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| {{#Wiki_filter:Westinghouse Non-Proprietary Class 3Page 1 of 6Attachment BOur ref: LTR-PAFM-1 6-8Revision 0February 12, 2016Attachment B(Non-Proprietary)Responses to the NRC RA~s Regarding ComanchePeak Unit 1 Extension of Required InspectionFrequency for Reactor Vessel Inlet Nozzle DissimilarMetal Welds from 7 to 9 Calendar YearsPortions of this report contain proprietary information. Proprietary information is identified andbracketed. For each of the bracketed sections, the reasons for the proprietary classification areprovided using superscripted letters "a" "" and "e". These letter designations are:a. The information reveals the distinguishing aspects of a process or component, structure, tool,method, etc. The prevention of its use by Westinghouse's competitors, without license fromWestinghouse, gives Westinghouse a competitive economic advantage.c. The information, if used by a competitor, would reduce the competitor's expenditure ofresources or improve the competitor's advantage in the design, manufacture, shipment,installation, assurance of quality, or licensing of a similar product.e. The information reveals aspects of past, present, or future Westinghouse- or customer-fundeddevelopment plans and programs of potential commercial value to Westinghouse.© 2016 Westinghouse Electric Company LLCAll Rights Reserved Westinghouse Non-Proprietary Class 3Page 2 of 6Attachment BOur ref: LTR-PAFM- 16-8Revision 0February 12, 2016Responses to the NRC RA~s Regarding Comanche Peak Unit 1Extension of Required Inspection Frequency for Reactor VesselInlet Nozzle Dissimilar Metal Welds from 7 to 9 Calendar YearsThe NRC submitted the RA~s shown below (Reference 1) to Comanche Peak Unit 1, after the Staffperformed a review of the Comanche Peak Unit 1 relief request (Reference 2) to defer the required reactorvessel inlet nozzle dissimilar metal (DM) weld from Spring 2016 RFO to the Spring 2019 REO.The RAT responses provided in this letter report are based on a supporting Westinghouse flaw toleranceevaluation developed for Comanche Peak Unit 1 to extend the volumetric examination interval for theinlet nozzle DM weld (Reference 3). The fracture mechanics technical basis in Reference 3 confirms thatthe DM weld inspection interval can be extended from Spring 2016 RFO to Spring 2019 RFO. The axialand circumferential crack growth evaluations performed in Reference 3 are plant specific to ComanchePeak Unit 1, and provide the necessary technical justification to extend the inspection interval from 7years to 9 years.The NRC RAIs based on Reference 1 are shown below, and the responses are given in the subsequentpages.By letter dated April120, 2015, (Agencywide Documents Access and Management System (ADAMS)Accession No. ML15119A216), as supplemented by letter dated October 15, 2015 (ADAMS Accession No.M!L15300AO13), Luminant Generation Company, LLC (the licensee), proposed an alternative to Title 10 ofthe Code of Federal Regulations (10 CFR), Paragraph 50.55a(g) (6) (i i)(F) for Comanche Peak NuclearPower Plant, Unit 1. This regulation, in part, defines the inspection frequency requirement for the reactorvessel inlet butt welds in accordance with American Society of Mechanical Engineer's Boiler and PressureVessel Code Case N-770-1, "Alternative Examination Requirements and Acceptance Standards for Class 1PWR [Pressurized Water Reactor] Piping and Vessel Nozzle Butt Welds Fabricated With UNS N06082 orUNS W86182 Weld Filler Material With or Without Application of Listed Mitigation Activities, Section XI,Division 1 "with U. S. Nuclear Regulatory Commission (NRC) conditions. The licensee is requesting anextension of the required inspection frequency from once every 7 calendar years to once every 9 calendaryears.The NRC staff has reviewed and evaluated the information provided by the licensee and has determinedthat the following information is needed in order to complete its review of the relief request.Discussion on Flow Tolerance (Page 3 of 7 of the Letter Dated October 15, 2015)A discussion offlaw tolerance is provided as part of the technical basis to support the relief request. Thelicensee states, in part,Based on the circumferential crack growth results, even for the most conservative case(high temperature with a 25% weld repair), a flaw with a depth of 15% of the wallthickness would not grow to the maximum allowable ASME flaw size in less than 10 yearsof continued operation.Additionally, Figure 4 of Attachment 9.1 of letter dated April20, 2015, shows that a "Long SE [Safe End]25% Repair AR [Aspect Ratio] =1 0, High Temp "flaw would grow from 10% through-wall to the ASMECode allowable flaw depth of 75% through-wall in approximately 20 years.