NL-09-0478, Unit 2, Thirteenth Maintenance/Refueling Outage Steam Generator Tube Inspection Report

Unit 2, Thirteenth Maintenance/Refueling Outage Steam Generator Tube Inspection Report

ML090990606
Person / Time
Site:	Vogtle
Issue date:	04/09/2009
From:	Ajluni M Southern Nuclear Operating Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NL-09-0478
Download: ML090990606 (11)

Text

Southern Nuclear Operating Company, Inc

-? 205 952 5000 SOUTHERN COMPANY A.

April 9, 2009 Ellergy to SaFe lOllr U?orld Docket No.: 50-425 NL-09-0478 U. S. Nuclear Regulatory Commission ATIN: Document Control Desk Washington, D. C. 20555-0001 Vogtle Electric Generating Plant - Unit 2 Thirteenth Maintenance/Refueling Outage Steam Generator Tube Inspection Report Ladies and Gentlemen:

In accordance with the requirements of Vogtle Electric Generating Plant Technical Specification 5.6.10, Southern Nuclear Operating Company submits this report of the steam generator tube inspections performed during the Unit 2 thirteenth maintenance/refueling outage (2R13). Entry into Mode 4 occurred on October 15, 2008.

This letter contains no NRC commitments. If you have any questions, please advise.

Sincerely,

~9r M. J. Ajluni Manager, Nuclear Licensing MJAITAH/daj

Enclosure:

2R13 Steam Generator Tube Inspection Report cc: Southern Nuclear Operating Company Mr. J. T. Gasser, Executive Vice President Mr. T. E. Tynan, Vice President - Vogtle Ms. P. M. Marino, Vice President - Engineering RType: CVC7000 U. S. Nuclear Regulatory Commission Mr. L. A. Reyes, Regional Administrator Mr. R. E. Martin, NRR Project Manager - Vogtle Mr. M. Cain, Senior Resident Inspector - Vogtle

Vogtle Electric Generating Plant - Unit 2 Thirteenth Maintenance/Refueling Outage Steam Generator Tube Inspection Report Enclosure 2R13 Steam Generator Tube Inspection Report

Enclosure Vogtle Electric Generating Plant - Unit 2 2R13 Steam Generator Tube Inspection Report Introduction The 2R13 outage was conducted after cumulative service equivalent to ~17.2 EFPY (effective full power years); the Cycle 13 power generation was ~1.3 EFPY. Analyses based on conservative assumptions used in the Condition Monitoring and Operation Assessments demonstrated that there were no tubes that exceeded the Reg. Guide 1.121 and NEI-97-06 Revision 2 criteria for tube integrity. The steam generator (SG) tubing eddy current inspections and primary analysis were performed by the Steam Generator Maintenance Services Group of the Westinghouse Nuclear Services Division. Secondary data analysis was performed by NDE Technologies under direct contract with Southern Nuclear.

2R13 Inspection Scope The inspection program required by Revision 7 of the EPRI PWR SG Examination Guidelines is detailed below:

o 100% Bobbin examination of tubes in SGs 1 and 4, full length except for Rows 1 and 2, which are inspected from tube end to TSP#7 from both HL and CL. Row 1 tubes will be scrutinized for suggestions of indications associated with the elevation of the sludge lance monorail that has been associated with tube damage in other plants.

o 50% +Point (mid-range) examination of small radius U-bends (Row 1 and Row 2) in SGs 1 and 4, including all Row 1 and Row 2 tubes that were not +Point inspected in the U-bend during 2R11.

o 50% +Point examination (mid-range) at HL TTS, +/- 3 in SGs 1 and 4. * +Point tests (mid-range) of Special Interest, HL and CL, of bobbin possible flaw locations (including U-bends). Tubes indicating Seabrook-type U-bend offset behavior with DSIs (TSP indications) that are not confirmed will nonetheless be preventively plugged.

o +Point inspection of expanded tubesheet section BLGs and OXPs in the region TEH+4 to TSH+3; 50% of SG1 (23 tubes) and 50% of SG4 population (36 tubes). The inspection extent for these tubes is TEH to TSH+3. The sampled extents in SG1 and SG4 for this inspection program include all BLG and OXP locations in this elevation range which were not tested during the 2R11 outage. Tubes actually tested: SG1 = 34 of 46 (74%); SG4 = 63 of 72 (88%).

