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Category:Letter type:RA
MONTHYEARRA-23-0325, Submittal of Procedures CSD-EP-HNP-0101-01, 02, CSD-EP-ONS-0101-01, CSD-EP-RNP-0101-01, and EP-RNP-EPLAN-ANNEX2024-01-0808 January 2024 Submittal of Procedures CSD-EP-HNP-0101-01, 02, CSD-EP-ONS-0101-01, CSD-EP-RNP-0101-01, and EP-RNP-EPLAN-ANNEX RA-23-0320, Notification of Deviation from MRP-227, Revision 1-A Baffle-to-Former Bolt Inspection Frequency2023-12-14014 December 2023 Notification of Deviation from MRP-227, Revision 1-A Baffle-to-Former Bolt Inspection Frequency RA-23-0318, Supplement to Request for Exemption from Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Implementation2023-12-0404 December 2023 Supplement to Request for Exemption from Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Implementation RA-23-0182, Duke Energy Carolinas, LLC - License Amendment Request to Revise Technical Specification 5.5.2, Containment Leakage Rate Testing Program for a One-Time Extension of the Units 1, 2 and 3 Type a Leak Rate Test Frequency2023-11-16016 November 2023 Duke Energy Carolinas, LLC - License Amendment Request to Revise Technical Specification 5.5.2, Containment Leakage Rate Testing Program for a One-Time Extension of the Units 1, 2 and 3 Type a Leak Rate Test Frequency RA-23-0284, RA-23-0284 Request for Exemption from Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Implementation2023-11-16016 November 2023 RA-23-0284 Request for Exemption from Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Implementation RA-23-0304, Transmittal of Core Operating Limits Report (COLR) for Oconee Unit 2 Cycle 32 (Revision 0)2023-11-14014 November 2023 Transmittal of Core Operating Limits Report (COLR) for Oconee Unit 2 Cycle 32 (Revision 0) RA-23-0281, Procedure EP-ALL-EPLAN, Duke Energy Common Emergency Plan, Revision 5, Summary of Changes2023-11-0101 November 2023 Procedure EP-ALL-EPLAN, Duke Energy Common Emergency Plan, Revision 5, Summary of Changes RA-23-0275, Subsequent License Renewal Application, Appendix E, Responses to Requests for Additional Information (Rai), and Request for Confirmation of Information (RCI)2023-10-12012 October 2023 Subsequent License Renewal Application, Appendix E, Responses to Requests for Additional Information (Rai), and Request for Confirmation of Information (RCI) RA-23-0268, Transmittal of Sixth 10-Year Inservice Testing Interval Program Plan2023-09-29029 September 2023 Transmittal of Sixth 10-Year Inservice Testing Interval Program Plan RA-23-0234, Update to the Response to NRC Regulatory Issue Summary 2023-01 Preparation and Scheduling of Operator Licensing Examinations for Oconee Nuclear Station (ONS)2023-09-28028 September 2023 Update to the Response to NRC Regulatory Issue Summary 2023-01 Preparation and Scheduling of Operator Licensing Examinations for Oconee Nuclear Station (ONS) RA-23-0225, Procedure AD-EP-ALL-0109, Offsite Protective Action Recommendations, Revision 9, and the Joint Information Center (JIC) Relocation, Summary of Changes2023-09-20020 September 2023 Procedure AD-EP-ALL-0109, Offsite Protective Action Recommendations, Revision 9, and the Joint Information Center (JIC) Relocation, Summary of Changes RA-23-0228, Registration for Use of General License Spent Fuel Cask Number 1752023-09-14014 September 2023 Registration for Use of General License Spent Fuel Cask Number 175 RA-23-0223, Registration for Use of General License Spent Fuel Cask Numbers 173 and 1742023-08-23023 August 2023 Registration for Use of General License Spent Fuel Cask Numbers 173 and 174 