Letter Sequence Request |
---|
|
|
MONTHYEARDCL-07-009, Additional Commitments Related to Inspection and Mitigation of Alloy 600/82/182 Pressurizer Butt Welds2007-02-20020 February 2007 Additional Commitments Related to Inspection and Mitigation of Alloy 600/82/182 Pressurizer Butt Welds Project stage: Request ML0706704252007-03-15015 March 2007 Confirmatory Action Letter Alloy 82/182 Pressurizer Butt Welds Project stage: Other ML0724101992007-08-0707 August 2007 Mitigation of Alloy 600/82/182 Pressurizer Butt Welds in 2008 Project stage: Request ML0724201162007-09-0707 September 2007 Evaluation of Finite Element Analysis in Support of Alloy 82/182 Pressurizer Butt Weld Inspections in 2008 as Provided by CAL NRR-07-007 (Tac MD4150) Project stage: Other DCL-07-099, ASME Section XI Inservice Inspection Program Relief Request REP-1 U2, Revision 1, and Response to Request for Additional Information2007-10-22022 October 2007 ASME Section XI Inservice Inspection Program Relief Request REP-1 U2, Revision 1, and Response to Request for Additional Information Project stage: Response to RAI DCL-07-105, ASME Section XI Inservice Inspection Program Relief Request REP-1 U2, Revision 1; Response to Request for Additional Information2007-11-29029 November 2007 ASME Section XI Inservice Inspection Program Relief Request REP-1 U2, Revision 1; Response to Request for Additional Information Project stage: Response to RAI ML0801100012008-02-0606 February 2008 Approval of Relief Request REP-1 U2, Revision 1, for the Application of Weld Overlay on Dissimilar Metal Welds of Pressurizer Nozzles Project stage: Acceptance Review ML0803700262008-02-13013 February 2008 Request for Additional Information Requests for Alternative ANO1-R&R-011 for Unit 1 and ANO2-R&R-005 for Unit 2, Structural Weld Overlay Repairs to Improve Dissimilar Metal Weld Integrity Project stage: RAI DCL-08-039, Mitigation Status of Alloy 600/82/182 Pressurizer Butt Welds, Structural Weld Overlay Ultrasonic Examination Results2008-04-24024 April 2008 Mitigation Status of Alloy 600/82/182 Pressurizer Butt Welds, Structural Weld Overlay Ultrasonic Examination Results Project stage: Other 2007-08-07
[Table View] |
|
---|
Category:Letter
MONTHYEARIR 05000275/20230042024-02-0909 February 2024 Integrated Inspection Report 05000275/2023004 and 05000323/2023004 ML24002B1802024-01-29029 January 2024 LRA Audit Plan DCL-24-010, Nuclear Material Transaction Report for New Fuel2024-01-29029 January 2024 Nuclear Material Transaction Report for New Fuel ML24018A0152024-01-29029 January 2024 License Renewal Application Review Schedule Letter ML24017A2492024-01-24024 January 2024 Letter to Neil Peyron, Chairman, Tule River Tribe, Re. Diablo Canyon ML24024A1752024-01-24024 January 2024 Letter to Tribal Council San Luis Obispo County Chumash Indians on Section 106 Consultation and Scoping Process for the Environmental Review of Diablo Canyon Nuclear Plant, Unit 1 and 2 License Renewal Application ML24003A8902024-01-24024 January 2024 Letter to P. Gerfen - Diablo Canyon Notice of Intent to Conduct Scoping and Prepare an Environmental Impact Statement ML24012A1582024-01-24024 January 2024 Letter to Hon. Violet Sage Walker, Chairwoman Northern Chumash Tribal Council on Section 106 Consultation and Scoping Process for the Environmental Review of Diablo Canyon Nuclear Plant, Unit 1 and 2 License Renewal Application ML24012A0062024-01-24024 January 2024 Achp Scoping Letter for Diablo Canyon License Renewal ML24012A0552024-01-24024 January 2024 Letter to J. Polanco, Shpo, on Request to Initiate Section 106 Consultation and Scooping Process for the Environmental Review of Diablo Canyon Nuclear Plant, Unit 1 and 2 License Renewal Application ML24024A1562024-01-24024 January 2024 Letter to Hon. Gabe Frausto, Coastal Band of Chumash Indians on Section 106 Consultation and Scoping Process for the Environmental Review of Diablo Canyon Nuclear Plant, Unit 1 and 2 License Renewal Application ML24024A1652024-01-24024 January 2024 Letter to Hon. Mona Olivas Tucker, Yak Tityu Tityu Yak Tilhini Northern Chumas Indians on Section 106 Consultation and Scoping Process for the Environmental Review of Diablo Canyon Nuclear Plant, Unit 1 and 2 License Renewal Application ML24024A1612024-01-24024 January 