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| | issue date = 04/05/2011 | | | issue date = 04/05/2011 |
| | title = Evaluation Regarding the 2009 Steam Generator Tube Inspections Performed During the 15th Refueling Outage (2R15) | | | title = Evaluation Regarding the 2009 Steam Generator Tube Inspections Performed During the 15th Refueling Outage (2R15) |
| | author name = Wang A B | | | author name = Wang A |
| | author affiliation = NRC/NRR/DORL/LPLIV | | | author affiliation = NRC/NRR/DORL/LPLIV |
| | addressee name = Conway J T | | | addressee name = Conway J |
| | addressee affiliation = Pacific Gas & Electric Co | | | addressee affiliation = Pacific Gas & Electric Co |
| | docket = 05000323 | | | docket = 05000323 |
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| =Text= | | =Text= |
| {{#Wiki_filter:UNITED NUCLEAR REGULATORY WASHINGTON, D.C. 20555*0001 April 5. 2011 Mr. John T. Conway Senior Vice President | | {{#Wiki_filter:UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555*0001 April 5. 2011 Mr. John T. Conway Senior Vice President -- Energy Supply and Chief Nuclear Officer Pacific Gas and Electric Company Diablo Canyon Power Plant 77 Beale Street, Mail Code B32 San Francisco, CA 94105 |
| --Energy Supply and Chief Nuclear Officer Pacific Gas and Electric Company Diablo Canyon Power Plant 77 Beale Street, Mail Code B32 San Francisco, CA 94105 DIABLO CANYON POWER PLANT, UNIT NO.2 -EVALUATION REGARDING THE 2009 STEAM GENERATOR TUBE INSPECTIONS (TAC NO. ME3995) | | |
| | ==SUBJECT:== |
| | DIABLO CANYON POWER PLANT, UNIT NO.2 - EVALUATION REGARDING THE 2009 STEAM GENERATOR TUBE INSPECTIONS (TAC NO. ME3995) |
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| ==Dear Mr. Conway:== | | ==Dear Mr. Conway:== |
| By letter dated May 5, 2010 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML 101330269), Pacific Gas and Electric Company (the licensee), submitted information summarizing the results of the 2009 steam generator (SG) tube inspections performed at Diablo Canyon Power Plant (DCPP), Unit No.2. These inspections were performed during the fifteenth refueling outage (2R15). In addition to these reports, the U.S. Nuclear Regulatory Commission (NRC) staff summarized additional information concerning the 2009 SG tube inspections at DCPP, Unit No.2, provided by the licensee in a letter dated November 24,2010 (ADAMS Accession No. ML 103300051). | | |
| The NRC staff has completed its review of these reports and concludes that the licensee provided the information required by the DCPP, Unit No.2, technical specifications. | | By letter dated May 5, 2010 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML101330269), Pacific Gas and Electric Company (the licensee), |
| No additional follow-up is required at this time. That staff's review of this report is enclosed. | | submitted information summarizing the results of the 2009 steam generator (SG) tube inspections performed at Diablo Canyon Power Plant (DCPP), Unit No.2. These inspections were performed during the fifteenth refueling outage (2R15). In addition to these reports, the U.S. Nuclear Regulatory Commission (NRC) staff summarized additional information concerning the 2009 SG tube inspections at DCPP, Unit No.2, provided by the licensee in a letter dated November 24,2010 (ADAMS Accession No. ML103300051). |
| | The NRC staff has completed its review of these reports and concludes that the licensee provided the information required by the DCPP, Unit No.2, technical specifications. No additional follow-up is required at this time. That staff's review of this report is enclosed. |
| If you have any questions regarding this matter, please contact me at (301) 415-1445. | | If you have any questions regarding this matter, please contact me at (301) 415-1445. |
| Sincerely, rll n.. \ . \ | | Sincerely, rll n.. \ . \ |
| .. Alan B. Wang, Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-323 | | ~ \J\)6.-~ .. |
| | Alan B. Wang, Projec(~nager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-323 |
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| ==Enclosure:== | | ==Enclosure:== |
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| As stated cc w/encl: Distribution via Listserv | | As stated cc w/encl: Distribution via Listserv |
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| ==SUMMARY== | | ==SUMMARY== |