© 2016 Westinghouse Electric Company LLCAll Rights Reserved Westinghouse Non-Proprietary Class 3Page 3 of 6Attachment BOur ref: LTR-PAFM-1 6-8Revision 0February 12, 2016NRC staff performed a series of independent calculations and determined these values are not conservative.Additionally, the NRC staff did not identify' a sufficient technical basis to address the potential of axial flawgrowth. Therefore, the NRC staff requests the following;"1. The axial and hoop weld residual stresses (WRS) at operating temperature of the subject welds. Ifa generic WRS is used, include a basis for the WRS being conservative. (e.g. 50% weld repair,WRS validation used, safe end length, etc.)2. Piping loads for the subject welds to include pressure, deadweight, 100% power normal operatingthermal expansion, seismic events, and Loss of Coolant Accident (LOCA).3. Weld dimensions for the subject welds include outside diameter and weld thickness.NRC RAJ 1. The axial and hoop weld residual stresses (WRS) at operating temperature of the subjectwelds. Ifra generic WRS is used, include a basis for the WRS being conservative. (e.g. 50% weld repair,WRS validation used, safe end length, etc.)Westinghouse Response:The axial and hoop welding residual stress (WRS) at normal operating pressure and temperature are givenin Figure 1 based on the information provided in Reference 3. The welding residual stresses areperformed based on the guidelines in MRP-287 (Reference 4); thus, the finite element model used in thegeneration of the WRS assumes a 36O° inside surface weld repair with a repair depth of 50% through theDM weld thickness. The WRS are calculated for an identical inlet nozzle to Comanche Peak Unit 1,which has the same DM welding geometry, material, configuration, and safe end length. A full discussionof the WRS is provided in Section 4.0 of Reference 3.© 2016 Westinghouse Electric Company LLCAll Rights Reserved Westinghouse Non-Proprietary Class 3Page 4 of 6Attachment BOur ref: LTR-PAFM-1 6-8Revision 0February 12, 2016a,c,eFigure 1: Reactor Vessel Inlet Nozzle DM Weld 100% Normal Operating Recommended Residual StressProfiles Through DM Weld with 50% Inside Surface Weld Repair© 20O16 Westinghouse Electric Company LL CAll Rights Reserved Westinghouse Non-Proprietary Class 3Page 5 of 6Attachment BOur ref: LTR-PAFM-1 6-8Revision 0February 12, 2016NRC RAI 2.' Piping loads for the subject welds to include pressure, deadweight, 100% power normaloperating thermal expansion, seismic events, and Loss of Coolant Accident (LOCA).Westinghouse Response:The Comanche Peak Unit 1 piping loads are given in Table 1 below based on the information provided inReference 3.Table 1: Comanche Peak Unit 1 Reactor Vessel Inlet Nozzle Piping LoadsForces MomentsLoading (kips) (in-kips)Fx Mx My Mz(Axial) (Torsion) (Bending) (Bending)Deadweight 0.29 -180.42 51.67 -451.26Pressure* 1333.5100% Normal Thermal Expansion 2.5 -5500.74 386.92 -9764.41OBE (Operational Basis Earthquake) 137 1752 4893 1496SSE (Safe Shutdown Earthquake) 164 2133 6267 1754LOCA/Pipe Break 514 1192 6281 2291*Axial force due to normal operating pressure of 2.25 ksiNRC RAI 3: Weld dimensions for the subject welds include outside diameter and weld thicknessWestinghouse Response:The weld dimensions are given in Table 2 below based on the information provided in Reference 3.Table 2: Comanche Peak Unit 1 Reactor Vessel (RV) Inlet Nozzle GeometryRV Inlet Nozzle DimensionOutside Diameter (in) 33.05Inside Diameter (in) 27.47Thickness (in) 2.79© 2016 Westinghouse Electric Company LLCAll Rights Reserved Westinghouse Non-Proprietary Class 3Page 6 of 6Attachment BOur ref: LTR-PAFM-1 6-8Revision 0February 12, 2016ConclusionIt is recommended that the above NRC RAI responses be reviewed along with the supplemental fracturemechanics evaluation performed in Reference 3 for Comanche Peak Unit 1 RV inlet nozzle DM weld.The results and conclusions based on the letter report in Reference 3 provide technical justification todefer the volumetric examination for the Comanche Peak Unit 1 RV inlet nozzle DM welds from theSpring 2016 RFO to the Spring 2019 lRFO.References1. NRC Email from Balwant Singal (NRC) to Timothy Hope (Luminant Power), Subject: "DraftRequest for Additional Information -Relief Request 1B3-3 for Comanche Peak Nuclear PowerPlant, Unit 1 (CAC No. MF6 125)," dated January 12, 2016.2. Letter from Luminant Generation Company LLC to NRC, TXX-15 139, "Comanche Peak NuclearPower Plant Docket No. 50-445 Revision to Relief Request 1B3-3 for Unit 1 Inservice Inspectionfor Application of an Alternative to the ASME Boiler and Pressure Vessel Code Section XIExamination Requirements for Reactor Pressure Vessel Cold Leg Weld Inspection Frequency(2007 Edition of ASME Code, section XI, 2008 Addenda Third Interval Start Date: August 13,2010 Third Interval End Date: August 12, 2020)," October 15, 2015. [ADA MS Accession NumberML15300AO13]3. Westinghouse Letter Report, LTR-PAFM- 16-2-NP, Revision 0. "Technical Justification toSupport Extended Volumetric Examination Interval for Comanche Peak Unit 1 Reactor VesselInlet Nozzle to Safe End Dissimilar Metal Welds." February 2016.4. Materials Reliability Program: Primary Water Stress Corrosion Cracking (PWSCC) FlawEvaluation Guidance (MRP-287), EPRI, Palo Alto, CA: 2010, 1021023.© 2016 Westinghouse Electric Company LLCAll Rights Reserved | | {{#Wiki_filter:Westinghouse Non-Proprietary Class 3 Page 1 of 6 Attachment B Our ref: LTR-PAFM-1 6-8 Revision 0 February 12, 2016 Attachment B (Non-Proprietary) |
| }} | | Responses to the NRC RA~s Regarding Comanche Peak Unit 1 Extension of Required Inspection Frequency for Reactor Vessel Inlet Nozzle Dissimilar Metal Welds from 7 to 9 Calendar Years Portions of this report contain proprietary information. |
| | Proprietary information is identified and bracketed. |
