIB NoSeq WearDepth PowerLevel MilswalR/C No Status Value Value Case AV~s Cyce I W1% 70% 160% 10. @ 80% Case AV~ls Cvde 1 M0% 70% 160% loss @t Sol.................... ...... ... ........... ................ 1 ............... ............................... a acR97C07 88 Active 25 27.4 38 4 46 511..19289 -. 9. ...A tv.. ...... .28 3..... 0... -10 3 ... 46...... ....... 5 5....... .6............. ..R121C91 89 Active 28 30.3 37 4 45 5x 30.3 x X 46 5x 30.3 x x 53 6R131C91 89 Active 21 23.5 17 2 38 4R129C93 89 Active 22 24.5 29 3 47 5R126C90 89 Active 21 23.5 45 5 60 7R112CBS 88 Stab 35 37.2 47 5 x KtR13C W 88 tab 35 37.2 38 43C; 45 5............ ..... L. " .. ......... .3........ .... .7.... ........... .3..8............ ..... ....... 4. .. ......... ...........R114C90 88 Stab 22 24.5 48 5 6..R111C91 88 Stab 26 28.4 38 4 x XR116C86 88 Stab 29 31.3 46 5 61 7R117C93 88 Stab 27 29.4 47 5 -X tR115C85 88 Stab 27 29.4 49 5 61 5R:IIA4 B6 .... .-Stab ..... ....21 _235 ....... .... .53 .6 _ _6. .. 8R112CB8 88 Stab 35 37.2 55 6 X XR128C94 88 Stab 32 34.3 60 7 t xR120C92 88 Stab 32 34.3 66 8 x xR121IC3 89 Stab 24 26.4 16 2 46 4R 117C89 89 Stab 26 28.4 46 5 X .XR108C90 89 Stab 27 29.4 53 6 X SR117C81 89 Stab 29 31.3 55 6 x.R .. 89 Sa.b 26 2&4 56 6 67 8I 8 5 S a .... I6 ; ....... , ..... .. .. .. ......... ...... .4 ............ .. ......oR114W88-89 ..Stab 24 26.4. 56_ 6 67 8.... ......... .... ............R1172C85 89 Stab 24 26.4 62 7 74 10R122C821 89 1Sta b 27 29.4 66 8 X StR112C84 89 Stab 27 29.4 67 8 1 xR113C81 89 Stab 16 18.6 28 3 S SR111C81 89 Sta b 18 2015 38 4 55 6X 16,6 x X 8Notes: No Seq AVBs -number of sequential AV assumed ineffective due to wear scars for base me plus additional check cases.Multiple cases were considered that are not shown. Many have multiple unstable modes, but only one is shown for Ri 11C81. -00-A)o0m0Page 276 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Table 7-4Summary Results from Detailed Review of ECT Files for the Region Having Multiple Consecutive Wear Scarson AVBs B5, B6, B7, B8, and B9 on Column 81 for SG 2 E89SG2-89B1 B2 63 B4 B5 B6B7 88 B9 B1O Bll B12C R81 12981 12781 12581 12381 12181 11981 11781 11581 11381 11181 10981 10781 10581 10381 10181 9981 9781 9581 9381 9181 8981 8781 8581 8381 81781 10 1XsXSX XIx xxSxS I 7S 5S.xSxS 148 11 5 25 5,,x1 __ xl_ IEiII 14 10 X X17D us xs 82 I 298SO _16~~I 12 19 29 108Slos9S7SI xSI I 4 4SD55xSxSxS II I I8S13S18sxS7S Twist iI112S13S11D8D7SI ___ 44I II 7SSD14D15D6S6 6s~srt 9 14 128 _ 7 _ 9 _ 1 1 6861176 6 12 121081117I 1x [ 1 5 1 12 1 xS6 1 1566 55 8 69Notes: 1) x = Location of low level wear from +Pt data, 2) s = Single-sided tube wear, 3) D = Double-sided tube wear,4) Yellow Highlight = One ofseveral consecutive wear scar locations, 5) Twist = Tapered wear scar, 6) Vertical Hash = Location with discrete shift in wear scar location,7) Double-lined Boxes = Locations with tube-to-tube proximity during PSI, 8) Rose Highlight = Region of maximum AVB symmetry variance. Page 277 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013000000O*eeoooooS000000600000000T000e0stTest 1o 00o0 0 ©Test 300000000000000000000Test 2p 00 0Test 4*S Rigid Tube0 Flexible TubeFlexible Instrumented TubeFigure 7-1Schematic Illustrations of Triangular Pitch Tube Array PatternsTested in the STC Water Tunnel with Pitch/Diameter Equal to 1.421814-AA086-M0238, REV. 0Page 278 of 415 O00m0o-Page 278 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Figure 7-2Comparison of Analytical Models of FIV Mechanisms withRMS Tube Displacements for Sample Vibration Test Dataa,b 0,1%.LO,m-AODPDXMPage 279 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 20136E0(Ua...0(0Velocity, UFigure 7-3FIV Mechanisms of Interest to U-bend Tube Wear Potential Page 280 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013b,eFigure 7-4Schematic Illustration of Quarter Scale U-bend Air Flow TestUsed to Obtain Instability Constants for Parallel Triangular Array Configuration -00CA)m00C)oPage 281 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013b,eFigure 7-5Comparison of Observed Vibration Amplitudes and Impact Forcesin Scaled U-bend Air-Flow Tests During Single-sided Interaction with an AVB Page 282 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013__3m0+ ~+-1-.-4-. 4+ 4- +4+.+44+~+ 4--ISIMULATEDOUT-OF-PLANEDIRECTIONTUBE EXTENSION MAKES INSTALLATIONOF SIMULATED AVB'S, IMPACT FORCEGAUGES, POSITION DETECTORS, ANDPRELOAD DEVICES SIMPLE TO ACCOIPLISHL FLAT STRIP PROVIDESOUT-OF-PLANEMOTIONFigure 7-6Conceptual Arrangement of Full-Size Cantilever Tube TestUsed to Simulate U-bend Response and Characterize Fluidelastic Driving Forces Page 283 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013b,eFigure 7-7Conceptual Sketch of Full-Size U-bend Shaker Test Used to Characterize Workratesfor Both Turbulence and Amplitude-Limited Fluidelastic Vibration(Full Size Westinghouse Model F or Delta 75 Design with -59-inch Radius) Page 284 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Running-inperiodK->1K58Figure 7-8Potential for Increased Wear Coefficient During Initial Operation(Reference 7-11) Page 285 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013a,c,eFigure 7-9Schematic Illustration of Initiation of Amplitude Limited Fluidelastic Excitationon Workrate Trend for Tube-to-AVB Interaction across a Gap if SR > 1 without the AVB 030000)00030Page 286 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013a,c,eFigure 7-10Typical Application of Semi-Empirical Wear Calculation Methodologyfor Amplitude Limited Fluidelastic Excitation in Steam Generator Design 0o00)90X3Page 287 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Drive Force, FOSFluidelastic Excitation Force, F,Figure 7-11Fundamental Characteristic Trends Treated in Semi-Empirical Methodology C).0;U.m0ýPage 288 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013CC-4)252015105002 4 6 8 10 12 14 16 18Wear Volume, V (0.0001 in3)20Figure 7-12Wear Depth vs. Wear Volume(0.750 inch OD Tube 0.59 inch AVB Width) CDC:)00US~Page 289 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013*~ ~.FEEDWATER NOZZLEAND ELEVATEDFEEDWATER RINGWRAPPER CONEiANTI-VIBRATION BARSHANDHOLE<(ROTATED INTO VIEW)TOP TUBESUPPORT PLATEINSPECTION PORTSIt VESSEL SHELLI-- STAYRODSTUBE BUNDLEHAN DHOLE% -BLOWDOWN NOZZLETUBE PLATECHANNEL HEADPARTITION PLATEINLET/OUTLET NOZZLESAND PRIMARY MANWAYSSUPPORT PEDESTALFigure 7-13Illustration of Tube Bundle Support Structure in Plant B Steam Generators 00.0,;0OCo,0,mPage 290 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013600* *** SONGS SG 2 (1 Cycle).C0.Uo0~0)500-- SONGS SG 3 (< 1 Cycle)-- Plant B (6 Cycles)400 F300 F2000000100.0-______t__C___t____00306090Angle Around U-bend120150180Figure 7-14Comparison of Number of AVB Wear Indications for Plant B versus SONGSRSGs -A00C>000,Pom0C)Page 291 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013b,eFigure 7-15Comparison of Observed Vibration Amplitudes and Impact Forcesin Scaled U-bend Air-Flow Tests During Single-Sided Interaction with an AVB Page 292 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013a,c,eFigure 7-16OP U-bend Mode in Sample Evaluation Showing First Unstable FASTVIB Caseand Postulated Initial Positions of AVBs 4 and 5 Relative to Mode Shape 0)0m0N)Page 293 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013a.ceFigure 7-17Significant OP U-bend Modes in Sample Evaluation Showing 2 FASTVIB Casesand Postulated Initial Positions of AVBs 3, 4, 5, and 6 Relative to Mode Shape Page 294 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013a,c,eFigure 7-18R131C91 Case 17 Tube Wear CalculationsCycle IR for 22 Months Followed by Various Load Levels for Cycle 2 03L00C)!OD(30mC0Page 295 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013a,ceFigure 7-19R131C91 Case 38 Tube Wear Calculations (Case 17 with Gap)Cycle IR for 22 Months Followed by Various Load Levels for Cycle 2 Page 296 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013a,c,eFigure 7-20R129C93 Case 28 Tube Wear CalculationsCycle 1 R for 22 Months Followed by Various Load Levels for Cycle 2[Final esults for Case 29 Not Plotted] -.L00C)ODCOmDPage 297 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013aceFigure 7-21R129C93 Case 46 Tube Wear Calculations (Ref. Case 28 + Gaps Each End)Cycle 1R for 22 Months Followed by Various Load Levels for Cycle 2 Page 298 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013a,c,eFigure 7-22R126C90 Case 45 Tube Wear CalculationsCycle IR for 22 Months Followed by Various Load Levels for Cycle 2 0002Cy)km0Page 299 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013a,c,eFigure 7-23R126C90 Case 60 Tube Wear CalculationsCycle IR for 22 Months Followed by Various Load Levels for Cycle 2 Page 300 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013a,c,eFigure 7-24R1 21 C91 Case 37 Tube Wear CalculationsCycle 1 R for 22 Months Followed by Various Load Levels for Cycle 2 Page 301 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013a,c,eFigure 7-25R121C91 Tube Wear Calculations (Cases 37, 45, 46, 53)Cycle 1R for 22 Months Followed by 80% PL for Cycle 2 0)0(C)0,mC0Page 302 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Figure 7-26R11 9C89 Case 46 Tube Wear CalculationsCycle 1R for 22 Months Followed by Various Load Levels for Cycle 2 Page 303 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Tubes may only be closeat this locationTop Cnter~Tube to Tube WearHere -RII11C81 andR113C81I IHo egSideRow 1Row 15Row 27Row 1421Row 48Figure 7-27Postulated Geometry for Tubes R111/C81 and R1131C811814-AA086-M0238, REV. 0Page 304 of 415 Page 304 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 20138.0 Additional Considerations8.1 Evidence for Lack of In-Plane Instability in Unit 28.1.1 FIV ResultsThe flow-induced vibration analysis has considered many postulated boundary conditionsregarding how AVBs can support the SG tubes in SONGS Unit 2. The potential for in-planeinstability being the primary reason for wear in Unit 2 has been explored by considering certainselected tubes having high degrees of wear. The analysis focused on certain tubes that areplugged since these tubes have the largest amount of wear. The analysis will consider tubesthat:1. Have the largest amount of wear at a given AVB location2. Have the largest number of ineffective AVBs as evidenced by the number of eddycurrent reported wear sitesUsing the above criteria, the following tubes will be addressed:SG 2E088:Tubes with largest amount of wear (35%TW) -R1 33C91, R1 12C88Tubes with largest number of ineffective AVBs (8) -R1 20C92, R97C85, R99C93SG 2E089:Tube with largest amount of wear (29%TW) R1 17C81Tubes with largest number of ineffective AVBs (8) R122C82, R106C84, R105C83,R104C86, R98C86, R123C91, R98C88, Rl12C84, R100C84Table 8-1 contains a summary of the in-plane stability ratios calculated for these tubes. Of theapproximately 1400 tubes found with indications of tube wear in the U-bend, only 3 of thesetubes have an in-plane stability ratio greater than 1.0 when calculated using an updated Beta ofI Ia,c,e. The limiting tube (R123C91) would require a Beta of approximately [ ]ac~e in order tohave a calculated in-plane stability ratio less than 1.0.The analysis indicates that for a very small population of tubes (3), the calculated instability ratiomarginally exceeds 1. However, as determined in the eddy current results review, the number oftubes with wear is on the order of 1400. Since all the tube wear found to date is very similar, itcan be concluded that the mechanism for this wear would also be similar. Since only 3 tubeshave calculated stability ratios greater than 1.0, and the wear on these tubes is similar to wearfound on other tubes with calculated stability ratios less than 1.0, it would be reasonable toexpect that the 3 tubes respond in a manner similar to the -1400 tubes with wear. This evidencesuggests that the actual Beta's (and potentially other related factors) associated with in-planemotion are such that the tubes remain stable in the in-plane direction. It should also be notedthat after review of the Unit 3 eddy current data, discussed in Section 9.0, it was determined thatthe two tubes with tube-to-tube wear in Unit 2 did not have the major characteristic associatedwith Unit 3 tubes exhibiting in-plane motion and tube-to-tube wear. All of the Unit 3 tubes in thesample population had indications of wear at the top TSP. An explanation of why that is relevantfor in-plane motion can also be found in Section 9.0. The observation that the two Unit 2 tubeswith tube-to-tube wear did not exhibit the major characteristic of tube-to-tube wear found in theUnit 3 sample is an important finding that further indicates that in-plane motion was not occurringin R1 11/113C81. As a result of the above, it can be concluded that the tube wear found in Unit 21814-AA086-M0238, REV. 0Page 305 of 415 Page 305 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013is not related to in-plane instability and therefore is not a credible mechanism from an analyticalpoint of view.Note that all of the tubes listed in Table 8-1 have been removed from service. In addition, anycurrently active tubes or plugged tubes would have calculated in-plane stability ratios less than1.0 for power levels of 70%.8.1.2 ECT ResultsA supplemental review of selected eddy current data was performed as part of the support effortfor the FIV analysis. This review included an investigation of the AVB and AVB wear data usingthe available +Pt data for all SG 2E089 tubes with bobbin coil indicated depths of 20% through-wall or greater; all other tubes in Columns 81 and 82 between Rows 120 and 110; and theidentified limiting tubes for the FIV analysis. The SG 2E088 review included the identified limitingtubes for the FIV analysis, which includes both tubes with 35%TW indication depths. Both thehot and cold leg +Pt RPC data for these tubes were reviewed (if available). A total of 70 tubes inSG 2E089 encompassing 394 bobbin reported indications and 5 tubes in SG 2E088encompassing 37 bobbin reported indications were reviewed.This review concluded that:1. All wear at the AVBs was found to be contained within the width of the AVBs.2. For tubes with both single- and double-sided AVB wear, the majority of single-sided AVBwear was found on one side of the tube.3. For tubes with the single-sided wear not on the same side, the side orientation of theindications was grouped. That is, wear could be observed at AVB2 on one side, withwear at AVB3, AVB4, AVB5, and AVB6 on the opposite side.4. AVB axial symmetry variance at AVB6, AVB1, and AVB7 had the largest amount ofvariance as indicated by the 95th percentile value (0.32, 0.25, and 0.23 inch, respectively);the variance at all other AVBs are approximately equal.5. The most extreme AVB symmetry variance of 0.50 inch was not associated with wear atthat AVB.When the bobbin coil inspection results are combined with a review of the +Pt data for the tubesidentified on Table 8-1, it is observed that the number of bobbin reported indications is equal tothe number of +Pt indications for all but SG 2E088, R113 C91 (7 consecutive wear sites),SG 2E089, R123 C91 (9 consecutive wear sites), and SG 2E089, R100 C84 (9 consecutive wearsites).In conclusion, there is no indication from the eddy current data that suggests in-plane instabilityhas occurred in the Unit 2 steam generators during the prior cycle of operation.8.2 Upper Bundle Tube Proximity8.2.1 Potential Manufacturing IssuesThere are several potential manufacturing issues associated with review of the design drawingsbased on Westinghouse experience. The first two are related to increased proximity potentialthat is likely associated with the ECT evidence for proximity that is described in Section 8.2.2.Two others are associated with the AVB configuration and the additional orthogonal support1814-AA086-M0238, REV. 0Page 306 of 415 Page 306 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013structure that can interact with the first two during manufacturing. Another relates to AVBfabrication tolerances. These potential issues include:1. The smaller nominal in-plane spacing between large radius U-bend tubes thancomparable Westinghouse experience. Differences in axial shrinkage of tube legs canchange the shape of the U-bends and reduce in-plane clearances between tubes fromwhat was installed prior to hydryaulic expansion.2. The much larger relative shrinkage of different sides of each tube that can occur withinthe tubesheet drilling tolerances.3. The potential for the ends of the lateral sets of AVBs (designated as side narrow and sidewide on the Design Drawing Anti-Vibration Bar Assembly Drawing LU-04FU116, Rev. 2)that are attached to the AVB support structure on the sides of the tube bundle to becomedisplaced from their intended positions during lower shell assembly rotation.4. The potential for the orthogonal bridge structure segments that are welded to the ends ofend cap extensions on 13 AVBs to produce reactions inside the bundle due to weldshrinkage and added weight during bundle rotation.5. Control of AVB fabrication tolerances sufficient to avoid undesirable interactions withinthe bundle. If AVBs are not flat with no twist in the unrestrained state they can tend tospread tube columns and introduce unexpected gaps greater than nominal inside thebundle away from the fixed weld spacing.The weight of the additional support structure after installation could accentuate any of the abovepotential issues. There is insufficient evidence to conclude that any of the listed potential issuesare directly responsible for the unexpected tube wear, but these issues could all lead tounexpected tube/AVB fit-up conditions that would support the amplitude limited fluidelasticvibration mechanism described in Section 7.1. None were extensively treated in the SCE rootcause evaluation.8.2.1.1 Nominal In-Plane Tube SpacingTable 7-1 shows that the nominal tube spacing between the apex of successive tubes in thesame column is 0.400 inch for the largest radius tubes and only 0.344 inch for the tubes inRows 101 through 124 that have much of the observed tube wear. This nominal at the apex ismisleading in the sense that it is the maximum clearance if all tube fabrication tolerances areprecisely maintained including the length of the straight legs which positions the U-bend relativeto the primary face of the tubesheet. The distance between tubes on the sides at the intersectionwith the top TSP is 0.250 inch plus or minus the small broached hole tolerances. The actualshape of the U-bend has a profile tolerance that is not provided in the referenced drawings, butWestinghouse experience is that it may be between [ ]a,c,e forsimilar size tubing. The only check during tube bundle assembly is the ability to pass a 0.12 to0.14 inch pin gauge between successive tubes1.Any tube that lies within the adjacent tubes withany tolerances will satisfy this check. However, any variations in leg length or form toleranceswill lead to tubes that are much closer than the nominal spacing, and most deviations will lead totubes being closer on one side, for example near AVB3 and AVB4 and farther from AVB9 andAVB1 0, or vice versa.ac,eWestinghouse does not have access to the assembly procedures. The 0.12 to 0.14 dimensionsare anecdotal without verification.1814-AA086-M0238, REV. 0Page 307 of 415 Page 307 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013[]a,c,e Therefore, it is expected that it would have been difficult to maintain uniformspacing in the U-bend given the smaller incremental spacing on the SONGS manufacturingdrawings. The SCE root cause evaluation notes that between 132 and 390 tubes requiredadjustment of tube bending radius for each of the steam generators. This process is inherentlydifficult to control in a manufacturing environment.8.2.1.2 Tube Leg Shrinkage During Hydraulic Expansion (HX)The entire tube bundle is assembled before hydraulic expansion is performed with no ability tosee the consequences of variations in leg shrinkage inside the bundle. Expansion is a processthat involves plastic deformation of the portion of tubing that is inside the tubesheet, and plasticdeformation is a constant volume process that necessitates shortening the length of the straightportions of tubing to account for the increase in diameter because wall thinning is small for thepressures involved. Figure 8-1 shows expectations for the range of relative shrinkage for Plant Band for the SONGS steam generators using drawing tolerances shown on Table 7-1. For mostof the holes, both applications would have a maximum variation of about [ ]a,c,e inch betweendifferent sides of the same tube. However, the SONGS drawing allows up to one percent of theholes to be so large that a difference twice that large is possible for about 100 tubes in eachRSG. When combined with the small clearances that are possible after installation, thesuperimposed HX shrinkage could lead to the level of proximity indications observed asdiscussed in Section 8.2.2. When installed and then heated and pressurized, it is possible thattube-to-tube contact would be possible, and in the extreme, there could be interference leadingto tubes pushing against each other and then against adjacent AVBs tending to increase thecolumn