ML23164A223

Response to Request for Confirmation of Information Regarding Review of the License Renewal Application - Set 1

ML23164A223
Person / Time
Site:	Comanche Peak
Issue date:	06/13/2023
From:	John Lloyd Luminant, Vistra Operations Company
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
T 254.897.5337, CP-202300248, TXX-23035
Download: ML23164A223 (1)

Text

Comanche Peak Jay Lloyd Nuclear Power Plant Senior Director, Engineering (Vistra Operations

& Regulatory Affairs Company LLC)

P.O. Box 1002 6322 North FM 56 Glen Rose, TX 76043 T 254.897.5337 CP-202300248 TXX-23035 June 13, 2023 U. S. Nuclear Regulatory Commission Ref 10 CFR 54 ATTN: Document Control Desk Washington, DC 20555-0001

SUBJECT:

COMANCHE PEAK NUCLEAR POWER PLANT, UNITS 1 AND 2 DOCKET NUMBERS 50-445 AND 50-446 FACILITY OPERATING LICENSE NUMBERS NPF-87 and NPF-89 RESPONSE TO REQUEST FOR CONFIRMATION OF INFORMATION REGARDING REVIEW OF THE LICENSE RENEWAL APPLICATION - SET 1

REFERENCES:

1. Letter TXX-22077, from Steven K. Sewell to the NRC, submitting Comanche Peak Nuclear Power Plant License Renewal Application, October 3, 2022 (ADAMS Accession No. ML22276A082)

2. Letter TXX-23012, from Jay Lloyd to the NRC, submitting Comanche Peak Nuclear Power Plant License Renewal Application Revision 0, Supplement 1, April 6, 2023 (ADAMS Accession No. ML23096A302)

3. Letter TXX-23022, from Jay Lloyd to the NRC, submitting Comanche Peak Nuclear Power Plant License Renewal Application Revision 0, Supplement 2, April 24, 2023 (ADAMS Accession No. ML23114A377)

4. Electronic Communications, from M. Yoo (NRC) to K. Peters (Vistra), "Comanche Peak LRA

- Request for Confirmation of Information - Set #1," May 23, 2023 (ADAMS Accession Nos.

ML23143A137 and ML23143A138)

Dear Sir or Madam:

In Reference 1, as supplemented by References 2 and 3, Vistra Operations Company LLC (Vistra OpCo) submitted a license renewal application (LRA) for the Facility Operating Licenses for Comanche Peak Nuclear Power Plant (CPNPP) Units 1 and 2. The NRC issued Requests for Confirmation (RCIs) to Vistra OpCo via Reference 4. Vistra OpCo hereby submits responses to these RCIs in the attachments to this letter.

For ease of reference, the index of attachments topics is provided on page 3 of this letter.

Should you have any questions, please contact Todd Evans at (254) 897-8987 or Todd.Evans@luminant.com.

TXX-23035 Page 2 of 3 I state under penalty of perjury that the foregoing is true and correct.

Executed on June 13, 2023 Sincerely, Jay Lloyd c: (email) w / o Attachments Mahesh Chawla, NRR, DORL [Mahesh.Chawla@mc.gov]

David Nani, RGN IV, CPNPP [David.Nani@mc.gov]

Victor Dricks, RGN IV /OPA [Victor.Dricks@mc.gov]

John Ellegood, RGN IV, CPNPP [John.Ellegood@mc.gov]

Dennis Galvin, NRR [Dennis.Galvin@mc.gov]

Lauren Gibson, NRR/DNRL [Lauren.Gibson.me.gov]

Jessica Hammock, NRR, DNRL Uessica.Hammock@mc.gov]

Jim Melfi, RGN IV [Jim.Melfi@mc.gov]

Robert Lewis, RGN IV [Robert.Lewis@mc.gov]

Greg Pick RGN IV [Greg.Pick@mc.gov]

David Proulx, NRR/RGN IV [David.Proulx@mc.gov]

Mark Yoo, NRR/DNRL [Mark.Yoo@mc.gov]

Chris Smith, RGN IV [Chris.Smith@mc.gov]

Theodore Smith, NMSS/REFS [Theodore.Smith@mc.gov]

Tam Tran, NMSS/REFS [Tam.Tran@mc.gov]

Nick Taylor, RGN IV [Nick.Taylor@mc.gov]

Greg Werner, RGN IV [Greg.Werner@mc.gov]

TXX-23035 Page 3 of 3 Attachments Index Attachment RCI Number CPNPP LRA Confirmation of Information Topics No.