| OF U.S. NUCLEAR REGULATORY COMMISSION STAFF'S REVIEW 2009 STEAM GENERATOR TUBE INSPECTIONS PACIFIC GAS AND ELECTRIC COMPANY DIABLO CANYON POWER PLANT, UNIT NO.2 DOCKET NO. 50-323 By letter dated May 5, 2010 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML 101330269), Pacific Gas and Electric Company (the licensee), submitted information summarizing the results of the 2009 steam generator (SG) tube inspections performed at Diablo Canyon Power Plant (DCPP), Unit No.2. These inspections were performed during the fifteenth refueling outage (2R 15). In addition to these reports, the U.S. Nuclear Regulatory Commission (NRC) staff summarized additional information concerning the 2009 SG tube inspections at DCPP, Unit No.2, provided by the licensee in a letter dated November 24,2010 (ADAMS Accession No. ML 103300051). | | OF U.S. NUCLEAR REGULATORY COMMISSION STAFF'S REVIEW 2009 STEAM GENERATOR TUBE INSPECTIONS PACIFIC GAS AND ELECTRIC COMPANY DIABLO CANYON POWER PLANT, UNIT NO.2 DOCKET NO. 50-323 By letter dated May 5, 2010 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML101330269), Pacific Gas and Electric Company (the licensee), |
| DCPP, Unit No.2, has four Westinghouse Model D54 SGs, each of which contains 4,444 thermally-treated Alloy 690 tubes. Each tube has a nominal outside diameter of 0.75 inches. During SG fabrication, the tubes were hydraulically expanded over the full depth of the tubesheet. | | submitted information summarizing the results of the 2009 steam generator (SG) tube inspections performed at Diablo Canyon Power Plant (DCPP), Unit No.2. These inspections were performed during the fifteenth refueling outage (2R 15). In addition to these reports, the U.S. Nuclear Regulatory Commission (NRC) staff summarized additional information concerning the 2009 SG tube inspections at DCPP, Unit No.2, provided by the licensee in a letter dated November 24,2010 (ADAMS Accession No. ML103300051). |
| The end of each tube is tack-expanded using a urethane plug expansion process. The tubes are arranged on a triangular pitch with 1.144-inch spacing. The tubes in rows 1 through 16 were full-length stress relieved following bending. Eight Type 405 stainless steel support plates, which have broached trefoil-shaped holes, support the vertical section of tubes. In the U-bend section, there are three sets of "V' shaped, rectangular stainless steel (Type 405) anti-vibration bars. The licensee provided the scope, extent, methods, and results of its SG tube inspections in the documents referenced above. In addition, the licensee described corrective actions (i.e., tube plugging) taken in response to the inspection findings. | | DCPP, Unit No.2, has four Westinghouse Model D54 SGs, each of which contains 4,444 thermally-treated Alloy 690 tubes. Each tube has a nominal outside diameter of 0.75 inches. During SG fabrication, the tubes were hydraulically expanded over the full depth of the tubesheet. The end of each tube is tack-expanded using a urethane plug expansion process. The tubes are arranged on a triangular pitch with 1.144-inch spacing. The tubes in rows 1 through 16 were full-length stress relieved following bending. Eight Type 405 stainless steel support plates, which have broached trefoil-shaped holes, support the vertical section of tubes. In the U-bend section, there are three sets of "V' shaped, rectangular stainless steel (Type 405) anti-vibration bars. |
| | The licensee provided the scope, extent, methods, and results of its SG tube inspections in the documents referenced above. In addition, the licensee described corrective actions (i.e., tube plugging) taken in response to the inspection findings. |
| After reviewing the information provided by the licensee, the NRC staff has the following comments or observations: | | After reviewing the information provided by the licensee, the NRC staff has the following comments or observations: |
| * There are 12 tubes with proximity indication Signals in the U-bend region. The signals were attributed to the proximity of a given tube to another tube. The licensee conducted | | * There are 12 tubes with proximity indication Signals in the U-bend region. The signals were attributed to the proximity of a given tube to another tube. The licensee conducted +Point probe inspections on the 12 tubes and no tube-to-tube contact or wear was associated with these proximity signals. These signals were observed during both the preservice inspection and the 2009 inspections. A potential cause of these Signals is manufacturing tolerances on a tube-to-tube basis (e.g., tolerances on U-bend profile and overall tube height). A tolerance stack-up indicates a reduced gap may occur, but tube-to-tube contact is not possible. Similar conditions have occurred at other plants. |
| +Point probe inspections on the 12 tubes and no tube-to-tube contact or wear was associated with these proximity signals. These signals were observed during both the preservice inspection and the 2009 inspections. | | * During fabrication, 12 tubes were reported to be visibly damaged by a grinding tool. Of these 12 tubes, 3 were plugged with welded plugs at the factory. The Enclosure |
| A potential cause of these Signals is manufacturing tolerances on a tube-to-tube basis (e.g., tolerances on U-bend profile and overall tube height). A tolerance stack-up indicates a reduced gap may occur, but tube-to-tube contact is not possible. | | |
