ML24281A149

Breakout Questions Aging Management Audit

ML24281A149
Person / Time
Site:	Diablo Canyon
Issue date:	02/12/2024
From:	Harris B NRC/NRR/DNRL/NLRP
To:
References
Download: ML24281A149 (181)

Text

BREAKOUT QUESTIONS Aging Management Audit Diablo Canyon Nuclear Power Plant, Units 1 and 2 License Renewal Application February 12, 2024 - August 20, 2024

Diablo Canyon Nuclear Power Plant License Renewal Application (LRA) Breakout Audit Questions LRA Section 2.3.3.12, Fire Protection System Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 1

Section 2.3.3.12 2.3-66 Table 2.3.3.12 of the LRA does not include the following fire protection components in the scope of license renewal and subject to an aging management review (AMR):

Passive components in very early warning fire detection system (VEWFDS) installed in cable spreading room and solid-state protection system room (for both Units 1 and 2).

Sprinklers Sight glass and body Odorizer assembly Filter housing Stainer housing and element Orifice Muffler Passive components in diesel driven fire pump engine, heat exchanger channel, shell, tube, and jacket water.

Verify whether the listed system and components are within the scope of LRA in accordance with 10 CFR 54.4(a) and whether they are subject to an AMR in accordance with 10 CFR 54.21(a)(1).

If the listed components are not within the scope of license renewal and are not subject to an AMR, the staff requests that the applicant justify the exclusion.

2 Section 2.3.3.13 LR-DCPP-18-106718-03 This boundary drawing shows the following fire protection systems/components as not within the scope of license renewal (i.e., not colored in green):

Fire pump Fire water tank Verify whether the fire protection systems/components listed are within the scope of license renewal in accordance with 10 CFR 54.4(a) and whether they are subject to an AMR in accordance with 10 CFR 54.21(a)(1). If they are not within the scope of license renewal and are not subject to an AMR, the staff requests that the applicant justify the exclusion.

Diablo Canyon LRA: Breakout Questions LRA Section B.2.3.5, Cracking of Nickel-Alloy Components and Loss of Material Due to Boric Acid-Induced Corrosion in Reactor Coolant Pressure Boundary Components Question Number LRA/SLRA Section LRA/SLRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 1

LRA Section B.2.3.5 The applicant identified several of the Diablo Canyons ASME Code Class 1 dissimilar metal (DM) butt welds were mitigated by the full structural weld overlay (FSWOL) in 2008. These FSWOL welds are required to be inspected in accordance with ASME Code N-770-5, Alternative Examination Requirements and Acceptance Standards for Class 1 PWR Piping and Vessel Nozzle Butt Welds Fabricated With UNS N06082 or UNS W86182 Weld Filler Material With or Without Application of Listed Mitigation Activities,Section XI, as mandated by 10 CFR 50.55a(g)(6)(ii)(F), Augmented ISI requirements:

Examination requirements for Class 1 piping and nozzle dissimilar metal butt welds.

Note 10 of ASME Code N-770-5 states, in part, Those welds not included in the 25 percent sample shall be examined prior to the end of the mitigation evaluation period if the plant is to be operated beyond that time.

In addition, Electric Power Research Institute (EPRI) Report 1021014, Materials Reliability Program: Technical Basis for Preemptive Weld Overlays for Alloy 82/182 Butt Welds in Pressurized Water Reactors (PWRs) (MRP-169) Revision 1-A, dated 2010, states, in part, that, Cack growth analysis is then conducted on a cycle-by-cycle basis for a period equal to standard ASME Section XI inspection interval (ten years) or to end of life, including license renewal period where applicable.

a. Confirm that the Note 10 requirement has been or will be met for the period of the extended operation.

b. In the portal, provide the 2008 flaw evaluations, or any subsequent evaluations, showing crack growth to verify mitigation effectiveness in accordance with Note 10.

This evaluation should be until the end of life including the period of extended operation or provide the methodology to otherwise meet the Note 10 evaluation requirements.

2 LRA Section B.2.3.5 Due to industry operating experience (OE), Electric Power Research Institute (EPRI) Technical Report 3002012244, Revision 3, Nondestructive Evaluation: Guideline for Conducting Ultrasonic Examinations of Dissimilar Metal Welds, dated February 2018, provides enhanced guidance and Nuclear Energy Institute (NEI) 03-08, Guideline for the Management of Materials Issues, requirements and recommendations for the examinations of DM welds.