| | For each of the bracketed sections, the reasons for the proprietary classification are provided using superscripted letters "a" "" and "e". These letter designations are: a. The information reveals the distinguishing aspects of a process or component, structure, tool, method, etc. The prevention of its use by Westinghouse's competitors, without license from Westinghouse, gives Westinghouse a competitive economic advantage. |
| | : c. The information, if used by a competitor, would reduce the competitor's expenditure of resources or improve the competitor's advantage in the design, manufacture, shipment, installation, assurance of quality, or licensing of a similar product.e. The information reveals aspects of past, present, or future Westinghouse-or customer-funded development plans and programs of potential commercial value to Westinghouse. |
| | © 2016 Westinghouse Electric Company LLC All Rights Reserved Westinghouse Non-Proprietary Class 3 Page 2 of 6 Attachment B Our ref: LTR-PAFM-16-8 Revision 0 February 12, 2016 Responses to the NRC RA~s Regarding Comanche Peak Unit 1 Extension of Required Inspection Frequency for Reactor Vessel Inlet Nozzle Dissimilar Metal Welds from 7 to 9 Calendar Years The NRC submitted the RA~s shown below (Reference |
| | : 1) to Comanche Peak Unit 1, after the Staff performed a review of the Comanche Peak Unit 1 relief request (Reference |
| | : 2) to defer the required reactor vessel inlet nozzle dissimilar metal (DM) weld from Spring 2016 RFO to the Spring 2019 REO.The RAT responses provided in this letter report are based on a supporting Westinghouse flaw tolerance evaluation developed for Comanche Peak Unit 1 to extend the volumetric examination interval for the inlet nozzle DM weld (Reference 3). The fracture mechanics technical basis in Reference 3 confirms that the DM weld inspection interval can be extended from Spring 2016 RFO to Spring 2019 RFO. The axial and circumferential crack growth evaluations performed in Reference 3 are plant specific to Comanche Peak Unit 1, and provide the necessary technical justification to extend the inspection interval from 7 years to 9 years.The NRC RAIs based on Reference 1 are shown below, and the responses are given in the subsequent pages.By letter dated April120, 2015, (Agencywide Documents Access and Management System (ADAMS)Accession No. ML15119A216), as supplemented by letter dated October 15, 2015 (ADAMS Accession No.M!L15300AO13), Luminant Generation Company, LLC (the licensee), proposed an alternative to Title 10 of the Code of Federal Regulations (10 CFR), Paragraph 50.55a(g) |
| | (6) (i i)(F) for Comanche Peak Nuclear Power Plant, Unit 1. This regulation, in part, defines the inspection frequency requirement for the reactor vessel inlet butt welds in accordance with American Society of Mechanical Engineer's Boiler and Pressure Vessel Code Case N-770-1, "Alternative Examination Requirements and Acceptance Standards for Class 1 PWR [Pressurized Water Reactor] 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 "with U. S. Nuclear Regulatory Commission (NRC) conditions. |
| | The licensee is requesting an extension of the required inspection frequency from once every 7 calendar years to once every 9 calendar years.The NRC staff has reviewed and evaluated the information provided by the licensee and has determined that the following information is needed in order to complete its review of the relief request.Discussion on Flow Tolerance (Page 3 of 7 of the Letter Dated October 15, 2015)A discussion offlaw tolerance is provided as part of the technical basis to support the relief request. The licensee states, in part, Based on the circumferential crack growth results, even for the most conservative case (high temperature with a 25% weld repair), a flaw with a depth of 15% of the wall thickness would not grow to the maximum allowable ASME flaw size in less than 10 years of continued operation. |
| | Additionally, Figure 4 of Attachment 9.1 of letter dated April20, 2015, shows that a "Long SE [Safe End]25% Repair AR [Aspect Ratio] =1 0, High Temp "flaw would grow from 10% through-wall to the ASME Code allowable flaw depth of 75% through-wall in approximately 20 years.© 2016 Westinghouse Electric Company LLC All Rights Reserved Westinghouse Non-Proprietary Class 3 Page 3 of 6 Attachment B Our ref: LTR-PAFM-1 6-8 Revision 0 February 12, 2016 NRC staff performed a series of independent calculations and determined these values are not conservative. |
| | Additionally, the NRC staff did not identify' a sufficient technical basis to address the potential of axial flaw growth. Therefore, the NRC staff requests the following;" 1. The axial and hoop weld residual stresses (WRS) at operating temperature of the subject welds. If a generic WRS is used, include a basis for the WRS being conservative. (e.g. 50% weld repair, WRS validation used, safe end length, etc.)2. Piping loads for the subject welds to include pressure, deadweight, 100% power normal operating thermal expansion, seismic events, and Loss of Coolant Accident (LOCA).3. Weld dimensions for the subject welds include outside diameter and weld thickness. |
| | NRC RAJ 1. The axial and hoop weld residual stresses (WRS) at operating temperature of the subject welds. Ifra generic WRS is used, include a basis for the WRS being conservative. (e.g. 50% weld repair, WRS validation used, safe end length, etc.)Westinghouse Response: The axial and hoop welding residual stress (WRS) at normal operating pressure and temperature are given in Figure 1 based on the information provided in Reference |