| Similar conditions have occurred at other plants. | | - 2 remaining nine tubes remain inservice and have no indication of degradation, but eight of the nine tubes have ding signals at the visibly damaged area. |
| * During fabrication, 12 tubes were reported to be visibly damaged by a grinding tool. Of these 12 tubes, 3 were plugged with welded plugs at the factory. The Enclosure | | Based on a review of the information provided, the NRC staff concludes that the licensee provided the information required by the DCPP, Unit No.2, technical specifications. In addition, the NRC staff concludes that there are no technical issues that warrant follow-up actions at this time since the inspections appear to be consistent with the objective of detecting potential tube degradation and the inspection results appear to be consistent with industry operating experience at similarly designed and operated units. |
| -remaining nine tubes remain inservice and have no indication of degradation, but eight of the nine tubes have ding signals at the visibly damaged area. Based on a review of the information provided, the NRC staff concludes that the licensee provided the information required by the DCPP, Unit No.2, technical specifications. | | |
| In addition, the NRC staff concludes that there are no technical issues that warrant follow-up actions at this time since the inspections appear to be consistent with the objective of detecting potential tube degradation and the inspection results appear to be consistent with industry operating experience at similarly designed and operated units. | | April 5, 2011 Mr. John T. Conway Senior Vice President - Energy Supply and Chief Nuclear Officer Pacific Gas and Electric Company Diablo Canyon Power Plant 77 Beale Street, Mail Code B32 San Francisco, CA 94105 |
| April 5, 2011 Mr. John T. Conway Senior Vice President | | |
| -Energy Supply and Chief Nuclear Officer Pacific Gas and Electric Company Diablo Canyon Power Plant 77 Beale Street, Mail Code B32 San Francisco, CA 94105 DIABLO CANYON POWER PLANT, UNIT NO.2 -EVALUATION REGARDING THE 2009 STEAM GENERATOR TUBE INSPECTIONS (TAC NO. ME3995) | | ==SUBJECT:== |
| | DIABLO CANYON POWER PLANT, UNIT NO.2 - EVALUATION REGARDING THE 2009 STEAM GENERATOR TUBE INSPECTIONS (TAC NO. ME3995) |
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| ==Dear Mr. Conway:== | | ==Dear Mr. Conway:== |
| By letter dated May 5, 2010 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML 101330269), Pacific Gas and Electric Company (the licensee), submitted information summarizing the results of the 2009 steam generator (SG) tube inspections performed at Diablo Canyon Power Plant (DCPP), Unit No.2. These inspections were performed during the fifteenth refueling outage (2R15). In addition to these reports, the U.S. Nuclear Regulatory Commission (NRC) staff summarized additional information concerning the 2009 SG tube inspections at DCPP, Unit No.2, provided by the licensee in a letter dated November 24,2010 (ADAMS Accession No. ML 103300051). | | |
| The NRC staff has completed its review of these reports and concludes that the licensee provided the information required by the DCPP, Unit No.2, technical specifications. | | By letter dated May 5, 2010 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML101330269), Pacific Gas and Electric Company (the licensee), |
| No additional follow-up is required at this time. That staff's review of this report is enclosed. | | submitted information summarizing the results of the 2009 steam generator (SG) tube inspections performed at Diablo Canyon Power Plant (DCPP), Unit No.2. These inspections were performed during the fifteenth refueling outage (2R15). In addition to these reports, the U.S. Nuclear Regulatory Commission (NRC) staff summarized additional information concerning the 2009 SG tube inspections at DCPP, Unit No.2, provided by the licensee in a letter dated November 24,2010 (ADAMS Accession No. ML103300051). |
| | The NRC staff has completed its review of these reports and concludes that the licensee provided the information required by the DCPP, Unit No.2, technical specifications. No additional follow-up is required at this time. That staff's review of this report is enclosed. |
| If you have any questions regarding this matter, please contact me at (301) 415-1445. | | If you have any questions regarding this matter, please contact me at (301) 415-1445. |
| Sincerely, IRA! Alan B. Wang, Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-323 | | Sincerely, IRA! |
| | Alan B. Wang, Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-323 |
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| ==Enclosure:== | | ==Enclosure:== |
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| As stated cc w/encl: Distribution via Listserv DISTRIBUTION: | | As stated cc w/encl: Distribution via Listserv DISTRIBUTION: |