• BLG = differential mix diameter discontinuity signal within the tubesheet of 18 volts or greater as measured by bobbin coil probe;

• OXP = a tube diameter deviation within the tubesheet of 1.5 mils or greater as measured by bobbin coil profile analysis.

o +Point inspection of expanded tubesheet section BLGs and OXPs in the region TEH to TEH+4; 50% of SG1 (11 tubes) and 50% of SG4 population (56 tubes). The inspection extent for these tubes is TEH to TEH+4. This population was not sampled during past inspections; tubes actually tested: SG1 = 15 of 21(71%); SG4 = 61 of 112 (54%).

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Enclosure Vogtle Electric Generating Plant - Unit 2 2R13 Steam Generator Tube Inspection Report o 40% +Point examination of the tubes in SG1 and SG4 from TEH to TEH+4.03 (the hot leg end of the tube including the tube-end weld) - in response to the replacement of the single-cycle B* Technical Specification requirements with the single-cycle Interim Alternate Repair Criterion (IARC) Technical Specification requirements, based on mid-outage approval of IARC by the NRC.

o 100% +Point examination of dents/dings > 2 volts in U-bends of SG1 and SG4, with the total number of inspected dents and dings to comprise no less than 25% of the total dents and dings > 2V in Vogtle Unit 2 SGs, and with any makeup required to meet the 25% quantity being selected from the HL straight lengths.

o Video inspection of tube plugs in SGs 1 and 4.

o All techniques used were in accordance with EPRI Steam Generator Management Program Pressurized Water Reactor Steam Generator Examination Guidelines, Revision 7 Appendix H.

Damage Mechanisms Found and NDE Techniques Utilized The following existing damage mechanisms were seen in Vogtle Unit 2 SGs during 2R13:

o Antivibration bar (AVB) wear was found in SGs 1 (70 locations) and 4 (178 locations).

AVB wear is identified during the bobbin inspection except for rows 1 and 2 which are inspected with +Point' RPC. Fourteen of the AVB wear indications were not seen in 2R11.

o The Volumetric (VOL) indications that were observed were verified as previously present and unchanged from prior inspections. They were inspected with +Point' RPC.

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Enclosure Vogtle Electric Generating Plant - Unit 2 2R13 Steam Generator Tube Inspection Report Service Induced Indication Descriptions The volumetric (VOL) indications seen previously in SG 1 and SG4 were unchanged in 2R13 and are provided in the table below.

SG Row Column Volts % Depth Location 1 1 46 0.24 17 TSH 1 1 78 0.96 19 TSH 1 1 78 0.65 13 TSH 4 12 57 0.17 16 TSH 4 42 93 1.29 24 TSC The AVB wear identified in Vogtle 2R13 in SG1 and SG4 is provided in the following tables.

One tube (SG1 R50C28) was plugged as a result of AVB wear.

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Enclosure Vogtle Electric Generating Plant - Unit 2 2R13 Steam Generator Tube Inspection Report Vogtle 2 Steam Generator 1 AVB Indications for 2R13 Row Column Location  % Depth Row Column Location % Depth 29 105 AV2 10 44 94 AV5 12 29 112 AV2 14 46 24 AV4 16 30 10 AV2 12 46 26 AV4 18 30 10 AV6 15 46 32 AV3 17 34 13 AV2 11 46 32 AV4 19 34 13 AV4 13 47 27 AV2 28 34 25 AV1 9 47 36 AV1 13 35 14 AV4 13 47 99 AV2 13 35 74 AV4 13 47 99 AV5 12 37 33 AV3 9 48 27 AV2 15 37 35 AV3 9 48 27 AV3 17 37 39 AV4 9 48 28 AV2 18 41 20 AV1 8 48 96 AV2 9 41 20 AV2 17 49 29 AV6 10 41 20 AV3 11 50 28 AV3 28 41 20 AV4 13 50 28 AV4 44 41 20 AV5 12 50 28 AV6 13 41 20 AV6 8 50 92 AV2 11 41 23 AV5 11 50 93 AV3 12 41 23 AV6 10 53 33 AV4 19 41 27 AV5 12 53 34 AV3 14 42 20 AV2 20 53 34 AV4 13 43 100 AV2 12 53 89 AV5 12 43 100 AV3 17 54 50 AV2 12 43 100 AV4 20 54 50 AV3 11 43 100 AV5 12 54 50 AV4 11 44 22 AV4 17 55 39 AV2 12 44 22 AV6 15 55 39 AV3 12 44 23 AV2 10 55 78 AV1 10 44 23 AV3 16 55 81 AV2 9 44 23 AV4 14 58 53 AV1 14 44 23 AV5 24 58 72 AV1 18 44 27 AV2 9 58 73 AV1 15 44 27 AV3 12 58 75 AV6 16 44 72 AV6 11 59 68 AV1 15 Page 4 of 9