RA-23-0222, On-Shift Staffing Analysis (Ossa), Revision 12023-08-23023 August 2023 On-Shift Staffing Analysis (Ossa), Revision 1 RA-23-0211, Reply to a Notice of Violation (NOV) 05000270/2023010-022023-08-17017 August 2023 Reply to a Notice of Violation (NOV) 05000270/2023010-02 RA-23-0154, Duke Energy - Response to Request for Additional Information Regarding Proposed Alternative for Pressurizer Welds in Accordance with 10 CFR 50.55a(z)(1)2023-07-20020 July 2023 Duke Energy - Response to Request for Additional Information Regarding Proposed Alternative for Pressurizer Welds in Accordance with 10 CFR 50.55a(z)(1) RA-23-0136, Duke Energy Response to Request for Additional Information Regarding Proposed Alternative for Steam Generator Welds in Accordance with 10 CFR 50.55a(z)(1)2023-07-20020 July 2023 Duke Energy Response to Request for Additional Information Regarding Proposed Alternative for Steam Generator Welds in Accordance with 10 CFR 50.55a(z)(1) RA-23-0186, Transmittal of Core Operating Limits Report (COLR) for Oconee Unit 2 Cycle 31 (Revision 3)2023-07-18018 July 2023 Transmittal of Core Operating Limits Report (COLR) for Oconee Unit 2 Cycle 31 (Revision 3) RA-23-0184, Registration for Use of General License Spent Fuel Cask Numbers 171 and 1722023-07-10010 July 2023 Registration for Use of General License Spent Fuel Cask Numbers 171 and 172 RA-23-0142, Mcguire, Units 1 and 2, Oconee, Units 1, 2, and 3, H. B. Robinson, Unit 2, Response to Request for Additional Information Regarding the License Amendment Request to Revise Restrictive Technical Specification Surveillance Require2023-07-0707 July 2023 Mcguire, Units 1 and 2, Oconee, Units 1, 2, and 3, H. B. Robinson, Unit 2, Response to Request for Additional Information Regarding the License Amendment Request to Revise Restrictive Technical Specification Surveillance Require RA-23-0146, Subsequent License Renewal Application, Appendix E, Responses to Requests for Additional Information (Rai), and Request for Confirmation of Information (RCI)2023-06-20020 June 2023 Subsequent License Renewal Application, Appendix E, Responses to Requests for Additional Information (Rai), and Request for Confirmation of Information (RCI) RA-23-0135, Submittal of 30 Day Report Per 10 CFR 26.719(c), Unsatisfactory Performance of Health and Human Services Certified Laboratory2023-06-0707 June 2023 Submittal of 30 Day Report Per 10 CFR 26.719(c), Unsatisfactory Performance of Health and Human Services Certified Laboratory RA-23-0041, Response to NRC Regulatory Issue Summary 2023-01 Preparation and Scheduling of Operator Licensing Examinations2023-05-30030 May 2023 Response to NRC Regulatory Issue Summary 2023-01 Preparation and Scheduling of Operator Licensing Examinations RA-23-0128, Refuel 32 (O1R32) Steam Generator Tube Inspection Report2023-05-18018 May 2023 Refuel 32 (O1R32) Steam Generator Tube Inspection Report RA-23-0018, Relief Request (RA-23-0018) to Utilize Code Case N-853 PWR Class 1 Primary Piping Alloy 600 Full Penetration Branch Connection Weld Metal Buildup for Material Susceptible to Primary Water Stress Corrosion Cracking Section XI, Division 12023-05-0404 May 2023 Relief Request (RA-23-0018) to Utilize Code Case N-853 PWR Class 1 Primary Piping Alloy 600 Full Penetration Branch Connection Weld Metal Buildup for Material Susceptible to Primary Water Stress Corrosion Cracking Section XI, Division 1 RA-23-0111, Withdrawal of License Amendment Request to Revise Technical Specification 5.5.2, Containment Leakage Rate Testing Program, for Permanent Extension of Type a and Type C Leak