| PUBLIC RidsNrrDorlLpl4 Resource RidsRgn4MailCenter Resource LPLIV Reading RidsNrrLAJBu rkhardt Resource KKarwoski, NRRIDCIICSGB RidsAcrsAcnw | | PUBLIC RidsNrrDorlLpl4 Resource RidsRgn4MailCenter Resource LPLIV Reading RidsNrrLAJBu rkhardt Resource KKarwoski, NRRIDCIICSGB RidsAcrsAcnw_MailCTR Resource RidsNrrPMDiabloCanyon Resource AObodoako, NRR/DCI/CSGB RidsNrrOciCsgb Resource RidsOgcRp Resource ADAMS Accession No. ML110940269 *Memo dated OFFICE NRR/DORLlLPL4/PM RLlLPL4/PM RLlLPL4/LA JPolickoski (AWang for) 4/5/11 NRR/DCI/CSGB/BC NRR/OORLlLPL4/PM RTaylor* AWang 3/9/11 4/5/11}} |
| _ MailCTR Resource RidsNrrPMDiabloCanyon Resource AObodoako, NRR/DCI/CSGB RidsNrrOciCsgb Resource RidsOgcRp Resource ADAMS Accession No. ML110940269
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| *Memo dated OFFICE NRR/DORLlLPL4/PM RLlLPL4/PM | |
| ----JPolickoski (AWang for) 4/5/11 NRR/DCI/CSGB/BC RTaylor* 3/9/11 RLlLPL4/LA NRR/OORLlLPL4/PM AWang 4/5/11}}
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Category:Letter
MONTHYEARML24302A1962024-11-0101 November 2024
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[Table view]
Category:Report
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ML23130A0052023-06-27027 June 2023
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ML22108A2892022-05-0303 May 2022
Enclosure - Response to Representative Carbajal Regarding OIG Report on Diablo
ML22108A1662022-05-0303 May 2022
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ML24289A0962022-03-31031 March 2022
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ML21188A0362021-07-0707 July 2021
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ML20353A3972020-12-18018 December 2020
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ML20328A3012020-11-23023 November 2020
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ML20239A9562020-08-26026 August 2020
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Flaw Evaluation of Unit 2, ASME Code Class 2 Charging Pump Discharge Lines: Welds WIC-45A and RB-46-7
DCL-18-027, Seismic Probabilistic Risk Assessment for the Diablo Canyon Power Plant, Units 1 & 2 - Response to NRC Request for Information Pursuant to 10 CFR 50.54(f) Regarding Recommendation 2.1: Seismic of the Near-Term Task Force Review of Insight2018-04-24024 April 2018
Seismic Probabilistic Risk Assessment for the Diablo Canyon Power Plant, Units 1 & 2 - Response to NRC Request for Information Pursuant to 10 CFR 50.54(f) Regarding Recommendation 2.1: Seismic of the Near-Term Task Force Review of Insights
ML17024A2072017-12-18018 December 2017
Staff Assessment of Response to 10 CFR 50.54(F) Information Request Flood-Causing Mechanism Reevaluation
ML17341A0652017-11-30030 November 2017
Technical Evaluation Report Diablo Canyon Nuclear Power Plant Tsunami Hazard Reevaluation Review
ML17334A1052017-11-29029 November 2017
Reactor Coolant System Pressure and Temperature Limits Report
ML17229B6172017-08-17017 August 2017
Flaw Evaluation of Residual Heat Removal Suction Weld Joint
DCL-17-064, Plant Focused Evaluation Report for External Flooding2017-07-19019 July 2017
Plant Focused Evaluation Report for External Flooding
DCL-17-049, Flaw Evaluation of Unit 2 Residual Heat Removal Suction Weld Joint2017-05-18018 May 2017
Flaw Evaluation of Unit 2 Residual Heat Removal Suction Weld Joint
DCL-16-117, Reactor Coolant System Pressure and Temperature Limits Report, Revision 152016-11-10010 November 2016
Reactor Coolant System Pressure and Temperature Limits Report, Revision 15
ML16314B0822016-11-0909 November 2016
Criteria for Protection Against Dynamic Effects Associated with a Postulated Rupture of Piping
ML16314C6912016-11-0909 November 2016
Enclosure, Statement of the Problem Concerning PWR Primary Coolant System Pipe Rupture
DCL-16-124, Implementation of Alternative Source Term Summary of Dose Analyses and Results Revision 52016-11-0909 November 2016
Implementation of Alternative Source Term Summary of Dose Analyses and Results Revision 5
ML16287A7552016-10-0606 October 2016
Technical Assessment Implementation of Alternative Source Terms Summary of Dose Analyses and Results Revision 4
ML16215A1092016-08-0202 August 2016
OEDO-16-00436 - Supplemental Information from Mr. Lochbaum 10 CFR 2.206 Petition on Apparent Violation of 10 CFR 50.9 at Diablo Canyon Nuclear Power Plant
ML16169A2652016-05-18018 May 2016
Technical Report, Implementation of Alternative Source Terms Summary of Dose Analysis and Results, Revision 3
ML16146A0952016-04-21021 April 2016
54006-CALC-01, Diablo Canyon Power Plant: Evaluation of Risk Significance of Permanent ILRT Extension.
ML16238A1042016-03-31031 March 2016
15-0681-RTM-001, Revision 0, System Level Requirements Traceability Matrix (Rtm).
DCL-16-081, 15-0681-RTM-001, Revision 0, System Level Requirements Traceability Matrix (Rtm).2016-03-31031 March 2016
15-0681-RTM-001, Revision 0, System Level Requirements Traceability Matrix (Rtm).