spacing. Any such tendencies would tend to make the next two issues more problematicduring fabrication.8.2.1.3 Lateral A VB Nose Movement During Shop RotationThe side-wide and side-narrow AVBs that are cantilevered from the sides of the bundle must beheld in place by attachments to the retaining bars, and these bars must in turn be held in positionby the orthogonal support bridge structure. For this design, gravity and friction tend to interactwith the cantilevered AVBs whenever the horizontal SG is rotated during fabrication in anasymmetric way that could potentially move the noses of the AVBs and deform the straightportions leading to bending or twisting that could expand the column spacing in some regionsand leave some regions of tubing with larger than nominal clearances. During shop rotation theoverhanging portion of the tube bundle (about 83 inches or almost 7 feet for SONGS) bendsdownward several inches when the tube U-bends are horizontal, less when they become vertical,and then several inches in the opposite direction at 180 degrees from the starting position. Thisrotation occurs several hundred times during welding operations for not only the channel headbut also the closing weld after AVB assembly. The ends of each leg of each AVB are deflectedthe same amount for AVBs that have their bends along the bundle centerline, but each rotationof the cantilevered AVBs deflects the leg that is nearest the center more than the one that isnearest the TSP. If the noses do not return to the original position they had when installedduring the tube column and AVB layering process, the tube column spacing could be adverselyimpacted from consequential bending or twisting of the AVB legs. If there were any extremeproximity conditions from a combination of the first two potential issues that tended to push onetube locally against its neighbor, there could be a tendency to push the AVB legs apart locallyand make it more difficult for all AVBs to maintain their original positions after rotation.1814-AA086-M0238, REV. 0Page 308 of 415 Page 308 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 20138.2.1.4 Orthogonal Bridge Structure Impact on Bundle During FabricationThe segments of the orthogonal bridge are welded to the ends of longer than normal AVB endcaps at 13 columns spaced evenly around each retaining ring. Weld shrinkage at theseattachments could possibly impose forces on the ends of those AVBs that must be reacted insidethe bundle. The added weight of the structure would also tend to amplify gravitational effectsduring shop rotations.8.2.1.5 Control of A VB Fabrication TolerancesLarge radius U-bend tubing has very little flexural rigidity out-of-plane of the tube even whenpressurized during SG operation. The tops of the straight leg portions are held in place by theTSP broached hole spacing, and the AVB end cap-to-retaining bar welds maintain spacingaround the periphery, more at the bundle center, but less so around the bundle because the barsare also flexible. However, there is no structural component to keep the interior of the bundle atthe intended nominal spacing in the region of most wear in the SONGS steam generators,especially along a line between the bottoms of the locations where the weight of the structure isreacted by retainer bars that can tend to push the columns apart near the Row 111 tube radius.Therefore, it is even more critical for the SONGS steam generators to maintain flatness and twisttolerances on AVBs so they will not have any tendency to separate the tube columns anywherebetween the end caps and the bends deep inside the bundle. If acceptance criteria for AVBtolerances did not include inspections for flatness and twist in the unrestrained condition2, theAVBs could contribute to the apparent off-nominal spacing in the SONGS steam generators.8.2.2 Summary Eddy Current Data -PSI / ISISection 5.2 describes the numerous proximity findings in the Unit 2 steam generators during bothPSI and ISI. There are no specific indications associated with the observed tube wear pattern,but there is much eddy current evidence of tubing much closer than nominal while not operatingin both the horizontal (PSI) and vertical (ISI) orientations. For example, a detailed study ofRows 80 and higher for Columns 50 through 110 found 334 indications of proximity less than0.125 inch during PSI and 363 in the same range during ISI for SG 2E089. The locations of theproximity indications shifted slightly between nearby tubes in the same column based onorientation, and they also sometimes shifted from one side of the bend region to the other. Thisis the kind of proximity response in unpressurized tubing that is a consequence of the first twopotential manufacturing issues noted above (small nominal spacing, added impact of hydraulicexpansion shrinkage). Pressurization would tend to move the proximity locations in a similarfashion, and when pressurized the tubing is much stiffer in the plane of the U-bend.ECT findings discussed in Section 5.1.4 also indicate that denting is associated with the bendregion of many of the smallest angle AVBs on the sides of the bundle (AVB2/AVB3 andAVB10/AVB11) at Rows 30 through 33. They are also noted to be on the outboard edge of eachAVB indicating not only a larger than expected spacing, but also a local twist. This kind of twistcould be from as-fabricated AVBs, or it could result from installing the AVBs deeper thanintended and bending the legs to match the retaining ring profile. In either case, there is ECT2 Westinghouse does not have access to final manufacturing or inspection details, but anecdotalinput indicates that six-pound weights were allowed and used during AVB inspection forconsistency with AVB drawing tolerances.1814-AA086-M0238, REV. 0Page 309 of 415 Page 309 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013evidence that the AVB tolerances and dimensions were not as expected in the Unit 2 steamgenerators.8.2.3 Additional Considerations from Unit 3Extensive review of ECT data available for the Unit 3 RSGs was conducted as described inSection 9.0 to develop conservative criteria for identifying tubes that could be susceptible totube-to-tube wear. Figures 8-2 through 8-6 identify various findings of tube proximity, AVBsymmetry variance on opposite sides of the same intersection, and tapered wear scarsassociated with twisted AVB legs that are inconsistent with assuming tube/AVB interactionsbased on Gaussian distributions about nominal design conditions. Figure 8-2 is an overview ofall the noted variables. There is a line of proximity indications in Rows 121 and 122 that is notrandom, but there is insufficient information to know if it is associated with the weight of the AVBstructure imparted here through the retainer bar supports or if it could be that the nextincremental tube index does not occur until Row 124. The distribution of significant symmetryvariances and tapered wear scar locations also does not appear random. The boundarybetween tubes with mostly double-sided wear scars inside the SVI region (the region on the tubewith the single volumetric indication) and single-sided wear scars above and below is not shownhere, but the boundary is consistent and markedly not random.Figure 8-3 shows both the spatial and quantitative distribution of AVB symmetry variance in thisregion. The maximum symmetry variance of 0.78 inches occurs at AVB 6 on Row 87 inColumn 85, and it decreases both going outward at larger radii going towards the tube/AVB weldand inward going towards the bend region. It is not likely that the middle of an AVB can bedisplaced this much in-plane without introducing significant bending and twist beyond designexpectations. The ECT review noted that more tubes in Unit 2 had symmetry variances than inUnit 3, but they were more scattered with a smaller maximum (about 0.5 inch). Figure 8-4 showsthat locations with twist are present in the vicinity with the largest taper distribution from about5 to 35%TW shown on Figure 8-5.8.2.4 ConclusionsThe mechanism considered most likely to be able to cause the wear observed in the SONGSsteam generators during the first cycle of operation is considered to be amplitude limitedfluidelastic excitation resulting from out-of-plane tube vibration within larger than expectedclearances in the U-bend tubing support structure. All of the potential issues described abovecould lead to such conditions in various combinations, but none were extensively considered inthe SCE root cause evaluation.8.3 Low Stability Ratio Tubes with Higher WearSeveral active tubes with significant wear had only a few ECT indications from the originalbobbin coil evaluation. If only the AVBs with wear were used to define FASTVIB cases, thencalculated excitation ratios would not be greater than one, apparently inconsistent with using thesemi-empirical wear calculation methodology described in Section 7.2 to explain the observedwear. Two limiting tubes in Table 7-2 for SG2E89 are examples that were evaluated assumingthat one or two additional adjacent AVBs were also ineffective as a consequence of the modeshape assumed for the reference case relative to the existing gaps as shown on Figure 7-17.Considering the slightly longer spans to define the characteristic FASTVIB case then allowsmatching the actual wear after the initial operating period and projecting the result as was done1814-AA086-M0238, REV. 0Page 310 of 415 Page 310 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013for all the other tubes shown on Figure 7-3. The R1 13C71 and R121C95 tubes had a referenceFASTVIB case 18 based on bobbin ECT indications at AVBs B6 and B7. Cases 38 and 46 bothproduce the observed wear at Ri 13C71 and project to 23.5 and 23.9 %TW after 6 months ofoperation at 80 percent part load. Cases 39 and 47 both produce the observed wear atR121C95 and project to 22.5 and 23.6 %TW respectively for the same 80 %PL operatingconditions. Thus, the apparent inconsistency of large wear and few bobbin indications isexplained by evaluating other likely cases, in effect moving the tubes to other locations in thetable.8.4 Wear Projection UncertaintyAs described in the prior subsections, the wear projection methodology applied here is based onselecting the input variables related to materials and geometry of the tube-AVB intersections tomatch the wear depth reported in the U2C17 inspection. The methodology then uses the samevalues of the input variables for projection of the wear depth in Cycle 17. Since values of severalinput variables are unknown, this approach involves selecting input values within an expectedrange based on test results, published data and experience and using these values to obtain amatch for the U2C17 inspection results by trial and error. There will a number of possible"solutions" (combinations of different values of the given input variables) that satisfy the criteria.The wear projection process applied here is very time consuming due to the trial and errorinvolved in obtaining a match for the inspection results, often for three different AVB wearindications in a given tube. Therefore the uncertainty evaluation is based on the followinganalysis applied to one tube. In this evaluation, the method uncertainty (standard deviation ofgrowth) is determined as a fraction of the mean estimated growth of an AVB wear indication.This allows estimation of the growth uncertainty from the estimated growth by applying this ratio.Tube R121C91 in SG 2E089, which has four AVB indications reported in the U2C17 inspection,was selected since this is one of the tubes that will be returned to service with the deepest wearscar.a,c,e1814-AA086-M0238, REV. 0Page 311 of 415 Page 311 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013a,c,eHence the standard deviation of growth will be calculated as [ ]a,c,e times the estimatedgrowth for an indication. Using this standard deviation, the growth at 95% probability and 50%confidence can be estimated using the normal distribution (z = 1.645).The growth uncertainty will be applied as follows:* [ ]a,c,e* [ ]a,c,e* [ ]ace* [ ]aceA common sense test of the derived normalized standard deviation was applied as follows.Using the first of the eleven solutions, the growth at 95% probability and 50% confidence wascalculated and added to the reported wear depth at U2C1 7. This was done for each of the threeAVB indications at each of the three loads and two durations of Cycle 17. The number of timesthe estimated Cycle 17 wear depth in the eleven solutions exceeded the 95% probability 50%confidence values by more than 0.5%3 was counted. It was found that, of the 198 projecteddepths in the eleven solutions, only 4 exceeded the 95 percentile values. Hence, the uncertaintyevaluation was validated.A question may be raised regarding the uncertainties in the supporting evaluations such asthermal-hydraulic evaluation and flow-induced vibration evaluations that formed the inputs to thewear projection. Results of those evaluations were applied consistently for both the Cycle 16assessments that benchmarked the solutions with the U2C17 inspection results and to theCycle 17 assessments resulting in the wear projection. Hence, the uncertainties in those resultsare present in both cases, balance out each other, and are considered irrelevant. Similarly, thecalculation of the excitation ratios (and stability ratios) is based on the thermal-hydraulic andvibration evaluation results and the support conditions. The support conditions of a tube are thesame during the first cycle of operation and the next operating cycle. Hence the change inexcitation ratios from the last cycle to the next cycle occurs only due to the change in operating3 For four of the 22 cases, the calculated growth was 0. Hence the estimated uncertainty(standard deviation) was also 0, although the true uncertainty is not. Thus the small 0.5% gracevalue was used to account for such cases. It is possible to apply a small (0.5% or 1%) gracevalue as the minimum uncertainty allowance (1.645 times the standard deviation) for growth toovercome this drawback. However, it is judged to be so small and, hence, inconsequential.Thus, the simple approach without any adjustment in the uncertainty value to overcome thecalculated growth value of 0 was applied in this evaluation.1814-AA086-M0238, REV. 0Page 312 of 415 Page 312 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013conditions (power reduction). Hence the conclusion related to the uncertainties balancing out duetheir presence in both cycles is also applicable to the excitation ratios and stability ratios.1814-AA086-M0238, REV. 0Page 313 of 415 Page 313 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Table 8-1Enveloping Cycle I TubesNo Missing IPSR100% IPSR70%Tube SG CaseAVBs power powerR!33C91 2e88 45 5 Nc:e!Ri12Css 2e88 55 6R120C92 2eSS 66 8R97C85 2e88 66 8R99C93 2e88 67 8R117C81, 2e89 55 6R122C82 2e89 66 8R!.06CS4, 2e89 66 8R205C83 2e89 66 8R0ICC86 2e89 66 8R98C86 2eS9 66 8%123C91 2e89 66 8R98C88 2e89 66 8RlI2CS4 2e89 67 8R100C84 2eS9 67 81) AVB5 assumed to be ineffective even though no wear was reported.1814-AA086-M0238, REV. 0Page 314 of 415 Page 314 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013 aceFigure 8-1Potential Range of Axial Shrinkage for Plant B and SONGSSteam Generators Using Drawing Tolerances for TS Drilled Hole Diameter1814-AA086-M0238, REV. 0Page 315 of 415 0000Page 315 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013a,c,eFigure 8-2Overview of ECT Results from SG 3E088 Using ISI Proximity Results Map with AVB Support Structure(Boxes with numbers are locations of AVB symmetry variance; smaller rectangles are locations with twist) O000(30C)9Dom0XPage 316 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013a,c,eFigure 8-3Locations and Magnitudes of AVB Symmetry Variances Near SVI Region of SG 3E088 -k00CO70Page 317 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013a,c,eFigure 8-4Distribution of AVB Locations with Tapered Wear Scars Indicating AVB Twist 0,0r,.3.Com00C)MPage 318 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013a,c,eFigure 8-5Largest Implied Twist from Preliminary Tapered Wear Scar Review Near SVI Region of SG 3E088 -00,-00co)m0PO(0CD0Page 319 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Figure 8-6Elevation View of Locations of AVB Misalignment and Tapered Wear ScarsObtained During ECT Review of the SG 3E088 SVI Regiona,c,e Page 320 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 20139.0 Consideration of Unit 3 Tube Wear on Wear Model Applied in Unit 29.1 Unit 3 Critical Tube Selection for Model ValidationMore severe tube/AVB wear occurred in Unit 3 than in Unit 2. Unit 3 also experienced significanttube-to-tube wear and more extensive tube/TSP wear than in Unit 2. Therefore, the Unit 3 tubewear experience was reviewed to develop refined criteria that correlate the Unit 3 results in orderto apply the same criteria to preclude similar tube-to-tube wear in Unit 2. Section 5.4 describesthe extensive ECT evaluation that was performed on a large (86) sample of tubes fromSG 3E088 that had experienced tube-to-tube wear to establish a consistent basis for thisevaluation. There was a focus on 16 tubes that had tube-to-tube wear with only a few bobbincalled indications of tube/AVB wear because these tubes would be the most difficult to explainusing other criteria. It is not likely just a coincidence that these tubes happened to be around theboundary of the region with the most severe tube-to-tube wear as shown on Figure 9_112. These"boundary tubes" reflect the transition from severe free span wear experienced by the "interiortubes" on Figure 9-1. While developing criteria to correlate these two extremes of tube-to-tubewear experience, 15 additional "adjacent tubes" were added to the evaluation.9.2 Unit 3 AnalysisThe 86 tubes from SG 3E088, comprising 55 interior tubes, 16 boundary tubes, and 15 adjacenttubes, were subjected to an in-depth, independent evaluation of RPC results contained in thedigital ECT files provided by SCE as described in Section 5.4. Both the original reported wearindications from bobbin data and the new RPC results were used to define a range of potentialineffective AVB locations. This range of potential support conditions was evaluated usingvarious FASTVIB cases using methods described in Section 4.2. Then, all calculations and ECTobservations were reviewed to establish the most likely physical explanation for the tube-to-tubewear that occurred in the Unit 3 RSGs. Tables 9-1 and 9-2 provide a summary of the pertinentresults. Note that all tables and figures discussed in Sections 9.2 through 9.5 were producedusing FASTVIB analyses that restricted degrees of freedom for modes in the plane of the U-bendfor the straight-leg portions of the tubes. This approach reflected the need to reduce the volumeof data being processed to concentrate on U-bend response. All analyses have been repeatedwithout this restriction with no impact on conclusions discussed in this sectionTable 9-1 addresses the more difficult to explain boundary tubes along with the adjacent tubesthat are required to explain the occurrence of free span (FS) tube-to-tube wear in someinstances. Notes explaining legends used in the evaluation follow at the bottom of the secondpage. The first tube in the table, R114C74, is a boundary tube that has an indicated FS weardepth of 26 %TW on the hot leg side between AVBs B3 and B4, but the only indications oftube/AVB wear are at AVBs B3 and B4 from the bobbin data plus an indication of very smallwear (too small for the bobbin detection threshold) at B2 from the RPC evaluation. The supportconditions evaluated for the implied support configuration Cases 15 and 25, that simulatedineffective supports at the AVBs with wear, show that OP gap-limited fluidelastic excitation couldproduce wear at those AVBs, but there was no indication of closer proximity to adjacent tubes ineither the PSI or the ISI inspections to explain how that could have caused the FS wear between12 Note that the tubes later called "boundary tubes" due to their location on the map wereoriginally selected by sorting ECT data results and choosing ones that appeared not to havemany consecutive tube wear indications at the AVBs. The adjacent tubes were added later. Theoriginal terminology was retained for the evaluation and the map labels.1814-AA086-M0238, REV. 0Page 321 of 415 Page 321 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013those AVBs. The same support configuration Cases 15 and 25 are also clearly insufficient tohave the possibility of IP fluidelastic instability as the explanation for the FS wear because thecalculated stability ratio is only about half the required threshold even using what is considered aconservative Pip [ a,c,e Furthermore, the wear scars that were present showed noextensions outside the AVB intersections, so there had been no apparent significant in-planemotion of this tube.The next tube in the Column R112C74 (nearest inside neighbor in the same column) wasalready in the list as a boundary tube because it had only one wear call at B5, so it was alsoreviewed to determine if it could be the source of the FS wear that had been found on R1 14C74.Table 9-1 shows how this is considered to be a possible