A RCI 4.7.3-1 Reactor Coolant Pump Flywheel Fatigue Crack Growth Analysis B RCI B.2.3.20-1 Buried and Underground Piping and Tanks C RCI B.2.3.31-1 ASME Section XI, Subsection IWF D RCI B.2.3.31-2 ASME Section XI, Subsection IWF

Comanche Peak Nuclear Power Plant Units 1 and 2 Dockets 50-445 and 50-446 Luminant Response to NRC RCI No. 4.7.3-1 TXX-23035 and CP-202300248 Attachment A Page 1 of 1 LRA Section: 4.7.3-1, Reactor Coolant Pump Flywheel Fatigue Crack Growth Analysis NRC RCI No: RCI 4.7.3-1 Based on the review of the applicants TLAA described in LRA Section 4.7.3, Reactor Coolant Pump Flywheel Fatigue Crack Growth Analysis, and the audit review of the associated documents (e.g., technical specifications), the staff needs confirmation that the analysis assumptions supporting the 20-year inspection interval for the flywheels bounds the operating conditions of the actual flywheels.

Confirm that the 6000 start/stop cycles assumed in the technical basis for the flywheel fatigue crack growth analysis bounds the actual start/stop cycles for the flywheels at the Comanche Peak nuclear power plant.

Luminant Response:

Considering the 60-year projected cycles for heatup/cooldown transient in the Comanche Peak Units 1 and 2 License Renewal Application [Reference 1], Table 4.3.1-2, the analyzed 6000 cycles would be equivalent to approximately 70 reactor coolant pump (RCP) start/stops per heatup/cooldown. Typical RCP start/stop is 10 cycles per heatup/cooldown. Additionally, Stretch Power Uprate (SPU) license report, WCAP-16840-NP [Reference 2] conservatively considered 3000 RCP start/stop cycles for 40 years. Scaling up this conservative assumption would be 4500 cycles for 60 years, which is less than the 6000 start/stop cycles evaluated in PWROG-17011-NP-A [Reference 3].

References:

1. Luminant License Renewal Application, Comanche Peak Nuclear Power Plant, Units 1 and 2 Docket Numbers 50-445 and 50-446 Facility Operating License Numbers NPF-87 and NPF-89 License Renewal Application, October 2022. (ADAMS Accession No. ML22276A082)

2. Westinghouse Report, WCAP-16840-NP, Rev. 0, Comanche Peak Nuclear Power Plant Stretch Power Uprate Licensing Report, August 2007. (ADAMS Accession No. ML072490310)

3. PWROG Report PWROG-17011-NP-A, Revision 2, Update for Subsequent License Renewal: WCAP-14535A, Topical Report on Reactor Coolant Pump Flywheel Inspection Elimination and WCAP-15666-A, Extension of Reactor Coolant Pump Motor Flywheel Examination, October 2019. (ADAMS Accession No. ML19318D194)

Associated LRA Revisions:

No LRA changes have been identified as a result of this response.

Comanche Peak Nuclear Power Plant Units 1 and 2 Dockets 50-445 and 50-446 Luminant Response to NRC RCI No. B.2.3.20-1 TXX-23035 and CP-202300248 Attachment B Page 1 of 1 LRA Section: B.2.3.27, Buried and Underground Piping and Tanks NRC RCI No: RCI B.2.3.20-1 As amended by letter dated April 24, 2023 (ML23114A377), LRA Section B.2.3.27, Buried and Underground Piping and Tanks, states [w]hen visual inspections of coating reveals evidence of coating damage, selective leaching inspections will also be performed in accordance with the Selective Leaching Program. In addition, a portion [emphasis added by staff] of inspections will be performed on buried piping/components that are susceptible to selective leaching.