ML16019A2242016-02-0101 February 2016
Record of Review, Dispositions to Diablo Canyon Nuclear Plant, Units 1 and 2, Internal Events, Internal Flooding, Seismic, and Fire PRA Facts and Observations
ML16061A4682016-01-15015 January 2016
9Revision 1 to 93754-12-862-NP, V&V Implementation Phase Summary Report PPSII-IV
DCL-16-020, Diablo Canyon, Units 1 and 2 - Revision 3 to 993754-11-861-NP, V&V Design Phase Summary Report Ppsi2016-01-15015 January 2016
Diablo Canyon, Units 1 and 2 - Revision 3 to 993754-11-861-NP, V&V Design Phase Summary Report Ppsi
DCL-16-020, Diablo Canyon, Units 1 and 2 - 9Revision 1 to 93754-12-862-NP, V&V Implementation Phase Summary Report PPSII-IV2016-01-15015 January 2016
Diablo Canyon, Units 1 and 2 - 9Revision 1 to 93754-12-862-NP, V&V Implementation Phase Summary Report PPSII-IV
ML16061A4642016-01-15015 January 2016
Revision 3 to 993754-11-861-NP, V&V Design Phase Summary Report Ppsi
DCL-16-020, Diablo Canyon, Units 1 and 2 - Revision 3 to 993754-11-854-1-NP, Protection Set I, Factory Acceptance Test Report2016-01-14014 January 2016
Diablo Canyon, Units 1 and 2 - Revision 3 to 993754-11-854-1-NP, Protection Set I, Factory Acceptance Test Report
ML16061A4592016-01-14014 January 2016
Revision 3 to 993754-11-854-1-NP, Protection Set I, Factory Acceptance Test Report
ML16048A2152015-12-15015 December 2015
Fleet Vehicle-Asset List
ML16048A2072015-12-15015 December 2015
Once Through Cooling
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Category:Miscellaneous
MONTHYEARML24129A1762024-06-14014 June 2024
National Historic Preservation Act Section 106 Consultation – Results of Identification and Evaluation (Docket Number: 72-026)
DCL-24-048, O CFR 50.59 and 1 O CFR 72.48 Summary Report for the Period of January 1, 2022, Through December 31, 20232024-04-30030 April 2024
O CFR 50.59 and 1 O CFR 72.48 Summary Report for the Period of January 1, 2022, Through December 31, 2023
ML23130A0052023-06-27027 June 2023
Report to Congress Regarding Diablo Canyon
ML22108A2892022-05-0303 May 2022
Enclosure - Response to Representative Carbajal Regarding OIG Report on Diablo
ML22108A1662022-05-0303 May 2022
Enclosure 1 - Assessment Event Inquiry Into the Nuclear Regulatory Commission Oversight of the Auxiliary Feedwater System at Diablo Canyon Nuclear
DCL-21-071, Federally Listed Species Affects Determination Memorandum2021-10-14014 October 2021
Federally Listed Species Affects Determination Memorandum
ML21188A0362021-07-0707 July 2021
Draft PG&E Letter DCL-21-046 - Diablo Canyon Unit 1: Emergency License Amendment Request 21-05, Revision to Technical Specification 3.7.8, Auxiliary Saltwater (Asw) System
DCL-20-102, Nuclear Material Transaction Report for New Fuel2020-12-0909 December 2020
Nuclear Material Transaction Report for New Fuel
ML20335A0132020-11-30030 November 2020
NRC Response to Public Watchdogs November 2
ML20328A3012020-11-23023 November 2020
NERC Reliability Standards for the Bulk Electric System of North America Updated July 20, 2020 (Cgnp Public Comments on Diablo Canyon Nuclear Power Plant, Units 1 and 2 - Pre-submittal Meeting of 11/24/2020)
ML18254A0402019-01-22022 January 2019
Staff Review of Seismic Probabilistic Risk Assessment Associated with Reevaluated Seismic Hazard Implementation of the Near Term Task Force Recommendation 2.1: Seismic
IR 05000275/20180052018-08-31031 August 2018
Updated Inspection Plan for Diablo Canyon Power Plant, Units 1 and 2 (Report 05000275/2018005 and 05000323/2018005)
ML17024A2072017-12-18018 December 2017
Staff Assessment of Response to 10 CFR 50.54(F) Information Request Flood-Causing Mechanism Reevaluation
DCL-16-117, Reactor Coolant System Pressure and Temperature Limits Report, Revision 152016-11-10010 November 2016
Reactor Coolant System Pressure and Temperature Limits Report, Revision 15
ML16215A1092016-08-0202 August 2016
OEDO-16-00436 - Supplemental Information from Mr. Lochbaum 10 CFR 2.206 Petition on Apparent Violation of 10 CFR 50.9 at Diablo Canyon Nuclear Power Plant
ML16019A2242016-02-0101 February 2016
Record of Review, Dispositions to Diablo Canyon Nuclear Plant, Units 1 and 2, Internal Events, Internal Flooding, Seismic, and Fire PRA Facts and Observations
ML16048A2152015-12-15015 December 2015
Fleet Vehicle-Asset List
ML16048A2072015-12-15015 December 2015
Once Through Cooling
DCL-15-102, 10 CFR 71.95 Report Regarding Energy Solutions' Model 8-120B Shipping Cask2015-08-24024 August 2015
10 CFR 71.95 Report Regarding Energy Solutions' Model 8-120B Shipping Cask
ML15231A5712015-07-28028 July 2015
Holtec Information Bulletin (HIB) No. 67 (Rev. 0), VCT Restraint Strap Weld Failure
ML15160A2612015-07-0101 July 2015
Letter to NMFS Notice of Intent to Reinitiate Scoping Process for Diablo Canyon Power Plant Units 1 and 2 License Renewal Application
ML16048A2042015-06-30030 June 2015
Notice of Intent, General Permit to Discharge Storm Water
ML16048A2132015-06-22022 June 2015
Permit Renewal No. 49-1
ML15355A2972015-05-31031 May 2015
DCPP Fsaru R22 File a Drawings - Combined - (Redacted)
ML15355A0792015-05-31031 May 2015
