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MONTHYEARML0714103002007-05-16016 May 2007 Submittal of Stress Evaluation, Preliminary Engineering Evaluation of Insurge/Outsurge Tranients and Examination Results for the Completed Alloy 600 Pressurizer Nozzle Alternative Weld Repair CMP-023R1 Project stage: Request ML0717205282007-05-24024 May 2007 Use of Weld Overlays (TAC Nos. MD3903/3904) Project stage: Other ML0717002682007-06-15015 June 2007 Response to Request for Additional Information on 05/24/2007 Weld Overlays as an Alternative Repair Technique Project stage: Response to RAI ML0715000152007-06-26026 June 2007 Request for Withholding Information from Public Disclosure Project stage: Withholding Request Acceptance ML0720703562007-07-25025 July 2007 CMP-022R1 and Unit 2, CMP-023R1, Response to Request for Additional Information Weld Overlays as an Alternative Repair Technique Project stage: Response to RAI ML0727500642007-10-0101 October 2007 Relief Request CMP-022R1 Revised Non-Destructive Examination Requirements for the 'A' Safety Valve Pressurizer Nozzle Using Weld Overlay as an Alternative Repair Technique Project stage: Request ML0722202282007-12-19019 December 2007 Relief Requests CMP-022 and CMP-023 Regarding Use of Weld Overlays as an Alternative Repair Technique Project stage: Other 2007-05-24
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Category:Letter
MONTHYEARML24221A1892024-08-0808 August 2024 Tribal Section 106 Letters-North Anna - Nansemond Indian Nation ML24221A1932024-08-0808 August 2024 Tribal Section 106 Letters-North Anna - Upper Mattaponi Tribe ML24221A1862024-08-0808 August 2024 Tribal Section 106 Letters-North Anna - Eastern Band of Cherokee Indians ML24221A1842024-08-0808 August 2024 Tribal Section 106 Letters-North Anna - Delaware Nation, Oklahoma ML24221A1902024-08-0808 August 2024 Tribal Section 106 Letters-North Anna - Pamunkey Indian Tribe ML24163A3002024-08-0808 August 2024 Request for Relief Request N1-I5-NDE-007 Inservice Inspection Alternative ML24206A0052024-08-0808 August 2024 SLR Final EIS Letter to Achp ML24221A1872024-08-0808 August 2024 Tribal Section 106 Letters-North Anna - Eastern Shawnee Tribe of Oklahoma ML24221A1942024-08-0808 August 2024 Tribal Section 106 Letters-North Anna-United Keetoowah Band of Cherokee Indians in Oklahoma ML24206A0062024-08-0808 August 2024 Notice of Availability of the Final Environmental Impact Statement for the North Anna Nuclear Power Station Unit Numbers 1 and 2 Subsequent License Renewal (Docket Numbers: 50-338 and 50-339) ML24221A1812024-08-0808 August 2024 Tribal Section 106 Letters-North Anna - Catawba Indian Nation ML24221A1852024-08-0808 August 2024 Tribal Section 106 Letters-North Anna - Delaware Tribe of Indians ML24208A0142024-08-0808 August 2024 Tribal Section 106 Letters-North Anna-Absentee-Shawnee Tribe of Indians of Oklahoma ML24221A1922024-08-0808 August 2024 Tribal Section 106 Letters-North Anna - Tuscarora Nation of New York ML24221A1882024-08-0808 August 2024 Tribal Section 106 Letters-North Anna - Monacan Indian Nation ML24221A1832024-08-0808 August 2024 Tribal Section 106 Letters-North Anna - Chickahominy Indian Tribe-Eastern Division ML24221A1822024-08-0808 August 2024 Tribal Section 106 Letters - North Anna - Chickahominy Indian Tribe ML24221A1912024-08-0808 August 2024 Tribal Section 106 Letters-North Anna - Rappahannock Tribe, Inc IR 05000338/20240022024-08-0202 August 2024 Integrated Inspection Report 05000338/2024002 and 05000339/2024002 ML24206A0432024-07-26026 July 2024 Feis - Letter to the Applicant ML24206A0902024-07-24024 July 2024 Owners Activity Report ML24178A2422024-06-25025 June 2024 2023 Annual Report of Emergency Core Cooling System (ECCS) Model, Changes Pursuant to the Requirements of 10 CFR 50.46 ML24177A2792024-06-20020 June 2024 Preparation and Scheduling of Operator Licensing Examinations ML24143A1622024-06-12012 June 2024 – Correction to Issuance of Amendment Nos. 297 and 280 and Surry Units 1 and 2, Correction to Issuance of Amendment Nos. 317 and 317, to Change Emergency Plan Staff Augmentation Times ML24170B0532024-06-10010 