explanation since it showed indicationsof in-plane motion outside the AVB at B8, and the IP stability ratio would have exceeded thethreshold if AVBs B2, B6, and B7 had been ineffective in providing support in-plane in addition tothe 7 other locations with small wear observed only with detailed RPC inspection. The weardepths on these two boundary tubes were similar (26%TW and 25%TW) to support thisconclusion. However, the requirement to find 7 small wear scars and assume three others is astretch when defining criteria based on analyses alone, so adjacent Tube R110C74 wasevaluated to determine if it could have provided some of the interaction as well.The inside neighbor adjacent Tube R1 10C74 had 4 bobbin indications and 4 more low level RPCindications, and it also required 3 additional AVBs to be ineffective at preventing in-plane motionin order to have potential IP instability. It also had reasonably similar FS wear between B3 andB4 (19%TW), so it could have provided some of the energy leading to FS wear for all threetubes. However, it also would be difficult to identify from a purely analytical perspective. Thesethree tubes illustrate tubes that are difficult to identify by any means other than observation of FSwear on the tube or an adjacent neighbor that interacts with it.The next two tubes are similar in that one (R101C75) has FS wear on the cold leg betweenAVBs B9 and B10, but there is no analytical basis to explain it. However, the adjacent tubeR103C75 is potentially unstable in the IP direction using support conditions evident from bothbobbin and RPC test results. The FS wear scars also match at 19% and 18%TW, and there isclear evidence of in-plane motion demonstrated by wear scar extensions.The remaining tubes in Table 9-1 with FS wear that were selected as being the most difficult toexplain all have adjacent neighbors that appear to be the sources of IP motions that cause wearat the interface of both tubes. Some are obvious after reviewing the additional RPC indicationswhile others require reasonable, but not obvious, assumptions that are consistent with physicalobservations and analytical predictions of potential for IP instability. However, the mainconclusion of the evaluation is that tubes with FS wear can all be explained as either having thatpotential, or by interacting with neighbors that have the potential to be unstable in-plane.A second major conclusion relates to the observed levels of TSP wear that characterize theresults shown for most of the interior tubes in Table 9-2 and for several of the adjacent tubes inTable 9-1. Tubes with significant TSP wear correspond to the calculated OP gap-limited tubeexcitation ratios from about 7 to 9 and IP stability ratios greater than about 1.5. As such, theycorrespond to tubes having very long unsupported spans with obvious potential for IP instabilitybased on the FASTVIB cases considered most representative of the available observations.This observation allowed the addition of another conservative criterion to identify tubes withpotential for FS tube-to-tube wear as explained in the following section under 9.3.4 Criterion 4 -Wear at Top TSP Sites.1814-AAO86-M0238, REV. 0Page 322 of 415 Page 322 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 20139.3 Plugging Criteria DevelopmentAs a result of the extensive review of the Unit 3 eddy current data, additional revisions to theplugging criteria were developed to address tubes not currently plugged. Revisions to theplugging criteria were necessary as the level of degradation experienced in Unit 3 was moresevere than that observed in Unit 2. Information obtained from the Unit 3 eddy current data hasprovided additional insights as to what should be considered to develop a more robust pluggingrecommendation or plugging criteria. Additional indications of wear were observed not only atAVB locations at Unit 3, but also at TSP locations that should also be considered in thedevelopment of the plugging recommendations.Note that each criterion has been developed to address the various boundary conditions that arenecessary for the tubes to experience wear. There is discussion provided for each criterion tohelp explain why it is important, and how the observed conditions coupled with analysis modelsexplain why a tube should be removed from service if one or more of the indicated eddy currentindications are found on a tube.The following is a summary of each criterion that should be considered to determine if anyadditional plugging is required beyond the tubes that are currently plugged. These criteria areapplicable for tubes in both the Unit 2 and Unit 3 steam generators.9.3.1 Criterion I -Free Span ContactAny tube with free span tube-to-tube wear will be plugged along with all immediately adjacenttubes. Review of the sample of 86 Unit 3 tubes has found that all 86 of these tubes haveindications of free span wear.9.3.2 Criterion 2 -Wear Outside A VB sitesAny tube with known wear outside the AVBs would be treated as potentially unstable andremoved from service. For suspected in-plane instability locations, a review of the surroundingtubes should be performed as well as the tubes surrounding those tubes with the largest numberof bobbin reported AVB indications.This indicates that in-plane motion could potentially be occurring, and as a result, the tube couldthen contact a neighboring tube and therefore should be removed from service.9.3.3 Criterion 3 -Ineffective A VB Sites and In-Plane MotionAny tube with a sufficient number of ineffective AVBs (as determined via wear at AVB sites) andis unstable in-plane would be removed from service. The in-plane instability potential would bedetermined based upon the power level and operating conditions associated with the next cycleof operation.Any tube with in-plane stability ratios greater than 1.0 would indicate that in-plane motion couldpotentially develop. As a result of the large stability ratios, the tube could then contact aneighboring tube and therefore should be removed from service.1814-AA086-M0238, REV. 0Page 323 of 415 Page 323 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 20139.3.4 Criterion 4 -Wear at Top TSP SitesThere are some instances where review of the AVB eddy current data for Unit 3 does not clearlyindicate that the tube has a sufficient number of ineffective AVBs to produce in-plane motion, butthere is evidence of tube-to-tube wear. This is possible since an ineffective AVB support can bea result of either a gap condition, where the tube contacts and then wears against an AVB as aconsequence of impacting due to out-of-plane gap-limited FEI, or the case where the gaps arelarger than modal displacements such that the tube would not contact an AVB. In the secondcase, where the tube does not contact an AVB, there might not be any tube wear at that locationand as a result would not be detectable by eddy current examination. However, in these casesthere may be evidence of wear at the top TSP. This TSP wear would be an indicator of out-of-plane tube excitation that would be a result of additional ineffective AVBs that are not detectedby eddy current, and the support conditions that allow this TSP wear are consistent withconditions where in-plane instability leading to tube-to-tube contact may be possible.Tube support conditions in the U-bend region usually have many ineffective AVBs such thatmultiple out-of-plane modes are present when in-plane instability is possible. For example,Figure 9-2 shows [a,c. The average wear for seven of the tubes in the most severe region of SG 3E088 isshown on the same plot as mode shapes from the FASTVIB analyses of a tube in the samevicinity. Wear depths depend upon the tube/AVB gaps relative to the unstable out-of-planemode nearest each AVB, and may not be above the detection threshold for locations away fromthe maximum modal displacement. The plotted average wear depths actually have contributionsfrom additional out-of-plane modes and increased work rates due to in-plane modes that aredescribed next, but gap-limited out-of-plane fluidelastic tube excitation alone can cause most ofthe observed wear in the U-bend region.Figure 9-3 shows how additional gap-limited FEI modes in the U-bend can add to wear at theAVBs, but more significantly, they can lead to highly loaded spans at the top of both the hot andcold legs consistent with the observed wear distribution for these severely worn tubes. Sometubes in this highly loaded region that have large gaps at all AVBs have only the additional thirdmode, while others have yet another fourth unstable out-of-plane mode. These appear to beconsistent with some tubes having wear at the top two TSPs and others having wear indecreasing amounts all the way down to the second TSP. No specific wear calculations havebeen made for the TSP wear, but the observed distributions match both the severity of the modaldisplacements and the nature of the rocking/whirling13 vibration that would be expected at theTSPs due to the mode shapes associated with the given support condition. Note this supportcondition could also result in in-plane instability.Figure 9-4 shows two in-plane mode shapes that can become unstable at about the sameexcitation levels and support conditions that lead to the third and fourth out-of-plane modes13 Fluidelastic instability in the U-bend region is predominantly characterized by out-of-planedisplacements usually considered to be the result of the significant differences in stiffnessesthere. However, tubes with instability in the straight leg region where stiffnesses are the same inall directions typically exhibit orbital motions. In this situation where energy derives from gap-limited excitation in the U-bend, tube motions in the straight leg may be limited by modalcharacteristics determined by the gaps in the U-bend, but the orbital displacements could beseveral times larger than they otherwise would have been due to flows in the straight leg alone.1814-AA086-M0238, REV. 0Page 324 of 415 Page 324 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013shown on Figure 9-3. The in-plane modes may have a significant contribution to observed tube-to-tube free span wear, but they do not contribute significantly to straight leg vibration based onthese simple linear analyses. However, they occur at about the same excitation levels andsupport conditions as the out-of-plane modes that lead to wear at the top two TSPs. This is thereason that wear at the top TSPs can be used to identify tubes with ineffective support conditionsthat could be indirect indicators of conditions leading to unacceptable free span wear eventhough one or two AVB locations may not be worn enough after Cycle 1 to clearly identify thatpotential directly. Updated analyses with no restraints on the degrees of freedom in the straightleg have small responses between the top TSPs, but they do not extend down to the lower TSPsas is the case for the out-of-plane modes with highest excitation ratios as shown on Figure 9-3.Figure 9-5 is included to confirm that inspections of tube wear scar extensions in SG 3E088 areconsistent with in-plane frame Mode 1. Dotted lines are theoretical first in-plane mode shapesfrom FASTVIB. This is the frame mode that is swaying from side to side at [ ]a. Thetangential part of that mode is the red dotted line and it would extend wear scars at B6 and B7,the most and least for AVBs closest to the TSP. The radial part of the frame mode is the lightblue dotted line with maximum impact on scar extension at B3-B4 and B9-B10 and no impact onscar extension at B6 and B7 (radial tube motion at B6 and B7 would increase wear depth, but notextension). The resultant of those two components is the double-humped darker black dottedline, and this is the one that would be closest to expectations of fitting scar extensions from ECTmeasurements. This is indeed the case for many tubes as illustrated by the one tube with a redline connecting its data points. There are at least three times this many tubes that could beadded to the plot, but they would not change the conclusion. The overall average of the datapoints is the very dark thick line. It has a single peak, but is obviously spread out more than thetangential mode alone as a consequence of the radial mode effects away from the center line.Based upon the above, Criterion 4 has been developed to remove from service any tube that haswear at the top TSP and has any wear at 2 or more consecutive AVB locations for power levelsbetween 80% and 100%. For power levels 70% or below, the tube would have wear at the topTSP and also have wear at 3 or more consecutive AVB locations. Analysis has determined thatit requires a minimum of 2 consecutive ineffective AVB locations at 80-100% power, and aminimum of 3 consecutive ineffective AVB locations at 70% power, before the tube becomesunstable in the out-of-plane direction at the limiting location in the SG tube bundle. This isconsidered to be a conservative criterion since the Unit 3 experience indicates that many moremissing supports are required before in-plane instability actually occurs. This criterion effectivelyenvelopes all possible fluidelastic wear mechanisms, considering both the in-plane and out-of-plane directions.9.3.5 Criterion 5- A VB Sites and Wear Potential due to Out-of-Plane MotionThere is a potential that additional tube wear would develop at the AVB locations that couldresult in leakage. This criterion has been developed to address the potential that out-of-planemotion could produce unacceptable amounts of tube wear during a given operating cycle. As aresult, any tube with a sufficient number of ineffective AVBs (via wear at AVB site) and hasindications of out-of-plane gap-limited fluidelastic tube excitation that results in additional tubewear greater than the plugging limit, will be removed from service.1814-AA086-M0238, REV. 0Page 325 of 415 Page 325 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 20139.4 Application of the Criteria to the Unit 3 Tube SampleThe criteria defined in the previous sections have been applied to the group of 87 Unit 3 tubesselected for validation of the plugging criteria. Table 9-3 contains a summary of the applicationsof the criteria. It is noted that in general all of the tubes considered in this sample have beenidentified for plugging by two or more of the criteria. The only exception where only one criterionwas found to be applicable is for tubes that are being contacted by tubes that are experiencingin-plane displacements. These tubes are experiencing wear as a result of an adjacent tube thatis experiencing in-plane motion. The following is a summary of how the samples of tubes meeteach of the criteria:Criterion 1: Review of the sample of 86 Unit 3 tubes has found that all 86 of these tubeshave indications of free span wear.Criterion 2: Review of the sample of 86 Unit 3 tubes has found that 17 of these tubeshave indications of wear outside the AVBs.Criterion 3: Review of the sample of 86 Unit 3 tubes has found that 56 of these tubeshave a sufficient number of ineffective AVBs (defined by wear noted at theAVB site) such that in-plane instability could potentially develop.Criterion 4: Review of the sample of 86 Unit 3 tubes has found that 79 of these tubeshave both sequential AVB wear and wear at the top TSP. In addition, all ofthe remaining 7 tubes (including R118C80 and R114C82, which are notexplicitly called out in Table 9-3) are experiencing wear as a result of tubesthat do not meet Criterion 4. So in essence, it could be stated that the entirepopulation of tubes that have experienced tube-to-tube wear have eitherbeen a tube that has not met this criterion, or is in contact with a tube thathas not met this criterion.Criterion 5: Wear calculations typically require significant amounts of time to complete;therefore, these calculations were not performed for the 86 Unit 3 tubessince these tubes had already been plugged.9.5 Application to Unit 2The five rules, or plugging criteria, developed to explain the tubes in Unit 3 that were developedto explain the limiting tubes are applied to the eddy current data for the Unit 2 steam generators.Only the eddy current bobbin data was used in the Unit 2 data since the five criteria weresufficient to bound the bobbin only data for Unit 3. The results found for the five criteria areexplained in the following paragraphs.The first criterion states that any tube with free span tube-to-tube wear or contact should beplugged as well as the surrounding tubes. There were only two tubes in Unit 2 which had freespan wear. These tubes are Row 111 Column 81 and Row 113 Column 81. These tubes havealready been plugged and in addition, all of the tubes surrounding these tubes have beenplugged. Therefore, it can be concluded that no additional tubes need to be plugged due to thiscriterion.The second criterion states that any tubes that show AVB wear indications outside of the AVBsupport location should be plugged. The criterion is designed to pick up any tubes with anindication of in-plane stability. There are no tubes in Unit 2 that show any indication of wear1814-AA086-M0238, REV. 0Page 326 of 415 Page 326 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013outside of the AVB locations and therefore this criterion does not identify any additional tubesto be plugged.The third criterion states that any tubes that have a number of sequential AVB wearindications in the eddy current data and that are predicted to be unstable for the next cycle'spower level should be plugged. A review of the FASTVIB results at different power levelsshows that a minimum of 5 sequential AVBs needs to be ineffective to have in-planeinstability, 8 sequential missing AVBs at 80% power, and 9 sequential missing AVBs at 70%power. A review of the eddy current data shows that there are no tubes that have 8 or moresequentially missing AVB supports. Therefore, it can be concluded that this criterion does notselect any additional tubes to be plugged.The fourth criterion states that any tubes having wear at the top tube support plate and AVBwear at two consecutive locations of the tube should be plugged. This criterion is based onthe premise that it takes a minimum of two sequential AVB supports at 100% power for theworst tube to have an out-of-plane tube excitation ratio over one. It also takes a minimum oftwo sequentially missing AVBs out-of-plane to obtain a tube excitation ratio above one at 80%power. It takes a minimum of three sequentially missing AVBs out-of-plane to obtain a tubeexcitation ratio above one at 70% power. In Table 9-4 for Steam Generator 2E088 andTable 9-5 for Steam Generator 2E089, the tubes that need to be plugged due to these criteriaat 70% power are shown in green. The tubes in these tables shown in yellow should beplugged for power levels of 80% and 100%. At 100 to 80% power, Steam Generator 2E088has 10 additional tubes that require plugging and Steam Generator 2E089 has 10 additionaltubes that require plugging. At 70% power, Steam Generator 2E088 has 2 additional tubesthat require plugging and Steam Generator 2E089 has 3 additional tubes that requireplugging.The fifth criterion states that any tube that has gap-limited FEI out-of-plane and has wearprojections exceeding the plugging limit should be plugged. The wear evaluation shows thatthe limiting tubes have small amounts of projected wear at both 80% and 70% power and thatno additional tubes will require plugging during the next cycle.In summary, it was found that by applying the five criteria that were developed based on theUnit 3 eddy current data to the Unit 2 eddy current data, 5 additional tubes (beyond thosecurrently plugged) would need to be plugged at 70% power and 15 additional tubes (beyondthose currently plugged) would be required to be plugged for operation at 100% to 80%power. A list of the additional tubes to be plugged at the 70% and 80% power levels is shownin Table 9-6.1814-AA086-M0238, REV. 0Page 327 of 415 00mC0Page 327 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Table 9-1Results of Eddy Current Review and Flow-Induced Vibration Analysesfor Boundary and Adjacent Tubes in Columns 74-85 (Page 1 of 2)Selected Tubes wiTubelD SG Row Col114074 SGM 114 74112074 5GM 112 74110074 5GM 110 74103075 SG88 103 75101075 5088 101 75115075 SG88 115 75U3075 5G88 113 75111075 ,568 111 751000176 SG88 1(30 7698076 5688 98 76121077 SG88 121 77119077 5G88 119 7798078 SG88 98 7896078 SG88 96 78122078 SG88 122 78120078 5G88 10 73113083 5G88 113 83111083 SG88 111 8392184 ,GM 92 849M4 SGM 90 8W93085 SG88 93 8591085 SG88 91 85SONGS-3 SG8Shis < 8 AVU Indlcation (Bobbin] Wth Adjacent Nelhbobr301 B02 3 M3 IF% 60 M M 6 M 1ON -I B10 B11 8I1IC 13812 2MOMNXxs-. It XC 7XX 191 1 U , x x 1I 6d.-19I74- X X , X 6d- 121 X 10 7IC S a Sj x 119x. x 2xl 1 9 x x x 12 5l7-X I 7 1221d-- 7s- X-. 6sX 23- .8- X 6X x 6 32 S X X 6s- XI 5 1151 6 9 I6M 6 x 6 9 S 1151 ,,x 12 4 24 20 8 xd I 1(7)014 11 55,Its 19d

