Letter Sequence RAI |
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EPID:L-2022-LLA-0171, Application to Revise Technical Specifications to Apply the Westinghouse Full Spectrum Loss of Coolant Accident Evaluation Model LAR 22-002 (Open) |
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Category:E-Mail
MONTHYEARML24025A0172024-01-22022 January 2024 NRC Request for Concurrence with Endangered Species Act Determinations for Comanche Peak License Renewal, Issuance of Draft Supplemental Environmental Impact Statement, and Opportunity for Public Comment ML24019A0742024-01-19019 January 2024 NRR E-mail Capture - Comanche Peak - Draft Request for Additional Information - License Amendment Request to Extend the Allowed Outage Time for an Inoperable Emergency Diesel Generator ML24008A2492023-12-18018 December 2023 Texas Shpo Response for Comanche Peak Deis Review and Comment ML23311A2202023-11-20020 November 2023 NRC to Fws, NRC Request for Concurrence with Endangered Species Act Determinations for Comanche Peak License Renewal, Issuance of Draft Supplemental Environmental Impact Statement, and Opportunity for Public Comment (Consultation Code: 2023 ML23255A2882023-09-12012 September 2023 NRR E-mail Capture - Comanche Peak - Acceptance of Request for Exemption from 10 CFR 50.71(e)(4) Final Safety Analysis Update Schedule ML23256A1492023-09-11011 September 2023 Email from Mark Yoo (NRC) to Ken Peters (Vistra) - Comanche Peak LRA - Request for Additional Information - Set 4 ML23226A0072023-08-11011 August 2023 NRR E-mail Capture - Comanche Peak 1 and 2 Audit Plan - License Amendment Request to Adopt 10 CFR 50.69, Risk-Informed Categorization and Treatment of Structures, Systems and Components for Nuclear Power Reactors ML23188A0442023-07-0707 July 2023 Email from Mark Yoo (NRC) to Ken Peters (Vistra) - Comanche Peak LRA - Request for Additional Information - Set 3 ML23181A0722023-06-29029 June 2023 NRR E-mail Capture - Comanche Peak - Acceptance of License Amendment Request to Adopt 10 CFR 50.69, Risk-Informed Categorization and Treatment of Structures, Systems and Components for Nuclear Power Reactors ML23181A0202023-06-29029 June 2023 Email from Mark Yoo (NRC) to Ken Peters (Vistra) - Comanche Peak LRA - Request for Additional Information - Set 2 ML23172A0152023-06-20020 June 2023 NRR E-mail Capture - Re Comanche Peak - Acceptance of License Amendment Request Regarding General Design Criterion 5 of Appendix a to 10 CFR Part 50 and Regulatory Guide 1.81 ML23167A0222023-06-14014 June 2023 Email: Request for Additional Information (RAI) Letter for the Review of the Comanche Peak Initial License Renewal Application, Set 1 ML23145A2332023-05-25025 May 2023 Email from Mark Yoo (NRC) to Ken Peters (Vistra) - Comanche Peak LRA - Request for Confirmation of Information - Set 2 ML23143A1382023-05-23023 May 2023 Email from Mark Yoo (NRC) to Ken Peters (Vistra) - Comanche Peak LRA - Request for Confirmation of Information - Set 1 ML23139A0802023-05-18018 May 2023 NRR E-mail Capture - Comanche Peak Draft Supplemental Information Request - License Amendment Request Regarding General Design Criterion 5 of Appendix a to 10 CFR Part 50 and Regulatory Guide 1.81 ML23138A1522023-05-18018 May 2023 Lr Docs - (External_Sender) Comanche Peak Nuclear Power Plants ML23135A9132023-05-15015 May 2023 NRR E-mail Capture - Comanche Peak - Draft Supplemental Information Request - License Amendment Request to 10 CFR 50.69 ML23131A2932023-05-11011 May 2023 Lr Docs - License Renewal for Comanche Peak Nuclear Power Plant, Units 1 and 2 ML23128A1612023-05-0808 May 2023 NRR E-mail Capture - Comanche Peak Nuclear Power Plant, Units 1 and 2, Beaver Valley Power Station, Unit Nos. 1 and 2, Davis-Besse Nuclear Power Station, Unit 1, and Perry