Rate Test Frequencies2023-04-27027 April 2023 Withdrawal of License Amendment Request to Revise Technical Specification 5.5.2, Containment Leakage Rate Testing Program, for Permanent Extension of Type a and Type C Leak Rate Test Frequencies RA-23-0104, Response to Request for Additional Information (RAI) Regarding Oconee Unit 3, Refuel 31 (O3R31) Steam Generator Tube Inspection Report2023-04-26026 April 2023 Response to Request for Additional Information (RAI) Regarding Oconee Unit 3, Refuel 31 (O3R31) Steam Generator Tube Inspection Report RA-23-0047, Duke Energy Annual Radiological Environmental Operating Report - 20222023-04-26026 April 2023 Duke Energy Annual Radiological Environmental Operating Report - 2022 RA-23-0044, Aduke Energy Annual Report of Changes Pursuant to 10 CFR 50.462023-04-26026 April 2023 Aduke Energy Annual Report of Changes Pursuant to 10 CFR 50.46 RA-23-0099, Subsequent License Renewal Application Second Annual Amendment to the License Renewal Application2023-04-25025 April 2023 Subsequent License Renewal Application Second Annual Amendment to the License Renewal Application RA-23-0046, Annual Radioactive Effluent Release Report - 20222023-04-24024 April 2023 Annual Radioactive Effluent Release Report - 2022 RA-22-0292, License Amendment Request to Revise Technical Specification 5.5.2, Containment Leakage Rate Testing Program, for Permanent Extension of Type a and Type C Leak Rate Test Frequencies2023-04-0404 April 2023 License Amendment Request to Revise Technical Specification 5.5.2, Containment Leakage Rate Testing Program, for Permanent Extension of Type a and Type C Leak Rate Test Frequencies RA-23-0036, Biennial Decommissioning Financial Assurance Reports2023-03-30030 March 2023 Biennial Decommissioning Financial Assurance Reports RA-23-0040, Onsite Property Insurance Coverage2023-03-30030 March 2023 Onsite Property Insurance Coverage RA-23-0039, 10 CFR 140.21 Licensee Guarantees of Payment of Deferred Premiums2023-03-30030 March 2023 10 CFR 140.21 Licensee Guarantees of Payment of Deferred Premiums RA-23-0037, Duke Energy - Decommissioning Funding Plan for Independent Spent Fuel Storage Installations (Isfsis)2023-03-30030 March 2023 Duke Energy - Decommissioning Funding Plan for Independent Spent Fuel Storage Installations (Isfsis) RA-23-0051, Response to Request for Additional Information (RAI) Regarding Proposed Alternative to Use American Society of Mechanical Engineers Code Case N-752, Risk-Informed Categorization and Treatment for Repair/Replacement Activities2023-03-0909 March 2023 Response to Request for Additional Information (RAI) Regarding Proposed Alternative to Use American Society of Mechanical Engineers Code Case N-752, Risk-Informed Categorization and Treatment for Repair/Replacement Activities RA-23-0052, Refuel 32 (O1R32) Inservice Inspection (ISI) Report, Fifth 10-Year ISI Interval2023-02-22022 February 2023 Refuel 32 (O1R32) Inservice Inspection (ISI) Report, Fifth 10-Year ISI Interval RA-22-0257, Proposed Alternative for Pressurizer Welds in Accordance with 10 CFR 50.55a(z)(1)2023-02-17017 February 2023 Proposed Alternative for Pressurizer Welds in Accordance with 10 CFR 50.55a(z)(1) RA-22-0091, Application to Revise Technical Specifications to Adopt TSTF-554, Revision 1, Revise Reactor Coolant Leakage Requirements2023-02-16016 February 2023 Application to Revise Technical Specifications to Adopt TSTF-554, Revision 1, Revise Reactor Coolant Leakage Requirements RA-23-0001, Request to Use a Provision of a Later Edition and Addenda of the ASME Boiler and Pressure Vessel Code, Section