June 2024 DOM-NAF-2-P/NP-A, Revision 0.5, Reactor Core Thermal-Hydraulics Using the VIPRE-D Computer Code IR 05000338/20240012024-05-10010 May 2024 Integrated Inspection Report 05000338/2024001 and 05000339/2024001 IR 05000338/20244032024-04-30030 April 2024 – Security Baseline Inspection Report 05000338-2024403 and 05000339-2024403 ML24054A0142024-04-22022 April 2024 Issuance of Amendment Nos. 297 and 280, and Surry Power Station Unit Nos. 1 and 2, Issuance of Amendment Nos. 317 and 317, to Change Emergency Plan Staff Augmentation Times ML24110A1462024-04-18018 April 2024 Independent Spent Fuel Storage Installation (Sfsi) - Annual Radiological Environmental Operating Report ML24110A1392024-04-18018 April 2024 Annual Environmental Operating Report ML24110A1502024-04-18018 April 2024 Independent Spent Fuel Storage Installation (ISFSI) - Annual Radioactive Effluent Release Report ML24087A0572024-04-16016 April 2024 Correction to Issuance of Amendment Nos. 296 and 279 ML24088A2692024-03-27027 March 2024 Core Operating Limits Report Cycle 31 Pattern Sos Revision 0 ML24086A4292024-03-25025 March 2024 Response to Request for Additional Information Associated with Alternative Request N1-I5-NDE-007 Request to Deter Additional Required Reactor Coolant Pump Casing Inspection ML24082A2742024-03-22022 March 2024 Request for Approval of Alternative Request N1-I5-NDE-007 to Deter Additional Required Reactor Coolant Pump Casing Inspection ML24086A4682024-03-21021 March 2024 Summary of Facility Changes, Tests and Experiments ML24074A3012024-03-14014 March 2024 Notification of Target Set Inspection and Request for Information (NRC Inspection Report 05000338-2024403 and 05000339-2024403) IR 05000338/20244012024-03-0808 March 2024 Security Baseline Inspection Report 05000338/2024401, 05000339/2024401 and 07200016/2024401 IR 05000338/20230062024-02-28028 February 2024 Annual Assessment Letter for North Anna Power Station, Units 1 and 2 - NRC Inspection Reports 05000338/2023006 and 05000339/2023006 ML24043A0672024-02-27027 February 2024 – Exemption from Select Requirements of 10 CFR Part 73 (Security Notifications, Reports, and Recordkeeping and Suspicious Activity Reporting) IR 05000338/20240102024-02-22022 February 2024 Notification of an NRC Fire Protection Team Inspection - NRC Inspection Report 05000338/2024010- 05000339/2024010- RFI ML24057A0612024-02-19019 February 2024 and Virgil C. Summer Power Nuclear Stations - Nuclear Property Insurance Coverage IR 05000338/20230042024-02-12012 February 2024 Integrated Inspection Report 05000338/2023004 and 05000339/2023004 ML24043A1442024-02-0909 February 2024 License Amendment Request to Revise the Emergency Plan Relocation of the Technical Support Center Supplemental Information ML24032A1112024-02-0101 February 2024 Owner'S Activity Report for North Anna, Unit 2, Refueling Outage N2R29 - First Period of the Fifth ISI Interval ML24032A4662024-01-16016 January 2024 Response to Comments on Draft Vpdes Permit No. VA0052451 ML24017A0802024-01-11011 January 2024 Notification of Licensed Operator Initial Examination 05000338/2024301 and 05000339/2024301 ML24003A8402024-01-0909 January 2024 Letter to Katelyn Lucas, Thpo, Delaware Nation, Oklahoma, Notice of Availability of Draft Site-Specific Environmental Impact Statement for North Anna Power Station Units 1 and 2, Subsequent License Renewal ML24003A8452024-01-0909 January 2024 Letter to Stephen Adkins, Chief, Chickahominy Indian Tribe, Notice of Availability of Draft Site-Specific Environmental Impact Statement for North Anna Power Station Units 1 and 2, Subsequent License Renewal ML24003A8482024-01-0909 January 2024 Notice of Availability of the Draft Site-Specific Environmental Impact Statement for the North Anna Power Station, Units 1 and 2, Subsequent License Renewal 2024-08-08
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VIRGINIA ELECTRIC AND POWER COMPANY RICHMOND, VIRGINIA 2326 1 June 15, 2007 U.S. Nuclear Regulatory Commission Attention: Document Control Desk One White Flint North 1 1 555 Rockville Pike Rockville, MD 20852-2738 Serial No. 07-0421 NLOS IETS Docket Nos.