Nuclear Power Plant, Unit No. 1 - Acceptance of Requested Licensing ML23110A7122023-04-20020 April 2023 NRR E-mail Capture - Comanche Peak - Verbal Authorization of Proposed Alternative RV-1 (L-2023-LLR-0019) ML23103A4682023-04-11011 April 2023 NRR E-mail Capture - Comanche Peak Request for Additional Information - License Amendment Request to Apply the Westinghouse Full Spectrum Loss of Coolant Accident Evaluation Model ML23086B9852023-03-27027 March 2023 NRR E-mail Capture - Comanche Peak Draft Request for Additional Information - Request to Apply the Westinghouse Full Spectrum Loss of Coolant Accident Evaluation Model ML23061A1612023-03-0202 March 2023 E-mail from David Griggs Regarding Submission to NRC Electronic Information Exchange on 03/01/2023 for Citizens for Fair Utility Regulation in Comanche Peak Proceeding ML23032A3842023-02-0101 February 2023 LRA On-Site Audit Needs List ML23214A0192023-01-30030 January 2023 (External_Sender) Request to Broaden Extended Deadline to the General Public (with Attachments) - C3 ML23214A0202023-01-29029 January 2023 (External_Sender) Requesting a Deadline Extension on NRC-2002-0183, Comanche Peak License Renewal - C2 ML23214A0182023-01-26026 January 2023 (External Sender) NRC-2022-0183-0003 (with Attachment) - C6 ML23214A0162023-01-24024 January 2023 (External Sender) EPA Scoping Comment Letter for the Comanche Peak Nuclear Power Plant License Renewal (with Attachment) - C8 ML23214A0142023-01-23023 January 2023 (External Sender) Docket NRC-2022-0183 Comanche Peak Nuclear Power Plant Renewal (with Attachment) - C1 ML23214A0172023-01-17017 January 2023 (External Sender) NRC License Extension? No! ML23214A0132023-01-17017 January 2023 (External Sender) Docket Id NRC-2022-0183, Request for Extension of License for Comanche Peak, Comment for Environmental Scoping - C9 ML23214A0122023-01-13013 January 2023 (External Sender) Correction to Comment Submitted 01-13-23 - C11 ML22362A0992022-12-28028 December 2022 NRR E-mail Capture - Comanche Peak - Acceptance of License Amendment Request to Apply Westinghouse Fsloca Evaluation Model ML22362A0972022-12-28028 December 2022 NRR E-mail Capture - Comanche Peak - Acceptance of License Amendment Request to Adopt WCAP-17661-P-A, Revision 1, Improved RAOC and CAOC Fq Surveillance Technical Specifications, ML22325A2742022-11-21021 November 2022 NRR E-mail Capture - Comanche Peak - Request for Additional Information - Proposed Alternative P-1 Regarding IST of Safeguards Building Sump Pumps ML22318A3102022-11-10010 November 2022 NRR E-mail Capture - Comanche Peak - Draft Request for Additional Information - Proposed Alternative P-1 Regarding IST of Safeguards Building Sump Pumps ML22237A2842022-08-25025 August 2022 CPNPP 2022 EP Program Inspection RFI Hjs 08252022 ML22230B1092022-08-17017 August 2022 NRR E-mail Capture - Comanche Peak Unit 2 - Request for Additional Information - 2RE19 Inspection Summary Report for Steam Generator Tubing ML22229A0792022-08-17017 August 2022 NRR E-mail Capture - Comanche Peak - Acceptance of Requested Licensing Action - Proposed Alternative P-1 Regarding IST of Safeguards Building Sump Pumps ML22220A1942022-08-0808 August 2022 NRR E-mail Capture - Comanche Peak Unit 2 - Draft Request for Additional Information - 2RE19 Inspection Summary Report for Steam Generator Tubing ML22133A0472022-05-13013 May 2022 July 2022 Emergency Preparedness Exercise Inspection - Request for Information ML22083A0262022-03-23023 March 2022 NRR E-mail Capture - Comanche Peak - Request for Additional Information - Request to Adopt TSTF 505 Revision 2 ML22031A2122022-01-31031 January 2022 NRR E-mail Capture - Comanche Peak - Acceptance of Requested Licensing Action - Proposed Alternative to Extend the Snubber Inservice Program