Confirm whether and when the applicant has reviewed this information and implemented any applicable guidance from it in this AMP. If applicable guidance has not been implemented, confirm when the applicant is planning to implement the guidance.

3 LRA Section B.2.3.5 NRC Regulator Issuance Summary (RIS) 2015-10, Applicability of ASME Code Case N-770-1 as Conditioned in 10 CFR 50.55a, Codes and Standards, to Branch Connection Butt Welds, issued on July 16, 2015, informs nuclear utilities about reactor coolant system (RCS) Alloy 82/182 branch connection DM nozzle welds that may be of a butt weld configuration, and therefore require inspection under 10 CFR 50.55a(g)(6)(ii)(F), Augmented ISI requirements: Examination requirements for Class 1 piping and nozzle dissimilar-metal butt welds.

Confirm whether and when the applicant has reviewed NRC RIS 2015-10 for applicability to their Alloy 600 management plan to ensure all applicable butt welds are being inspected as required by the NRC regulations.

4 LRA Section B.2.3.5 Due to lessons learned and industry OE, EPRI Report 3002017288, Materials Reliability Program: Guideline for Nondestructive Examination of Reactor Vessel Upper Head Penetrations, Revision 1 (MRP-384), dated 2019 as required under Nuclear Energy Institute (NEI) 03-08 implementation criteria, provides guidance for planning and executing reactor vessel upper head (RVUH) penetration examinations.

Confirm whether and when the applicant has reviewed this information and implemented any applicable guidance from it in this AMP. If applicable guidance has not been implemented, confirm when the applicant is planning to implement the guidance.

5 LRA Section B.2.3.5 Due to industry OE, EPRI Report 3002000091, Nondestructive Evaluation: Guideline for Conducting Ultrasonic Examinations of Dissimilar Metal Welds, Revision 1, dated 2013 and EPRI Reports 3002000041, Nondestructive Evaluation Improvement Focus Group Extent of Condition Actions in Response to North Anna Dissimilar Metal Weld Operating Experience, Revision 1, dated 2013 as required under Nuclear Energy Institute (NEI) 03-08 implementation criteria, provides necessary guidance for the improvement of DM welds examinations.

Confirm whether and when the applicant has reviewed this information and implemented any applicable guidance from it in this AMP. If applicable guidance has not been implemented, confirm when the applicant is planning to implement the guidance.

Diablo Canyon LRA: Breakout Questions LRA Section B.2.3.6, Thermal Aging Embrittlement of Cast Austenitic Stainless Steel (CASS)

Question Number LRA/SLRA Section LRA/SLRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 1

LRA Section B.2.3.6 The applicant identified the reactor coolant loop elbow fittings fabricated with CASS are in-scope components that are determined to be susceptible to thermal embrittlement.

In Item No. 8 of Table A-3 of LRA, the applicant committed to implement the new Thermal Aging Embrittlement of Cast Austenitic Stainless Steel program prior to November 2, 2024.

In its basis document posted in the Portal, the applicant stated, in part, that, it will either use a qualified ultrasonic testing (UT) method for enhanced volumetric examination if one become available or perform a component-specific flaw tolerance evaluation method.

a. Provide results of the inspections performed if the applicant has chosen the GALL recommended inspection method (i.e.,

enhanced visual examination or qualified UT).

b. Provide Diablo component-specific flaw tolerance evaluation if the applicant has chosen the GALL recommended evaluation method.

Diablo Canyon LRA: Breakout Questions Cracking due to Stress Corrosion Cracking Question Number LRA/SLRA Section LRA/SLRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 1

Section 3 Table 3.2-1 Item 3.2-1, 021 The applicant claimed that Generic Aging Lessons Learned (GALL) Report item 3.2-1, 021 is not applicable because the Diablo Canyon safety injection (SI) accumulators are maintained at containment ambient conditions (<140 °F). The staff is unable to verify the applicants claim.

According to Diablo Canyon Updated Final Safety Analysis Report, the accumulators operating temperature are between 70 °F to 150 °F.

According to 10 CFR 54.21 and GALL Report, accumulators exposed to treated water (borated) >140 °F is within scope of license renewal and subject to aging management review.

Justify inconsistency and not scoping in Diablo Canyon SI accumulators.

Diablo Canyon Power Plant LRA: Breakout Questions LRA Section B.2.2.1, Fatigue Monitoring Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 1

B.2.2.1 B.2-5 LRA Section B.2.2.1 addresses the Fatigue Monitoring AMP. The LRA section identifies four enhancements to the AMP.