DCPP Fsaru R22 File B Drawings - Combined (Redacted)
RIS 2014-07, Regulatory Issue Summary (RIS) 2014-07, Enhancements to the Vendor Inspection Program- Vendor Information Request. Part 2 of 52014-06-19019 June 2014
Regulatory Issue Summary (RIS) 2014-07, Enhancements to the Vendor Inspection Program- Vendor Information Request. Part 2 of 5, Regulatory Issue Summary (RIS) 2014-07, Enhancements to the Vendor Inspection Program- Vendor Information Request. Part 3 of 5, Regulatory Issue Summary (RIS) 2014-07, Enhancements to the Vendor Inspection Program- Vendor Information Request. Part 4 of 5, Regulatory Issue Summary (RIS) 2014-07, Enhancements to the Vendor Inspection Program- Vendor Information Request. Part 5 of 5
ML14189A5432014-06-19019 June 2014
Regulatory Issue Summary (RIS) 2014-07, Enhancements to the Vendor Inspection Program- Vendor Information Request. Part 5 of 5
ML14189A5372014-06-19019 June 2014
Regulatory Issue Summary (RIS) 2014-07, Enhancements to the Vendor Inspection Program- Vendor Information Request. Part 4 of 5
ML14189A5332014-06-19019 June 2014
Regulatory Issue Summary (RIS) 2014-07, Enhancements to the Vendor Inspection Program- Vendor Information Request. Part 3 of 5
ML14189A5312014-06-19019 June 2014
Regulatory Issue Summary (RIS) 2014-07, Enhancements to the Vendor Inspection Program- Vendor Information Request. Part 2 of 5
ML14189A5002014-06-19019 June 2014
Regulatory Issue Summary (RIS) 2014-07, Enhancements to the Vendor Inspection Program- Vendor Information Request. Part 1 of 5
RIS 2014-07, Regulatory Issue Summary (RIS) 2014-07, Enhancements to the Vendor Inspection Program- Vendor Information Request. Part 5 of 52014-06-19019 June 2014
Regulatory Issue Summary (RIS) 2014-07, Enhancements to the Vendor Inspection Program- Vendor Information Request. Part 5 of 5
RIS 2014-07, Regulatory Issue Summary (RIS) 2014-07, Enhancements to the Vendor Inspection Program- Vendor Information Request. Part 4 of 52014-06-19019 June 2014
Regulatory Issue Summary (RIS) 2014-07, Enhancements to the Vendor Inspection Program- Vendor Information Request. Part 4 of 5, Regulatory Issue Summary (RIS) 2014-07, Enhancements to the Vendor Inspection Program- Vendor Information Request. Part 5 of 5
RIS 2014-07, Regulatory Issue Summary (RIS) 2014-07, Enhancements to the Vendor Inspection Program- Vendor Information Request. Part 3 of 52014-06-19019 June 2014
Regulatory Issue Summary (RIS) 2014-07, Enhancements to the Vendor Inspection Program- Vendor Information Request. Part 3 of 5, Regulatory Issue Summary (RIS) 2014-07, Enhancements to the Vendor Inspection Program- Vendor Information Request. Part 4 of 5, Regulatory Issue Summary (RIS) 2014-07, Enhancements to the Vendor Inspection Program- Vendor Information Request. Part 5 of 5
RIS 2014-07, Regulatory Issue Summary (RIS) 2014-07, Enhancements to the Vendor Inspection Program- Vendor Information Request. Part 1 of 52014-06-19019 June 2014
Regulatory Issue Summary (RIS) 2014-07, Enhancements to the Vendor Inspection Program- Vendor Information Request. Part 1 of 5, Regulatory Issue Summary (RIS) 2014-07, Enhancements to the Vendor Inspection Program- Vendor Information Request. Part 2 of 5, Regulatory Issue Summary (RIS) 2014-07, Enhancements to the Vendor Inspection Program- Vendor Information Request. Part 3 of 5, Regulatory Issue Summary (RIS) 2014-07, Enhancements to the Vendor Inspection Program- Vendor Information Request. Part 4 of 5, Regulatory Issue Summary (RIS) 2014-07, Enhancements to the Vendor Inspection Program- Vendor Information Request. Part 5 of 5
DCL-14-030, Diablo, Units 1 and 2 - Report of 10 CFR 50.59, Changes, Tests and Experiments, for the Period of January 1, 2012 Through December 31, 20132014-04-17017 April 2014
Diablo, Units 1 and 2 - Report of 10 CFR 50.59, Changes, Tests and Experiments, for the Period of January 1, 2012 Through December 31, 2013
DCL-14-021, Reactor Coolant System Pressure and Temperature Limits Report for Units 1 and 22014-03-25025 March 2014
Reactor Coolant System Pressure and Temperature Limits Report for Units 1 and 2
ML13364A1922014-02-0303 February 2014
Interim Staff Evaluation Relating to Overall Integrated Plan in Response to Order EA-12-049 (Mitigation Strategies)
DCL-13-094, and Humboldt Bay Power Plant, 10 CFR 71.95 Reports Regarding Energysolutions' Model 8-120B Shipping Cask2013-09-30030 September 2013
and Humboldt Bay Power Plant, 10 CFR 71.95 Reports Regarding Energysolutions' Model 8-120B Shipping Cask
DCL-12-080, Nonroutine Report of Planned Disturbance of Archaeological Site SLO-22012-08-21021 August 2012
Nonroutine Report of Planned Disturbance of Archaeological Site SLO-2
DCL-12-050, Diablo Canyon, Units 1 and 2, Attachment 16 to DCL-12-050, PGE-12-52 Np, Westinghouse Input to Diablo Canyon Digital Process Protection System Replacement Uncertainty Calculations Summary Lar.2012-06-0606 June 2012
Diablo Canyon, Units 1 and 2, Attachment 16 to DCL-12-050, PGE-12-52 Np, Westinghouse Input to Diablo Canyon Digital Process Protection System Replacement Uncertainty Calculations Summary Lar.