Third Interval ML21300A1342021-10-27027 October 2021 NRR E-mail Capture - Comanche Peak Units 1 and 2 - License Amendment Request to Adopt TSTF-505 - Audit Plan Update and Audit Questions (L-2021-LLA-0085) ML21286A7912021-10-13013 October 2021 NRR E-mail Capture - Comanche Peak - Request for Additional Information - Request to Adopt TSTF-577 Revision 1 ML21272A2002021-09-29029 September 2021 NRR E-mail Capture - Comanche Peak Unit 2 - Upcoming Steam Generator Tube Inservice Inspection (L-2021-NFO-0013) ML21270A1632021-09-27027 September 2021 NRR E-mail Capture - Comanche Peak - Acceptance of Quality Assurance Program Change Request Regarding Internal Audit Frequency ML21253A2242021-09-0909 September 2021 Request for Information Occupational Radiation Safety Inspection (71124.01, 71124.02, and 71151) from 10/18-22/2021 ML21252A0062021-08-26026 August 2021 NRR E-mail Capture - Comanche Peak - Acceptance of License Amendment Request Regarding Adoption of TSTF-577, Revised Frequencies for Steam Generator Tube Inspections 2024-01-22
[Table view] Category:Request for Additional Information (RAI)
MONTHYEARML24019A0742024-01-19019 January 2024 NRR E-mail Capture - Comanche Peak - Draft Request for Additional Information - License Amendment Request to Extend the Allowed Outage Time for an Inoperable Emergency Diesel Generator ML24018A1072024-01-18018 January 2024 Notification of Commercial Grade Dedication Inspection (05000445/2024012 and 05000446/2024012) and Request for Information ML23256A1502023-09-11011 September 2023 Request for Additional Information Requests - Comanche Peak - Set 4 ML23256A1492023-09-11011 September 2023 Email from Mark Yoo (NRC) to Ken Peters (Vistra) - Comanche Peak LRA - Request for Additional Information - Set 4 ML23213A2162023-08-0202 August 2023 Vistra Operations Company, LLC Notification of License Renewal Inspection and Request for Information ML23188A0452023-07-0707 July 2023 Request for Additional Information Requests - Comanche Peak - Set 3 ML23188A0442023-07-0707 July 2023 Email from Mark Yoo (NRC) to Ken Peters (Vistra) - Comanche Peak LRA - Request for Additional Information - Set 3 ML23181A0212023-06-29029 June 2023 Request for Additional Information Requests - Comanche Peak - Set 2 ML23181A0202023-06-29029 June 2023 Email from Mark Yoo (NRC) to Ken Peters (Vistra) - Comanche Peak LRA - Request for Additional Information - Set 2 ML23167A0222023-06-14014 June 2023 Email: Request for Additional Information (RAI) Letter for the Review of the Comanche Peak Initial License Renewal Application, Set 1 ML23167A0232023-06-14014 June 2023 Request for Additional Information (RAI) for the Review of the Comanche Peak Initial License Renewal Application (Lra), Set 1 ML23145A2322023-05-25025 May 2023 LRA - Request for Confirmation of Information - Set 2 ML23143A1372023-05-23023 May 2023 LRA - Request for Confirmation of Information - Set 1 ML23132A2542023-05-23023 May 2023 Supplemental Information Needed for Acceptance of Requested Licensing Action LAR to Adopt 10 CFR 50.69,Risk-Informed Categorization & Treatment of Structures,Systems & Components for Nuclear Power Reactors EPID L-2023-LLA-0057 ML23068A0562023-05-0909 May 2023 Request for Additional Information - Comanche Peak License Renewal Application Environmental Review ML23068A0732023-04-13013 April 2023 Requests for Confirmation of Information for the Environmental Review of the Comanche Peak Nuclear Power Plant, Units 1 and 2, Licensed Renewal Application (EPID Number: L-2022-LNE-0004) (Docket Numbers 50-445 and 50-446) ML23103A4682023-04-11011 April 2023 NRR E-mail Capture - Comanche Peak Request for Additional Information - License Amendment Request to Apply the Westinghouse Full Spectrum Loss of Coolant Accident Evaluation