XI2023-02-0202 February 2023 Request to Use a Provision of a Later Edition and Addenda of the ASME Boiler and Pressure Vessel Code, Section XI RA-22-0118, License Amendment Request to Revise Restrictive Technical Specification Surveillance Requirement Frequencies2023-02-0101 February 2023 License Amendment Request to Revise Restrictive Technical Specification Surveillance Requirement Frequencies RA-22-0256, Proposed Alternative for Steam Generator Welds in Accordance with 10 CFR 50.55a(z)(1)2023-01-23023 January 2023 Proposed Alternative for Steam Generator Welds in Accordance with 10 CFR 50.55a(z)(1) RA-22-0335, Submittal of 30-Day Report Per 10CFR26.719(c)(1) - Unsatisfactory Performance of a Health & Human Services Certified Lab2022-12-0505 December 2022 Submittal of 30-Day Report Per 10CFR26.719(c)(1) - Unsatisfactory Performance of a Health & Human Services Certified Lab RA-22-0334, Refuel 31 (O3R31) Steam Generator Tube Inspection Report2022-11-21021 November 2022 Refuel 31 (O3R31) Steam Generator Tube Inspection Report RA-22-0329, Transmittal of Core Operating Limits Report (COLR) for Oconee Unit 1 Cycle 33 (Revision 0 and Revision 1)2022-11-11011 November 2022 Transmittal of Core Operating Limits Report (COLR) for Oconee Unit 1 Cycle 33 (Revision 0 and Revision 1) RA-22-0285, Subsequent License Renewal - Appendix E Environmental Report Supplement 22022-11-0707 November 2022 Subsequent License Renewal - Appendix E Environmental Report Supplement 2 RA-22-0313, Emergency Action Level (EAL) Technical Basis Document, Revision 4, EAL Wallchart, Revision 3 and Alternate TSC and OSC Renovations2022-10-27027 October 2022 Emergency Action Level (EAL) Technical Basis Document, Revision 4, EAL Wallchart, Revision 3 and Alternate TSC and OSC Renovations RA-22-0270, Response to Request for Additional Information Regarding License Amendment Request to Address Technical Specifications Mode Change Limitations2022-10-0707 October 2022 Response to Request for Additional Information Regarding License Amendment Request to Address Technical Specifications Mode Change Limitations RA-22-0192, Subsequent License Renewal Application Response to ONS SLRA Second Round RAI B2.1.7-4a2022-09-0202 September 2022 Subsequent License Renewal Application Response to ONS SLRA Second Round RAI B2.1.7-4a 2024-01-08
[Table view] |
Text
U.S. Nuclear Regulatory Commission RA-19-0027 Page 2 cc : (all with Enclosure unless otherwise noted)
C. Haney, Regional Administrator USNRC Region II E. L. Crowe, USNRC Senior Resident Inspector - ONS A. L. Klett, NRR Project Manager - ONS
U.S. Nuclear Regulatory Commission RA-19-0027 Page 3 bcc: (all with Enclosure unless otherwise noted)
Mark Pyne Art Zaremba Austin Keller Kate Nolan
David Cummings ELL File: (Corporate)
Ed Burchfield
Sheila Dalton
Dave Peltola
RA-19-0027
Enclosure 1 Relief Request 19-ON-002 Relief Request Serial #19-ON-00 2 RA-19-0027, Enclosure 1 Page 1 of 4 1. ASME Code Components Affected:
The Code Components included in the scope of this relief request are the nozzle
-to-safe end Dissimilar Metal Butt Welds (DMBWs) for the core flood nozzles on Oconee Nuclear Station's Unit 3 (ONS 3). This relief request addresses the following welds: Weld
Description:
ONS 3: 3-RPV-WR53 - Reactor Vessel Core Flood Nozzle
-to-Safe End, 14" DMBW ONS 3: 3-RPV-WR53A - Reactor Vessel Core Flood Nozzle
-to-Safe End, 14" DMBW
2. Applicable Code Edition and Addenda
The current edition for the Inservice Inspection (ISI) interval for ONS3 is the ASME Boiler and Pressure Vessel Code,Section XI, 2007 Edition and 2008 Addenda.