• 14i , Hll 12 10 8 5 1 1610 16 xI 1U as-. 1- 7 3W IS 1628 37 37 17 XC 11 19 20 IS15 MMN2611812 17 IC 1x 67 16 18 17 21 .-6d 9 146- 44 14 6x x 14 1411 17 M I X 9 12 6 xý4 is1401 30 --Ud Sd &M 11d 11 7[X13 17 19 X X 123L1Cases1152627773664527878472273 4 543 7667 71766D 6976 78% 6a U8365277 78isOut of Plane In Plane Ali WearSR for 0- 5D SRfor p7.8 ContainedOP0 OP2 0P3 0P4 0PS IP2 IP3 IP4 1, within AM?YesNoYesNoYesYesYesNoNoYesNoNoNoYesYesNoYesNoYesYesNoYesNoNoNo63 77 7836 66 To74267378457861 73 7827 45 6166 70732955167839 47 65 70111085 SG88109085 S588107085 SG88111109107as8585664670 77 0,-.310000,m0Page 328 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Table 9-1 (Continued)Results of Eddy Current Review and Flow-Induced Vibration Analysesfor Boundary and Adjacent Tubes in Columns 88-90 (Page 2 of 2)a.CeI *5 -It-96M~ S68894088 SG8810O89~ SG88103089 SG8830M SG88104090 S68896941051051061U488886 X 1211 6L!gj A23 Xa-. 7 1189 xa9X 133 _ 12 X_1311 -10, Xa7828 37 4576 7847 61 6655 66 7s55 7054 61744=NoYesNoNoYesNo9090S 7 X IMMM M241 XIIX X X X X 6"- X 1MISNotev/Lgend:RNxR CID SG RowNumbers In black font under AVS locations Indicate bobbin %rW from original data ieNumbers In red font under AVS locations Indicate RPC%TW from original data fileIndicates low level wear from WEC evaluation of RPCECT fileBlack box shows extent of consecutive AVis In the OP mode that best fits the data and analysesDark red box shows extent of consecutive AVMs In IP mode that best fits the data and analysesArrows show direction of wear scar extent outside AVI, s or d for single- or double-dded wear on tub*ULght red shading Indicates AVB anomaly such as observable taper/twist In wear scarLIght green shading Indicates oneaof a number of consecutive AVIBs with wearYellow shading Indicates a potential Ineffective site when defining cases to evaluateOrange shading corresponds to tubes with 4 or more TSP wear calls on both sidesAVB misalignment or off-nominal Interaction (other than twist)Col Tubes Identified by blue font Indicate tubes that could have TtT wear due to IF lnstabilt (either alone or due to adjacent tube In same column)

Page 329 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Table 9-2Results of Eddy Current Review and Flow-Induced Vibration Analysesfor Interior Tubes in Columns 76-80 (Page I of 2)m0C<Selected Tubes wlki 7AVy3lndlcatons lftbbin) Cases T_ SRfor f.-5.0 SR f.oF 7.8TuMlD SG Row C0l881 O02SM JFS4l *06 WS BOO B07 BW 80 FStl 510511 BL21 23 4OP1 0P2 0P3 0P4 0P51 IPt 1P2 INIM IP4 L11M076 S.(21 106 76103077 SGB8 103 77107077 SG88 107 7109077 5388 109 77113077 SG8H 113 77118977 S(M 115 77117077 SG88 117 77107078 52m 107 78104078 5,G8 104 78MOMB S(M8 lUb 18108078 SG88 108 7811D078 5;83 118 78103079 SG88 103 79105079 5(88 105 79107079 UM 107 79109079 5(188 109 791U./9 S(, l, /9117079 SG88 117 79121079 S088 121 7996080 5G88 95 809800 SG88 98 80100080 SG88 100 80102080 SG88 102 8010408) 5G88 104 80106080 SGBB 106 80109M80 SG88 103 80112080 5G88 112 80114080 S(88 114 80116080 SG88 116 80118000 SG88 118 80131315211418211911 40 2123 37 1428 80 2025 39 14S6xx1598613897-9 14 11 21 6 9 623 77 9 0 11 14 1' 17 7 53 12 8 22 27 Ii0 712S 1322 14S 2413 '911 1110 181U 1817 111j 9 1324 S9 23lb 99 X17 65 1017 18 1218 39 2015 5D 201. .57 1418 39 16lb 24 1U18 81 10151466111110717816i16 1720 1417 910 109 69 13.13 810 129 118 1111 1612 714 1611 135.5 17127 1413 2316 lb11 13is 1213 2311 1713 7016 10I 1411 10461948483170464922453B43413b3817 10 158 7 2216 13 1711 8 1715 1216 1112 1324 14 141i 25 201815 27 255 6 X14 i1 2313 23 2617 19 2413 13 2521 14 1813 10 20787674787818 90 101 21 22 17 27 13 13 13 13 12 7 1133111719201331171062271616221622242218152410 1518 7218 8114 5717 5911 1118 2220 3317 3512 3115 3126 1611 1819 7'23 712 722 1321 922 517 79x7x12514x13998106586x8107129999a87713 328 319 1910 1414 3019 5716 519 338 47121312151117151796613171516182314129781019172626261619777825 23 19 is 18 20 10 13 1010 1176 78I I 4., _L00ODCON,m0;UPage 330 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Table 9-2 (Continued)Results of Eddy Current Review and Flow-Induced Vibration Analysesfor Interior Tubes in Columns 81-86 (Page 2 of 2)S* ctd Tlswith > 7AV Indkctlm IBon 1801% Cases SR to- 5.0 SR tot f 7.8TUab.1 50 Row CaSolO 0 IF5 wo. OW Mo n7 606 am IFScl BIG 811 8121 2 3 4"01)(D0--hC,'95061 5688 95 8197OR1 WM 97 8199"61 M 99 81101081 S88 101 81103091 SG88 103 81107081 5388 107 8111mil SGM 111 A1113081 588 113 81113261 SG88 115 8196082 SG88 06 822UJ8IU 14, IM 82104082 5M88 104 82206082 SG88 106 82108082 5G88 108 82114062 SG88 114 82103063 5688 101 93103083 SG8 103 83100284 SG88 100 84102084 SG88 102 94104084 5488 104 8410(04 SGS8 108 84112084 SGR3 112 8499083 5(38 99 85104086 5(38 104 8622 918 16it 1220 1513 137- 1910 197 1?9 1018 68 16 12 8 1118 67 16 16 7 1715 z18 78 25 15 7 620 SO 16 6 12 623 W 13 X 9 I22 59 15 6 8 317 % 14 5 r18is S 3 10 9119S711889I10 41 125 45 644 128 27 611 41 910 38 X9 35 116 13 109 98 6 258 30 910 39 2113 48 1I8 51 914 22 166 99 54 9X 46 85R101013910111011112D17211971181817if142351821201919X2325X 269 814 I15 1020 813 12129 821131411is1312151443 2242 1459 1852 1346 1218 1531 is15 2222 710 615 617 177 1913 109 I1 X_oP1 oP2 OP3 oP4 oP51 iP1 IP2 IP3 gP4 IP5ace-I1861U12168276xx9881015810l7878437878/878.5743787878796377787872517878707851W3 /84357787A7812 12 16 42 1678787850.. .. .g .. .. ..17 17 3 7 25 X 8 11 8 7 5. 131i 23 11 1411 X11 21 37 1321 1720 2D 22 37 I11 8 14 613 21 12 37 1414 20 9 50 618 12 t 1011 11 5 11X 16 13 75 6 9 68 6 9 129 12 11111292310936 1266 1910 1114 1044 1144 810B7171817786 159 1573 7650 73 00(3o,)ro3m<CoPage 331 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Table 9-3Application of Criteria to Unit 3 Tube Sample (Page 1 of 2)31 1be So Row Co0 Gm 214 N.568 112 M40 5SM 110 74M SGSI 103 7Sa* SCGI 115 7555 SGSI 113 so SG3S 111 7SU5 S88 10.0 76U59G83 93 766* SCSI 1U 77* SC88 119 770 SGSS 95 78" 5SS3 96 730 $GOS 122 73* 5GMI 12'0 78I MSCI 111 83to~ OWI 07S13 1915 1410 914in 1411 31W1923 1923 27624 3221) 32801 M M iW MON W9 i'll s18all 5217OX121113is22S a S xi119Y,~ x A 6I 10 9, Xý .x 12- 5-5~i~~ 7 1201 A x~ fit x 1231xA 0A 5 ;: 7122 I II -Cx AdJ-. XI- 5,W- 69- 1231 XS-.IAV Weir¥e5oPI IPI SM1 vwthoýAVKIYesNoYesNo12 YesYes11 YesNo13 NoYeNNo13 No2) NoYesYetyet30 Nosx0 ?xIIa I l 3 4) x *ixx#A2343xxx9N2043II-I;=I26 1181 17 9 'x X 6.11-"'TubeV-41)YetYesyesrl)Yes(IYesYesYe',(l)yes~iyesYesYesNoYe,Ye.4.)YesyesYesYesNoyes-I7SGBSs 5GM8N# SG8MM S38Ia* SCSIGISSCSGSS65SGSB92wo9391W19107%94106103106104AMf8eBS56ISas7-q35 2SIx13 17 29 .X 1231 1 1S A: 405 9as-. 20 x9 x 12115 10x17 2313 9 ,13 R14 140 7 18555389SO90'43 AYesYetNoYesNoNoNoNoYesNoNoMeNoKxIt"I:1:XM9K(x9Atl4'as4',ý At- 6 7(W

• A 12! 3 XI; 7 I.is 231516 1519 22js -t5iLE z s x.. ........ .. ?,? .. ..14k 1311Ill1213191211:1::a 7 7x x Xx Ok-I A16 15,...Yet 0,Oo00o0m0Page 332 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Table 9-3 (Continued)Application of Criteria to Unit 3 Tube Sample (Page 2 of 2)S2M455418,4 Raw Cul o AM* 0344 Ml1 gal IF, we4 WS4 A44 go1 M6 M J~ ;-U oil g12Sets310676t:39 SO 1.3 14 1114021 6 is 13 it 16 46 17 1o 1stSs0313 r, 35 46 13 i 2 37 14 6 9 a 13 7 19 9 7 71" Sets37 r 3 44 1s 31 1n so 0 x I 9 14 16 a 16 12 17aSet 1097 41 t 21 19 i19 14 x 6 7 11 13 4 11 a 170 Sets1Ili77 327 9 14 11.33 4 9 S 31 IS U5son13t 1 .9 as 22 9 10 U 14 S 12 20 ,1 13son117 77 17 30 117 7 s,10 a 32 lIV 1 12 1355 232 1I10 41 1 21 12 " 12 1i 16 17 7 14 34 14 14*S2 IN1 47 s54 35 13 24 97 3 14 10 14 13 23 is is 20noS38 10 t1 44 SO 92 14 17 fib to & 17 1 11 13 49 5 so3ses1 is n 173 9 W4 17 is 13 11 10 10 16 12 22 S & 9" so M103 Is 041, on Sis470 123930 11 9 11 13461 4 1.1 33, W 53114IS654 " 13 9 14 So 20 tO 9 .11 17 25213 23 2M *6 M 107 79 0 44 it It i1 Is "7 14 7 13 a1 1 22 0 4317 V 1I 2449I13979 402010 19 1o i 14 13 10 t 2 16 10 413 13 3 a'a2SetsS671 333 13 0 Is 1is 6 10 4 9 11 1 14 3 21 14 toSSets177n5 39 6 17 1 1 0 10 15 13 11 103 13 1055Sts13:21 76 23 33 E1 3 1 E is is 113 1 12 7155 e96 3 10 3 7 11 ,101 16 31 9 9 1t 13 32 12 13 Ia 52138 " a, 11 16 1w 73 5 15 n I 7 w 31 12 17 105523129247463 19 33 1:1111 it 7t 11 11 9 19116 14 isa Se3s 201 Ws 16 14 V7 19 ? x 6 9 10 14 31 1i 1I552Se31M, 9204 01441M 13 la 17 443 21 1 62 9 14 30 17 is It0 3SG 1 0 37 SS 21 24 11 U 17 7 6. 9 4 1967 16 33 ,65590312w91542 17 32 17 n 13 14 6 9 1 1 17 145 13113 JS 54 10 Is 20 13 31 2 3 9 2 9 $2 9 U 3455 31 0 40 4 76 173621 6 t3 11 7 i7 6 9 19552G 316 17 22 21 24 12 311 17 7 1 a 7 13 6 7a0S31t 36 3t1 19 1 9 30 10 13 10 13 11.2 .1.47 5 194411 It 6 11 11 10 41 12 6 19554G1 3971 903 1 14 1947 14 16 17 1 V S 46 4 a 7t15Sets "9W. 43 a 17 1 IS 172 U 1321 6 5 441% 10 i2" Sea3101 M 044 672 1t 152s 3s 7 Is is 9 It 7 6 10 is603 113 it 37 B 13 is 20 SO 1 6 10 7 1141 9 10 1755 213 13 r, 44 19 is 7 11 10 A 9x 13 17551109 27201 19 3341 31 W 6o 9, 9 9i 3S2 9l 145 5t 111'1 44S 7 it 17 44 I& s 4 2 s 130 10 3, W3 113 M 37 40 0 10 1i M1 as 106 9 0 9 9 11 6a 5 S 9 112 I t s 35 21 14 16 It 4 It I 6 is 10N 55t 91962 V is 13103 43 72 7 9 $ 30 .1 U 1359 S,03 09 44 67 13 7 14 41 14 10 6 0 8 10 Ut It 7 2155G 3104 W 1 44 63 1S 10 11 49 is 16
• 13
• 13 43 16 11 20No9Ses M W 43 S4 N a 1 166 13 37 14 96 "0 1 S1 I is 19"12 103 & AD 13 13 13 46 13 7 a is 14 11 W 19550 31143 1N 13 1 1i i 7 1t 7 a .x 9" Scat 101 in # SS a 1 631 6s 13 10 6 9 $ M 17 2366 Sets 103 Io S 44 61l 11 %a 16 a s 9 i x _ 0 x 46 Is aset l1v 84 43 11 17 A aSX 8 Ita 7 6 255903 ~ A 1221764so Se IO S 23 1 41 1 1! 11 1 1 36 12 10 315 511314 M 244 0 Is 21 17 93 17 11 1 11 6 31 14 66 19 a 195so s3as i 746 10 20 It 37 9 1 x 1s 1. 7 9 to 11 7 171Ox 10 l 14 10on Seat " M, 33 5 13 21 Il 3"7 14 a 9 12 1041 11 6st 1" 141 S 42 58 1 14 21 9 s0 6 9 1 11 9 44 a 2 1636121117' w4-1 NI1 233467IYrdýIVVI.Ye.V_Y_5Ve_YetYV'SVI'V.',Y15YV,sVI'01-,VI'IVI'.ON',VI'KVI',VI',VI',VI',VI'.ON'S 000,m0Page 333 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Table 9-4Steam Generator 2E088 Application of Criterion 4Row Col 07C B12 B11 B10 B09 B08 B07 B06 B05 B04 B03 B02 B01 07H123 133 676 120 6142 86 7140 82 893 113 83 115 10138 108 12 6132 120 12134 116 13138 96 7109 79 6 8137 65 8135 91 6 8 10 7 5 9135 63 9138 68 10136 72 10134 88 8 7 19 11139 73 12113 81 6 9 8 6 9 13134 62 13133 65 14136 64 16 0.0C,)m0Page 334 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Table 9-5Steam Generator 2E089 Application of Criterion 4I Row I Col 107C I B12 B11 B10 B09 B08 B07 B06 B05 B04 B03 B02 B01 107H I-u(A0139 109 9103 97 16 1 31116 96 6 12 14 7 8126 78 10 13 7 8134 88 8 6 8 6 6 8120 96 r9 13 7 6 5 9141 89 9132 102 9138 90 16 14 9 I11 6 10134 92 8 9 5 7 10118 98 10132 104 1095 91 11 6 14137 111 14 Page 335 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Table 9-6Tube Plugging RecommendationSteam Generator 2E088 Steam Generator 2E08980% Power 70% Power 80% Power 70% PowerRow Column Row Column Row Column Row Column113 81 135 93 80 68 80 68134 88 137 89 103 97 104 72135 91 104 72 132 94135 93 116 96137 89 120 96126 78132 94134 88134 92138 901814-AA086-M0238, REV. 0Page 336 of 415 0)00IA*.0.Page 336 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 201316 Boundary Tubes-Have FS wear but only a fewbobbin ECT indications atAVBs15 Adjacent Tubes-Investigated as potentialsources of TtT interaction55 Interior Tubes-All have clear evidence ofmultiple ineffective AVBsupports based on bobbinECT indications-) <-) U(j)S00b%0eo 0oo0J38)Condition Reoort: 201836127 Rev. 0 4/30112 D. 60Figure 9-1 Location of SG 3E088 Tubes Evaluated to Develop Criteria for Tube-to-Tube Wear Page 337 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013a,c,eFigure 9-2 RowlOOCBO Case 78 OP Modes I and 2-UBend Tube/AVB Wear* is Consistent with Gap-Limited FEI-(*Average for Seven Tubes in R102-R106 SG 3-88)0,0m0Page 338 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013a,,c,eFigure 9-3 RowlOOC8O Case 78 OP Modes 1 through 4-Both Straight Leg and UBend Tube/AVB Wear* are Consistent with Out-of-Plane FEI-(*Average for Seven Tubes in R102-R106 SG 3-88)00000)0CD0O0CA"13Page 339 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013a,c,eFigure 9-4 R100C.O IP Modes 1 and 2 Become Possibleat Similar Excitation Levelsto OP Modes 3 and 4 (00Page 340 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013 a,c,e000Co0Figure 9-5 Tube Wear Scar Extension in SG 3E088 are Consistent with IP Frame Mode 1 Page 341 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 201310.0 Recommendations Regarding Operation at Reduced Power LevelsThe prior section developed a set of plugging criteria considering both the Unit 2 experience andthe Unit 3 experience. Five general criteria were developed and focused on tubes not currentlyplugged. The first two criteria (Criterion 1 and Criterion 2) are not related to power level; howeverthe remaining three are related to power level. Criterion 3 considered the effects of ineffectiveAVBs and the potential for in-plane motion. It was determined that no currently unplugged Unit 2tubes were affected by this criterion, therefore this criterion would not affect the selection of anacceptable future power level, as all tubes passed this criterion even at 100% power. Thiscriterion indicates that operation at a reduced power level will not adversely affect the remainingunplugged tubes in Unit 2. However, both Criterion 4 and Criterion 5 are affected by the powerlevel. These two criteria are discussed in the following sections.Recommendations regarding operation of the SONGS Unit 2 steam generators during the nextoperating period are then summarized in the last section and are based upon application of allapplicable criteria.10.1 Additional Unit 2 Tube Plugging Due to Criterion 4As discussed in Section 9, there are 5 additional tubes in SG 2E088, and 10 additional tubes inSG 2E089 that do not meet this criterion for power levels at 80% or larger. For operation at 70%power, 2 additional tubes in SG 2E088 and 3 additional tubes in SG 2E089 fail to meet thiscriterion. All other active tubes in Unit 2 do not show the ECT characteristics associated withtube-to-tube contact observed in Unit 3. These ECT characteristics were developed after reviewof the Unit 3 data. Consideration should be given to plug these tubes for operation at theindicated power level.10.2 Tube Wear Criterion 5It is known that wear at the U-bends is typically a result of limited displacement fluidelastic tubeexcitation and extensive testing has been performed (Reference 10-1, 10-2, 10-3) to developmethods to predict wear associated with this mechanism. As long as the gaps are reasonablysmall and the other wear parameters, such as [ ]a,c,e etc., can bequantified, then it is possible to effectively manage the amount of wear that could occur while thetube is vibrating within a limited gap. The amount of tube wear that is acceptable depends upondesign allowances incorporated into the tube relative to the SONGS technical specification limits,and what is considered acceptable based upon operational or commercial considerations.With respect to the SONGS technical specification limits, as long as the wear is less than 35%through-wall, then the tube is considered to be acceptable and will not require plugging shouldwear progress to this depth. With respect to SONGS Unit 2, the primary concern is to maintainan acceptable amount of tube wall thickness (SONGS technical specification limit) after the nextperiod of operation such that appropriate SG performance criteria would be met. In addition, it isdesirable not to have a large amount of additional tube wall degradation such that many moretubes would then be required to be removed from service during some future outage after1814-AA086-M0238, REV. 0Page 342 of 415 Page 342 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013additional cycles of operation. Since there are plans to implement a longer term fix, higher wearrates are considered to be acceptable for a short period of time. Once the longer term fix isimplemented, there would be a reduction in the rate of wear that would occur over subsequentperiods of operation.Calculations performed in Section 7.0 indicate that for the power levels considered, the amount ofwear that could occur on the limiting tubes over the next period of operation, 6 months, would besmall (less than [ ]a,c,e). Additional analysis was performed in Reference 10-4 to considerthe effect of wear after 18 months of operation. This analysis indicates that additional wear wouldoccur, but this level of wear was also relatively low. This was found to be the case for both thelimiting active tubes, and the limiting plugged tubes14.Tube wear rates of these amounts wouldnot impact the pressure boundary and also would not be expected to significantly increase tubeplugging levels before implementation of the longer term fix. Operation for longer periods of timecould potentially result in additional tubes requiring plugging, however since SCE is planning on alonger term fix, this is currently judged to be acceptable.10.3 RecommendationsThe wear analysis indicates that SCE can operate the SONGS Unit 2 steam generators withoutsignificant additional tube wear at power levels of at least 80% at the current plugging level. Theanalysis has determined that some tubes would vibrate between AVBs in the out-of-planedirection but the amplitude would be limited. Therefore the tubes would not be unstable in theclassical sense, as large motions are prevented by the tube impacting on the AVBs. In addition,no active tubes were found to be unstable in the in-plane direction for operation at 100% power.Displacements between AVBs will cause some tubes to experience additional wear over the nextperiod of operation. However, the amount of wear associated with that mechanism would bemanageable over that period of time with maximum additional wear on both active and pluggedtubes to be less than [ ]a,c,e mils. Note that operation of Westinghouse steam generators withmarginally unstable tubes in the constrained amplitude sense is not uncommon since the amountof wear that occurs during operation is small and within design wear allowances. Theconsequences of this type of motion are modulated, or reduced by random flow turbulence for thecondition where there are effective supports with small clearances.The amount of wear that has been experienced at the SONGS Unit 2 SGs during the prioroperating cycle is larger than what would normally be considered acceptable. As a result, certainactions have been taken by SCE to reduce the likelihood of a tube leakage event. This includesplugging and stabilizing certain tubes with large wear scars along with tubes with little or no wearin affected regions of the SG. In addition to these actions, Westinghouse recommends that SCEoperate the SONGS Unit 2 SGs at a 70% power level for the operational period after plugging theadditional tubes as indicated in Section 9.14 Some tubes with very low level wear may have more absolute wear depth increase whensharing of tube/AVB interaction involves locations that are on the beginning of the depth-volumecurve (see Figure 7-12), but the total %TW depth for such cases will be much less than for thelimiting tube locations with fully developed wear characteristics.1814-AA086-M0238, REV. 0Page 343 of 415 Page 343 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 201310.4 References10-1 P. J. Langford, "Design, Assembly, and Inspection of Advanced U-Bend/Anti-VibrationBar Configurations for PWR Steam Generators," Transactions of the ASME Journal ofPressure Vessel Technology, Vol. 111, Nov. 1989, pp. 371-377.10-2 H. J. Connors and F. A. Kramer, "U-bend Shaker Test Investigation of Tube/AVB WearPotential," Fifth International Conference on Flow-lnduced Vibrations, Paper C416/014,IMechE, Brighton, U. K., May, 1991, pp. 57-67..10-3 P. J. Langford and H. J. Connors, "Calculation of Tube/AVB Wear from U-Bend ShakerTest Data," Fifth International Conference on Flow-Induced Vibrations, Paper C416/040,IMechE, Brighton, U. K., May, 1991, pp. 45-55.10.4 LTR-SGMP-12-73, "San Onofre Nuclear Generating Station (SONGS) Unit 2 -ProjectedTube Wear Values for 18 Month Refuel Cycle at 70% Power Level", J. X. Jenko.1814-AA086-M0238, REV. 0Page 344 of 415 Page 344 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Appendix A: NomenclatureAAiA,A,B,CASMEATHOSATHOGPPATHOSGPPAVBClCLCmCRCCQRCECFDCLCLCOLDCLEGGCCLHOTCLSEPd, DDeDitubeEECTEFPMEPRIERfnFFASTVIBFLOVIBFIVFSRFWHLHTRESFIDIPareatube inside areastabilizer areaempirical constants in damping correlationsAmerican Society of Mechanical EngineersAnalysis of the Thermal-Hydraulics of Steam GeneratorsWestinghouse's version of the pre-processor program to ATHOSEPRI's version of the pre-processor program to ATHOSanti-vibration barempirical turbulence constant (magnitude)lift coefficientadded mass coefficientrandom excitation coefficientpressure loss factors for AVBs in the U-bend regionCombustion Engineeringcomputational fluid dynamicscold legpressure loss factors for the downcomer on cold legpressure loss factors for the tube support platespressure loss factors for the downcomer on hot legpressure loss factors for the primary separatorstube diameterequivalent hydraulic diametertube inner diametermodulus of elasticityeddy current testeffective full power monthsElectric Power Research InstituteExcitation Ratiovibration frequency in nth mode (Hz)forcecomputer code for FIV analysiscomputer code for FIV analysisflow-induced vibrationfluidelastic instability ratio = Ue/Ucfeedwaterhot legfouling factor value input to ATHOSinside diameterin-plane1814-AA086-M0238, REV. 0Page 345 of 415 Page 345 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013ISIIX, IY, IZKLmMHIMs, msNNDDNSSSODOPpPDRUMPeff