CP-201500441, Response to Request for Additional Information, 2RF14 Steam Generator Tube Inservice Inspection Report - TAC MF5052
| ML15114A198 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 04/16/2015 |
| From: | Flores R, Madden F Luminant Generation Co, Luminant Power |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| CP-201500441, TAC MF5052, TXX-15067 | |
| Download: ML15114A198 (7) | |
Text
Rafael Flores Luminant Power Senior Vice President P 0 Box 1002
& Chief Nuclear Officer 6322 North FM 56 rafael.flores@Luminant.com Glen Rose, TX 76043 Lum inant T254 897 5590 C 817 559 0403 F 254 897 6652 CP-201500441 Ref. # 10CFR50.55a TXX-15067 April 16, 2015 ATTN: Document Control Desk U. S. Nuclear Regulatory Commission Washington, DC 20555-0001
SUBJECT:
COMANCHE PEAK NUCLEAR POWER PLANT UNIT 2, DOCKET NO. 50-446 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION, 2RF14 STEAM GENERATOR TUBE INSERVICE INSPECTION REPORT - TAC NO. MF5052
REFERENCE:
- 1) Lunmnant Power letter, logged TXX-14127, from Rafael Flores to the U. S. Nuclear Regulatory Commission dated October 21, 2015, 2RF14 Steam Generator Inservice Inspection 180-Day Report
Dear Sir or Madam:
By means of the letter in Reference 1, Luminant Generation Company LLC (Luminant Power) previously submitted the Comanche Peak Nuclear Power Plant (CPNPP) Unit 2 Model D5 steam generator tube inspection report for 2RF14 as required by Technical Specification 5.6.9.
Based upon questions provided by Mr. Balwant Singal of the NRC in an email dated March 17, 2015, Luminant Power hereby provides the following additional information regarding the report detailed in Reference 1. The attachment to this letter contains the NRC questions and Luminant Power's response immediately following each question.
This communication contains no new licensing basis commitments regarding Comanche Peak Unit 2.
U. S. Nuclear Regulatory Commission TXX-15067 Page 2 04/16/2015 Should you have any questions, please contact Mr. Jim Barnette at (254) 897-5866 or James.bamette@luminant.com.
Sincerely, Luminant Generation Company LLC Rafael Flores By: 4r Fred-W. Madden Director, External Affairs Attachment - Luminant Power Response to Request for Additional Information, 2RF14 Steam Generator Tube Inspection Report - TAC No. MF5052 c- Marc L. Dapas, Region IV B. K. Singal, NRR Resident Inspectors, Comanche Peak
Attachment to TXX-15067 (4 pages not including this cover page)
Comanche Peak Nuclear Power Plant Luminant Power Response to Request for Additional Information 2RF14 Steam Generator Tube Inspection Report TAC No. ME5052 Docket No. 50-446
Attachment to TXX-15067 Luminant Power Response to Request for Additional Information 2RF14 Steam Generator Tube Inspection Report TAC No. MF5052
- 1. For the seven tubes showing strong evidence of high residual stress, please discuss the following:
- a. Were these tubes low row or high row "-2 sigma" tubes, or was there some other indicator of the high residual stress?
Luminant Response:
These tubes were plugged based on the eddy current data showing evidence of high residual stress in accordance with EPRI SGMP Letter dated 9/1412004, "SGMP Information Letter on Example Methodology for Screening of Alloy 600TT Tubing for the Seabrook Elevated Stress Issue."
The following plugged tubes are considered to have U-bend offset signals indicative of elevated residual stress in low row tubes: R1C23, R1C89, R2C88, R2C92, R2C93, and R5C61 (all tubes were in SG 2). For SG 1, R27C28 is considered to contain possible elevated residual stress in a high row tube (-2 sigma tube).
- b. Has an analysis of all tubes in all four SGs been performed to identify all tubes with the potential of high residual stress?
Luminant Response:
Yes, screening of all Unit 2 tubes in all four SGs has been performed to identify low row tubes (rows I through 9) and high row tubes (row 10 and higher) that may contain eddy current signals indicative of tubes containing possible elevated residual stress.
- c. Are there any tubes with potentially elevated residual stress (low row offset,
-2 sigma tubes) in service? If so, how many?
Luminant Response:
Yes, there are potentially elevated residual stress tubes (both low row offset and -2 sigma tubes) in service. Table 1, shows the remaining potentially elevated residual stress tubes in each steam generator. These tubes are examined when the applicable SG is available for eddy current inspection.