ONS3 is in the fifth inspection interval with a scheduled end date of July 15, 2024. 10 CFR 50.55a(g)(6)(ii)(F)(1) mandates the use of ASME Code Case N-770-2 for the augmented inspection program. 3. Applicable Code Requirement:
Code Case N
-770-2, Table 1, Item B requires volumetric examination of unmitigated butt welds at Cold Leg operatevery second inspection period not to exceed 7 years. Code Case N-770-5, Table 1, Item B-2 requires volumetric examination of unmitigated butt NPS 14 inches or larger once per interval. Note 11(d) to N-770-5, Table 1, states that "Examinations for Inspection Item B
-2 may be deferred to the end of the interval and performed coincident with the reactor vessel nozzle examinations required by Examination Category B-D, as provided by IWA
-2430. The time between examinations shall not exceed 13 yr." 4. Reason for Request:
Relief is being requested to allow the examination frequency of every second inspection period (7 year maximum) to be extended to every 10
-year interval (13 year maximum as described in ASME Code Case N
-770-5, Table 1, Category B-2). This alternative will allow the N-770 inspections of the requested welds to coincide with the core barrel removal in the 10 Year Reactor Vessel ISI Refueling Outage for Unit 3 (O3R32
), currently scheduled in Spring 2024.
Oconee's plant design limits access to the outer surface of the core flood nozzle-to-Safe End DMBWs.
The core flood DMBWs are obstructed from examination from the outer diameter. Examination from the DMBW inner diameter is required to achieve acceptable examination coverage.
The outer surfaces of these welds are obstructed by an approximately 3 ft. wide reactor vessel annulus, and underneath the annulus shield blocks.
The physical interferences and high dose rates associated with the weld location, prevent Relief Request Serial #19-ON-00 2 RA-19-0027, Enclosure 1 Page 2 of 4 effective ultrasonic examinations from being performed from the outside diameter of the core flood nozzles. It is possible to access and perform an effective volumetric examination of the weld from the inner diameter, provided the reactor vessel core barrel is removed; however, core barrel removal represents a hardship that produces increased plant risk and elevates the outage dose to workers. To date, Code Case N
-770-5 has not been endorsed by the NRC, but has been reviewed by the NRC and is proposed to replace N
-770-2 in 10 CFR 50.55a(g)(6)(ii)(F), with conditions (Reference 8.4). Therefore, Duke Energy is requesting relief under 10 CFR 50.55a(z)(2) from the examination requirements of Code Case N
-770-2. 5. Proposed Alternative and Basis for Use:
The proposed alternative is to extend the weld examination frequency required by Code Case N-770-2, Table 1, Item B for the ONS3 Core Flood nozzle DMBWs (listed in Section 1 above) from "every second inspection period not to exceed 7 years
" to every interval not to exceed 13 years from the previous examination.
The ONS3 welds had volumetric examinations performed during their last Reactor Vessel 10 Year ISI in the spring of 2014 with essentially 100% coverage. The inspections were performed in accordance with ASME Section XI, Appendix VIII, Supplement 10 requirements and found no reportable circumferential or axial indications. ASME Code Case N
-770-2 is approved by the NRC for generic use and provides alternative examination requirements and acceptance standards for volumetric examination, and surface examination of DMBW NPS 2" and greater. On November 7, 2016, the ASME approved Revision 5 of ASME BPV Code Case N 770 (N
-770-5). The major changes from N-770-2 to N-770-5 include:
- 1. Table 1 Inspection Item B replaced with B
-1 and B-2, separating welds for pipes with NPS less than 14 inches and 14 inches or greater. Examinations for item B
-2 (NPS 14 inches or greater) may be deferred to the end of the interval and performed coincident with the reactor vessel nozzle examinations and the time between examinations shall not exceed 13 years.
- 2. Performance criteria and inspections for peening mitigated welds.
- 3. Inservice inspection requirements for excavate and weld repair mitigations.
- 4. Minor editorial and clarification changes.
The basis for the N
-770 Code Case change to extend the inspection frequency for cold leg temperature dissimilar metal butt welds for 14 inches is discussed in Reference 8.3, "Changing the Frequency of Inspections for PWSCC Susceptible Welds at Cold Leg Temperatures." Applicable excerpts supporting this request are below:
Relief Request Serial #19-ON-00 2 RA-19-0027, Enclosure 1 Page 3 of 4 There are a number of technical and practical arguments in favor of making this change, even beyond the excellent service experience, and these arguments are summarized in this paper.
Pulling the reactor vessel (RV) core barrel is a serious activity which can entail many risks, so additional pulls should be avoided. Inspection at a frequency of less than 10 years involves additional core barrel pulls.