50-3381339 License Nos.
NPF-417 VIRGINIA ELECTRIC AND POWER COMPANY (DOMINION)
NORTH ANNA POWER STATION UNlT 1 - CIMP-022R1 NORTH ANNA POWER STATION UNlT 2 - CIMP-023R1 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION WELD OVERLAYS AS AN ALTERNATIVE REPAIR TECHNIQUE In a letter dated March 17, 2007 (Serial No. 06-1007A), Dominion requested approval to use the proposed alternative to apply dissimilar metal weld overlays for repairlreplacement activities. That request contained alternative requirements for the lnservice Inspection (ISI) program for scheduled full structural preemptive weld overlays (PWOLs) that are planned to mitigate the potential for primary water stress corrosion cracking (PWSCC) susceptibility at North Anna Units 1 and 2. Since that time, several issues associated with the application of the weld overlays have been identified by the NRC and industry experience. Based on the ongoing industry experience with the application of weld overlays, on May 24, 2007 the NRC requested further clarification of our March 17, 2007 alternative. The attachment to this letter contains the requested information. PWOLs were completed on the North Anna lJnit 2 pressurizer welds in the spring 2007 refueling outage and are scheduled to be calmpleted on North Anna Unit 1 pressurizer welds in the fall 2007 refueling outage. No pre-weld overlay ultrasonic examinations are planned. This is part of the control and remediation plan for Alloy 821182 dissimilar metal piping butt welds susceptible to potential PWSCC at North Anna Units 1 and 2. If you have any questions regarding this submittal, please contact Mr. Thomas Shaub at (804) 273-2763.
Very truly yours, '~erald T. Bischof i/ Vice President - Nuclear Engineering Commitments made in this letter: None Attachment
- 1. Response to NRC May 24,2007 Request for Additional Information.
Serial No. 07-0421 Docket Nos. 50-3381339 RAI - CMP-022R11023R1 Page 2 of 2 cc: U.S. Nuclear Regulatory Commission Region II Sam Nunn Atlanta Federal Center 61 Forsyth Street, SW Suite 23T85 Atlanta, Georgia 30303 Mr. J. E. Reasor, Jr. Old Dominion Electric Cooperative lnnsbrook Corporate Center 4201 Dominion Blvd.