AirPeffWaterPLATESPs,psPw, PwRRMSRPCRSGRxCySSCESGSONGSSRSSSVItTAPE7, TAPE20TodTwTEMATHTSPTTWUUc, UcnUe, Uenin-service inspectionindex directions, x, y, and z in ATHOS modelappropriate tube wear coefficientlengthmass per unit lengthMitsubishi Heavy Industriesstabilizer weight per lengthnumberno detectable degradationnuclear steam supply systemouter diameterout-of-planetube pitchpressure in the steam domestabilizer effective density with air surroundingstabilizer effective density with water surroundingpre-processor program to ATHOSstainless steel densitywater densityradius, radial directionroot mean squarerotating pancake coilreplacement steam generatorrow x column y tube locationempirical turbulence constant (slope)Southern California Edisonsteam generatorSan Onofre Nuclear Generating Stationstability ratio or instability ratio (same as FSR)stainless steelsingle volumetric indicationtimebinary files to the PLATES programtube outer diametertube wall thicknessTubular Exchanger Manufacturers Associationthermal-hydraulictube support platetube-to-tube wearvelocitycritical velocityeffective velocity1814-AA086-M0238, REV. 0Page 346 of 415 Page 346 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013V calculated wear volumeVGUB post-processor program from ATHOSWr workrate coefficientWR workrateZW axial locations in ATHOS model1814-AA086-M0238, REV. 0Page 347 of 415 Page 347 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Greekoa modal effective slip void fractionj3 threshold fluidelastic instability constant6 damping log decrement, 5=2nr8(x) displacement at position x in ASME terminologycritical damping ratio (%)Tcircumference/diameter of circle, 3.141...p densitynormalized mode shape factor0 circumferential directionSubscriptsupstreama TSP/AVBse equivalentEff effectivef liquid phaseg vapor phaseG geometryinside, index for summation or integrationindex for summation or integrationm massmax maximumn mode numbero outside, reference conditiont tubeSuperscriptsempirical exponent in damping correlation1814-AA086-M0238, REV. 0Page 348 of 415 Page 348 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Abbreviations for Units in Measurement SystemsHzkg, IbmIb, lbftm, mm, ft, inhr, sec or sbar, Pa, psia, ksiW, BtuOK, °C, OFHertz (cycles/s)kilograms, pounds masspounds force1000 kg or metric tonmeters, millimeters, feet, incheshours, seconds105 Pascals, Pascals, pounds per square inch absolute, 1000 psiWatts, British thermal unitsdegrees Kelvin, Celsius, Fahrenheit1814-AA086-M0238, REV. 0Page 349 of 415 Page 349 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Appendix B Additional Proximity Analysis for R111/1113C81This appendix contains additional discussion and analysis results not contained in Revision 0 ofthis report. This discussion provides a reasonable explanation of how the two SG 2E089 tubeswere in contact and produced the free span wear found on R11IC81 and R113C81. It isrecognized that there may be other explanations regarding how this wear was produced,however, the following provides a basis for the observations found during both the PSI and therecent ISI inspections.B-1 IntroductionSection 7.5 addresses the two tubes found with tube-to-tube wear in Unit 2. After completion ofthe original report, additional eddy current and computer analysis of the conditions associatedwith SG 2E089 was performed. The following contains results of this analysis. One key aspectof the analysis is the condition of the SG tube bundle prior to start up. During the pre-serviceinspection, it was determined that a proximity condition existed for these two tubes(R111/113C81). These indications are likely to be associated with conditions that developedduring SG manufacture. Section 8.2.1 discusses issues that can occur during assembly of theSG tube bundle that could affect how proximity conditions could develop.B-2 Eddy Current ReviewThe FIV analysis performed by Westinghouse concludes that tube locations Ri 11 C81 andR113 C81 in SG 2E089 remain stable in the in-plane direction at both 100% and 70% powerlevels. The review of AVB wear scar characteristics indicates that there was no extension of thewear scars beyond the width of the AVBs, thus supporting the analysis results that these tubes,as well as all other tubes in SGs 2E088 and 2E089 that had a review of their ECT dataperformed, remained stable in the in-plane direction.Westinghouse was requested to provide an explanation as to how freespan wear could beobserved on R1ll C81 and R113 C81 without extension of the wear scars beyond the AVBs.The following discussion presents an explanation of how this could occur.B-2.1 Industry Freespan Wear Experience Without In-Plane InstabilityIn recirculating style SGs, there have been numerous examples of tube-to-tube wear without in-plane instability; these examples are exclusive to the original Combustion-Engineering (C-E) SGplants, in the upper bundle square bend region. The tube OD and triangular pitch array in theoriginal C-E style is identical to the SONGS RSGs. In the original C-E SG design, variances inthe tube horizontal run dimension, square bend control, and eggcrate tube support positioningcan create a reduced tube-to-tube gap condition. Tube wear patterns at the vertical strapassembly often showed tapered wear scars on both of the vertical strips, and sometimes at bothedges of the vertical strips. This would indicate that the tube was experiencing out-of-planedisplacement, with an oscillatory pattern. It is then entirely plausible that tube-to-tube wear couldbe experienced at reduced tube-to-tube gap conditions just below the square bend region.1814-AA086-M0238, REV. 0Page 350 of 415 Page 350 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013At one plant, tube-to-tube wear was experienced in the horizontal run region, just outside of thesquare bend. In this instance, variance in the tube vertical straight leg dimension created areduced tube-to-tube gap dimension at this location.At another plant in 2004, tube-to-tube wear was reported on a tube in the vertical straight legregion, just below the square bend. The elevation of the indication was actually within the boundsof the diagonal bar, but clearly rotated 90 degrees from the diagonal bar on the +Pt terrain plot.One of the adjacent tubes in the same column was degradation free; the other tube was pluggedseveral outages prior and no RPC data was available for this tube at the time of plugging. Itshould be noted that this indication would have remained in service if the RPC testing had notbeen performed. This SG has mill annealed tubing and one of the special interest RPC programsimplemented was a sampling of historical bobbin signals at tube support structures to confirm thedegradation morphology. Due to the tubing material, axial ODSCC was a potential degradationmechanism thus the RPC sampling program intended to confirm the morphology of the historicbobbin signals.Scrutiny of the bobbin data could not identify presence of tube-to-tube proximity below theindication. In the square bend region, it was judged that the inherent interference associated withthe square bend geometry, limited proximity detection using the bobbin coil. RPC data isavailable for both 3-coil and single coil +Pt probes. The 3-coil probe includes a +Pt coil, a0.115 inch pancake coil, and a 0.080 inch high frequency pancake coil. The single coil +Pt andthe +Pt coil of the 3-coil probe did not detect proximity above or below the indication. Theelevation of the indication was such that a substantial length of tube above the indication could beacquired with the 3-coil probe, thus adequate pancake coil data is available to formulate proximityjudgments. The 0.115 inch pancake coil does not show proximity below the indication, butproximity is observable immediately above the indication, in the square bend, and in-line with thewear indication. A short portion of the wear length and proximity length overlap, but wear is notreported over the entire length of proximity. The 0.115 inch pancake coil signal amplitudesuggests a proximal gap of approximately [ ]a,b,c inch. Figure B-1 presents the 0.115 pancakecoil terrain plot showing the proximity signal and the tube-to-tube wear signal. The cursor (smallwhite arrow) is located at the upper edge of the wear signal.B-2.2 Causative Mechanism for Explanation of the Presence of Freespan Wear Without WearExtension from A VBsA review of the PSI bobbin data for SG 2E089 indicates that numerous proximity reports wereobserved on the Row 95 to 123 tubes in Column 81. Based on the bobbin coil proximityamplitude on Rlll C81, the estimated gap with R113 is [ ]a,b,c inch. The signalamplitude on R113 C81 could estimate the gap at [ ]a,bc inch, however, a proximitysignal with Rl15 C81 is also present. Since RPC data was not collected at the PSI, the truecontribution to the signal observed on RI13 C81 cannot be determined. Therefore, the gapcondition has to apply the most conservative value of 0.11 to 0.12 inch.The proximity review described in Section 5 shows that between the PSI and ISI inspections,proximity signals can remain unaffected, could no longer be observable, could be created, or1814-AA086-M0238, REV. 0Page 351 of 415 Page 351 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013could shift from one leg to the other on the same tube. With that said, the proximal condition atany point in time during the first operating cycle could be indeterminate.The PSI proximity condition suggests that the U-bend shape could be non-uniform. This non-uniform condition will create residual stresses within the U-bend. Contact forces between tubesand AVBs could be such that tubes could be held in position for some operating period until suchtime that these forces are reduced or relaxed, thereby allowing the tube to return to its equilibriumcondition.An evaluation of tube motions due to thermal, pressure, and turbulence effects indicate thatrelative displacements of these tubes to each other can close a proximal gap of 0.03 inch but isnot quite sufficient to close a gap of 0.11 to 0.12 inch.The ISI bobbin data could not identify a proximity condition on these (RI1l/R113 C81) tubes.Similarly, a proximity condition was not observed on R115 C81 in the ISI data. UT examinationperformed by AREVA suggests a tube-to-tube proximity condition between Ri 11 C81 andR113 C81 of approximately 0.19 inch in the area of the tube-to-tube wear, while at the sameelevation, the tube-to-tube gap between R113 C81 and Rl15 C81 was approximately 0.31 inch,or near the design nominal condition. Thus, the UT data suggests that the proximity conditionbetween R111, R113, and R115 could imply that if these tubes returned to an equilibriumcondition during the first operating cycle, the gap between RI13 and Ri15 is near nominal,whereas the gap between R1 11 and R1 13 could suggest that the R1 11 U-bend length is longerthan design nominal. Alternatively, this condition could be attributed to a longer than designvertical straight leg dimension for RI 11, which would only increase the potential for tube-to-tubewear due to out-of-plane vibration. The UT data for Ri I1 C81 also indicates that the dimensionsto R112 C80 and R112 C82 are much smaller than nominal, while the dimensions to R110 C80and R1 10 C82 are larger than nominal. These observations also support the judgment that eitherthe R1 11 U-bend is not near normal, or the vertical straight leg length of R1 11 C81 is longer thannominal.Still the question which must be answered is how the current gaps could be justified. Anextensive review of the wear scars on the Column 81 tubes was performed. A pattern quicklyemerged, which was that oddly shaped wear scars were observed at AVB 5. The profile of thesewear scars has a differing depth profile that is not uniformly deep (flat wear) and not a singletapered indication. Instead, these wear scars exhibited a "saw-tooth" profile, clearly formed bytwo distinct wear scars. This pattern can be explained by a sudden shift in the tube positionrelative to the AVB, in other words, the tube "skipped" relative to the AVB. The proximity reviewconcludes that changing proximity condition is common within these SGs. To rule outdisplacement of the AVB, the bobbin data of the PSI and ISI examinations was reviewed. Sinceno RPC data is available for the PSI, bobbin data must be used. The bobbin low frequencydifferential channel was used to establish that the overall length of the bobbin signal response(from a null-to-null condition) was essentially identical between the PSI and ISI exams, thus it canbe concluded that the AVBs did not change position.These characteristic wear scars were observed on R113 C81, R115 C81, R117 C81, R119 C81,R121 C81 and R123 C81, all at the AVB 5 location. An example of such wear scars is shown on1814-AA086-M0238, REV. 0Page 352 of 415 Page 352 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Figure B-2, Figure B-3, and Figure B-4. Figure B-3 presents the +Pt terrain plot of R113 C81 atthe AVB 5 location. Each figure includes the +Pt 300/100 mix channel (for flaw detection) and the35 kHz channel response, for identification of the edges of the AVBs. If the wear bounded by theAVB edges represents the most recent wear (prior to shutdown), and the wear is tapered, thedistance from the edge of the original wear to the edge of the AVB can be used to estimate theamount of tube displacement. This dimension has been estimated to range from 0.12 to0.40 inches, for those tubes which show this characteristic. Note also that this samecharacteristic was observed on R1 29 C91, at AVB 5. This tube was reported with a proximity callon the cold leg in the PSI data but in the ISI data, a proximity call was reported on the hot leg.Another characteristic of the wear at AVB 5 on these tubes was that shallow depth, short lengthwear scars were sometimes observed on the opposite AVB. These wear scars were clearly ofmuch shallower depth than the wear scars which exhibited the odd shape. The only way that awear scar could be observed in the middle of the AVB (not extending to any AVB edge) is if thetube shifted relative to the AVB at some point in time during operation.These atypical indications are associated with significant observations of AVB symmetryvariance. In SG 2E089, the largest AVB symmetry variance is observed at AVB 6, and forColumn 81, AVB 7 also has significant AVB symmetry variance. If the AVB symmetry variance isassociated with AVB twist, and the amount of twist is correlated with symmetry variance, then thelargest contact forces would be observed for AVB 6 and AVB 7. As the larger contact forceswould reduce the potential for wear, once sufficient wear has occurred at other AVBs to reducethe overall contact force thus permitting the tube to return to its equilibrium condition, the tube canthen skip to its current condition. For AVBs 5, 6, 7, and 8, the 95th percentile AVB wear depthsare essentially equal, but the AVB 5 depths are deeper for Column 81. For Ri 13 C81, thedeepest AVB wear depth is observed at AVB 5 (based on +Pt results).The deepest AVB wear depth reported from +Pt analysis in SG 2E089 was reported on R121C83 at AVB 5. The indication appears to be uniformly deep and does not show signs of tubedisplacement relative to the AVB. The wear is single sided; the opposite AVB has not causeddegradation of the tube. The +Pt 35 kHz residual data suggest no AVB twist on either bar,however the residual responses for the AVB without wear are modestly less than the AVB withwear. The deepest indication in SG 2E089 reported by bobbin coil analysis was reported onRi 17 C81 at AVB 9; this indication also appears to have a uniformly deep profile. The deepestwear depth reported from bobbin coil analysis in SG 2E088 was reported on R1 33 C91 at AVB 6.The +Pt terrain plot indicated the indication is stepped. The opposite AVB does not contain wear.The +Pt 35 kHz residual voltages are essentially equal for this AVB, indicating no twist. The35 kHz +Pt residual voltages on the AVB with wear show a large variance, suggesting significantAVB twist (about 2 degrees).B-2.3 Detection Condition Associated with Wear Extension from AVBsThe detection condition associated with wear extension from AVBs was investigated. To performthis assessment, the +Pt 300/100 mix channel noise was compared for the middle of the AVBregion and the freespan region just outside of the AVB. The vertical maximum noise conditionoutside of the AVB was exceptionally small; on the order of 0.02 to 0.04 volt. The noise condition1814-AA086-M0238, REV. 0Page 353 of 415 Page 353 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013within the AVB was typically 50% larger than just outside of the AVB. Therefore, if tapered wearis experienced, and the shallower edge of the wear has a distinct character (i.e., the tapered wearextends for the full length of the AVB width) and no wear is observed outside of the AVB, it canbe concluded that no wear is present outside of the AVB as the length along the tube axis fromthe edge of the wear to just outside of the AVB is short, and not of sufficient length to allow thewear to runout to the tube OD. Since the noise condition within the AVB is greater than justoutside of the AVB, the detection of wear within the AVB would then imply a detectable conditionand the wear extension would be detected.B-3 Temperature Pressure and FIV EffectsA tube-to-tube gap of approximately 0.19 inch near the tube-to-tube wear region was measuredafter the first cycle of operation between the Rl11C81 and RI13C81 tubes. The gaps betweenAVBs 3 and 4 were also measured for these tubes. The gap between R1 11C81 and R113C81was not measurable but a gap of 0.18 inch was measured between R109C81 and R111C81. Thegaps between AVBs 3 and 4 and AVBs 9 and 10 between R113C81 and R115C81 weremeasured around 0.30 to 0.31 inch which is close to the nominal gap of 0.31 inch for this locationin the U-bend. The maximum design spacing is 0.344 inch at the top of the U-bend for thesetubes. The design spacing of the tubes is shown in Figure B-5. In the UT data there is noreference point to determine if any of the tubes are in the design shape so an assumption needsto be made for the geometry of these tubes. It appears that the RI111C81 tube is deformedrelative to the other tubes so it will be assumed that the Ri 13C81 tube is nominal in shape andthe R1l1C81 tube is deformed in a way that follows the gap measurements. A sketch of thisgeometry is shown in Figure B-6.B-3.1 Tube Thermal ExpansionOne way to postulate a closure in the tube spacing is to assume that the two tubes with tube-to-tube wear are allowed to move within the tube support plate holes as they expand due to normaloperating temperature and pressure.Using the tube support plate drawing, Reference B.1, for the broached hole pattern, the maximumgeometrical tolerances for the tube support plate holes were considered. Using the maximumtube support plate dimensions and the minimum tube size, it was determined that the tube canmove [ ]a,c,e inch within the tube support plate before it comes to rest on the opposite side ofthe tube. The maximum dimensions of the tube support plate broaching are shown in Figure B-7.The maximum tube movement within the tube hole is also shown in Figure B-7. The scenariothat would cause the maximum movement between the tube support plate is the scenario whenR1 11C81 is resting on the left side of the broaching at the hot leg and cold leg side. When thetube is brought up to the normal operating temperature and pressure, the tube will expandoutward which will cause the tube to move to the outside positions in the tube support plate holes.The RI 13C81 tube is assumed to be in the exact opposite configuration where the tube is pushedto the right side of the tube support plate holes. A schematic of this effect is shown in Figure B-8.This tube model was simulated using the ANSYS finite element program using Solid186 three-dimensional structural solid elements and Solid90 thermal elements. These elements are a 201814-AA086-M0238, REV. 0Page 354 of 415 Page 354 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013node brick element. A plot of the meshed model in the U-bend region is shown in Figure B-9.The temperature solution was obtained from the FASTVIB output for the 100% power case for theRi11C81 tube. The temperature profile for the Ri13C81 tube was almost identical to theRi11C81 tube so the same temperature profile was applied to both tubes. The temperaturedistribution was applied to the tube by fixing the temperature at the tube support plate locationsand then solving for the steady state temperature solution. The temperature change around thetube is fairly gradual such that the steady state solution from ANSYS matches the ATHOS datafairly closely.The tubes were fixed at the tubesheet end of the model and nodes were pinned in the X and Zdirections at the tube support plate locations. The AVB supports were neglected in the model.The AVB supports are assumed to be sufficiently loose such that they do not provide support inthe in-plane direction.The results show that the R111C81 displaces 1.181 inches and R113 displaces 1.159 incheswhich gives a relative displacement of negative 0.022 inches.B-3.2 Tube Movement