Model ML23086B9852023-03-27027 March 2023 NRR E-mail Capture - Comanche Peak Draft Request for Additional Information - Request to Apply the Westinghouse Full Spectrum Loss of Coolant Accident Evaluation Model ML23010A1442023-01-0909 January 2023 Inservice Inspection Request for Information ML22325A2742022-11-21021 November 2022 NRR E-mail Capture - Comanche Peak - Request for Additional Information - Proposed Alternative P-1 Regarding IST of Safeguards Building Sump Pumps ML22318A3102022-11-10010 November 2022 NRR E-mail Capture - Comanche Peak - Draft Request for Additional Information - Proposed Alternative P-1 Regarding IST of Safeguards Building Sump Pumps ML22230B1092022-08-17017 August 2022 NRR E-mail Capture - Comanche Peak Unit 2 - Request for Additional Information - 2RE19 Inspection Summary Report for Steam Generator Tubing ML22220A1942022-08-0808 August 2022 NRR E-mail Capture - Comanche Peak Unit 2 - Draft Request for Additional Information - 2RE19 Inspection Summary Report for Steam Generator Tubing ML22179A3032022-06-28028 June 2022 Information Request for the Cyber-Security Baseline Inspection, Notification to Perform Inspection 05000445/2022401; 05000446/2022401 ML22083A0262022-03-23023 March 2022 NRR E-mail Capture - Comanche Peak - Request for Additional Information - Request to Adopt TSTF 505 Revision 2 ML21286A7912021-10-13013 October 2021 NRR E-mail Capture - Comanche Peak - Request for Additional Information - Request to Adopt TSTF-577 Revision 1 ML21253A2242021-09-0909 September 2021 Request for Information Occupational Radiation Safety Inspection (71124.01, 71124.02, and 71151) from 10/18-22/2021 ML21253A2332021-09-0909 September 2021 Request for Information: Comanche Peak Nuclear Power Plant, Units 1 and 2 (05000445 and 05000446); Occupation Radiation Safety (71124.01, 71124.02, 7511) ML21245A3072021-09-0202 September 2021 Request for Information ML21245A307 ML21166A3382021-06-22022 June 2021 Supplemental Information Needed for Acceptance of Requested Licensing Action LAR to Adopt TSTF-505, Rev. 2, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b ML21165A1022021-06-13013 June 2021 Pi&R; Request for Information ML21103A3982021-04-13013 April 2021 CP Security Inspection Information Request 2021403 ML20225A0932020-08-12012 August 2020 Notification of Inspection 05000445/2020004 and 05000446/2020004 and Request for Information ML20105A1072020-04-13013 April 2020 NRR E-mail Capture - Comanche Peak - Request for Additional Information - Exigent Amendment Request for One Time Change to Unit 2 Steam Generator Inspection Frequency ML20104A0022020-04-11011 April 2020 NRR E-mail Capture - Comanche Peak Unit 2 - Request for Additional Information - Proposed Alternative to ASME OM Code for Deferral of Snubber Testing (SNB-1) and Visual Examinations (SNB-2) ML20045E3512020-02-13013 February 2020 Information Request February 13, 2020 Notification of Inspection and Request for Information Comanche Peak Unit 2 NRC Inspection Report 05000446/2020002 ML19346B3812019-12-11011 December 2019 NRR E-mail Capture - Comanche Peak RAIs - Quality Assurance Program Reduction in Commitment ML19319A5432019-11-14014 November 2019 NRR E-mail Capture - Draft Comanche Peak RAIs - Quality Assurance Program Reduction in Commitment ML19058A3592019-02-27027 February 2019 NRR E-mail Capture - Comanche Peak Nuclear Power Plant, Unit Nos. 1 and 2 - Final Request for Additional Information Concerning License Amendment Request to Revise the Emergency Plan IR 05000445/20170072018-02-0808 February 2018 Notification of Nrc Design Bases Assurance Inspection (Programs) (05000445/2017007 and 05000446/2017007) ML17276B8622017-10-0303 October 2017 Notification of NRC Design Bases Assurance Inspection (Programs)(05000445/2017007 