Enclosure Vogtle Electric Generating Plant - Unit 2 2R13 Steam Generator Tube Inspection Report Vogtle 2 Steam Generator 4 AVB Indications for 2R13 Row Column Location Depth Row Column Location % Depth 15 36 AV6 12 43 69 AV5 17 15 46 AV1 12 43 71 AV4 12 27 79 AV5 10 43 76 AV5 18 29 14 AV6 9 43 85 AV4 13 30 9 AV5 19 44 29 AV3 16 31 113 AV2 8 44 29 AV4 16 32 109 AV6 10 44 42 AV3 11 34 81 AV1 10 44 42 AV4 18 35 81 AV1 10 44 42 AV5 24 36 13 AV3 10 44 42 AV6 14 36 14 AV2 15 44 44 AV3 16 37 74 AV3 12 44 54 AV1 11 37 79 AV1 11 44 54 AV2 11 37 81 AV1 10 44 54 AV5 18 38 39 AV4 10 44 59 AV1 11 38 79 AV1 10 44 59 AV3 15 38 81 AV1 11 44 59 AV4 13 39 26 AV3 11 44 85 AV3 11 39 64 AV1 15 45 22 AV2 11 39 64 AV2 21 45 22 AV3 13 39 64 AV3 31 45 23 AV2 10 39 64 AV4 16 45 23 AV3 10 39 64 AV6 18 45 23 AV5 11 40 79 AV1 11 45 32 AV3 21 40 106 AV1 11 45 42 AV4 11 40 106 AV3 11 45 58 AV3 19 42 51 AV6 11 45 58 AV4 13 42 56 AV6 13 45 58 AV5 18 42 87 AV3 11 45 66 AV2 17 43 21 AV5 12 45 66 AV5 19 43 22 AV4 12 46 26 AV4 13 43 36 AV2 12 46 26 AV6 15 43 47 AV2 12 46 31 AV3 16 43 51 AV6 12 46 31 AV4 14 43 53 AV3 10 46 31 AV5 17 43 58 AV5 10 46 51 AV6 12 43 65 AV4 15 46 88 AV3 9 43 68 AV3 20 47 36 AV4 11 43 68 AV4 24 47 41 AV2 13 43 68 AV5 23 47 41 AV3 12 Page 5 of 9

Enclosure Vogtle Electric Generating Plant - Unit 2 2R13 Steam Generator Tube Inspection Report Vogtle 2 Steam Generator 4 AVB Indications for 2R13 (continued)