Buried components within the scope of the Selective Leaching program include the following: (a) gray cast iron valve bodies and fire hydrants; and (b) cement-lined ductile iron piping. The use of the term a portion (italicized by the staff in the above paragraph) lacks specificity with respect to the extent of inspections for buried components susceptible to selective leaching. Confirm that, as discussed in the audit, a portion is consistent with one sample as defined in the GALL Report. Specifically, confirm that at a minimum, the following one-time inspections will be performed within the five (5) year period prior to entering the period of extended operation:

The external surface of one buried gray cast iron valve body or one buried gray cast iron fire hydrant.

The external surfaces of a 10-foot section of buried cement-lined ductile iron piping.

Luminant Response:

At a minimum, the following one-time inspections will be performed within the five (5) year period prior to entering the period of extended operation:

The external surface of one buried gray cast iron valve body or one buried gray cast iron fire hydrant.

The external surfaces of a 10-foot section of buried cement-lined ductile iron piping.

References:

None.

Associated LRA Revisions:

No LRA changes have been identified as a result of this response.

Comanche Peak Nuclear Power Plant Units 1 and 2 Dockets 50-445 and 50-446 Luminant Response to NRC RCI No. B.2.3.31-1 TXX-23035 and CP-202300248 Attachment C Page 1 of 2 LRA Section: B.2.3.31, ASME Section XI, Subsection IWF NRC RCI No: RCI B.2.3.31-1 10 CFR 54.21(a)(3) requires demonstration that the effects of aging will be adequately managed for structures and components within the scope of license renewal. GALL-LR Report, Revision 2, AMP XI.S3, ASME Section XI, Subsection IWF, Operating Experience program element states that [d]egradation of threaded bolting and fasteners has occurred from boric acid corrosion, SCC, and fatigue loading (NRC IE Bulletin 82-02, NRC Generic Letter 91-17). GALL-LR Revision 2, AMP XI.M10, Boric Acid Corrosion, Corrective Actions, program element states that [b]orated water leakage and areas of resulting boric acid corrosion are evaluated and corrected in accordance with the applicable provisions of NRC GL 88-05 and the corrective action program. Any detected boric acid crystal buildup or deposits should be cleaned.

During the audit, the NRC staff held discussion with the applicant regarding LRA AMP B.2.3.31, ASME Section XI, Subsection IWF, on the existence of boric acid and management of its aging effects on the reactor vessel (RV) support assemblies. During the audit, the applicant informed the NRC staff that:

Future IWF inspections of the RV supports will, based on the 1RF22 and 2RF19 inspections, assess the condition of the supports and enter the corrective action process and contact the owner of the Boric Acid Corrosion AMP IF additional boric acid accumulation is identified.

Confirm that future IWF inspections of the RV support assemblies (including bolting) will, based on the 1RF22 and 2RF19 inspections, assess the condition of the supports, enter any deficient conditions into the corrective action process, and IF additional boric acid accumulation is identified, ensure the owner of the Boric Acid Corrosion AMP will perform an evaluation, corrective actions, and cleaning consistent with GALL-LR Report, Revision 2, so that an acceptable level of safety is maintained during the period of extended operation.