| | : 3. The welding residual stresses are performed based on the guidelines in MRP-287 (Reference 4); thus, the finite element model used in the generation of the WRS assumes a 36O° inside surface weld repair with a repair depth of 50% through the DM weld thickness. |
| | The WRS are calculated for an identical inlet nozzle to Comanche Peak Unit 1, which has the same DM welding geometry, material, configuration, and safe end length. A full discussion of the WRS is provided in Section 4.0 of Reference 3.© 2016 Westinghouse Electric Company LLC All Rights Reserved Westinghouse Non-Proprietary Class 3 Page 4 of 6 Attachment B Our ref: LTR-PAFM-1 6-8 Revision 0 February 12, 2016 a,c,e Figure 1: Reactor Vessel Inlet Nozzle DM Weld 100% Normal Operating Recommended Residual Stress Profiles Through DM Weld with 50% Inside Surface Weld Repair© 20O16 Westinghouse Electric Company LL C All Rights Reserved Westinghouse Non-Proprietary Class 3 Page 5 of 6 Attachment B Our ref: LTR-PAFM-1 6-8 Revision 0 February 12, 2016 NRC RAI 2.' Piping loads for the subject welds to include pressure, deadweight, 100% power normal operating thermal expansion, seismic events, and Loss of Coolant Accident (LOCA).Westinghouse Response: The Comanche Peak Unit 1 piping loads are given in Table 1 below based on the information provided in Reference 3.Table 1: Comanche Peak Unit 1 Reactor Vessel Inlet Nozzle Piping Loads Forces Moments Loading (kips) (in-kips)Fx Mx My Mz (Axial) (Torsion) (Bending) (Bending)Deadweight 0.29 -180.42 51.67 -451.26 Pressure* |
| | 1333.5 100% Normal Thermal Expansion 2.5 -5500.74 386.92 -9764.41 OBE (Operational Basis Earthquake) 137 1752 4893 1496 SSE (Safe Shutdown Earthquake) 164 2133 6267 1754 LOCA/Pipe Break 514 1192 6281 2291*Axial force due to normal operating pressure of 2.25 ksi NRC RAI 3: Weld dimensions for the subject welds include outside diameter and weld thickness Westinghouse Response: The weld dimensions are given in Table 2 below based on the information provided in Reference 3.Table 2: Comanche Peak Unit 1 Reactor Vessel (RV) Inlet Nozzle Geometry RV Inlet Nozzle Dimension Outside Diameter (in) 33.05 Inside Diameter (in) 27.47 Thickness (in) 2.79© 2016 Westinghouse Electric Company LLC All Rights Reserved Westinghouse Non-Proprietary Class 3 Page 6 of 6 Attachment B Our ref: LTR-PAFM-1 6-8 Revision 0 February 12, 2016 Conclusion It is recommended that the above NRC RAI responses be reviewed along with the supplemental fracture mechanics evaluation performed in Reference 3 for Comanche Peak Unit 1 RV inlet nozzle DM weld.The results and conclusions based on the letter report in Reference 3 provide technical justification to defer the volumetric examination for the Comanche Peak Unit 1 RV inlet nozzle DM welds from the Spring 2016 RFO to the Spring 2019 lRFO.References |
| | : 1. NRC Email from Balwant Singal (NRC) to Timothy Hope (Luminant Power), |
| | |
| | ==Subject:== |
| | "Draft Request for Additional Information |
| | -Relief Request 1B3-3 for Comanche Peak Nuclear Power Plant, Unit 1 (CAC No. MF6 125)," dated January 12, 2016.2. Letter from Luminant Generation Company LLC to NRC, TXX-15 139, "Comanche Peak Nuclear Power Plant Docket No. 50-445 Revision to Relief Request 1B3-3 for Unit 1 Inservice Inspection for Application of an Alternative to the ASME Boiler and Pressure Vessel Code Section XI Examination Requirements for Reactor Pressure Vessel Cold Leg Weld Inspection Frequency (2007 Edition of ASME Code, section XI, 2008 Addenda Third Interval Start Date: August 13, 2010 Third Interval End Date: August 12, 2020)," October 15, 2015. [ADA MS Accession Number ML15300AO13] |
| | : 3. Westinghouse Letter Report, LTR-PAFM-16-2-NP, Revision 0. "Technical Justification to Support Extended Volumetric Examination Interval for Comanche Peak Unit 1 Reactor Vessel Inlet Nozzle to Safe End Dissimilar Metal Welds." February 2016.4. Materials Reliability Program: Primary Water Stress Corrosion Cracking (PWSCC) Flaw Evaluation Guidance (MRP-287), EPRI, Palo Alto, CA: 2010, 1021023.© 2016 Westinghouse Electric Company LLC All Rights Reserved}} |
Letter Sequence Other |
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MONTHYEARCP-201500402, Relief Request 1B3-3 Inservice Inspection for Application of an Alternative to ASME Boiler & Pressure Vessel Code Section XI Examination Requirements for Reactor Pressure Vessel Cold Leg Weld Inspection Frequency2015-04-20020 April 2015
Relief Request 1B3-3 Inservice Inspection for Application of an Alternative to ASME Boiler & Pressure Vessel Code Section XI Examination Requirements for Reactor Pressure Vessel Cold Leg Weld Inspection Frequency
Project stage: Request
CP-201500999, Revision to Relief Request 1B3-3 Inservice Inspection for Application of an Alternative to the ASME Boiler and Pressure Vessel Code Section XI Examination Requirements for Reactor Pressure Vessel Cold Leg Weld Inspection..2015-10-15015 October 2015
Revision to Relief Request 1B3-3 Inservice Inspection for Application of an Alternative to the ASME Boiler and Pressure Vessel Code Section XI Examination Requirements for Reactor Pressure Vessel Cold Leg Weld Inspection..