at A VB 5It has been found that at AVB 5 for Tube R1 13C81 that there appears to be a jump in the positionof the wear scar found in the eddy current data. There are two sawtooth marks on the one side ofthe tube which indicates that the AVB is twisted and wore a mark that moved slightly then beganto wear in a different spot. In the opposite side of the tube, the AVB also appears to be twistedbut the wear scar is near the center of the AVB position at the cold leg. This is an indication thatthe tube has shifted in position relative to AVB 5. The postulation that R 110C81 and Ri 13C81were initially much closer than the current measurement states that they moved farther apartwhen this shift in tube position occurred. The finite element model works backwards from thisscenario by assuming the inspection geometry of the tubes and then applying a displacement todetermine how close the tube was prior to the displacement. The eddy current wear scarsindicate the tube moved approximately 0.12 inch to 0.18 inch.The deformed shape model from Section B-3.1 was used and the tube was displaced towards thecold leg side in the X direction 0.12 inch then 0.18 inch. The displacement was applied to themodel at the centerline where AVB 5 would cross Tube R1 13C81. A local coordinate system wasthen used to determine the amount of displacement of Tube Ri 110C81 relative to Tube R1 13C81.The results of the displacement models are shown in Figure B-10 and Figure B-11 for the0.12 inch and 0.18 inch displacement, respectively. It is shown that for a displacement of0.12 inch or 0.18 inch, the close up in the gap is approximately one for one. The difference indisplacement versus gap closure is only 1 mil different.B-3.3 In-Plane Turbulent DisplacementIn addition to the finite element models used to show that the tube gap closes, there can also bein-plane motion due to flow turbulence. This in-plane turbulence motion is displacement limitedand should not be considered a similar effect as in-plane stability. The purpose of this section isto evaluate the magnitude of turbulent displacement to be used to support the explanation that1814-AA086-M0238, REV. 0Page 355 of 415 Page 355 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013the tubes with tube-to-tube contact are not unstable in-plane. It is known that these tubes havecloser than nominal proximity at the cold condition so the tube-to-tube contact is being explainedas extreme tube-to-tube proximity with a combination of in-plane turbulent motion and out-of-plane fluidelastic motion.A FASTVIB evaluation was performed for the tubes that had tube-to-tube contact in SteamGenerator 2E089. These tubes are R111C81 and R113C81. The turbulent constants C1 and Sapplicable to the SONGS steam generators are shown in Table B-i. There are two sets ofconstants based on the flow characteristics around the tube. Two FASTVIB runs for each caseare run based on each set of constants. The FASTVIB evaluation was condensed to only includethe tubes in Row 111 and Row 113. T he two tubes, R11IC81 and R113C81, have a definedmissing AVB Case 61.The results of the FASTVIB runs show that the root mean square (RMS) turbulent displacementis approximately [ Ia,c,e inch for each tube using either set of turbulence constants. UsingReference B.2, the RMS turbulent displacement can be converted to a peak displacement by afactor of 3.5. Assuming both tubes are vibrating, the maximum distance the tubes can be apartand touch due to turbulent displacement is [ ]a,c,eB-4 SummaryFrom the review of the eddy current data and the analysis of the tubes response due to pressuretemperature and FIV effects, it appears that the two tubes were very close or were in contact atthe start of operation following replacement. The tubes would not have necessarily been incontact before operation, but could have contacted due to peak displacements as a result of in-plane turbulence. Note that displacements associated with the fluidelastic mechanism are notsimilar to turbulence induced displacements, as the turbulence mechanism is self limiting.UT measurements performed during the recent outage indicates that the tubes could be as closeas 0.19 inch. As with all measurements of this type, there are measurement uncertainties thatare present in the signals. The uncertainty associated with the UT measurements could rangefrom an estimated low of 4 mils to approximately 20 mils. This means that the actual low end ofthe gap could range from 170 mils to 186 mils. This is the range of gap sizes that could havedeveloped after the tubes have shifted to the current location. Figure B-12 describes how thetubes could have initially worn due to proximity, and then moved or shifted during operationcoupled with temperature and pressure effects to result in the currently observed condition.In summary, it appears as if the tubes were initially very close, or actually contacting prior tooperation, where FIV induced turbulence vibration could have produced the observed wear.Then after operation for a period of time, the tubes moved, or skipped to a new location, similar tothe skip found in other tubes in the region (up to 0.4 inches). Figures B-13 and B-14 provide avisual indication of how these tubes could have moved. Additional movement of the tubes ispossible due to pressure and temperature effects that would then result in the currently observedcondition.1814-AA086-M0238, REV. 0Page 356 of 415 Page 356 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013B-5 ReferencesB-I. SanMHIA.B.C.D.E.F.G.H.I.J.K.Onofre Nuclear Generating Station Units 2 and 3 Replacement SteamDesign Drawings:L5-04FU001, Rev. 6, "Component and Outline Drawing 1/3".L5-04FU051, Rev. 1, "Tube Bundle 1/3".L5-04FU052, Rev. 1, "Tube Bundle 2/3".L5-04FU053, Rev. 3, "Tube Bundle 3/3".L5-04FU 101, Rev. 5, "Wrapper Assembly 1/5".L5-04FU 107, Rev. 3, "Tube Support Plate Assembly 2/3".L5-04FU108, Rev. 3, "Tube Support Plate Assembly 3/3".L5-04FU112, Rev. 1, "Anti-Vibration Bar Assembly 2/9".L5-04FU1 18, Rev. 3, "Anti-Vibration Bar Assembly 8/9".L5-04FU 134, Rev. 6, "Moisture Separator Assembly 4/6".L5-04FU135, Rev. 5, "Moisture Separator Assembly 5/6".GeneratorsB-2. B. Brenneman and J. Q. Talley, "RMS Fatigue Curves for Random Vibrations,"Transactions of the ASME,Vol. 108, Nov. 1986.1814-AA086-M0238, REV. 0Page 357 of 415 Page 357 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Table B-1Turbulence Constantsaiqht LeQ ReQion I U-bend Reqion ,Parameter I Str4 ---I -Turbulence (fD/U > 0.13)C,STurbulence (fD/U < 0.13)C,S1814-AA086-M0238, REV. 0Page 358 of 415 Page 358 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Figure B-1Other Plant Experience Showing Relation of Tube-to-Tube Wear and Proximity atShutdown Condition1814-AA086-M0238, REV. 0Page 359 of 415 Page 359 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Figure B-2SONGS SG 2E089 Stepped Indication at AVB 5 on RIl 15 C811814-AA086-M0238, REV. 0Page 360 of 415 Page 360 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Figure B-3SONG SG 2E088 Stepped Indication at AVB 6 on R133 C911814-AA086-M0238, REV. 0Page 361 of 415 Page 361 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Figure B-4SONGS SG 2E089 Stepped Indication at AVB 5 on R113 C811814-AA086-M0238, REV. 0Page 362 of 415 Page 362 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013-.34113-I01 _ .34DETAIL A113I'llI1DETAIL BFigure B-5Shape of R1IIC81 and R113C81 Tubes Based on Nominal Dimensions1814-AA086-M0238, REV. 0Page 363 of 415 Page 363 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013113DETAI I1DETAIL B "-Io-9" .18DETAIL AAVB 3-4AVB 9-101 13 -I'll -.109.Figure B-6Shape of R111C81 and R113C81 Tubes Based on Measured Gaps1814-AA086-M0238, REV. 0Page 364 of 415 Page 364 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013 *bFigure B-7Tube Support Plate Maximum Dimensions1814-AA086-M0238, REV. 0Page 365 of 415 Page 365 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013COLDHOTNQT TO SCALE TO S£OW EXA=,ET-AT EhO Figure B-8Tube Support Plate Hole -Tube Movement1814-AA086-M0238, REV. 0Page 366 of 415 Page 366 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Figure B-9Meshed Tube Model1814-AA086-M0238, REV. 0Page 367 of 415 Page 367 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 20130.000 1.000 (in)0.500Figure B-100.12 Inch Displacement at AVB 5 Results (inches)1814-AA086-M0238, REV. 0Page 368 of 415 Page 368 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 20130.000 10.000 (in)5.000inIFigure B-110.18 Inch Displacement at AVB 5 Results (inches)1814-AA086-M0238, REV. 0Page 369 of 415 Page 369 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Gap -> 0 Mils1I R11IC81 and R113C81 Tube in Contact DuringOperation (Including Turbulent Displacement)IGap ->[21 M,1. ]a c,eI Tube Gap without Peak Turbulent Displacement][ T b G (2 1 M l ) ] , ,IGap ->141 to -201 ]rc'eMils Tube Gap Including Tube Shift in Eddy Current3 Wear Data (120 to ~180 mils)Mils 1 Tube Gap Including Pressure and Thermal4H Effects on One Tube (11 mils)170 -186 milminimummeasure gapwith these*7 ranges5 ap-4 °3to 315KlTube Gap Including Pressure and ThermalEffects on 2nd Tube (11 mils)Figure B-12Tube Gap Development1814-AA086-M0238, REV. 0Page 370 of 415 Page 370 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013AVB 5--CURRENT POSITIONR1 13C81, AVB 5INITIAL POSITION\\INITIALWEAR SCARIFigure B-13R113C81 AVB "A" Eddy Current Wear Profile1814-AA086-M0238, REV. 0Page 371 of 415 Page 371 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013CURRENT POSITIONPOSITIONR 1 13C 81-jiDCURRENTWEAR SCARFigure B-14R113C81 AVB "B" Eddy Current Wear Profile1814-AA086-M0238, REV. 0Page 372 of 415 Page 372 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Appendix C Effect of Installation of Split Cable Stabilizers in the Tube FIV ResponseC-1 IntroductionThe main body of this report documents the acceptability of operation of the SONGS Unit 2steam generators after finding significant tube wear during the recent eddy current inspection.The analysis determined that future operation at 70% power would result in all active tubessatisfying the applicable SG tubing performance criteria. During the course of the outage asignificant number of tubes were removed from service, and many of these tubes will bestabilized using AREVA split stabilizers. The post-inspection tube FIV analysis addressed futureoperation at a reduced power level of 70%, but it did not address changes in FIV response withthe addition of the AREVA split stabilizers. The purpose of this appendix is to determine how thetube FIV response changes once the stabilizers are installed while the SGs are operated at 70%power. This information was originally transmitted in Reference C-2 and has been included as asupplementary appendix to this report.The effects of the addition of stabilizers in the tubes will be determined as indicated below:1) Generate stability ratio maps for all tubes for the more limiting support condition cases(higher number of missing AVBs) for the conditions both with and without stabilizersfor operation at 70% power.2) Prepare a more detailed analysis of the limiting tubes as identified in Table 8-1. Thiswill look at specific tubes with the specific support condition at 70% power. Stabilityratios will be presented for the cases both with and without stabilizers for operation at70% power.The following is a summary of the methods and results associated with this analysis. Note thatthe analysis focused on the fluidelastic stability ratios calculated for the in-plane direction. Out-of-plane excitation ratios were also included for the limiting plugged tubes.C-2 MethodC-2.1 FASTVIBThe analysis makes use of the FASTVIB computer code used in the original analysis anddiscussed in the main body of the report. The inputs and boundary conditions used in thecurrent analysis are the same as those used in the original analysis for the base case(70% power, no stabilizers). The prior analysis contains all the relevant background informationassociated with the FIV analysis. For the cases where a stabilizer is to be installed, theproperties associated with the stabilizer are those defined in Section C-2.2.1814-AA086-M0238, REV. 0Page 373 of 415 Page 373 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013C-2.2 Stabilizer PropertiesThe stabilizer is a 1/2 inch diameter wire rope manufactured from 304 or 316 stainless steel. Theweight and damping properties for the stabilizers have been defined in Reference C-1 and arerepeated below:I I]a,b,c,e -Minimum additional damping0.46 lbs/ft -WeightThe length of the stabilizer varies depending upon which row the cable is to be installed.Table C-1 contains a summary of lengths associated with each of the rows. Each tube will havetwo cables installed, one in the hot leg and one in the cold leg. Note that the design objective isto have the cable installed from the tubesheet and extend into the U-bend to a point 60 degreesfrom the top of the straight leg (not the top tube support plate (TSP)). This places the ends of thestabilizers 30 degrees from the top of the U-bend on both of the of the tube legs.1814-AA086-M0238, REV. 0Page 374 of 415 Page 374 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Table C-1Cable Stabilizer Lengths per Row b1814-AA086-M0238, REV. 0Page 375 of 415 Page 375 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013C-3 ResultsThe out-of-plane and in-plane results for both active tubes and stabilized tubes were tabulatedfor the limiting tubes in Table C-2. These results were compared at 70% power where an activetube is the result for unplugged tube and the stabilized result is for a plugged tube containing astabilizer. The stabilized tube is also assumed to be filled with water. It was shown inSection 4.4.2 that the difference between the excitation/stability ratios is small whether the tubeis surrounded by air or is surrounded by water. In all cases, the stability ratio decreased as aresult of the introduction of the stabilizer in the tube.Stability ratio plots are also provided for a set of representative cases for the in-plane direction.Figure C-1 through Figure C-13 show the active tube stability ratio maps calculated at70% power. Figure C-14 through Figure C-26 show the stability ratio plots for the cases wherethe split cable stabilizer is considered with operation at 70% power. A summary table of all of theincluded stability ratio maps is included in Table C-3. Note that these figures have beengenerated assuming that all of the tubes in the maps have been stabilized with the split stabilizer.Tables C-4 and C-5 contain the actual tube plugging/stabilization lists for SONGS Unit 2.Figures C-27 and C-28 provide the same information in a tubesheet map form.1814-AA086-M0238, REV. 0Page 376 of 415 Page 376 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Table C-2Limiting Plugged Tube Stabilizer Excitation/Stability Ratio ComparisonNumber No Stabilizer No Stabilizer witho Stabilizer with Water Stabilizer WaterSG Case of 70% Power 70% Power 70% Power 70% PowerMissing Out-of-Plane Out-of- In-Plane In-PlaeAVBs PlaneIn-PlaneI __ Limiting Plugged and Stabilized TubesR133C91 2E088 45 5RI12C88 2E088 55 6R120C92 2E088 66 8R97C85 2E088 66 8R99C93 2E088 67 8R117C81 2E089 55 6R122C82 2E089 66 8R106C84 2E089 66 8R105C83 2E089 66 8R104C86 2E089 66 8R98C86 2E089 66 8R123C91 2E089 66 8R98C88 2E089 66 8R112C84 2E089 67 8R100C84 2E089 67 8F _ _Tubes with Tube-to-Tube WearR111C81 2E089 61 7 [R113C81 2E089 61 7 Ea,c,e1814-AA086-M0238, REV. 0Page 377 of 415 Page 377 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Table C-3FASTVIB IN-Plane Stability Ratio PlotsNumber of Figure Number forCase Missing Power Plugged andNo. AVB Level Active Tube StabilizedTube17 2 70% C-1 C-1428 3 70% C-2 C-1 537 4 70% C-3 C-1638 4 70% C-4 C-1745 5 70% C-5 C-1846 5 70% C-6 C-1953 6 70% C-7 C-2054 6 70% C-8 C-2160 7 70% C-9 C-2266 8 70% C-10 C-2371 9 70% C-11 C-2475 10 70% C-12 C-2578 12 70% C-13 C-261814-AA086-M0238, REV. 0Page 378 of 415 Page 378 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Table C-4SG 2E088 Tube Plugging/Stabilization List (Page 1 of 3)RSG 2E088 Tube Plugging/Stabilizing ListdRow J Col Plug I Stab Type"121 1 81-1 Yes SplitStab Length (in)Reason~-1 -. -NotebPreventative -FSW120 82 Yes Split Note b Preventative FSW105 Z3 "fes Split Note b Prevenlative -FSW107 83 Yes Split Note b Prepvntativa -FSW104 84 Yes Split Note b Preventative -FSW106 84 Yes Split Note b Preventative -FSW108 84 Yes Split Note b Preventative .FSW122 84 Yes Split Note b Preventative -FSW97 85 Yes Split Note b Preventative -FSW99 85 Yes Split Note b Preventative -FSW103 85 Yes Split Note b Preventative -1-SW1D 25 Yes Split Note b Preventative -FSW107 85 Yes Split Note b Preventative -FSW115 85 Yes Split Note b Preventative -FSW121 85 Yes Split Note b Preventative- FSW123 85 Yes Split Note b Preventative -FSW133 85 Yes Split Note b Preventative -FSW98 86 Yes Split Note b Preventative -rsw100 86 Yes Split Note b Preventative -FSW102 86 Yes Split Note b Preventative FSW104 86 Yes Split Note b Preventative.- FSW106 86 Yes Split Note b Preventative -FSW108 86 Yes Split Note b Preventative FSW112 86 Yes Split Note b Preventative -FSW114 86 Yes Split Note b Preventative -FSW116 86 Yes Split Note b Pteventative -FSW122 86 Yes Split Note b Preventative -FSW124 86 Yes Split Note b Preventative -FSW' 26 86 Yes Split Nnte h Preventative -FSW101 87 Yes Split Note b Preventative -FSWlM 87 Yes Split Note b Preventative -FSW105 87 Yes Split Note b Preventative -FSW111 87 Yes Split Note b Preventative -FSW113 87 Yes Split Note b Preventative -PSW115 87 Yes Split Note b Preventative -FSW121 Yes Split Note b Preventative -FSW123 87 Yes Split Note b Preventative -FSW125 87 Yes Split Note b Preventative -FSW100 88 Yes Split Note b Preventative -rSW102 88 Yes Split NOte b Preventative -FSW104 88 Yes Split Note b Preventative -FSW106 88 Yes Split Note b Preventative -FSW110 88 Yes Split Note b Preventative -FSW114 88 Yes Split Note b Preventative -FSWa) Split stabilizers are installed on the hot and cold side of the tubeb) See AREVA ProduLt Information Sheet for Stabilizer U-Bend (Ref. 7) for split stabilizer lengtthc) Conservatively plugged as a defense in depth action per WEC recommendation (Ref 9)d) See Table 1 in "8. Functional Objective of the Change" section for tubes that will maintain single stabilizer1814-AA086-M0238, REV. 0Page 379 of 415 Page 379 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Table C-4 (Continued)SG 2E088 Tube Plugging/Stabilization List (Page 2 of 3)RSG 2E088 Tube Plugging/Stabilizing ListdRow Col Plug Stab Type* Stab Length (in) Reason116 88 Yes Split Note b Preventative -FSW118 88 Yes Split Note b Preventative -FSW120 88 Yes Split Note b Preventative -FSW122 88 Yes Split Note b Preventative -FSW124 88 Yes Split Note b Preventative -FSW95 89 Yes Split Note b Preventative -FSW101 89 Yes Split Note b Preventative -FSW103 89 Yes Split Note b Preventative -FSW105 89 Yes Split Note b Preventative -FSW107 89 Yes Split Note b Preventative -FSW111 89 Yes Split Note b Preventative -FSW113 89 Yes Split Note b Preventative -FSW115 89 Yes Split Note b Preventative -FSW117 89 Yes Split Note b Preventative -FSW119 89 Yes Split Note b Preventative -FSW121 89 Yes Split Note b Preventative -FSW123 89 Yes Split Note b Preventative -FSW127 89 Yes Split Note b Preventative -FSW94 90 Yes Split Note b Preventative -FSW100 90 Yes Split Note b Preventative -FSW102 90 Yes Split Note b Preventative -FSW104 90 Yes Split Note b Preventative -FSW106 90 Yes Split Note b Preventative -FSW110 90 Yes Split Note b Preventative -FSW112 90 Yes Split Note b Preventative -FSW114 90 Yes Split Note b Preventative -FSW116 90 Yes Split Note b Preventative -FSW95 91 Yes Split Note b Preventative -FSW101 91 Yes Split Note b Preventative -FSW103 91 Yes Split Note b Preventative -FSW105 91 Yes Split Note b Preventative -FSW107 91 Yes Split Note b Preventative -FSW109 91 Yes Split Note b Preventative -FSW111 91 Yes Split Note b Preventative -FSW113 91 Yes Split Note b Preventative FSW115 91 Yes Split Note b Preventative -FSW117 91 Yes Split Note b Preventative -FSW98 92 Yes Split Note b Preventative -FSW100 92 Yes Split Note b Preventative -FSW102 92 Yes Split Note b Preventative -FSW104 92 Yes Split Note b Preventative -FSW106 92 Yes Split Note b Preventative -FSW108 92 Yes Split Note b Preventative -FSW110 92 Yes Split Note b Preventative -FSWa) Split stabilizers are installed on the hot and cold side of the tubeb) See AREVA Product Information Sheet for Stabilizer U-Bend (Ref. 7) for split stabilizer lengthsc) Conservatively plugged as a defense in depth action per WEC recommendation (Ref 9)d) See Table 1 in "B. Functional Objective of the Change" section for tubes that will maintain single stabilizer1814-AA086-M0238, REV. 0Page 380 of 415 Page 380 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Table C-4 (Continued)SG 2E088 Tube PlugginglStabilization List (Page 3 of 3)RSG 2E088 Tube Plugging/Stabilizing ListdStab Type' I Stab Length(in)Row112ColPlugReason.ventative -FSW92YesSplitNote bPre114 92 Yes Split Note b Preventative -FSW116 92 Yes Split Note b Preventative -FSW118 92 Yes Split Note b Preventative -FSW136 92 Yes Split Note b Preventative -FSW99 