Suite 300 Glen Allen, Virginia 23060 Mr. J. T. Reece NRC Senior Resident lnspector North Anna Power Station Mr. R. A. Jervey NRC Project Manager -North Anna U. S. Nuclear Regulatory Commission One White Flint North 1 1555 Rockville Pike Mail Stop 8-G9A Rockville, Maryland 20852 Mr. S. P. Lingam NRC Project Manager - Surry U. S. Nuclear Regulatory Commission One White Flint North 1 1 555 Rockville Pike Mail Stop 8-G9A Rockville, Maryland 20852 Mr. M. M. Grace Authorized Nuclear Insurance lnspector North Anna Power Station Serial No. 07-0421 Docket Nos. 50-3381339 ATTACHMENT 1 RESPONSE TO MAY 24.2007 REQUEST FOR ADDITIONAL INFORMATION WELD OVERLAYS AS AN ALTERNATIVE REPAIR TECHNIQUE CMP-022 R1 AND CMP-023 R1 NORTH ANNA POWER STATION UNITS 1 AND 2 VIRGINIA ELECTRIC AND POWER COMPANY (DOMINION)
Serial No. 07-0421 Docket Nos. 50-3381339 RAI - CMP-022R11023R1 Attachment 1 Page 1 of 2 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION WELD OVERLAYS AS AN ALTERNATIVE REPAIR TECHNIQUE CMP-022 R1 AND CMP-023 R1 NRC Question 1 Section 2(a)(2)(c) does not specify the depth of the base metal that ultrasonic (UT) testing would be qualified to detect flaws after weld overlay installation.
The staff believes that a region of the base metal MAY not be qualified.
In such case, the staff considers that the initial flaw size assumed in the crack growth calculation should be the as-found flaw depth plus the postulated worst-case flaw in the unqualified region of the base metal. The postulated worst-case flaw size should be the depth of the base metal that UT is not qualified (to examine). The initial flaw size should be clarified.
Dominion R~SDO~S~ The provisions of Section 2(a)(2)(c) will not be used. Since an examination prior to the application of the preemptive weld overlay is not practical, an assumed initial flaw size of 100% original wall thickness will be used for the crack growth calculations, as stated in Paragraph 2(a)(2)(b) of the Enclosure in Dominion's March 17, 2007 proposed alternative.
NRC Question 2 In Section 2(a)(2)(d), the current UT is not qualified to inspect the inner 75% of the base metal once the weld overlay is installed on the pipe. Therefore, UT is not capable of detecting any indication that is connected to the inside surface of the pipe during pre- service inspection. Does Dominion agree that the pre-service inspection is the post-installation pre-service inspection, not prle-installation inspection?
Dominion Res~onse Yes, Dominion agrees that the pre-service inspection is the post-installation pre-service inspection, not pre-installation inspection.
NRC Question 3 In Section 3(b)(2), the licensee stated that
... if flaws are found in the outer 25% of the existing base metal or original weld and cannot be determined to be isolated from the inside diameter (ID) of the existing base metal or weld, the flaw depth will be conservatively sized by adding the thicknelss of the remaining 75% of the original existing base metal or weld thickness to the through wall dimension for any flaw growth calculations performed.
Serial No. 07-0421 Docket Nos. 50-3381339 RAI - CMP-022R11023R1 Attachment 1 Page 2 of 2 The Staff's position is that the Licensee will use the actual UT determined through wall dimension in the crack growth analysis for those flaws that do not intrude on the interface between the outer 25% of the original base metal or weld thickness and the inner 75% of the same existing materials and that can be determined by the qualified UT examination to not be connected to the interface between the outer 25% and the inner 75% of the base metal or weld. For the actual UT determined flaw in the outer 25% of the base metal that is connected to the interface between the outer 25% and the inner 75% of the pipe wall thickness, the initial flaw size would be the as-found flaw size plus the inner 75% pipe wall thickness. Clarify the initial flaw size that will be used in the crack growth calculation.
Dominion R~SDO~S~ Dominion agrees with the staff position stated above for Section 3(b)(2). As stated in the response to Question 1, the assumed initial flaw size of 100% original wall thickness will be used for the crack growth calculations.
NRC Question 4 Section 3(c)(4) relates to accepting flaws found in weld overlay.
The licensee should add that IWB-3600 is not permitted to accept PWSCC flaws. Dominion R~SDO~S~ Section 4.3.1, Required Activities, in the March 17, 2007 proposed alternative includes the following statement. "If flaw growth in the weld overlay occurs arid acceptance Standards of IWB-3514-2 cannot be met, a determination will be made to prove that the flaw is not PWSCC. If the cause is determined to be PWSCC or the cause of the flaw can not be determined, North Anna will repair the flaw
- and will not use IWB-3600, IWC-3600, or IWD-3600 to accept these types of flaws."