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Attachment to TXX-15067
- 2. Under Table 3D on page 14 of 25 of the Enclosure, a note mentions legacy indications being shown in blue/italic font, but none are shown in the table. Please confirm whether or not Table 3D does, in fact, include any legacy indications. If not, please include them in your response.
Luminant Response:
See revised Table 3D on page 3 of this attachment. Legacy indications resulting from parts removed from their vicinity in prior outages are shown in blue font, or with an asterisk (*) in the SGID column. The new indications are in black font.
- 3. Please discuss the results of your tube plug inspections. Were all plugs present and in their proper locations? Was any degradation observed?
Luminant Response:
Each plugged tube was inspected. No degradation was observed and each plug was present in their correct tube.
- 4. Table 3A of the Enclosure provides the number of anti-vibration bar (AVB) wear indications detected. Were all tubes with prior indications inspected (i.e., do the values in Table 3A provide the total number of AVB wear indications or just a subset of the total since a sampling program was implemented during RFO 14)?
Luminant Response:
Yes, all tubes with prior indications were inspected. Table 3A (page 4 of this attachment) provides the total number of AVB wear indications found since the first primary side inspection outage for Unit 2. The new AVB wear indications are only derived from the sampling program during RFO 14.
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Attachment to TXX-15067 Table 3D. Summary of Loose Part Wear Indications SGID Outage Row Col Volts Deg Ind Per CrLen CrWid Chn Locn Inch1 BegT EndT PDia PType Cal 1 U2RF1 48 38 0.22 0 PCT 4 P3 C2 0.14 Cl1 CTE 0.61 ZBAZC 54 2* U2RF1 6 1 0.12 0 VOL 17 0.14 0.2 P4 Cl 0.51 Cl C1 0.61 ZPS3C 16 2* U2RF1 6 2 0.3 0 VOL 27 0.14 0.17 6 C1 0.44 C1 Cl 0.61 ZPS3C 16 2* U2RF1 6 2 0.14 0 VOL 16 0.11 0.19 6 C1 0.91 Cl C1 0.61 ZPS3C 16 2 U2RF1 12 23 0.07 0 PCT 10 0.16 0.30 P4 C6 0.35 C6 C6 0.61 ZPS3C 32 2 U2RF1 13 23 0.04 0 PCT 6 0.20 0.35 P4 C6 0.39 C6 C6 0.61 ZPS3C 32 2 U2RF1 12 24 0.22 98 VOL 19 0.15 0.33 6 C6 0.55 C6 C6 0.61 ZPS3C 14 2* U2RF1 3 114 0.2 260 PCT 24 0.18 0.21 P4 C4 0.41 C4 C4 0.61 ZPS3C 14 2* U2RF1 4 114 0.14 0 PCT 17 0.18 0.2 P4 C4 0.43 C4 C4 0.61 ZPS3C 14 4 U2RF1 26 69 0.18 0 PCT 19 0.41 0.43 6 C2 1.31 C2 C2 0.61 ZPS3C 52 4 U2RF1 32 71 0.28 0 PCT 25 0.24 0.34 6 C2 0.55 C2 C2 0.61 ZPS3C 52 4 U2RF1 34 77 0.15 0 PCT 16 0.21 0.31 6 C2 0.5 C2 C2 0.61 ZPS3C 52 Legacy indications resulting from parts removed from their vicinity in prior outages are shown in blue font or with an asterisk (*) in the SGID column. Those in black font represent new indications.
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Attachment to TXX-15067 Table 1: List of Active Tubes with Potentially Elevated Residual Stress.
No SG-1 SG-2 SG-3 SG-4 Row Col Row Col Row Col Row Col 1 18 5 36 35 14 24 29 15 2 16 6 10 36 44 30 18 26 3 17 8 47 37 42 31 10 31 4 18 13 20 45 14 35 10 34 5 17 19 10 48 12 47 10 35 6 21 22 49 50 12 48 32 35 7 33 55 1 55 12 49 10 36 8 1 1 95 13 50 15 36 9 14 50 10 37 10 12 52 10 53 11 14 57 28 55 12 11 58 13 77 13 13 59 13 82 14 1 13 62 28 88 15 44 63 15 103 16 11 65 17 24 66 18 49 72 19 48 78
- 20. 38 79 21 49 79 22 48 80 23 49 80 24 48 81 25 14 83 26 48 83 27 48 84 28 28 85 29 48 85 30 12 86 31 48 86 32 28 91 33 38 93 34 1 25 102 4