ML23143A137

LRA - Request for Confirmation of Information - Set 1

ML23143A137
Person / Time
Site:	Comanche Peak
Issue date:	05/23/2023
From:	Mark Yoo NRC/NRR/DNRL/NLRP
To:	Peters K Vistra Operations Company
References
Download: ML23143A137 (1)

Text

REQUEST FOR CONFIRMATION OF INFORMATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION COMANCHE PEAK UNITS 1 & 2 LICENSE RENEWAL APPLICATION REVIEW VISTRA OPERATIONS COMPANY LLC COMANCHE PEAK, UNITS 1, 2 DOCKET NO. 05000445, 05000446 Set #1 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.

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.

RCI B.2.3.31-1

Background:

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.

RCI B.2.3.31-2

Background:

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.