2024 Letter Hon. Gary Pierce, Salian Tribe of Monterey and San Luis Obispo Counties on Section 106 Consultation and Scoping Process for the Environmental Review of Diablo Canyon Nuclear Plant, Unit 1 and 2 License Renewal Application ML24012A0362024-01-24024 January 2024 Request to Initiate Section 106 Consultation and Scoping Process for the Environmental Review License Renewal Application DCL-24-009, Nuclear Material Transaction Report for New Fuel2024-01-17017 January 2024 Nuclear Material Transaction Report for New Fuel DCL-24-008, Schedule Considerations for Review of the DCPP License Renewal Application2024-01-17017 January 2024 Schedule Considerations for Review of the DCPP License Renewal Application DCL-24-004, Supplement to License Amendment Request 23-01 Revision to Technical Specifications to Adopt Risk-Informed Completion Times TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b2024-01-15015 January 2024 Supplement to License Amendment Request 23-01 Revision to Technical Specifications to Adopt Risk-Informed Completion Times TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b IR 05000275/20230112024-01-12012 January 2024 NRC License Renewal Phase 1 Inspection Report 05000275/2023011 DCL-23-129, Nuclear Material Transaction Report for New Fuel2023-12-27027 December 2023 Nuclear Material Transaction Report for New Fuel ML23326A0122023-12-21021 December 2023 12-21-23 Letter to the Honorable Byron Donalds from Chair Hanson Responds to Letter Regarding 2.206 Petition to Close Diablo Canyon Nuclear Power Plant, Unit 1 ML23341A0042023-12-19019 December 2023 LRA Acceptance Letter ML23352A2342023-12-18018 December 2023 Notification of Age-Related Degradation Inspection (05000275/2024014 and 05000323/2024014) and Request for Information DCL-23-122, Request for Exemption from Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Implementation2023-12-14014 December 2023 Request for Exemption from Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Implementation DCL-23-128, Emergency Plan Update2023-12-13013 December 2023 Emergency Plan Update ML23355A0952023-12-0808 December 2023 License Renewal Application Online Reference Portal DCL-23-125, Core Operating Limits Report for Unit 1 Cycle 252023-12-0606 December 2023 Core Operating Limits Report for Unit 1 Cycle 25 ML23291A2702023-11-28028 November 2023 Letter to Nakia Zavalla, Shpo, the Santa Ynez Band of Chumash Indians; Re., Diablo Canyon ISFSI Initiating Section 106 Consultation ML23320A2442023-11-28028 November 2023 Letter to Kerri Vera, Director of Department of Environmental Protection, Tule River Tribe; Re., Diablo Canyon ISFSI Initiating Section 106 Consultation ML23325A1382023-11-27027 November 2023 ISFSI Tribal Letter to San Luis Obispo County Chumash Indians ML23325A1322023-11-27027 November 2023 ISFSI Tribal Letter to Salian Tribe of Montgomery, San Luis Obispo ML23325A1332023-11-27027 November 2023 ISFSI Tribal Letter to Yak Tityu Tityu Northern Chumash Indians ML23307A0062023-11-27027 November 2023 ISFSI Tribal Letter to Northern Chumash Tribal Council ML24003A7242023-11-27027 November 2023 Independent Safety Committee; Diab Lo Canyon Nuclear Power Plant Operations, Thirty-Third Annual Report on the Safety ML23325A1292023-11-27027 November 2023 ISFSI Tribal Letter to Coastal Band of Chumash ML23320A1502023-11-17017 November 2023 Individual Notice of Consideration of Issuance of Amendment to Facility Operating License, Proposed No Significant Hazards Consideration Determination, & Opportunity for Hearing (Exigent Circumstances) (EPID L-2023-LLA-0155) - LTR DCL-23-121, Supplement to License Amendment Request 23-03, Revision to Technical Specification3.7.8, Auxiliary Saltwater System2023-11-16016 November 2023 Supplement to License Amendment Request 23-03, Revision to Technical Specification3.7.8, Auxiliary Saltwater System ML23296A0982023-11-15015 November 2023 Notification and Request for Consultation Regarding Pacific Gas and Electric Diablo Canyon Independent Spent Fuel Storage Installation Material License Renewal Request (Docket Number: 72-26) DCL-23-120, License Amendment Request 23-03 Revision to Technical Specification 3.7.8, Auxiliary Saltwater (Asw) System2023-11-14014 November 2023 License Amendment Request 23-03 Revision