Project stage: Request
ML16015A0032016-01-14014 January 2016
NRR E-mail Capture - Request for Additional Information - Relief Request 1B3-3 for Comanche Peak Nuclear Power Plant, Unit 1
Project stage: RAI
ML16057A3102016-02-12012 February 2016
Westinghouse LTR-PAFM-16-8 Attachment B - Responses to the NRC RAIs Re Comanche Peak Unit 1 Extension of Required Inspection Frequency for Reactor Vessel Inlet Nozzle Dissimilar Metal Welds from 7 to 9 Calendar Years
Project stage: Other
ML16057A3092016-02-15015 February 2016
Response to Request for Additional Information Re Relief Request 1B3-3
Project stage: Response to RAI
CP-201600097, Westinghouse LTR-PAFM-16-2-NP, Technical Justification to Support Extended Volumetric Examination Interval for Comanche Peak Unit 1 Reactor Vessel Inlet Nozzle to Safe End Dissimilar Metal Welds.2016-02-29029 February 2016
Westinghouse LTR-PAFM-16-2-NP, Technical Justification to Support Extended Volumetric Examination Interval for Comanche Peak Unit 1 Reactor Vessel Inlet Nozzle to Safe End Dissimilar Metal Welds.
Project stage: Other
ML16053A4462016-03-10010 March 2016
Request for Withholding Information from Public Disclosure, 2/10/16 Affidavit Executed by J. Gresham, Westinghouse Electric Company LLC LTR-PAFM-16-8 and LTR-PAFM-16-2-P, Revision 0, Relief Request 1B3-3
Project stage: Withholding Request Acceptance
ML16074A0012016-03-14014 March 2016
Relief Request 1B3-3, Alternative for Reactor Pressure Vessel Cold Leg Weld Inspection Frequency from Not to Exceed 7 Years to 9 Years for the Third 10-Year Inservice Inspection Interval
Project stage: Other
2016-02-12
[Table View] |
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Category:Response to Request for Additional Information (RAI)
MONTHYEARCP-202300432, Response to Request for Additional Information Regarding the Safety Review of the License Renewal Application - Set 42023-10-0404 October 2023
Response to Request for Additional Information Regarding the Safety Review of the License Renewal Application - Set 4
CP-202300322, Response to Requests for Additional Information Regarding Review of the License Renewal Application Sets 2 and 32023-07-27027 July 2023
Response to Requests for Additional Information Regarding Review of the License Renewal Application Sets 2 and 3
CP-202300285, Response to Request for Additional Information Regarding Review of the License Renewal Application - Set 12023-07-12012 July 2023
Response to Request for Additional Information Regarding Review of the License Renewal Application - Set 1
CP-202300262, Response to Request for Confirmation of Information Regarding Review of the License Renewal Application - Set 22023-06-20020 June 2023
Response to Request for Confirmation of Information Regarding Review of the License Renewal Application - Set 2
ML23164A2232023-06-13013 June 2023
Response to Request for Confirmation of Information Regarding Review of the License Renewal Application - Set 1
CP-202300248, Response to Request for Additional Information Regarding License Renewal Application - Set 12023-06-13013 June 2023
Response to Request for Additional Information Regarding License Renewal Application - Set 1
CP-202300270, (CPNPP) - Response to Request for Supplemental Information for License Amendment Request to Adopt 10 CFR 50.59, Risk-Informed Categorization and Treatment of Structures, Systems and Components for Nuclear Power Reactors2023-06-0808 June 2023
(CPNPP) - Response to Request for Supplemental Information for License Amendment Request to Adopt 10 CFR 50.59, Risk-Informed Categorization and Treatment of Structures, Systems and Components for Nuclear Power Reactors
CP-202300209, Response to Request for Additional Information - License Renewal Application Environmental Review2023-06-0606 June 2023
Response to Request for Additional Information - License Renewal Application Environmental Review
TXX-2304, (Cpnpp), Response to Request for Information for Application to Revise Technical Specifications to Apply the Westinghouse Full Spectrum Loss of Coolant Accident Evaluation Model LAR 22-0022023-06-0101 June 2023
(Cpnpp), Response to Request for Information for Application to Revise Technical Specifications to Apply the Westinghouse Full Spectrum Loss of Coolant Accident Evaluation Model LAR 22-002
CP-202300182, Response to Requests for Confirmation of Information Regarding the Environmental Review of the License Renewal Application2023-05-0808 May 2023
Response to Requests for Confirmation of Information Regarding the Environmental Review of the License Renewal Application
CP-202200481, Response to Request for Additional Information - Relief Request Application P-1, Inservice Testing (IST)2022-12-0707 December 2022
Response to Request for Additional Information - Relief Request Application P-1, Inservice Testing (IST)
CP-202200357, (CPNPP) Unit 2 - Response to Request for Additional Information, Fall 2021 (2RF19) Steam Generator Tube Inspection Report2022-09-14014 September 2022
(CPNPP) Unit 2 - Response to Request for Additional Information, Fall 2021 (2RF19) Steam Generator Tube Inspection Report
ML22228A0942022-08-17017 August 2022
Notification of Inspection (NRC Inspection Report 05000445/2022004 and 05000446/2022004) and Request for Information
CP-202200123, (CPNPP) - License Amendment Request (LAR) 20-006 Application to Revise Technical Specifications to Adopt Risk Informed Completion Times TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times.2022-03-29029 March 2022
(CPNPP) - License Amendment Request (LAR) 20-006 Application to Revise Technical Specifications to Adopt Risk Informed Completion Times TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times.