93 Yes Split Note b Preventative -FSW101 93 Yes Split Note b Preventative -FSW103 93 Yes Split Note b Preventative -FSW107 93 Yes Split Note b Preventative -FSW111 93 Yes Split Note b Preventative -FSW117 93 Yes Split Note b Preventative -FSW129 93 Yes Split Note b Preventative -FSW94 94 Yes Split Note b Preventative -FSW137 89 Yes Split Note b Preventative -FSW'135 93 Yes Split Note b Preventative -FSWf98 84 Yes Split Note b Wear at 6 Continuous AVBs88 88 Yes Split Note b Wear at 6 Continuous AVBs97 89 Yes Split Note b Wear at 6 Continuous AVBs108 90 Yes Split Note b Wear at 6 Continuous AVBs124 92 Yes Split Note b Wear at 6 Continuous AVBs134 94 Yes Split Note b Wear at 6 Continuous AVBsa) Split stabilizers are installed on the hot and cold side of the tubeb) See AREVA Product Information Sheet for Stabilizer U-Bend (Ref. 7) for split stabilizer lengthsc) Conservatively plugged as a defense in depth action per WEC recommendation (Ref 9)d) See Table I in "8. Functional Objective of the Change" section for tubes that will maintain single stabilizer1814-AA086-M0238, REV. 0Page 381 of 415 Page 381 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Table C-5SG 2E089 Tube Plugging/Stabilization List (Page 1 of 5)RSG 2E089 Tube Plugging/Stabilizing ListRow Col Plug StabTypet Stab Length (in) Reason111 81 Yes Split Note b 14% TWD -FSW (Preventative)113 81 Yes Split Note b 14% TWDD- FSW(Preventative)103 77 Yes Split Note b Preventative -FSW109 77 Yes Split Note b Preventative -FSW111 77 Yes Split Note b Preventative -FSW100 78 Yes Split Note b Preventative -FSW102 78 Yes Split Note b Preventative -FSW104 78 Yes Split Note b Preventative -FSW108 78 Yes Split Note b Preventative -FSW110 78 Yes Split Note b Preventative -FSW112 78 Yes Split Note b Preventative -FSW97 79 Yes Split Note b Preventative -FSW99 79 Yes Split Note b Preventative -FSW101 79 Yes Split Note b Preventative -FSW111 79 Yes Split Note b Preventative -FSW92 80 Yes Split Note b Preventative -FSW94 80 Yes Split Note b Preventative -FSW96 80 Yes Split Note b Preventative -FSW98 80 Yes Split Note b Preventative -FSW100 80 Yes Split Note b Preventative -FSW102 80 Yes Split Note b Preventative -FSW110 80 Yes Split Note b Preventative -FSW112 80 Yes Split Nute b Preventdtive -FSW114 80 Yes Split Note b Preventative -FSW91 81 Yes Split Note b Preventative -FSW93 81 Yes Split Note b Preventative -FSW95 81 Yes Split Note b Preventative -FSW97 81 Yes Split Note b Preventative -FSW99 81 Yes Split Note b Preventative -FSW101 81 Yes Split Note b Preventative -FSW103 81 Yes Split Note b Preventative -FSW105 81 Yes Split Note b Preventative -FSW107 81 Yes Split Note b Preventative -FSW109 81 Yes Split Note b Preventative -FSW115 81 Yes Split Note b Preventative -FSW117 81 Yes Split Note b Preventative -FSW119 81 Yes Split Note b Preventative -FSW121 81 Yes Split Note b Preventative -FSW90 82 Yes Split Note b Preventative -FSW92 82 Yes Split Note b Preventative -FSW94 82 Yes Split Note b Preventative -FSW96 82 Yes Split Note b Preventative -FSW98 82 Yes Split Note b Preventative -FSW100 82 Yes Split Note b Preventative -FSW102 82 Yes Split Note b Preventative -FSWa) Split stabilizers are installed on the hot and cold side of the tubeb) See AREVA Product Information Sheet for Stabilizer U-Bend (Ref, 7) for split stabilizer lengthsc) Conservatively plugged as a defense in depth action per WEC recommendation (Ref 9)1814-AA086-M0238, REV. 0Page 382 of 415 Page 382 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Table C-5 (Continued)SG 2E089 Tube Plugging/Stabilization List (Page 2 of 5)r104RSG ZE089 Tube Plugging/Stabilizing ListC!O~l82PlugYesStab Type' Stab Length (in)Split T Note bReasonPreventative FSW106 82 Yes Split Note b Preventative FSW108 82 Yes Split Note b Preventative -FSW110 82 Yes Split Note b Preventative -FSW112 82 Yes Split Note b Preventative -FSW114 82 Yes Split Note b Preventative -FSW116 82 Yes Split Note b Preventative -FSW118 82 Yes Split Note b Preventative -FSW120 82 Yes Split Note b Preventative -FSW122 82 Yes Split Note b Preventative -FSW91 83 Yes Split Note b Preventative -FSW93 83 Yes Split Note b Preventative -FSW95 83 Yes Split Note b Preventative -FSW97 83 Yes Split Note b Preventative -F$W99 83 Yes Split Note b Preventative -FSW101 83 Yes Split Note b Preventative -FSW103 83 Yes Split Note b Preventative -FSW10S 83 Yes Split Note b Preventative -FSW107 83 Yes Split Note b Preventative -FSW109 83 Yes Split Note b Preventative FSW111 83 Yes Split Note b Preventative -FSW113 83 Yes Split Note b Preventative -FSW115 83 Yes Split Note b Preventative FSW117 83 Yes Split Note b Preventative -FSW119 83 Yes Split Note b Preventative -FSW121 83 Yes Split Note b Preventative -FSW90 84 Yes Split Note b Preventative -FSW92 84 Yes Split Note b Preventative -FSW94 84 Yes Split Note b Preventative -FSW96 84 Yes Split Note b Preventative -FSW98 84 Yes Split Note b Preventative -FSW100 84 Yes Split Note b Preventative -FSW102 84 Yes Split Note b Preventative -FSW104 84 Yes Split Note b Preventative -FSW1OG 84 Yes Split Note b Preventative -FSW108 84 Yes Split Note b Preventative -FSW110 84 Yes Split Note b Preventative -FSW112 84 Yes Split Note b Preventative -FSW114 84 Yes Split Note b Preventative- FSW116 84 Yes Split Note b Preventative -FSW118 84 Yes Split Note b Preventative -FSW120 84 Yes Split Note b Preventative FSW126 84 Yes Split Note b Preventative -FSW128 84 Yes Split Note b Preventative -FSW132 84 Yes Split Note b Preventative -FSWa) Split stabilizers are installed on the hot and cold side of the tubeb) See AREVA Product Information Sheet for Stabilizer U-Bend (Ref. 7) for split stabilizer lengthsc) Conservatively plugged as a defense in depth action per WEC recommendation tRef 9)1814-AA086-M0238, REV. 0Page 383 of 415 Page 383 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Table C-5 (Continued)SG 2E089 Tube Plugging/Stabilization List (Page 3 of 5)R~C 2~flR~ Tube PlneelnelStnbllltlne ListRow Col Plug Stab Typeb Stab Length (in) Reason91 85 Yes Split Note b Preventative -FSW93 85 Yes Split Note b Preventative -FSW95 85 Yes Split Note b Preventative -FSW97 85 Yes Split Note b Preventative -FSW99 85 Yes Split Note b Preventative -FSW101 85 Yes Split Note b Preventative -FSW103 85 Yes Split Note b Preventative -FSW105 85 Yes Split Note b Preventative -FSW107 85 Yes Split Note b Preventative -FSW109 85 Yes Split Note b Preventative -FSW111 85 Yes Split Note b Preventative -FSW113 85 Yes Split Note b Preventative -FSW115 85 Yes Split Note b Preventative -FSW117 85 Yes Split Note b Preventative -FSW119 85 Yes Split Note b Preventative -FSW121 85 Yes Split Note b Preventative -FSW127 85 Yes Split Note b Preventative -FSW88 86 Yes Split Note b Preventative -FSW92 86 Yes Split Note b Preventative -FSW94 86 Yes Split Note b Preventative -FSW96 86 Yes Split Note b Preventative- FSW98 86 Yes Split Note b Preventative -FSW100 86 Yes Split Nute U Preventative -FSW102 86 Yes Split Note b Preventative -FSW104 86 Yes Split Note b Preventative -FSW106 86 Yes Split Note b Preventative -FSW108 86 Yes Split Note b Preventative -FSW110 86 Yes Split Note b Preventative -FSW112 86 Yes Split Note b Preventative -FSW114 86 Yes Split Note b Preventative -FSW116 86 Yes Split Note b Preventative -FSW118 86 Yes Split Note b Preventative -FSW122 86 Yes Split Note b Preventative -FSW130 86 Yes Split Note b Preventative -FSW93 87 Yes Split Note b Preventative -FSW95 87 Yes Split Note b Preventative- FSW97 87 Yes Split Note b Preventative -FSW99 87 Yes Split Note b Preventative -FSW101 87 Yes Split Note b Preventative -FSW103 87 Yes Split Note b Preventative -FSW105 87 Yes Split Note b Preventative -FSW107 87 Yes Split Note b Preventative -FSW109 87 Yes Split Note b Preventative -FSW111 87 Yes Split Note b Preventative -FSW113 87 Yes Split Note b Preventative -FSWa) Split stabilizers are installed on the hot and cold side of the tubeb) See AREVA Product Information Sheet for Stabilizer U-Bend (Ref. 7) for split stabilizer lengthsc) Conservatively plugged as a defense in depth action per WEC recommendation (Ref 9)1814-AA086-M0238, REV. 0Page 384 of 415 Page 384 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Table C-5 (Continued)SG 2E089 Tube Plugging/Stabilization List (Page 4 of 5)7 Row1 ColPIu~RSG 2E089 Tube Plugging/Stabilizing ListStab Type[ Stab Length (in) ReasonPlug11587YesSplitNote bPreventative -FSW117 87 Yes Split Note b Preventative -FSW119 87 Yes Split Note b Preventative -FSW129 87 Yes Split Note b Preventative -FSW94 88 Yes Split Note b Preventative -FSW96 88 Yes Split Note b Preventative -FSW98 88 Yes Split Note b Preventative -FSW100 88 Yes Split Note b Preventative -FSW102 88 Yes Split Note b Preventative -FSW104 88 Yes Split Note b Preventative -FSW106 88 Yes Split Note b Preventative -FSW108 88 Yes Split Note b Preventative -FSW110 88 Yes Split Note b Preventative -FSW112 88 Yes Split Note b Preventative -FSW114 88 Yes Split Note b Preventative -FSW116 88 Yes Split Note b Preventative -FSW118 88 Yes Split Note b Preventative -FSW138 88 Yes Split Note b Preventative -FSW95 89 Yes Split Note b Preventative -FSW97 89 Yes Split Note b Preventative -FSW99 89 Yes Split Note b Preventative -FSW101 89 Yes Split Note b Preventative -FSW103 89 Yes Split Note b Preventative -FSW105 89 Yes Split Note b Preventative -FSW107 89 Yes Split Note b Preventative -FSW109 89 Yes Split Note b Preventative -FSW111 89 Yes Split Note b Preventative -FSW113 89 Yes Split Note b Preventative -FSW115 89 Yes Split Note b Preventative -FSW117 89 Yes Split Note b Preventative -FSW131 89 Yes Split Note b Preventative -FSW100 90 Yes Split Note b Preventative -FSW102 90 Yes Split Note b Preventative -FSW104 90 Yes Split Note b Preventative -FSW106 90 Yes Split Note b Preventative -FSW108 90 Yes Split Note b Preventative -FSW110 90 Yes Split Note b Preventative -FSW112 90 Yes Split Note b Preventative -FSW114 90 Yes Split Note b Preventative -FSW116 90 Yes Split Note b Preventative -FSW118 90 Yes Split Note b Preventative -FSW130 90 Yes Split Note b Preventative -FSW132 90 Yes Split Note b Preventative -FSW134 90 Yes Split Note b Preventative -FSW99 91 Yes Split Note b Preventative -FSWa) Split stabilizers are installed on the hot and cold side of the tubeb) See AREVA Product Information Sheet for Stabilizer U-Bend (Ref. 7) for split stabiliier lengthsc) Conservatively plugged as a defense in depth action per WEC recommendation (Ref 9)1814-AA086-M0238, REV. 0Page 385 of 415 Page 385 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013Table C-5 (Continued)SG 2EO89Tube Plugging/Stabilization List (Page 5 of 5)RSG 2E089 Tube Plugging/Stabilizing ListStab Type" I Stab Length (in)Row I ColPlug,Reasoneventative -FSW10591YesSolitNote bPrc107 91 Yes Split Note b______ Preventative -FSW109 91 Yes Split Note b Preventative -FSW113 91 Yes Split Note b Preventative -FSW115 91 Yes Split Note b Preventative -FSW117 91 Yes Split Note b Preventative -FSW123 91 Yes Split Note b Preventative -FSW98 92 Yes Split Note b Preventative -FSW104 92 Yes Split Note b Preventative -FSW108 92 Yes Split Note b Preventative -FSW114 92 Yes Split Note b Preventative -FSW116 92 Yes Split Note b Preventative -FSW103 93 Yes Split Note b Preventative -FSW115 93 Yes Split Note b Preventative -FSW102 94 Yes Split Note b Preventative -FSW114 94 Yes Split Note b Preventative -FSW116 94 Yes Split Note b Preventative -FSW103 95 Yes Split Note h Preventative -FSW105 95 Yes Split Note b Preventative -FSW107 95 Yes Split Note b Preventative -FSW109 95 Yes Split Note b Preventative -FSW115 95 Yes Split Note b Preventative -FSW109 97 Yes Split Note b Preventative -FSW110 98 Yes Split Note b Preventative -FSW112 98 Yes Split Note b Preventative -FSW80 68 Yes Split Note b Preventative -104 72 Yes Split Note b Preventative -FSW'132 94 Yes Split Note b Preventative -FSW'98 76 Yes Split Note b Wear at 6 Continuous AVBs87 79 Yes Split Note b Wear at 6 Continuous AVBs89 83 Yes Split Note b Wear at 6 Continuous AVBs128 84 Yes Split Note b Wear at 6 Continuous AVBs121 89 Yes Split Note b Wear at 6 Continuous AVBs120 90 Yes Split Note b Wear at 6 Continuous AVBsa) Split stabilizers are installed on the hot and cold side of the tubeb) See AREVA Product Information Sheet for Stabilizer U-Send (Ref. 7) for split stabilizer lengthsc) Conservatively plugged as a defense in depth action per WEC recommendation (Ref 9)1814-AA086-M0238, REV. 0Page 386 of 415 Page 386 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013a,c,eFigure C-1In-Plane Stability Ratio Map -Active Tube -70% Power -2 AVBs Missing(Case 17)1814-AA086-M0238, REV. 0Page 387 of 415 Page 387 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013a,c,eFigure C-2In-Plane Stability Ratio Map -Active Tube -70% Power -3 AVBs Missing(Case 28)1814-AA086-M0238, REV. 0Page 388 of 415 Page 388 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013a,c,eFigure C-3In-Plane Stability Ratio Map -Active Tube -70% Power -4 AVBs Missing(Case 37)1814-AA086-M0238, REV. 0Page 389 of 415 Page 389 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013a,c,eFigure C-4In-Plane Stability Ratio Map -Active Tube -70% Power -4 AVBs Missing(Case 38)1814-AA086-M0238, REV. 0Page 390 of 415 Page 390 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013a,c,eFigure C-5In-Plane Stability Ratio Map -Active Tube -70% Power -5 AVBs Missing(Case 45)1814-AA086-M0238, REV. 0Page 391 of 415 Page 391 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013a,c,eFigure C-6In-Plane Stability Ratio Map -Active Tube -70% Power -5 AVBs Missing(Case 46)1814-AA086-M0238, REV. 0Page 392 of 415 Page 392 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013a,c,eFigure C-7In-Plane Stability Ratio Map -Active Tube -70% Power -6 AVBs Missing(Case 53)1814-AA086-M0238, REV. 0Page 393 of 415 Page 393 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013a,c,eFigure C-8In-Plane Stability Ratio Map -Active Tube -70% Power -6 AVBs Missing(Case 54)1814-AA086-M0238, REV. 0Page 394 of 415 Page 394 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013a,c,eFigure C-9In-Plane Stability Ratio Map -Active Tube -70% Power -7 AVBs Missing(Case 60)1814-AA086-M0238, REV. 0Page 395 of 415 Page 395 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013a,c,eFigure C-10In-Plane Stability Ratio Map -Active Tube -70% Power -8 AVBs Missing(Case 66)1814-AA086-M0238, REV. 0Page 396 of 415 Page 396 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013a,c,eFigure C-llIn-Plane Stability Ratio Map -Active Tube -70% Power -9 AVBs Missing(Case 71)1814-AA086-M0238, REV. 0Page 397 of 415 Page 397 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013a,c,eFigure C-12In-Plane Stability Ratio Map -Active Tube -70% Power- 10 AVBs Missing(Case 75)1814-AA086-M0238, REV. 0Page 398 of 415 Page 398 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013a,c,eFigure C-13In-Plane Stability Ratio Map -Active Tube -70% Power -12 AVBs Missing(Case 78)1814-AA086-M0238, REV. 0Page 399 of 415 Page 399 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013a,c,eFigure C-14In-Plane Stability Ratio Map -Stabilized Tube -70% Power -2 AVBs Missing(Case 17)1814-AA086-M0238, REV. 0Page 400 of 415 Page 400 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013a,c,eFigure C-15In-Plane Stability Ratio Map -Stabilized Tube -70% Power -3 AVBs Missing(Case 28)1814-AA086-M0238, REV. 0Page 401 of 415 Page 401 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013a,c,eFigure C-16In-Plane Stability Ratio Map -Stabilized Tube -70% Power -4 AVBs Missing(Case 37)1814-AA086-M0238, REV. 0Page 402 of 415 Page 402 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013a,c,eFigure C-17In-Plane Stability Ratio Map -Stabilized Tube -70% Power -4 AVBs Missing(Case 38)1814-AA086-M0238, REV. 0Page 403 of 415 Page 403 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013 aceFigure C-18In-Plane Stability Ratio Map -Stabilized Tube -70% Power -5 AVBs Missing(Case 45)1814-AA086-M0238, REV. 0Page 404 of 415 Page 404 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013a,c,eFigure C-19In-Plane Stability Ratio Map -Stabilized Tube -70% Power -5 AVBs Missing(Case 46)1814-AA086-M0238, REV. 0Page 405 of 415 Page 405 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013a,c,eFigure C-20In-Plane Stability Ratio Map -Stabilized Tube -70% Power -6 AVBs Missing(Case 53)1814-AA086-M0238, REV. 0Page 406 of 415 Page 406 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013a,c,eFigure C-21In-Plane Stability Ratio Map -Stabilized Tube -70% Power -6 AVBs Missing(Case 54)1814-AA086-M0238, REV. 0Page 407 of 415 Page 407 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013a,c,eFigure C-22In-Plane Stability Ratio Map -Stabilized Tube -70% Power -7 AVBs Missing(Case 60)1814-AA086-M0238, REV. 0Page 408 of 415 Page 408 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013a,c,e7Figure C-23In-Plane Stability Ratio Map -Stabilized Tube -70% Power -8 AVBs Missing(Case 66)1814-AA086-M0238, REV. 0Page 409 of 415 Page 409 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013a,c,eFigure C-24In-Plane Stability Ratio Map -Stabilized Tube -70% Power -9 AVBs Missing(Case 71)1814-AA086-M0238, REV. 0Page 410 of 415 Page 410 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013a,c,eFigure C-25In-Plane Stability Ratio Map -Stabilized Tube -70% Power -10 AVBs Missing(Case 75)1814-AA086-M0238, REV. 0Page 411 of 415 Page 411 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013a,c,eFigure C-26In-Plane Stability Ratio Map -Stabilized Tube -70% Power -12 AVBs Missing(Case 78)1814-AA086-M0238, REV. 0Page 412 of 415 Page 412 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013222S ~ ~ z'C2* ~ 2Qj9~A~i~( ~.-17k-S22C~03,CaEEV" V2:jaqwflN MOHRFigure C-27Unit 2 SG 2E088 Plugging/Stabilization Map1814-AA086-M0238, REV. 0Page 413 of 415 Page 413 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 20133'-4o AA-AA'A~3A A>A:AAlASA. A ~::,~- 's.-,m0.Cd,£/CqCl'A~A ~ -, -AA>I -~ASSA: ACS'3/4 CA~4s>; ~AU:5z2,=='5,. ~-C -- -~ ~ ~.-..C,. 'LA> ALALA >'5,-~ .5c->~:.* Al c~'~AAP5li-ISA SAW>SA',AS ~'Ail>AAS'i-~ [.2 '>0 A -C I!SC~ A-~ A AA~. A -IjaquwnN mok1 IFigure C-28Unit 2 SG 2E089 Plugging/Stabilization Map1814-AA086-M0238, REV. 0Page 414 of 415 Page 414 of 414LTR-SGDA-12-36, Rev. 3 NP-AttachmentFebruary 15, 2013C-4 ConclusionsIt has been shown that in all cases the introduction of the stabilizer into the tubes reduces thestability ratio of that tube. It had been found that the stabilizer reduced the out-of-planeexcitation ratio by approximately 7% on average and reduced the in-plane stability ratio byapproximately 12% on average. It can also be concluded that the wear calculations fromSection 7.0 remain conservative with the addition of the split cable stabilizer. The wearcalculations are a function of the tube excitation ratio and therefore a reduction in the tubeexcitation ratio will also reduce the projected wear during operation. In summary, it has beenfound that the conclusions in the main body of the report remain valid and are conservative fortubes that have the split cable stabilizer installed.C-5 ReferencesC-1 LTR-SGDA-12-55, Rev. 1, "Documentation of Properties Associated with theAREVA Split Stabilizers to be Used at SONGS Unit 2," September 20, 2012.C-2 LTR-SGDA-12-56, "Effect of Installation of Split Cable Stabilizers in the Tube FIVResponse at SONGS Unit 2," September 21, 2012.1814-AA086-M0238, REV. 0Page 415 of 415 ENCLOSURE 7Affidavit by MHI forL5-04GA567, Evaluation of Stability Ratio for Return toService (Enclosure 1), andL5-04GA585, Analytical Evaluations for OperationalAssessment (Enclosure 2)

MITSUBISHI HEAVY INDUSTRIES, LTD.AFFIDAVITI, Jinichi Miyaguchi, state as follows:1. I am Director, Nuclear Plant Component Designing Department, of Mitsubishi HeavyIndustries, Ltd. ("MHI"), and have been delegated the function of reviewing thereferenced documentations to determine whether they contain MHI's information thatshould be withheld from public disclosure pursuant to 10 C.F.R. § 2.390 (a)(4) as tradesecrets and commercial or financial information that is privileged or confidential.2. In accordance with my responsibilities, I have reviewed the following documentations andhave determined that they contain MHI proprietary information that should be withheldfrom public disclosure. Those pages containing proprietary information have beenbracketed with an open and closed bracket as shown here "[ I" / and should bewithheld from public disclosure pursuant to 10 C.F.R. § 2.390 (a)(4).MHI's documents-L5-04GA567Evaluation of Stability Ratio for Return to Service-L5-04GA585Analytical Evaluations for Operational AssessmentSCE's documents-1 OCFR50.59 Evaluation, ScreeningNECP 800175663Steam Generator Replacement Mstr ECP U2-1 OCFR50.59 Evaluation, ScreeningNECP 800175664Steam Generator Replacement Mstr ECP U33. The information identified as proprietary in the documents have in the past been, andwill continue to be, held in confidence by MHI and its disclosure outside the company islimited to regulatory bodies, customers and potential customers, and their agents,suppliers, and licensees, and others with a legitimate need for the information, and isalways subject to suitable measures to protect it from unauthorized use or disclosure.