to Technical Specification 3.7.8, Auxiliary Saltwater (Asw) System ML23293A1052023-11-14014 November 2023 Receipt and Availability of License Renewal Application IR 05000275/20230032023-11-13013 November 2023 Integrated Inspection Report 05000275/2023003 and 05000323/2023003 ML23311A2082023-11-0909 November 2023 Reassignment of U.S. Nuclear Regulatory Commission Branch Chief in the Division of Operating Reactor Licensing for Plant Licensing Branch IV DCL-23-118, License Renewal Application2023-11-0707 November 2023 License Renewal Application ML23318A2102023-10-31031 October 2023 Independent Safety Committee; Thirty-Third Annual Report on the Safety of Diablo Canyon Nuclear Power Plant Operations DCL-2023-520, Discharge Self-Monitoring at Diablo Canyon Power Plant (DCPP)2023-10-19019 October 2023 Discharge Self-Monitoring at Diablo Canyon Power Plant (DCPP) DCL-23-103, Independent Spent Fuel Storage Installation - Withdrawal of License Amendment Request 22-01, Request for Approval of Alternative Security Measures for Early Warning System2023-10-13013 October 2023 Independent Spent Fuel Storage Installation - Withdrawal of License Amendment Request 22-01, Request for Approval of Alternative Security Measures for Early Warning System IR 05000275/20240152023-10-10010 October 2023 Information Request for the Cybersecurity Baseline Inspection, Notification to Perform Inspection (050002752024015 and 050003232024015) 2024-02-09
[Table view] |
Text
r WE Pacific Gas and Electric Company'John S. Keenan Senior Vice President Generation
& Chief Nuclear Officer August 7, 2007 77 Beale Street, Mailcode B32 San Francisco, CA 94105 Mailing Address Mail Code B32, Room 3235 P. 0. Box 770000 San Francisco, CA 94177 415.973.4684 Internal:
223.4684 Fax: 415.973.2313 PG&E Letter DCL-07-077 Mr. James E. Dyer Director, Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 Docket No. 50-323, OL-DPR-82 Diablo Canyon Unit 2 Mitiaation of Alloy 600/82/182 Pressurizer Butt Welds in 2008
References:
1.PG&E Letter DCL-07-009 from John S. Keenan, Senior Vice President
-Generation and Chief Nuclear Officer of Diablo Canyon Power Plant, to U. S. NRC, "Inspection and Mitigation of Alloy 600/82/182 Pressurizer Butt Welds," dated January 31, 2007 2. PG&E Letter DCL-07-019 from John S. Keenan, Senior Vice President
-Generation and Chief Nuclear Officer of Diablo Canyon Power Plant, to U. S. NRC, "Additional Commitments Related to Inspection and Mitigation of Alloy 600/82/182 Pressurizer Butt Welds," dated February 20, 2007 3. Letter from James E. Dyer, Director of Office of Nuclear Reactor Regulation (U. S. NRC), to John 'S. Keenan, Senior Vice President
-Generation and Chief Nuclear Officer of Diablo Canyon Power Plant, "Confirmatory Action Letter, Diablo Canyon Power Plant, Unit No. 2 (TAC No. MD4150)," dated March 15; 2007 4. Electric Power Research Institute Final Report, "Advanced FEA Evaluation of Growth of Postulated Circumferential PWSCC Flaws in Pressurizer Nozzle Dissimilar Metal Welds, (MRP-216):
Evaluations Specific to Nine Subject Plants," EPRI, Palo Alto, CA: 2007; 1015383 dated July 31, 2007 5. Nuclear Energy Institute Letter to James E. Dyer, Director of Office of Nuclear Reactor Regulation (U S. NRC), "Transmitta:
of EPRI Report," dated August 1, 2007 A member of Lhe STARS (Strategic Teaming and Resource Sharing) Attiance Callaway = Comanche Peak
- Diablo Canyon @ Palo Verde ° South Texas Project
- Wolf Creek ,4iio 0 Document Control Desk PG&E Letter DCL-07-077 August 7, 2007 Page 2 In the Reference 1 submittal, Pacific Gas and Electric (PG&E) provided the plans and schedule for the mitigation of pressurizer Alloy 600/82/182 butt welds for Diablo Canyon Power Plant (DCPP) Unit 2. In that submittal, PG&E stated that, based on the current refueling outage schedule, PG&E would complete the mitigation action during the DCPP Unit 2 Fourteenth Refueling Outage (2R14) currently scheduled to begin February 4, 2008 (i.e., beyond the industry-sponsored Materials Reliability Program MRP-139 implementation deadline of December 31, 2007).Reference 2 provided regulatory commitments regarding the DCPP Unit 2 schedule for mitigation actions, enhanced reactor coolant system (RCS) leakage monitoring, and inspection reporting requirements.