CP-202100694, (CPNPP) - NRC Request for Additional Information for Application to Revise Technical Specifications to Adopt TSTF 577, Revised Frequencies for Steam Generator Tube Inspections2021-10-25025 October 2021
(CPNPP) - NRC Request for Additional Information for Application to Revise Technical Specifications to Adopt TSTF 577, Revised Frequencies for Steam Generator Tube Inspections
CP-202000428, (CPNPP) - Response to Request for Additional Information Regarding Proposed Alternative SNB-1 for a One-Time Extension of Snubber Testing2020-08-0505 August 2020
(CPNPP) - Response to Request for Additional Information Regarding Proposed Alternative SNB-1 for a One-Time Extension of Snubber Testing
TXX-2003, Response to Request for Additional Information Regarding Exigent License Amendment 20-003 Revision to Technical Specification 5.5.9, Unit 1 Model D76 and Unit 2 Model D5 Steam Generator (SG) Program2020-04-14014 April 2020
Response to Request for Additional Information Regarding Exigent License Amendment 20-003 Revision to Technical Specification 5.5.9, Unit 1 Model D76 and Unit 2 Model D5 Steam Generator (SG) Program
CP-202000273, Response to Request for Additional Information Regarding Snubber Testing (SNB-1) and Snubber Visual Examination (SNB-2) Relief Requests2020-04-13013 April 2020
Response to Request for Additional Information Regarding Snubber Testing (SNB-1) and Snubber Visual Examination (SNB-2) Relief Requests
CP-202000024, Response to NRC Request for Additional Information on Biennial Review of Procedures and Station Operations Review Committee Meetings2020-01-14014 January 2020
Response to NRC Request for Additional Information on Biennial Review of Procedures and Station Operations Review Committee Meetings
CP-201800659, (Cpnpp), Unit 1 - Response to Request for Additional Information Regarding Exigent License Amendment Request (LAR) 18-001, Revision to Technical Specification 3.8.4, 11DC Sources - Operating, Condition B2018-09-20020 September 2018
(Cpnpp), Unit 1 - Response to Request for Additional Information Regarding Exigent License Amendment Request (LAR) 18-001, Revision to Technical Specification 3.8.4, 11DC Sources - Operating, Condition B
CP-201700904, Response to Request for Additional Information Regarding Relief Request 1/2B3-2 for the Units 1 and 2 Third Ten Year Inservice Inspection Interval2017-11-0101 November 2017
Response to Request for Additional Information Regarding Relief Request 1/2B3-2 for the Units 1 and 2 Third Ten Year Inservice Inspection Interval
CP-201600934, Information Regarding NRC Order Approving Transfer of Licenses and Conforming License Amendments (CPNPP Unit 1 Operating License (NPF-87) and CPNPP Unit 2 Operating License (NPF-89))2016-09-29029 September 2016
Information Regarding NRC Order Approving Transfer of Licenses and Conforming License Amendments (CPNPP Unit 1 Operating License (NPF-87) and CPNPP Unit 2 Operating License (NPF-89))
CP-201600328, Additional Information Regarding Application for Order Approving Transfer of Licenses and Conforming License Amendments (CPNPP Unit 1 Operating License (NPF-87) and CPNPP Unit 2 Operating License (NPF-89))2016-03-29029 March 2016
Additional Information Regarding Application for Order Approving Transfer of Licenses and Conforming License Amendments (CPNPP Unit 1 Operating License (NPF-87) and CPNPP Unit 2 Operating License (NPF-89))
CP-201600136, and Independent Spent Fuel Storage Installation (Isfsi), Additional Information Regarding Application for Order Approving Transfer of Licenses and Conforming License Amendments2016-03-14014 March 2016
and Independent Spent Fuel Storage Installation (Isfsi), Additional Information Regarding Application for Order Approving Transfer of Licenses and Conforming License Amendments
CP-201600177, Supplemental to Response to Request for Additional Information Regarding License Amendment Request 15-003 for Revision to Emergency Action Levels2016-03-0303 March 2016
Supplemental to Response to Request for Additional Information Regarding License Amendment Request 15-003 for Revision to Emergency Action Levels
CP-201600148, Requesting Additional Information for Relief Request b-9 for Unit 2 Second Ten Year Inservice Inspection Interval2016-03-0202 March 2016
Requesting Additional Information for Relief Request b-9 for Unit 2 Second Ten Year Inservice Inspection Interval
CP-201600147, Revision Response to Request for Additional Information Regarding for Relief Request B-3 for Second Ten Year Interval Inspection Requirements Due to Physical Interferences (1998 Edition of ASME Code Section XI, 2000 Addenda.2016-03-0202 March 2016
Revision Response to Request for Additional Information Regarding for Relief Request B-3 for Second Ten Year Interval Inspection Requirements Due to Physical Interferences (1998 Edition of ASME Code Section XI, 2000 Addenda.