ML12170A8402012-06-0606 June 2012
Attachment 16 to DCL-12-050, PGE-12-52 Np, Westinghouse Input to Diablo Canyon Digital Process Protection System Replacement Uncertainty Calculations Summary Lar.
DCL-12-023, Third Interval Snubber Program, Revision 12012-02-28028 February 2012
Third Interval Snubber Program, Revision 1
DCL-11-136, Annual Update to the DCPP License Renewal Application and License Renewal Application Amendment Number 452011-12-21021 December 2011
Annual Update to the DCPP License Renewal Application and License Renewal Application Amendment Number 45
DCL-11-073, Diablo Canyon, Unit 2 - Core Operating Limits Report for Cycle 172011-06-18018 June 2011
Diablo Canyon, Unit 2 - Core Operating Limits Report for Cycle 17
ML1116803532011-06-18018 June 2011
Core Operating Limits Report for Cycle 17
ML1109402692011-04-0505 April 2011
Evaluation Regarding the 2009 Steam Generator Tube Inspections Performed During the 15th Refueling Outage (2R15)
DCL-10-158, CFR 54.21(b) Annual Update to the DCPP License Renewal Application and Amendment No. 342010-12-29029 December 2010
CFR 54.21(b) Annual Update to the DCPP License Renewal Application and Amendment No. 34
DCL-10-081, Diablo Canyon, Units 1 and 2, Backup 60M Tower Data File, Calendar Year 2008, Part 2 of 52010-08-0202 August 2010
Diablo Canyon, Units 1 and 2, Backup 60M Tower Data File, Calendar Year 2008, Part 2 of 5
ML1025803172010-08-0202 August 2010
2009 Meteorological Data
2024-06-14
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Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555*0001 April 5. 2011 Mr. John T. Conway Senior Vice President -- Energy Supply and Chief Nuclear Officer Pacific Gas and Electric Company Diablo Canyon Power Plant 77 Beale Street, Mail Code B32 San Francisco, CA 94105
SUBJECT:
DIABLO CANYON POWER PLANT, UNIT NO.2 - EVALUATION REGARDING THE 2009 STEAM GENERATOR TUBE INSPECTIONS (TAC NO. ME3995)
Dear Mr. Conway:
By letter dated May 5, 2010 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML101330269), Pacific Gas and Electric Company (the licensee),
submitted information summarizing the results of the 2009 steam generator (SG) tube inspections performed at Diablo Canyon Power Plant (DCPP), Unit No.2. These inspections were performed during the fifteenth refueling outage (2R15). In addition to these reports, the U.S. Nuclear Regulatory Commission (NRC) staff summarized additional information concerning the 2009 SG tube inspections at DCPP, Unit No.2, provided by the licensee in a letter dated November 24,2010 (ADAMS Accession No. ML103300051).
The NRC staff has completed its review of these reports and concludes that the licensee provided the information required by the DCPP, Unit No.2, technical specifications. No additional follow-up is required at this time. That staff's review of this report is enclosed.
If you have any questions regarding this matter, please contact me at (301) 415-1445.
Sincerely, rll n.. \ . \
~ \J\)6.-~ ..