LRA Section A.4 and Table A-3 also identify these enhancements as license renewal Commitment Number 1, Items (a) through (d). LRA Table A-3 indicates that these enhancements are planned to be implemented by November 2, 2024.

Considering the staffs review of the LRA in 2024 and the implementation schedule for the enhancements by November 2, 2024, the staff needs clarification on whether these enhancements have been implemented or there is a need to revise the implementation schedule.

1. Clarify whether the enhancements of the Fatigue Monitoring AMP have been implemented. If so, discuss whether the enhancements have been implemented as described in LRA Section B.2.2,1 and the implementation results (e.g., the identification of the additional limiting locations for environmentally-assisted fatigue other than the NUREG/CR-6260 locations per Enhancement 1).

If not, discuss whether there is a need to revise the implementation schedule for the enhancements that is listed in LRA Table A.4.

2 B.2.2.1 B.2-5 LRA Section B.2.2.1 addresses the Fatigue Monitoring AMP. Enhancement 1 of the Fatigue Monitoring AMP indicates that the AMP will be modified to include additional analyses and critical thermal and pressure transients for components that have been identified to have a fatigue TLAA, which are not covered by the current Fatigue Monitoring AMP.

1. Identify the fatigue TLAAs that are not currently covered by the Fatigue Monitoring AMP and are subject to Enhancement 1 of the program.

Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request However, LRA Section B.2.2.1 does not clearly describe the fatigue TLAAs that are not currently covered by the Fatigue Monitoring AMP.

3 B.2.2.1 B.2-5 Regulatory Issue Summary (RIS) 2008-30, Fatigue Analysis of Nuclear Power Plant Components, addresses a potential concern regarding fatigue usage calculations that considers components response to a step change in temperature. The RIS indicates that the concern involves an input in which only one value of stress is used for the evaluation of the actual plant transients.

The RIS indicates that the detailed stress analysis requires consideration of six stress components, as discussed in ASME Code,Section III, Subsection NB, Subarticle NB-3200.

In comparison, the operating experience section in LRA Section B.2.19 evaluates the operating experience related to the Fatigue Monitoring aging management program (AMP). However, the operating experience section does not include the evaluation regarding RIS 2008-30.

The staff needs to confirm that the Fatigue Monitoring AMP does not have the concern addressed in RIS 2008-30.

1. Discuss the operating experience evaluation regarding the concern addressed in RIS 2008-30 to confirm that the Fatigue Monitoring AMP does not have such a concern.

Diablo Canyon Power Plant LRA: Breakout Questions LRA Section 4.3.1, DCPP Transient Monitoring and Projections Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 1

4.3.1, Table 4.3-1 4.3-4 LRA Table 4.3-1 describes the design basis transients (also called design transients) and 60-year projected cycles for fatigue analyses.

LRA Section 4.3.1 indicates that, for each of the design transients, the applicant determined two cycle accumulation rates as follows: (1) a long-term rate of accumulation based on the entire history (i.e., the number of cycles since the start of the plant operation); and (2) a short-term rate of accumulation (i.e., the incremental cycles over the 10 years prior to baseline).

The LRA further explains that these two rates were combined using a weighted average, where the weighting factor for a long-term cycle accumulation rate is 1 and the weighting factor for the short-term accumulation rate is 3.

In addition, the LRA indicated that the future cycle count projections will be based on the actual accumulation history over each analysis period, adjusted on a component-specific basis by scaling factors to account for expected future operating conditions.

2. With respect to the short-term rate of cycle accumulation, clarify the meaning of the 10 year time period prior baseline. As part of the discussion, clarify the following: (1) whether the 10-year time period for the short-term accumulation rate is the most recent 10-year time period for the cycle data and (2) the specific time period for the short-term accumulation rate used in LRA Table 4.3-1 (e.g., from year X1 to year X2).

3. In addition, clarify the following items: (1) whether the scaling factors for the future cycle projections are the factors adjusting the weighting factors for the long-term and short-term cycle accumulation rates in the cycle projections and, if not, the meaning of the scaling factors; and (2) whether the scaling factors are determined in such a manner to ensure a close fit to the actual cycle data and, if not, how the scaling factors are determined.

4. In relation to LRA Table 4.3-1, describe the up-to-date accumulated cycles to support that the 60-year cycle projections are reasonable and consistent with the actual accumulation rates of the transient cycles.

Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request However, the staff needs clarification as to the following items: (1) the time period for which the short-term accumulation rate is calculated and the meaning of the incremental cycles over the 10 years prior to baseline; (2) the specific time period for the short-term accumulation rate used in LRA Table 4.3-1; (3) whether the scaling factors for the future cycle projections are the factors adjusting the weighting factors for the long-term and short-term accumulation rates in the cycle projections; and (4) whether the scaling factors are determined to ensure a close fit to the actual cycle data.

In addition, LRA Table 4.3-1 does not describe the up-to-date accumulated cycles to support that the 60-year cycle projections are reasonable and consistent with the actual accumulation rates of the transient cycles.

3 4.3.1 4.3-4 As discussed in Question 2 above, LRA Table 4.3-1 indicates that the 60-year projected cycles of the Units 1 and 2 loss of charging with prompt return to service (loop 4/3) transient, Unit 2 step load decrease of 10% of full power transient and Unit 2 "partial loss of flow (1 RCP) transient exceed the limiting analyzed cycles, respectively.

In comparison, LRA Section 4.3 and its subsections address the fatigue TLAAs

1. In relation to the fatigue TLAAs dispositioned per 10 CFR54.21(c)(1)(iii), clarify whether the 60-year projected cycles, which exceed the limiting analyzed cycles, increase the 60-year projected CUF and CUFen values of the components and piping above 1.0 in such a manner to affect the effectiveness of the Fatigue Monitoring AMP and the timeliness of corrective actions. If not, provide the technical basis of the applicants determination. If so, identify the affected components, their 60-year projected CUF and CUFen values and any additional activities needed

Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request for ASME Code Class A (Class 1) components and piping and the reactor vessel internal components. Some of the fatigue TLAAs are dispositioned in accordance with 10 CFR54.21(c)(1)(iii) using the Fatigue Monitoring AMP to ensure that the CUF and CUFen values do not exceed the fatigue design limit for the period of extended operation.

However, the LRA does not clearly discuss whether the 60-year projected cycles, which exceed the limiting (lowest) analyzed cycles for the fatigue analyses in LRA Section 4.3 and its subsections, can increase the 60-year projected CUF and CUFen values above 1.0 in such a manner to affect the effectiveness of the Fatigue Monitoring AMP and the timeliness of corrective actions of the AMP.

In addition, the staff needs similar clarification on whether the 60-year projected cycles, which exceed the limiting (lowest) analyzed cycles for the fatigue analyses in LRA Section 4.3 and its subsections, can affect the validity of the fatigue crack growth analyses discussed in LRA Sections 4.3.2.7, 4.3.2.10 and 4.3.2.12.

to enhance the fatigue monitoring and management for the affected components.

2. Clarify whether the 60-year projected transient cycles, which exceed the limiting analyzed cycles respectively, can invalidate the fatigue crack growth analyses discussed in LRA Sections 4.3.2.7, 4.3.2.10 and 4.3.2.12 in such a manner to affect the effectiveness of the Fatigue Monitoring AMP and the timeliness of corrective actions.

Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 4

4.3.1 4.3-5 4.3-6 LRA Table 4.3-1 describes the design basis transients and their 60-year cycle projections. LRA Table 4.3-1 does not describe the projected cycles of the steam generator tube leak tests transient of Units 1 and 2 for the period of extended operation.

Note (h) of LRA Table 4.3-1 indicates that this test transient has insignificant effect on the fatigue of primary side components. The note also explains that the test transient was incorporated into the DCPP design basis with the replacement steam generators, whose design is valid for the period of extended operation and, therefore, a cycle projection is not required.

However, the following items are not clear to the staff: (1) how the applicant determined that the tube leak tests transient has insignificant effect on the fatigue of the primary side components (e.g., confirmation that the stress amplitude associated with the transient is less than the fatigue endurance limit); (2) whether the design cycles of 800 for this transient listed in LRA Table 4.3-1 is significantly greater than the projected cycles throughout the period of extended operation; (3) additional clarification as to why fatigue monitoring is not needed (e.g., design cycles used in the fatigue

1. Clarify the following items: (1) how the applicant determined that the tube leak tests transient has insignificant effect on the fatigue of the primary side components (e.g., confirmation that the stress amplitude associated with the transient is less than the fatigue endurance limit); (2) whether the design cycles of 800 for this transient listed in LRA Table 4.3-1 is significantly greater than the projected cycles throughout the period of extended operation; (3) additional clarification as to why fatigue monitoring is not needed (e.g.,

design cycles used in the fatigue analyses significantly greater than the projected cycles through the period of extended operation); and (4) the fatigue analyses of the replace steam generators consider this test transient and, if not, the technical basis for why this transient is not considered.

Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request analyses significantly greater than the projected cycles through the period of extended operation); and (4) the fatigue analyses of the replace steam generators consider this test transient and, if not, the technical basis for why this transient is not considered.

Diablo Canyon Power Plant LRA: Breakout Questions LRA Section 4.3.2, ASME Section III, Class A Fatigue Analyses Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 1

4.3.2.1 4.3-7 LRA Section 4.3.2 addresses that the fatigue time-limited aging analyses (TLAAs) for ASME Code Section III, Class A components and piping. In terms of component and piping classification, the Class A component and piping in the 1965 edition through 1966 addenda of ASME Code Section III, which the applicant uses as a design code, correspond to the Class 1 component and piping in the 1971 or later edition of ASME Code,Section III.

Specifically, LRA Section 4.3.2.1 addresses the fatigue analysis for the reactor pressure vessel, nozzles, and studs. The LRA section explains that the cumulative usage factor (CUF) values were calculated for these components based on the 50-year design basis transient cycles (also called design transient cycles).

However, LRA Section 4.3.2.1 does not provide the limiting (highest) CUF values for these components. The staff needs the limiting CUF values for these components based on 50-year design cycles to confirm that the fatigue monitoring can adequately manage the

5. Describe the limiting CUF values and associated components for the reactor pressure vessel, nozzles and studs based on 50-year design cycles to confirm that the fatigue monitoring can adequately manage the aging effect of fatigue and can perform corrective actions in a timely manner before the actual CUF values exceed the fatigue design limit for these components.

Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request aging effect of fatigue and can perform corrective actions in a timely manner before the actual CUF values exceed the fatigue design limit (1.0).

2 4.3.2.2 4.3-7 LRA Section 4.3.2.2 addresses the fatigue TLAAs for the reactor vessel closure heads and associated components.

LRA Section 4.3.2.2 explains that the replacement reactor pressure vessel closure heads (RRVCHs), control rod drive mechanism (CRDM) pressure housings, core exit thermocouple nozzle assemblies (CETNAs) and thermocouple nozzles have been analyzed for a 50-year design life from the date of replacement (i.e., 2010 for Unit 1 and in 2009 for Unit 2). The LRA also explains that the 50-year design life will extend beyond the period of extended operation.

The applicant dispositioned the fatigue TLAA for the components in accordance with 10 CFR 54.21(c)(1)(i) (i.e., validation of the existing analyses for the period of extended operation).

However, LRA Section 4.3.2.2 does not describe the CUF values for these components for the 50-year design life.

1. Provide the CUF values for the reactor vessel closure heads and associated components to demonstrate that the CUF values for these replacement components based on the 50-year design life is less than the fatigue design limit (1.0) and that fatigue monitoring is not needed for these components based on sufficient margins associated with the CUF values against the fatigue design limit. As part of the discission, if the previous CUF calculations have been updated based on component modifications or updated cycle data, provide the latest CUF values of these components

Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 3

4.3.2.3 4.3-8 LRA Section 4.3.2.3 addresses the fatigue TLAA for the reactor coolant pump (RCP) pressure boundary components.

The LRA section indicates that some of the RCP components were evaluated for fatigue waiver in accordance with the fatigue waiver provisions in ASME Code,Section III.

LRA Section 4.3.2.3 explains that the transient cycles used in the fatigue waiver analysis are consistent with a subset of those identified in UFSAR Table 5.2-4 except for using a lower number of (1) plant heatup and cooldown transient cycles and (2) primary side leak test transient cycles.

LRA Section 4.3.2.3 also indicates that the Fatigue Monitoring AMP incorporates the lower, more conservative number of transients to determine an action limit and will monitor transient cycles used in the RCP fatigue analyses and waivers to ensure that corrective actions are taken if any of the actual cycles approach their analyzed numbers.

However, LRA Section 4.3.2.3 does not clearly address the following items related to the fatigue waiver analysis: (1) the RCP components evaluated in the fatigue waiver analysis; (2) the lower cycles of the plant heatup and cooldown

1. Describe the following: (1) the RCP components evaluated in the fatigue waiver analysis; (2) the cycles of the plant heatup and cooldown and primary side leak test transient cycles evaluated in the fatigue waiver in comparison with the 60-year projected cycles; and (3) whether the incorporation of the lower number of transient cycles as action limits into the fatigue monitoring is a program enhancement to the Fatigue Monitoring AMP or has been already completed and, if this is a program enhancement, the specific enhancement of the program.