ML16057A3092016-02-15015 February 2016
Response to Request for Additional Information Re Relief Request 1B3-3
ML16057A3102016-02-12012 February 2016
Westinghouse LTR-PAFM-16-8 Attachment B - Responses to the NRC RAIs Re Comanche Peak Unit 1 Extension of Required Inspection Frequency for Reactor Vessel Inlet Nozzle Dissimilar Metal Welds from 7 to 9 Calendar Years
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Westinghouse Non-Proprietary Class 3 Page 1 of 6 Attachment B Our ref: LTR-PAFM-1 6-8 Revision 0 February 12, 2016 Attachment B (Non-Proprietary)
Responses to the NRC RA~s Regarding Comanche Peak Unit 1 Extension of Required Inspection Frequency for Reactor Vessel Inlet Nozzle Dissimilar Metal Welds from 7 to 9 Calendar Years Portions of this report contain proprietary information.
Proprietary information is identified and bracketed.
For each of the bracketed sections, the reasons for the proprietary classification are provided using superscripted letters "a" "" and "e". These letter designations are: a. The information reveals the distinguishing aspects of a process or component, structure, tool, method, etc. The prevention of its use by Westinghouse's competitors, without license from Westinghouse, gives Westinghouse a competitive economic advantage.
- c. The information, if used by a competitor, would reduce the competitor's expenditure of resources or improve the competitor's advantage in the design, manufacture, shipment, installation, assurance of quality, or licensing of a similar product.e. The information reveals aspects of past, present, or future Westinghouse-or customer-funded development plans and programs of potential commercial value to Westinghouse.
© 2016 Westinghouse Electric Company LLC All Rights Reserved Westinghouse Non-Proprietary Class 3 Page 2 of 6 Attachment B Our ref: LTR-PAFM-16-8 Revision 0 February 12, 2016 Responses to the NRC RA~s Regarding Comanche Peak Unit 1 Extension of Required Inspection Frequency for Reactor Vessel Inlet Nozzle Dissimilar Metal Welds from 7 to 9 Calendar Years The NRC submitted the RA~s shown below (Reference
- 1) to Comanche Peak Unit 1, after the Staff performed a review of the Comanche Peak Unit 1 relief request (Reference
- 2) to defer the required reactor vessel inlet nozzle dissimilar metal (DM) weld from Spring 2016 RFO to the Spring 2019 REO.The RAT responses provided in this letter report are based on a supporting Westinghouse flaw tolerance evaluation developed for Comanche Peak Unit 1 to extend the volumetric examination interval for the inlet nozzle DM weld (Reference 3). The fracture mechanics technical basis in Reference 3 confirms that the DM weld inspection interval can be extended from Spring 2016 RFO to Spring 2019 RFO. The axial and circumferential crack growth evaluations performed in Reference 3 are plant specific to Comanche Peak Unit 1, and provide the necessary technical justification to extend the inspection interval from 7 years to 9 years.The NRC RAIs based on Reference 1 are shown below, and the responses are given in the subsequent pages.By letter dated April120, 2015, (Agencywide Documents Access and Management System (ADAMS)Accession No. ML15119A216), as supplemented by letter dated October 15, 2015 (ADAMS Accession No.M!L15300AO13), Luminant Generation Company, LLC (the licensee), proposed an alternative to Title 10 of the Code of Federal Regulations (10 CFR), Paragraph 50.55a(g)
(6) (i i)(F) for Comanche Peak Nuclear Power Plant, Unit 1. This regulation, in part, defines the inspection frequency requirement for the reactor vessel inlet butt welds in accordance with American Society of Mechanical Engineer's Boiler and Pressure Vessel Code Case N-770-1, "Alternative Examination Requirements and Acceptance Standards for Class 1 PWR [Pressurized Water Reactor] 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 "with U. S. Nuclear Regulatory Commission (NRC) conditions.
The licensee is requesting an extension of the required inspection frequency from once every 7 calendar years to once every 9 calendar years.The NRC staff has reviewed and evaluated the information provided by the licensee and has determined that the following information is needed in order to complete its review of the relief request.Discussion on Flow Tolerance (Page 3 of 7 of the Letter Dated October 15, 2015)A discussion offlaw tolerance is provided as part of the technical basis to support the relief request. The licensee states, in part, Based on the circumferential crack growth results, even for the most conservative case (high temperature with a 25% weld repair), a flaw with a depth of 15% of the wall thickness would not grow to the maximum allowable ASME flaw size in less than 10 years of continued operation.
Additionally, Figure 4 of Attachment 9.1 of letter dated April20, 2015, shows that a "Long SE [Safe End]25% Repair AR [Aspect Ratio] =1 0, High Temp "flaw would grow from 10% through-wall to the ASME Code allowable flaw depth of 75% through-wall in approximately 20 years.© 2016 Westinghouse Electric Company LLC All Rights Reserved Westinghouse Non-Proprietary Class 3 Page 3 of 6 Attachment B Our ref: LTR-PAFM-1 6-8 Revision 0 February 12, 2016 NRC staff performed a series of independent calculations and determined these values are not conservative.