Alan B. Wang, Projec(~nager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-323
Enclosure:
As stated cc w/encl: Distribution via Listserv
SUMMARY
OF U.S. NUCLEAR REGULATORY COMMISSION STAFF'S REVIEW 2009 STEAM GENERATOR TUBE INSPECTIONS PACIFIC GAS AND ELECTRIC COMPANY DIABLO CANYON POWER PLANT, UNIT NO.2 DOCKET NO. 50-323 By letter dated May 5, 2010 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML101330269), Pacific Gas and Electric Company (the licensee),
submitted information summarizing the results of the 2009 steam generator (SG) tube inspections performed at Diablo Canyon Power Plant (DCPP), Unit No.2. These inspections were performed during the fifteenth refueling outage (2R 15). In addition to these reports, the U.S. Nuclear Regulatory Commission (NRC) staff summarized additional information concerning the 2009 SG tube inspections at DCPP, Unit No.2, provided by the licensee in a letter dated November 24,2010 (ADAMS Accession No. ML103300051).
DCPP, Unit No.2, has four Westinghouse Model D54 SGs, each of which contains 4,444 thermally-treated Alloy 690 tubes. Each tube has a nominal outside diameter of 0.75 inches. During SG fabrication, the tubes were hydraulically expanded over the full depth of the tubesheet. The end of each tube is tack-expanded using a urethane plug expansion process. The tubes are arranged on a triangular pitch with 1.144-inch spacing. The tubes in rows 1 through 16 were full-length stress relieved following bending. Eight Type 405 stainless steel support plates, which have broached trefoil-shaped holes, support the vertical section of tubes. In the U-bend section, there are three sets of "V' shaped, rectangular stainless steel (Type 405) anti-vibration bars.
The licensee provided the scope, extent, methods, and results of its SG tube inspections in the documents referenced above. In addition, the licensee described corrective actions (i.e., tube plugging) taken in response to the inspection findings.
After reviewing the information provided by the licensee, the NRC staff has the following comments or observations:
- There are 12 tubes with proximity indication Signals in the U-bend region. The signals were attributed to the proximity of a given tube to another tube. The licensee conducted +Point probe inspections on the 12 tubes and no tube-to-tube contact or wear was associated with these proximity signals. These signals were observed during both the preservice inspection and the 2009 inspections. A potential cause of these Signals is manufacturing tolerances on a tube-to-tube basis (e.g., tolerances on U-bend profile and overall tube height). A tolerance stack-up indicates a reduced gap may occur, but tube-to-tube contact is not possible. Similar conditions have occurred at other plants.
- During fabrication, 12 tubes were reported to be visibly damaged by a grinding tool. Of these 12 tubes, 3 were plugged with welded plugs at the factory. The Enclosure
- 2 remaining nine tubes remain inservice and have no indication of degradation, but eight of the nine tubes have ding signals at the visibly damaged area.
Based on a review of the information provided, the NRC staff concludes that the licensee provided the information required by the DCPP, Unit No.2, technical specifications. In addition, the NRC staff concludes that there are no technical issues that warrant follow-up actions at this time since the inspections appear to be consistent with the objective of detecting potential tube degradation and the inspection results appear to be consistent with industry operating experience at similarly designed and operated units.
April 5, 2011 Mr. John T. Conway Senior Vice President - Energy Supply and Chief Nuclear Officer Pacific Gas and Electric Company Diablo Canyon Power Plant 77 Beale Street, Mail Code B32 San Francisco, CA 94105
SUBJECT:
DIABLO CANYON POWER PLANT, UNIT NO.2 - EVALUATION REGARDING THE 2009 STEAM GENERATOR TUBE INSPECTIONS (TAC NO. ME3995)
Dear Mr. Conway:
By letter dated May 5, 2010 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML101330269), Pacific Gas and Electric Company (the licensee),
submitted information summarizing the results of the 2009 steam generator (SG) tube inspections performed at Diablo Canyon Power Plant (DCPP), Unit No.2. These inspections were performed during the fifteenth refueling outage (2R15). In addition to these reports, the U.S. Nuclear Regulatory Commission (NRC) staff summarized additional information concerning the 2009 SG tube inspections at DCPP, Unit No.2, provided by the licensee in a letter dated November 24,2010 (ADAMS Accession No. ML103300051).
The NRC staff has completed its review of these reports and concludes that the licensee provided the information required by the DCPP, Unit No.2, technical specifications. No additional follow-up is required at this time. That staff's review of this report is enclosed.
If you have any questions regarding this matter, please contact me at (301) 415-1445.
Sincerely, IRA!
Alan B. Wang, Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-323
Enclosure:
As stated cc w/encl: Distribution via Listserv DISTRIBUTION:
PUBLIC RidsNrrDorlLpl4 Resource RidsRgn4MailCenter Resource LPLIV Reading RidsNrrLAJBu rkhardt Resource KKarwoski, NRRIDCIICSGB RidsAcrsAcnw_MailCTR Resource RidsNrrPMDiabloCanyon Resource AObodoako, NRR/DCI/CSGB RidsNrrOciCsgb Resource RidsOgcRp Resource ADAMS Accession No. ML110940269 *Memo dated OFFICE NRR/DORLlLPL4/PM RLlLPL4/PM RLlLPL4/LA JPolickoski (AWang for) 4/5/11 NRR/DCI/CSGB/BC NRR/OORLlLPL4/PM RTaylor* AWang 3/9/11 4/5/11