and 05000446/2017007) and Initial Request for Information ML17087A2032017-03-28028 March 2017 NRR E-mail Capture - Comanche Peak, Unit 2 - Final Request for Additional Information Regarding Request No. 2B3-1 ML17066A2372017-03-0707 March 2017 Notification of NRC Triennial Fire Protection Baseline Inspection (05000445/2017008 and 05000446/2017008) and Request for Information ML17048A4172017-02-17017 February 2017 Notification of NRC Inspection of the Implementation of Mitigation Strategies and Spent Fuel Pool Instrumentation Orders and Emergency Preparedness Communication/ Staffing/Multi-Unit Dose Assessment... ML16034A1962016-02-0808 February 2016 Independent Spent Fuel Storage Installation - Request for Additional Information, Application for Order Approving Transfer of Facility Operating Licenses and Conforming Amendment 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 ML15345A0112015-12-16016 December 2015 Request for Additional Information, License Amendment Request, Revise Emergency Action Levels Based on Nuclear Energy Institute (NEI) 99-01, Revision 6 ML15317A1582015-11-13013 November 2015 Request for Additional Information Email, Relief Request B-15, C-2, and C-4 for Welds in the RPV and Containment Spray and Residual Heat Removal Heat Exchanger Shells, Second 10-year Inservice Inspection Interval ML15317A1482015-11-13013 November 2015 Request for Additional Information Email, Relief Request No. B-9 for Reactor Pressure Vessel Outlet Nozzle Safe End to Piping Welds, Second 10-year Inservice Inspection Interval ML15317A1502015-11-13013 November 2015 Request for Additional Information Email, Relief Request No. B-3 for Reactor Coolant System Pipe to Pipe Flange Weld, Second 10-year Inservice Inspection Interval 2024-01-19
[Table view] |
Text
From: Dennis Galvin Sent: Tuesday, April 11, 2023 5:04 PM To: Jack Hicks (Jack.Hicks@luminant.com)
Cc: Nic Boehmisch (Nicholas.Boehmisch@luminant.com)
Subject:
Comanche Peak - Request for Additional Information - License Amendment Request to Apply the Westinghouse Full Spectrum Loss of Coolant Accident Evaluation Model. (EPID: L-2022-LLA-0171)
Attachments: Comanche Peak Adopt FSLOCA LAR - RAI Issued 2023-04-11.pdf
Dear Mr. Hicks,
By letter dated November 21, 2022 (ML22325A324), Vistra Operations Company LLC ("Vistra OpCo", the licensee) submitted a license amendment request (LAR) to the U.S. Nuclear Regulatory Commission (NRC) for Comanche Peak, Units 1 and 2 (Comanche Peak). The proposed amendment would revise the Comanche Peak Technical Specification (TS) to reflect the adoption of topical report (TR) WCAP-16996-P-A, Revision 1, "Realistic LOCA [loss-of-coolant accident] Evaluation Methodology Applied to the Full Spectrum of Break Sizes (Full Spectrum LOCA Methodology), (FSLOCA)" (ML16343A238). The proposed amendments revise TS 2.1.1.2 reactor core safety limit (SL), to reflect the peak fuel centerline melt temperature specified in TR WCAP-17642-P-A, Revision 1, Westinghouse Performance Analysis and Design Model (PAD5) (ML17335A334), and revise the TS 4.2.1 reactor core fuel assemblies design feature by removing the discussion of Zircalloy fuel rods and ZIRLO lead test assemblies for Comanche Peak Unit 1 and Unit 2. The amendment also proposes to delete references 11 through 14 in the TS 5.6.5.b list of analytical methods and to add a new approved analytical method, i.e., FSLOCA.
The NRC staff has determined that additional information is needed to complete its review. The requests for additional information (RAIs) were transmitted to the licensee in draft form on March 27, 2023. A clarification call was held with your staff on April 6, 2023, and the licensee agreed to provide responses to the RAls by June 5, 2023. The NRC staff agrees with this date.