Additionally, the NRC staff did not identify' a sufficient technical basis to address the potential of axial flaw growth. Therefore, the NRC staff requests the following;" 1. The axial and hoop weld residual stresses (WRS) at operating temperature of the subject welds. If a generic WRS is used, include a basis for the WRS being conservative. (e.g. 50% weld repair, WRS validation used, safe end length, etc.)2. Piping loads for the subject welds to include pressure, deadweight, 100% power normal operating thermal expansion, seismic events, and Loss of Coolant Accident (LOCA).3. Weld dimensions for the subject welds include outside diameter and weld thickness.
NRC RAJ 1. The axial and hoop weld residual stresses (WRS) at operating temperature of the subject welds. Ifra generic WRS is used, include a basis for the WRS being conservative. (e.g. 50% weld repair, WRS validation used, safe end length, etc.)Westinghouse Response: The axial and hoop welding residual stress (WRS) at normal operating pressure and temperature are given in Figure 1 based on the information provided in Reference
- 3. The welding residual stresses are performed based on the guidelines in MRP-287 (Reference 4); thus, the finite element model used in the generation of the WRS assumes a 36O° inside surface weld repair with a repair depth of 50% through the DM weld thickness.
The WRS are calculated for an identical inlet nozzle to Comanche Peak Unit 1, which has the same DM welding geometry, material, configuration, and safe end length. A full discussion of the WRS is provided in Section 4.0 of Reference 3.© 2016 Westinghouse Electric Company LLC All Rights Reserved Westinghouse Non-Proprietary Class 3 Page 4 of 6 Attachment B Our ref: LTR-PAFM-1 6-8 Revision 0 February 12, 2016 a,c,e Figure 1: Reactor Vessel Inlet Nozzle DM Weld 100% Normal Operating Recommended Residual Stress Profiles Through DM Weld with 50% Inside Surface Weld Repair© 20O16 Westinghouse Electric Company LL C All Rights Reserved Westinghouse Non-Proprietary Class 3 Page 5 of 6 Attachment B Our ref: LTR-PAFM-1 6-8 Revision 0 February 12, 2016 NRC RAI 2.' Piping loads for the subject welds to include pressure, deadweight, 100% power normal operating thermal expansion, seismic events, and Loss of Coolant Accident (LOCA).Westinghouse Response: The Comanche Peak Unit 1 piping loads are given in Table 1 below based on the information provided in Reference 3.Table 1: Comanche Peak Unit 1 Reactor Vessel Inlet Nozzle Piping Loads Forces Moments Loading (kips) (in-kips)Fx Mx My Mz (Axial) (Torsion) (Bending) (Bending)Deadweight 0.29 -180.42 51.67 -451.26 Pressure*
1333.5 100% Normal Thermal Expansion 2.5 -5500.74 386.92 -9764.41 OBE (Operational Basis Earthquake) 137 1752 4893 1496 SSE (Safe Shutdown Earthquake) 164 2133 6267 1754 LOCA/Pipe Break 514 1192 6281 2291*Axial force due to normal operating pressure of 2.25 ksi NRC RAI 3: Weld dimensions for the subject welds include outside diameter and weld thickness Westinghouse Response: The weld dimensions are given in Table 2 below based on the information provided in Reference 3.Table 2: Comanche Peak Unit 1 Reactor Vessel (RV) Inlet Nozzle Geometry RV Inlet Nozzle Dimension Outside Diameter (in) 33.05 Inside Diameter (in) 27.47 Thickness (in) 2.79© 2016 Westinghouse Electric Company LLC All Rights Reserved Westinghouse Non-Proprietary Class 3 Page 6 of 6 Attachment B Our ref: LTR-PAFM-1 6-8 Revision 0 February 12, 2016 Conclusion It is recommended that the above NRC RAI responses be reviewed along with the supplemental fracture mechanics evaluation performed in Reference 3 for Comanche Peak Unit 1 RV inlet nozzle DM weld.The results and conclusions based on the letter report in Reference 3 provide technical justification to defer the volumetric examination for the Comanche Peak Unit 1 RV inlet nozzle DM welds from the Spring 2016 RFO to the Spring 2019 lRFO.References
- 1. NRC Email from Balwant Singal (NRC) to Timothy Hope (Luminant Power),
Subject:
"Draft Request for Additional Information
-Relief Request 1B3-3 for Comanche Peak Nuclear Power Plant, Unit 1 (CAC No. MF6 125)," dated January 12, 2016.2. Letter from Luminant Generation Company LLC to NRC, TXX-15 139, "Comanche Peak Nuclear Power Plant Docket No. 50-445 Revision to Relief Request 1B3-3 for Unit 1 Inservice Inspection for Application of an Alternative to the ASME Boiler and Pressure Vessel Code Section XI Examination Requirements for Reactor Pressure Vessel Cold Leg Weld Inspection Frequency (2007 Edition of ASME Code, section XI, 2008 Addenda Third Interval Start Date: August 13, 2010 Third Interval End Date: August 12, 2020)," October 15, 2015. [ADA MS Accession Number ML15300AO13]
- 3. Westinghouse Letter Report, LTR-PAFM-16-2-NP, Revision 0. "Technical Justification to Support Extended Volumetric Examination Interval for Comanche Peak Unit 1 Reactor Vessel Inlet Nozzle to Safe End Dissimilar Metal Welds." February 2016.4. Materials Reliability Program: Primary Water Stress Corrosion Cracking (PWSCC) Flaw Evaluation Guidance (MRP-287), EPRI, Palo Alto, CA: 2010, 1021023.© 2016 Westinghouse Electric Company LLC All Rights Reserved