Also, specific to DCPP Unit 2, a commitment was made to accelerate the mitigation actions, currently scheduled during the 2R14 outage, into 2007 if the results of ongoing analytical work do not demonstrate to the NRC that the current schedule is adequate.
These regulatory commitments were confirmed in the Reference 3 Confirmatory Action Letter (CAL).EPRI's advanced finite element analysis, Reference 4, was recently completed and submitted by Reference
- 5. The analysis, which is applicable to DCPP Unit 2, assumed the existence of large circumferential cracks in all the analyzed locations.
This assumption is very conservative considering industry field inspections and experience that has shown a relatively low number of primary water stress corrosion cracking (PWSCC) indications in these components.
With this conservatism, the analysis concluded that there is significant time for crack growth between the onset of detectable leakage and development of critical flaw size. The rolled and welded stainless steel liners within the spray, safety, and relief nozzles, which are designed to seal the low alloy steel nozzle and dissimilar metal weld from the pressurizer vapor space, have not been credited in the analysis.This letter confirms that the Reference 4 EPRI Advanced Finite Element Analysis report bounds the DCPP Unit 2 pressurizer Alloy 82/182 welded pipe/nozzle components.
PG&E has reviewed the report and verified that the inputs address DCPP Unit 2 weld configurations and loads, that the analysis and conclusions are applicable to the DCPP Unit 2 design, and that all welds representative of DCPP Unit 2 are adequately addressed by the crack growth analyses and associated sensitivity cases. Finally, the analytical results applicable to DCPP Unit 2 satisfy the leakage evaluation criteria presented in the report.Therefore, PG&E concludes the analytical results presented in Reference 4, and the current DCPP Unit 2 enhanced leakage monitoring program, provide a reasonable and adequate basis for performing mitigation activities during DCPP 2R14, currently scheduled to begin February 4, 2008, as committed to in Reference 2, after which time DCPP Unit 2 will fully satisfy the MRP-139 inspection/mitigation requirements for pressurizer Alloy 600/82/182 components.
A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Callaway e Comanche Peak 9 Diablo Canyon 9 Palo Verde 9 South Texas Project 9 Wolf Creek Document Control Desk August 7, 2007 Page 3 PG&E Letter DCL-07-077 If you have any questions concerning this submittal, please contact Stan Ketelsen at 805-545-4720.
Sincerely, n S. Keenan enenior Vice President
-Generation and Chief Nuclear Officer kjse/4328 cc: Michael A. Brown, DCPP NRC Resident Inspector Bruce S. Mallett, NRC Region IV Sandra Shewry, Director, California Department of Health Services Alan B. Wang, Project Manager, Office of Nuclear Reactor Regulation Diablo Distribution A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Callaway -Comanche Peak 9 Diablo Canyon
- Wolf Creek Padic Gas and Electric Company Senior Vice President 77 Beale Street San Francisco, CA 94106 IVa,.P O.&-., 02 1M $ 00.410 000421 4.397 AUG 07 200 MAILED FROM ZIPCODE 941 5 tt" M nJa mes<E D~yer D~irector Office eo f Nuclear lto U: lUlS N.i~aiclear
[.Regulatory.:CQommissienWa sh1indgton- ,DO: ".:0555,-0001;
- .i.. "'--4..., ...- ,. .. ....I"'N"J.HH)
~ ~ ~ ; j.. ;ll :hj ..I .