Respectfully, Dennis Galvin Project Manager U.S Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Division of Operating Reactor Licensing Licensing Project Branch 4 301-415-6256 Docket Nos. 50-445 and 50-446
Hearing Identifier: NRR_DRMA Email Number: 2037 Mail Envelope Properties (SA1PR09MB8111118152832D54B631CE9CFB9A9)
Subject:
Comanche Peak - Request for Additional Information - License Amendment Request to Apply the Westinghouse Full Spectrum Loss of Coolant Accident Evaluation Model. (EPID L-2022-LLA-0171)
Sent Date: 4/11/2023 5:04:24 PM Received Date: 4/11/2023 5:04:00 PM From: Dennis Galvin Created By: Dennis.Galvin@nrc.gov Recipients:
"Nic Boehmisch (Nicholas.Boehmisch@luminant.com)" <Nicholas.Boehmisch@luminant.com>
Tracking Status: None "Jack Hicks (Jack.Hicks@luminant.com)" <Jack.Hicks@luminant.com>
Tracking Status: None Post Office: SA1PR09MB8111.namprd09.prod.outlook.com Files Size Date & Time MESSAGE 1831 4/11/2023 5:04:00 PM Comanche Peak Adopt FSLOCA LAR - RAI Issued 2023-04-11.pdf 388051 Options Priority: Normal Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:
REQUEST FOR ADDITIONAL INFORMATION LICENSE AMENDMENT REQUEST VISTRA OPERATIONS COMPANY LLC COMANCHE PEAK UNIT 1 AND 2 DOCKET NOS. 50445 AND 50446 INTRODUCTION By letter dated November 21, 2022 (Reference 1), Vistra Operations Company LLC ("Vistra OpCo," the licensee) submitted a license amendment request (LAR) to the U.S. Nuclear Regulatory Commission (NRC) for Comanche Peak, Units 1 and 2 (Comanche Peak). The proposed amendment would revise the Comanche Peak Technical Specification (TS) to reflect the adoption of topical report (TR) WCAP16996P-A, Revision 1, "Realistic LOCA
[loss-ofcoolant-accident] Evaluation Methodology Applied to the Full Spectrum of Break Sizes (Full Spectrum LOCA Methodology), (FSLOCA)" (Reference 2). The proposed amendments revise TS 2.1.1.2 reactor core safety limit (SL), to reflect the peak fuel centerline melt temperature specified in TR WCAP17642P-A, Revision 1, Westinghouse Performance Analysis and Design Model (PAD5) (Reference 3), and revise the TS 4.2.1 reactor core fuel assemblies design feature by removing the discussion of Zircalloy fuel rods and ZIRLO lead test assemblies for Comanche Peak Unit 1 and Unit 2. The amendment also proposes to delete references 11 through 14 in the TS 5.6.5.b list of analytical methods and to add a new approved analytical method (Reference 2).
After reviewing the LAR (Reference 1), the staff requests responses to the requests for additional information (RAIs) given below.
RAI 1
Regulatory Basis:
The regulations in 10 CFR 50.46(b) require the following criteria to be met during LOCA events:
(1) Peak cladding temperature. The calculated maximum fuel element cladding temperature shall not exceed 2200° F.
(2) Maximum cladding oxidation. The calculated total oxidation of the cladding shall nowhere exceed 0.17 times the total cladding thickness before oxidation.
(3) Maximum hydrogen generation. The calculated total amount of hydrogen generated from the chemical reaction of the cladding with water or steam shall not exceed 0.01 times the hypothetical amount that would be generated if all of the metal in the cladding cylinders surrounding the fuel, excluding the cladding surrounding the plenum volume, were to react.
(4) Coolable geometry. Calculated changes in core geometry shall be such that the core remains amenable to cooling.
Regarding errors in evaluation models, 10 CFR 50.46(a)(3)(i) states:
Each applicant for or holder of an operating license or construction permit issued under this part, applicant for a standard design certification under Part 52 of this chapter (including an applicant after the Commission has adopted a final design certification regulation), or an applicant for or holder of a standard design approval, a combined license or a manufacturing license issued under Part 52 of this chapter, shall estimate the effect of any change to or error in an acceptable evaluation model or in the application of such a model to determine if the change or error is significant. For this purpose, a significant change or error is one which results in a calculated peak fuel cladding temperature different by more than 50 °F from the temperature calculated for the limiting transient using the last acceptable model, or is a cumulation of changes and errors such that the sum of the absolute magnitudes of the respective temperature changes is greater than 50 °F.
10 CFR 50.46(a)(3)(ii) states in part For each change to or error discovered in an acceptable evaluation model or in the application of such a model that affects the temperature calculation, the applicant or holder of a construction permit, operating license, combined license, or manufacturing license shall report the nature of the change or error and its estimated effect on the limiting ECCS
[emergency core cooling system] analysis to the Commission at least annually as specified in § 50.4 or § 52.3 of this chapter, as applicable. If the change or error is significant, the applicant or licensee shall provide this report within 30 days and include with the report a proposed schedule for providing a reanalysis or taking other action as may be needed to show compliance with § 50.46 requirements.
RAI:
LAR Attachment 4 indicates that it was prepared in 2019. Further, in LAR, Attachment 4, Limitation and Condition Number 2, under Compliance, the licensee indicates that the analyses reflects changes to the FSLOCA methodology as described in LTR-NRC1830 (Reference 4) but does not incorporate changes to address errors described in LTR-NRC196 (Reference 5), which reports two errors were discovered in the WCOBRA/TRAC-TF2 code that can occur under certain conditions in the ECCS evaluation models. The letter LTR-NRC196 report that these errors were found to have negligible impact on analysis results with the FSLOCA EM. In addition, the LTR-NRC196 report (and similar Westinghouse annual submittals) states:
It is noted that plant-specific peak cladding temperature (PCT) variations are not addressed in this letter.