The flaw tolerance of these large diameter cold leg pipes is very good, and example calculations show that reasonably large flaws are acceptable for ten years. The probability of cracks initiating in cold leg piping is significantly lower than that for piping at hotter temperatures, and a detailed model has been developed to demonstrate this.
While there has been a large amount of service experience with primary water stress corrosion cracking of Alloy 82/182 welds, this experience has been limited to those welds operating at hot leg temperatures or higher.
There have been no incidents of cracking in welds operating at cold leg temperatures that can be attributed to PWSCC.
Though the MRP
-139 and Code Case N
-770 requirements for more frequent inspection were taken as a proactive measure, the accumulation of more positive service experience indicates that perhaps this increased inspection frequency for cold legs in particular is not necessary to maintain an acceptable level of safety and quality. Furthermore, it has been realized that accessing these cold leg weld locations for inspection presents a hardship to utilities and may present an increased risk due to the complications associated with removal of the reactor vessel core barrel.
There have been numerous studies performed to evaluate the likelihood of through-wall cracking and flaw tolerance in cold leg Alloy 82/182 welds. The analyses performed as the original basis for MRP
-139 showed that the large diameter cold leg welds had high flaw tolerance and a very low probability of failure. More recent analyses, which considered design specific residual stress distributions, have confirmed the original conclusions that the flaw tolerance is high. Furthermore, the more recent analyses have shown that even large circumferential flaws, with a high likelihood of being detected during inservice inspection, will not grow to the maximum depth allowed by ASME Section XI in 10 years. These analyses have been performed based on the assumption that a flaw has initiated, which as shown by more recent probabilistic analyses based on service data is unlikely at the present time.
Code Case N
-770-5 is not yet NRC
-approved, but it has been reviewed by the NRC and is proposed to replace N
-770-2 in 10 CFR 50.55a(g)(6)(ii)(F), with conditions (Reference 8.4). The conditions have been reviewed and would not preclude this proposed relief request. In summary, Duke Energy is seeking approval of the proposed alternative in accordance with 10 CFR 50.55a(z)(2) on the basis that the proposed alternative would result in hardship or unusual difficulty without a compensating increase in the level of quality or safety.
Relief Request Serial #19-ON-00 2 RA-19-0027, Enclosure 1 Page 4 of 4 6. Duration of Proposed Alternative:
This request may be implemented for the remainder of the 5th Interval ISI plan and applies to ONS 3. This relief will be re
-submitted, if needed, for subsequent ISI intervals.
- 7. Precedents The following relief request includes a requested frequency extension for the same welds for ONS Units 1 and 2; however, the basis for use is different. Due to the subsequent proposed adoption of Code Case N
-770-5 by the NRC, the basis of this request is consistent with that of Code Case N
-770-5. 7.1 Oconee Units 1 and 2 Docket Numbers 50
-269 and 50
-270, Relief Request No. 17-ON-001, Alternative to extend the Code Case N
-770, Inspection Item B Examination Frequency, including NRC Safety Evaluation dated April 13, 2018 (ADAMS Accession Number ML18100A005). 8. References 8.1 ASME Code Case N-770-2 , Alternative Examination Requirements and Acceptance Standards for Class 1 PWR Piping and Vessel Nozzle Butt Welds Fabricated with UNS N06082 or UNS W86182 Weld Filler Material With or Without Application of Listed Mitigation Activities,Section XI, Division 1, Approval Date: June 9, 2011. 8.2 ASME Code Case N
-770-5, Alternative Examination Requirements and Acceptance Standards for Class 1 PWR Piping and Vessel Nozzle Butt Welds Fabricated with UNS N06082 or UNS W86182 Weld Filler Material With or Without Application of Listed Mitigation Activities,Section XI, Division 1, Approval Date: November 7, 2016. 8.3 Proceedings of 2011 ASME Pressure Vessels and Piping Conference PVP2011-57829, Changing the Frequency of Inspections for PWSCC Susceptible Welds at Cold Leg Temperatures , July 17-21, 2011. 8.4 Federal Register 56156
-56196, American Society of Mechanical Engineers 2015
-2017 Code Editions Incorporation by Reference, Vol. 83, No. 218, dated November 9, 2018
.