Row Column Location Depth Row Column Location % Depth 48 31 AV3 9 52 33 AV6 16 48 31 AV4 13 52 45 AV2 9 48 57 AV3 13 52 45 AV3 14 48 57 AV4 14 52 45 AV4 16 48 57 AV5 20 52 45 AV5 12 48 58 AV4 13 52 66 AV1 10 48 79 AV2 11 52 66 AV2 20 48 79 AV3 9 52 66 AV3 13 48 81 AV1 10 52 71 AV1 11 48 97 AV2 12 52 71 AV2 19 48 97 AV3 11 52 71 AV3 25 49 53 AV3 11 52 72 AV2 27 49 53 AV4 10 52 72 AV3 15 49 83 AV3 17 52 78 AV4 13 49 93 AV4 20 52 85 AV1 11 49 93 AV5 24 53 34 AV2 12 49 96 AV2 13 53 34 AV6 9 50 53 AV3 12 53 36 AV5 12 50 55 AV3 7 53 43 AV1 11 50 70 AV3 16 53 43 AV2 11 51 35 AV4 18 53 43 AV3 34 51 39 AV2 12 53 43 AV4 22 51 39 AV3 11 53 43 AV5 21 51 39 AV4 18 53 43 AV6 11 51 43 AV3 11 53 44 AV3 15 51 43 AV4 14 53 80 AV5 14 51 43 AV5 14 53 89 AV6 12 51 54 AV3 11 54 35 AV4 11 51 54 AV4 23 54 35 AV5 18 51 54 AV5 12 54 35 AV6 12 51 55 AV2 14 54 37 AV1 12 51 55 AV3 24 54 37 AV6 12 51 60 AV3 16 54 83 AV5 11 51 76 AV4 17 55 41 AV5 15 51 76 AV5 14 55 83 AV5 13 51 92 AV1 14 56 42 AV6 11 52 33 AV2 15 56 45 AV4 13 52 33 AV3 18 56 45 AV5 11 52 33 AV4 17 56 47 AV3 19 52 33 AV5 37 56 82 AV2 15 Page 6 of 9

Enclosure Vogtle Electric Generating Plant - Unit 2 2R13 Steam Generator Tube Inspection Report Vogtle 2 Steam Generator 4 AVB Indications for 2R13 (continued)

Row Column Location Depth Row Column Location % Depth 57 48 AV2 13 57 78 AV4 11 57 48 AV3 19 57 78 AV6 13 57 48 AV4 13 57 78 AV6 13 57 48 AV5 32 58 47 AV5 11 57 48 AV6 11 58 57 AV3 12 57 71 AV6 14 58 57 AV4 15 57 73 AV2 16 58 75 AV2 11 57 76 AV5 15 59 63 AV6 11 57 78 AV2 14 59 66 AV6 12 Page 7 of 9

Enclosure Vogtle Electric Generating Plant - Unit 2 2R13 Steam Generator Tube Inspection Report Number of Tubes Plugged One tube (SG1 R50C28) was plugged during 2R13.

Total plugging in the Vogtle 2 SGs after 2R13 is as follows:

SG 1 - 6 tubes for a total of .11% tubes plugged SG 2 - 12 tubes for a total of .21% tubes plugged SG 3 - 4 tubes for a total of .07% tubes plugged SG 4 - 21 tubes for a total of .37% tubes plugged Secondary Side Activities FOSAR was performed in both SG1 and in SG4. In SG4, one small wire was removed and eleven small objects were not removed. A loose parts analysis considering the mass, location, and dimensions of the unretrieved items in SG4 confirms that these objects will not cause excessive wear for at least two cycles.

In addition, 5 PLP indications with no wear were seen in SG 1. FOSAR in SG 1 confirmed that the locations identified with PLP signals exhibited only sludge agglomerations.

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Enclosure Vogtle 2R13 Steam Generator Tube Inspection Report Condition Monitoring Results No indications were found to exceed the condition monitoring limits specified in the Degradation Assessment.

No tubes exhibited degradation that required in situ pressure testing to demonstrate structural integrity. The tube plugged due to an AVB wear indication exceeded the Tech Spec plugging criteria, but the reported degradation satisfies the Condition Monitoring limit, and therefore the SG Performance Criteria were not exceeded.

There was no primary to secondary leakage during the 2R13 operating cycle. Therefore, the calculated accident leakage, in accordance with the IARC Tech Spec change commitment is zero.

Given the absence of operating leakage during Cycle 13, it is concluded that there was no leakage from plugs. This is consistent with the video inspection of the tube plugs in SG 1 and SG 4 which identified no leakage.

Evaluation of the indications found in the 2R13 inspection indicate that the condition monitoring requirements for structural and leakage integrity as specified in NEI-97-06 Revision 2 are satisfied. No SG tube samples were pulled for laboratory examination during 2R13.

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