- i. Confirm that the applicable changes and errors described in LTR-NRC1830 are reflected in the Comanche Peak analyses and the results are quantitively obtained using the revised code.
ii. For each change to or error discovered in the FSLOCA model not reflected in the analyses supporting LAR Attachment 4, including those described in Westinghouse LTR-NRC235, dated March 10, 2023 (Reference 6), which reports two errors discovered in the
WCOBRA/TRAC-TF2 code, quantitatively describe its plant-specific effect on the results, errors and uncertainties.
RAI 2
Regulatory Basis:
Same as in RAI 1 RAI:
In LAR, Attachment 4, Section 1.3, the description of the small break OCA (Region I) analysis does not provide the range of break areas/sizes that were analyzed. LAR, Attachment 4, Section 1.3.2 identifies the break sizes and LAR, Attachment 4, Tables 8A and 8B, represent the time sequence of events for the PCTs results given in LAR, Attachment 4, Tables 7A and 7B. However, corresponding break sizes and sequence of events are not provided for maximum local oxidations (MLOs), core-wide oxidations (CWOs) results given in LAR, Attachment 4, Tables 7A and 7B., Identify the range of range of break areas/sizes that were analyzed and the break areas/sizes for which MLOs and CWOs, and the time sequence of events for the Region I results given in LAR, Attachment 1, Tables 7A and 7B.
RAI3 Regulatory Basis:
Same as in RAI 1 RAI:
In LAR, Attachment 4, Section 1.4, the description of the large break LOCA (Region II) analysis does not provide the break spectrum scenarios that were analyzed. LAR, Attachment 4, Tables 9A and 9B, represent the time sequence of events for the PCTs results given in LAR, , Tables 7A and 7B. However, the corresponding break sizes are not provided for the PCTs results, and the corresponding break sizes and sequence of events are not provided MLOs,and CWOs results given in LAR, Attachment 4, Tables 7A and 7B. Provide the scatter pots of the PCT vs break size, transient equivalent cladding reacted vs PCT, core wide oxidation vs PCT, and the time sequence of events for the Region II results given in LAR, attachment 1, Tables 7A and 7B.
RAI 4
Regulatory Basis:
10 CFR 50.46(b)(4) on Coolable Geometry: Calculated changes in core geometry shall be such that the core remains amenable to cooling.
RAI:
LAR, Attachment 4, Section 1.5, addresses compliance with 10 CFR 50.46. Regarding compliance with 10 CFR 50.46(b)(4), the last sentence of third paragraph, states:
Inboard grid deformation due to combined LOCA and seismic loads is not calculated to occur for Comanche Peak.
The LAR does not provide any summary of the calculations or the results or other technical basis to support this statement. Provide a summary of the calculations and the results or other technical basis to support the statement.
REFERENCES
- 1. Vistra Operations Company LLC ("Vistra OpCo") letter to NRC, Application to Revise Technical Specifications to Apply the Westinghouse Full Spectrum Loss of Coolant Accident Evaluation Model. LAR 22-002 License Amendment Request 273, Update Listing of Approved LOCA Methodologies to Adopt FULL SPECTRUMTM LOCA Methodology, dated November 21, 2022 (ML22325A324).
- 2. Realistic LOCA Evaluation Methodology Applied to the Full Spectrum of Break Sizes (FULL SPECTRUM LOCA Methodology), WCAP16996P-A, Revision 1, dated November 2016 (ML16343A238).
- 3. Westinghouse Performance Analysis and Design Model (PAD5), WCAP17642P-A, Revision 1, dated November 2017 (ML17335A334).
- 4. U.S. Nuclear Regulatory Commission 10 CFR 50.46 Annual Notification and Reporting for 2017, LTR-NRC1830, dated July 18, 2018 (ML19288A174).
- 5. U.S. Nuclear Regulatory Commission 10 CFR 50.46 Annual Notification and Reporting for 2018, LTR-NRC-19-6, dated February 7, 2019 (ML19042A378).
- 6. U.S. Nuclear Regulatory Commission 10 CFR 50.46 Annual Notification and Reporting for 2022, LTR-NRC-23-5, dated March 10, 2023 (ML23072A071).