4. The basis for holding the referenced information confidential is that they describeunique design, manufacturing, experimental and investigative information developed byMHI and not used in the exact form by any of MHI's competitors. This information wasdeveloped at significant cost to MHI, since it is the result of an intensive MHI effort.5. The referenced information was furnished to the Nuclear Regulatory Commission("NRC") in confidence and solely for the purpose of information to the NRC staff.6. The referenced information is not available in public sources and could not be gatheredreadily from other publicly available information. Other than through the provisions inparagraph 3 above, MHI knows of no way the information could be lawfully acquired byorganizations or individuals outside of MHI.7. Public disclosure of the referenced information would assist competitors of MHI in theirdesign and manufacture of nuclear plant components without incurring the costs or risksassociated with the design and the manufacture of the subject component. Therefore,disclosure of the information contained in the referenced documents would have thefollowing negative impacts on the competitive position of MHI in the U.S. and worldnuclear markets:A. Loss of competitive advantage due to the costs associated with development oftechnologies relating to the component design, manufacture and examination.Providing public access to such information permits competitors to duplicate ormimic the methodology without incurring the associated costs.B. Loss of competitive advantage of MHI's ability to supply replacement or new heavycomponents such as steam generators.

I declare under penalty of perjury that the foregoing affidavit and the matters stated thereinare true and correct to the best of my knowledge, information and belief.Executed on this /8 day of.. AJ"'Y ,2013.Jinichi Miyaguchi,Director- Nuclear Plant Component Designing DepartmentMitsubishi Heavy Industries, LTDSworn to and subscribed31-Before me this / dayof -.0&, ,201o3 FEB, 82013AMK04A A1ýA_, / , C;, , .\ i " ..... ".... ?. , .Notary PublicMy Commission Expires k'7 , X. IIVZ X. III/i 3x- -Xý: -7ý -XI -lx- -X. X. X.- ýK- X. X. X. -ý, Ix ýK- -X. X- X. ý;Il ýK- -X. X, -"k- ý;, ýSll -X. -xz N X. X. X. -X- X.ME 2.X-X.~~ ...... .. ._.. ... ......... .... ......./6X.789TK----------------------- ---- ..................................... I ................................... ...... ............... .............101213t5/A'K'KiMIZJ 2 5 4f 2 ,~1 8 Fl................ .. .. .......... .......... ..°,1617X -. ..... .. .. -- -.... ... ..... .. .. ... ... ... .. ... ... .. ... .... .... .. .. .. ... ... ...... ..... .... --- --- --/-K, 1920'K 21y ......... ................... -..-------.-.----.. .........'K-'K '__ _ _ _ _ __ _ _ _ _ _ 2__ __ _ __ _ ' Registered Number 3 1Date FEB.18.2013NOTARIAL CERTIFICATEThis is to certify that JINICHI MIYAGUCHI , Director-Nuclear PlantComponent Designing Department MITSUBISHI HEAVY INDUSTRIES, LTDhas affixed his signature in my very presence to the attacheddocument. .-K//' : ,..~ ~ ~~. ,......... ..' .. .".. .MASAHIKO KUBOTANotary44 Akashimachi, Chuo-Ku,Kobe, JapanKobe District Legal Affairs Bureau(fAM2) ENCLOSURE 8Affidavit by WEC forLTR-SGDA-12-36, Flow-Induced Vibration and Tube WearAnalysis of the San Onofre Nuclear Generating Station Unit 2Replacement Steam Generators Supporting Restart(Enclosure 3) Westinghouse100WsigueW a.st in gh useWestinghouse Electric CompanyNuclear Services1000 Westinghouse DriveCranberry Township, Pennsylvania 16066USAU.S. Nuclear Regulatory Commission Direct tel: (412) 374-4643Document Control Desk Direct fax: (724) 720-075411555 Rockville Pike e-mail: greshaja@westinghouse.comRockville, MD 20852 Proj letter: CONO-1 3-16CAW-13-3623February 15, 2013APPLICATION FOR WITHHOLDING PROPRIETARYINFORMATION FROM PUBLIC DISCLOSURESubject: LTR-SGDA-12-36, Rev. 3 P-Attachment, "Flow-Induced Vibration and Tube Wear Analysis ofthe San Onofre Nuclear Generating Station Unit 2 Replacement Steam Generators"(Proprietary)The proprietary information for which withholding is being requested in the above-referenced report isfurther identified in Affidavit CAW-I 3-3623 signed by the owner of the proprietary information,Westinghouse Electric Company LLC. The affidavit, which accompanies this letter, sets forth tie basison which the information may be withheld from public disclosure by the Commission and addresses withspecificity the considerations listed in paragraph (bX4) of 10 CFR Section 2.390 of the Commission'sregulations.Accordingly, this letter authorizes the utilization of the accompanying affidavit by Southern CaliforniaEdison.Correspondence with respect to the proprietary aspects of the application for withholding or theWestinghouse affidavit should reference CAW- 13-3623 and should be addressed to James A. Gresham,Manager, Regulatory Compliance, Westinghouse Electric Company, Suite 428, 1000 WestinghouseDrive, Cranberry Township, Pennsylvania 16066.Very truly yours,JaesuA.tGresamp ManagerRegulatory ComplianceEnclosures CAW-13-3623AFFIDAVITCOMMONWEALTH OF PENNSYLVANIA:ssCOUNTY OF BUTLER:Before me, the undersigned authority, personally appeared James A. Gresham, who, being by meduly sworn according to law, deposes and says that he is authorized to execute this Affidavit on behalf ofWestinghouse Electric Company LLC (Westinghouse), and that the averments of fact set forth in thisAffidavit are true and correct to the best of his knowledge, information, and belief:*James A. Gresham, ManagerRegulatory ComplianceSworn to and subscribed before methis 15' day of February 2013Notary Public /COMMONWEALTH OF PENNSYLVANIANotarial soAw FStmegMa. % Notary Pu*ieUnift ThP. weme CWIMy corrmission 15"Me Aug. ?, 2016KEMPE PENSMlAJIIA ASSOCIAlIOI OF NOUNzS 2CAW-13-3623(1) I am Manager, Regulatory Compliance, in Nuclear Services, Westinghouse ElectricCompany LLC (Westinghouse), and as such, I have been specifically delegated the function ofreviewing the proprietary information sought to be withheld from public disclosure in connectionwith nuclear power plant licensing and rule making proceedings, and am authorized to apply forits withholding on behalf of Westinghouse.(2) I am making this Affidavit in conformance with the provisions of 10 CFR Section 2.390 of theCommission's regulations and in conjunction with the Westinghouse Application for WithholdingProprietary Information from Public Disclosure accompanying this Affidavit.(3) I have personal knowledge of the criteria and procedures utilized by Westinghouse in designatinginformation as a trade secret, privileged or as confidential commercial or financial information.(4) Pursuant to the provisions of paragraph (b)(4) of Section 2.390 of the Commission's regulations,the following is furnished for consideration by the Commission in determining whether theinformation sought to be withheld from public disclosure should be withheld.(i) The information sought to be withheld from public disclosure is owned and has been heldin confidence by Westinghouse.(ii) The information is of a type customarily held in confidence by Westinghouse and notcustomarily disclosed to the public. Westinghouse has a rational basis for determiningthe types of information customarily held in confidence by it and, in that connection,utilizes a system to determine when and whether to hold certain types of information inconfidence. The application of that system and the substance of that system constitutesWestinghouse policy and provides the rational basis required.Under that system, information is held in confidence if it falls in one or more of severaltypes, the release of which might result in the loss of an existing or potential competitiveadvantage, as follows:(a) The information reveals the distinguishing aspects of a process (or component,structure, tool, method, etc.) where prevention of its use by any of 3CAW-13-3623Westinghouse's competitors without license from Westinghouse constitutes acompetitive economic advantage over other companies.(b) It consists of supporting data, including test data, relative to a process (orcomponent, structure, tool, method, etc.), the application of which data secures acompetitive economic advantage, e.g., by optimization or improvedmarketability.(c) Its use by a competitor would reduce his expenditure of resources or improve hiscompetitive position in the design, manufacture, shipment, installation, assuranceof quality, or licensing a similar product.(d) It reveals cost or price information, production capacities, budget levels, orcommercial strategies of Westinghouse, its customers or suppliers.(e) It reveals aspects of past, present, or future Westinghouse or customer fundeddevelopment plans and programs of potential commercial value to Westinghouse.(f) It contains patentable ideas, for which patent protection may be desirable.There are sound policy reasons behind the Westinghouse system which include thefollowing:(a) The use of such information by Westinghouse gives Westinghouse a competitiveadvantage over its competitors. It is, therefore, withheld from disclosure toprotect the Westinghouse competitive position.(b) It is information that is marketable in many ways. The extent to which suchinformation is available to competitors diminishes the Westinghouse ability tosell products and services involving the use of the information.(c) Use by our competitor would put Westinghouse at a competitive disadvantage byreducing his expenditure of resources at our expense. 4CAW-13-3623(d) Each component of proprietary information pertinent to a particular competitiveadvantage is potentially as valuable as the total competitive advantage. Ifcompetitors acquire components of proprietary information, any one componentmay be the key to the entire puzzle, thereby depriving Westinghouse of acompetitive advantage.(e) Unrestricted disclosure would jeopardize the position of prominence ofWestinghouse in the world market, and thereby give a market advantage to thecompetition of those countries.(f) The Westinghouse capacity to invest corporate assets in research anddevelopment depends upon the success in obtaining and maintaining acompetitive advantage.(iii) The information is being transmitted to the Commission in confidence and, under theprovisions of 10 CFR Section 2.390, it is to be received in confidence by theCommission.(iv) The information sought to be protected is not available in public sources or availableinformation has not been previously employed in the same original manner or method tothe best of our knowledge and belief.(v) The proprietary information sought to be withheld in this submittal is that which isappropriately marked in LTR-SGDA-12-36, Rev. 3 P-Attachment, "Flow-InducedVibration and Tube Wear Analysis of the San Onofre Nuclear Generating Station Unit 2Replacement Steam Generators," dated February 15, 2013, for submittal to theCommission, being transmitted by Southern California Edison Letter and Application forWithholding Proprietary Information from Public Disclosure, to the Document ControlDesk. The proprietary information as submitted by Westinghouse is that associated withthe calculation of fluidelastic excitation of steam generator tubes and may be used onlyfor that purpose. 5CAW-13-3623This information is part of that which will enable Westinghouse to:(a) Respond to Nuclear Regulatory Commission (NRC) Request for AdditionalInformation regarding stability ratios calculated for certain anti-vibration bar(AVB) support conditions for the San Onofre Nuclear Generating Station Unit 2steam generators.Further this information has substantial commercial value as follows:(a) Westinghouse plans to sell the use of similar information to its customers for thepurpose of evaluating the impact of fluidelastic excitation on steam generatortube integrity.(b) Westinghouse can sell support and defense of the thermal hydraulic analysis ofsecondary side flow field in the steam generator shell.(c) The information requested to be withheld reveals the distinguishing aspects of amethodology which was developed by Westinghouse.Public disclosure of this proprietary information is likely to cause substantial harm to thecompetitive position of Westinghouse because it would enhance the ability ofcompetitors to provide similar information and licensing defense services for commercialpower reactors without commensurate expenses. Also, public disclosure of theinformation would enable others to use the information to meet NRC requirements forlicensing documentation without purchasing the right to use the information.The development of the technology described in part by the information is the result ofapplying the results of many years of experience in an intensive Westinghouse effort andthe expenditure of a considerable sum of money. 6 CAW-13-3623In order for competitors of Westinghouse to duplicate this information, similar technicalprograms would have to be performed and a significant manpower effort, having therequisite talent and experience, would have to be expended.Further the deponent sayeth not. Proprietary Information NoticeTransmitted herewith are proprietary and/or non-proprietary versions of documents furnished to the NRCin connection with requests for additional information regarding stability ratios calculated for certain anti-vibration bar (AVB) support conditions for the San Onofre Nuclear Generating Station Unit 2 steamgenerators.In order to conform to the requirements of 10 CFR 2.390 of the Commission's regulations concerning theprotection of proprietary information so submitted to the NRC, the information which is proprietary in theproprietary versions is contained within brackets, and where the proprietary information has been deletedin the non-proprietary versions, only the brackets remain (the information that was contained within thebrackets in the proprietary versions having been deleted). The justification for claiming the informationso designated as proprietary is indicated in both versions by means of lower case letters (a) through (f)located as a superscript immediately following the brackets enclosing each item of information beingidentified as proprietary or in the margin opposite such information. These lower case letters refer to thetypes of information Westinghouse customarily holds in confidence identified in Sections (4)(ii)(a)through (4)(ii)(f) of the affidavit accompanying this transmittal pursuant to 10 CFR 2.390(b)(1).Copyright NoticeThe reports transmitted herewith each bear a Westinghouse copyright notice. The NRC is permitted tomake the number of copies of the information contained in these reports which are necessary for itsinternal use in connection with generic and plant-specific reviews and approvals as well as the issuance,denial, amendment, transfer, renewal, modification, suspension, revocation, or violation of a license,permit, order, or regulation subject to the requirements of 10 CFR 2.390 regarding restrictions on publicdisclosure to the extent such information has been identified as proprietary by Westinghouse, copyrightprotection notwithstanding. With respect to the non-proprietary versions of these reports, the NRC ispermitted to make the number of copies beyond those necessary for its internal use which are necessary inorder to have one copy available for public viewing in the appropriate docket files in the public documentroom in Washington, DC and in local public document rooms as may be required by NRC regulations ifthe number of copies submitted is insufficient for this purpose. Copies made by the NRC must includethe copyright notice in all instances and the proprietary notice if the original was identified as proprietary. Southern California EdisonLetter for Transmittal to the NRCThe following paragraphs should be included in your letter to the NRC:Enclosed is:1. _ copies of LTR-SGDA-12-36, Rev. 3 P-Attachment, "Flow-Induced Vibration and Tube WearAnalysis of the San Onofre Nuclear Generating Station Unit 2 Replacement Steam Generators"(Proprietary)2. _ copies of LTR-SGDA-12-36, Rev. 3 NP-Attachment, "Flow-Induced Vibration and Tube WearAnalysis of the San Onofre Nuclear Generating Station Unit 2 Replacement Steam Generators"(Non-Proprietary)Also enclosed is the Westinghouse Application for Withholding Proprietary Information from PublicDisclosure CAW-1 3-3623, accompanying Affidavit, Proprietary Information Notice, and CopyrightNotice.As Item I contains information proprietary to Westinghouse Electric Company LLC, it is supported by anaffidavit signed by Westinghouse, the owner of the information. The affidavit sets forth the basis onwhich the information may be withheld from public disclosure by the Commission and addresses withspecificity the considerations listed in paragraph (b)(4) of Section 2.390 of the Commission's regulations.Accordingly, it is respectfully requested that the information which is proprietary to Westinghouse bewithheld from public disclosure in accordance with 10 CFR Section 2.390 of the Commission'sregulations.Correspondence with respect to the copyright or proprietary aspects of the items listed above or thesupporting Westinghouse affidavit should reference CAW-13-3623 and should be addressed toJ. A. Gresham, Manager, Regulatory Compliance, Westinghouse Electric Company LLC, Suite 428,1000 Westinghouse Drive, Cranberry Township, PA 16066. }}