Luminant Response:

Inspections of ASME Class 1 component supports (including bolting), such as for the RV support assemblies, through the CPNPP ASME Section XI, Subsection IWF (LRA Section B.2.3.31) AMP assess the conditions of the supports, with deficient conditions entered into the corrective action process and evaluations that include comparing examination results with previous results to determine their significance. For completeness, an issue report has been entered in the corrective action process for further evaluation of the evidence of old (inactive) traces of boric acid residue identified in 1RF22 and 2RF19 by the owner of the Boric Acid Corrosion AMP. As described in LRA Section B.2.3.4, The Boric Acid Corrosion AMP provides for screening of new and changed leakage conditions; corrosion evaluations that address the structural integrity of the affected component and any targets; and corrective actions to remedy, prevent, or mitigate the corrosion. Therefore, any additional (newly formed) boric acid accumulation is addressed in a manner consistent with the program

Comanche Peak Nuclear Power Plant Units 1 and 2 Dockets 50-445 and 50-446 Luminant Response to NRC RCI No. B.2.3.31-1 TXX-23035 and CP-202300248 Attachment C Page 2 of 2 described in NUREG-1801, Revision 2,Section XI.M10, so that an acceptable level of safety is maintained during the PEO.

References:

None.

Associated LRA Revisions:

No LRA changes have been identified as a result of this response.

Comanche Peak Nuclear Power Plant Units 1 and 2 Dockets 50-445 and 50-446 Luminant Response to NRC RCI No. B.2.3.31-2 TXX-23035 and CP-202300248 Attachment D Page 1 of 2 LRA Section: B.2.3.31, ASME Section XI, Subsection IWF NRC RCI No: RCI B.2.3.31-2 10 CFR 54.21(a)(3) requires demonstration that the effects of aging will be adequately managed for structures and components within the scope of license renewal. Appendix Quality Assurance for Aging Management Programs, to GALL-LR Report, Revision 2, states that [t]he license renewal applicant must demonstrate that the effects of aging on structures and components (SC) subject to an aging management review (AMR) will be managed in a manner that is consistent with the CLB of the facility for the period of extended operation [] subject to the quality assurance (QA) requirements of Appendix B to 10 CFR Part 50.

Exception to LRA AMP B.2.3.31, ASME Section XI, Subsection IWF, Scope of Program program element states that [t]he ISI Program Plan does not include the requirements for the examination of ASME [] Class MC component supports. It also states that these are inspected for effects of aging by the ASME Section XI, Subsection IWE (LRA AMP B.2.3.29), and other supports and attachments by Inspection of Overhead Heavy Load and Light Load (Related to Refueling) Handling Systems (LRA AMP B.2.3.13), and Structures Monitoring (LRA AMP B.2.3.34) AMPs as applicable.

Confirm that the effects of aging for the supports and attachments excepted from ASME Section XI, Subsection IWF, are managed in a manner consistent with the CLB of the facility [CPNPPP],the QA requirements of Appendix B and by the ASME Section XI, Subsection IWE (LRA AMP B.2.3.29) and by the Inspection of Overhead Heavy Load and Light Load (Related to Refueling) Handling Systems (LRA AMP B.2.3.13) and by the Structures Monitoring (LRA AMP B.2.3.34) AMPs for the period of extended operation as applicable.

Luminant Response:

The effects of aging for Class MC component supports (which are not examined as part of the CPNPP ASME Section XI, Subsection IWF AMP) are managed by the ASME Section XI, Subsection IWE (LRA AMP B.2.3.29) AMP in a manner consistent with the CLB of CPNPP for the PEO. Likewise, other supports and attachments are managed by the Inspection of Overhead Heavy Load and Light Load (Related to Refueling) Handling Systems (LRA AMP B.2.3.13) and the Structures Monitoring (LRA AMP B.2.3.34) AMPs in a manner consistent with the CLB of CPNPP for the PEO as applicable. The CPNPP QA Program (described in LRA Section B.1.3) implements the requirements of 10 CFR Part 50, Appendix B, for corrective actions, confirmation process, and administrative controls elements of all CPNPP AMPs for LR.

References:

None.

Comanche Peak Nuclear Power Plant Units 1 and 2 Dockets 50-445 and 50-446 Luminant Response to NRC RCI No. B.2.3.31-2 TXX-23035 and CP-202300248 Attachment D Page 2 of 2 Associated LRA Revisions:

No LRA changes have been identified as a result of this response.