2. Clarify whether the 60-year projected cycles, which exceed the corresponding limiting analyzed cycles in LRA Table 4.3-1, affect the validity of the fatigue waiver analysis so that there is a need to revise the fatigue waiver analysis. If not, provide the technical basis of the determination (e.g., non-applicability of these transients to the fatigue waiver analysis and bounding nature of the analyzed cycles for the fatigue waiver analysis). If so, discuss the results of the revised fatigue waiver analysis considering the 60-year projected cycles of these transients.

Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request and primary side leak test transient cycles evaluated in the fatigue waiver in comparison with the 60-year projected cycles; and (3) whether the incorporation of the lower number of transients into the fatigue monitoring is a program enhancement to the Fatigue Monitoring AMP or has been already completed.

In addition, LRA Table 4.3-1 indicates that the 60-year projected cycles of the Units 1 and 2 loss of charging with prompt return to service (loop 4 / 3) transient for loop 4 are 92 and 87 cycles, respectively. These projected cycles exceed the limiting analyzed cycle number of 25 (i.e., the minimum number of cycles analyzed in the applicants fatigue analyses in LRA Section 4.3), as described in LRA Table 4.3-1.

LRA Table 4.3-1 also indicates that, for the Unit 2 step load decrease of 10% of full power and Unit 2 partial loss of flow (1 RCP)" transients, the number of 60-year projected cycles is slightly larger than the limiting analyzed cycle number (by 2 cycles and 1 cycle, respectively).

Therefore, the staff needs clarification on whether these projected cycles, which exceed the limiting analyzed cycles in LRA Table 4.3-1, affect the validity of the fatigue waiver analysis so that there is a

Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request need to revise the fatigue waive analysis considering these cycles.

4 4.3.2.3 4.3-8 LRA Section 4.3.2.3 addresses the fatigue TLAA for the reactor coolant pump (RCP) pressure boundary components.

The LRA section indicates that some of the RCP components will be monitored by the Fatigue Monitoring AMP to ensure that the CUF values continue to meet the design limit (1.0). LRA Section 4.3.2.3 also indicates that a fatigue analysis has been completed, which demonstrate the CUF values of these components are less than the design limit (1.0).

However, LRA Section 4.3.2.3 does not describe the limiting CUF values of the RCP components. The staff needs this information to confirm that the fatigue monitoring can adequately manage the aging effect of fatigue and can perform corrective actions in a timely manner before the actual CUF values do not exceed the fatigue design limit (1.0) for these components.

1. Describe the limiting CUF values and associated components and transient time period (e.g., based on 50-year design cycles) for the RCP components to confirm the effectiveness of the fatigue monitoring and timeliness of corrective actions. As part of the discission, if the previous CUF calculations have been updated based on component modifications or updated cycle data, provide the latest CUF values of the limiting RCP components.

Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 5

4.3.2.4 4.3-9 LRA Section 4.3.2.4 describes the fatigue analyses for the pressurizer and pressurizer nozzle components. The LRA section also indicates that the fatigue analysis uses the 60-year projected cycles of the insurge-outsurge transients.

However, LRA Section 4.3.2.4 does not clearly describe how the fatigue analyses determine the 60-year projected cycles of the insurge-outsurge transients.

1. Describe how the fatigue analyses determine the 60-year projected cycles of the insurge-outsurge transients. As part of the response, discuss (1) the insurge-outsurge transients and their cycles evaluated in the analyses; (2) how the number of the insurge-outsurge transient cycles per unit time period (e.g., annual cycles) are determined; and (3) how the cycles are projected to estimate the 60-year cycles.

Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 6

4.3.2.4 4.3-9 LRA Section 4.3.2.4 addresses the fatigue TLAA for the pressurizer and pressurizer nozzle components.

LRA Section 4.3.2.4 explains that, using transient cycles consistent with UFSAR Table 5.2-4, all of the locations that were analyzed to incorporate the effects of insurge-outsurge transients demonstrated a CUF of less than 1.0, except for the Unit 1 heater penetration. The LRA also indicates that, to meet the Code requirement, the fatigue analysis for the Unit 1 heater penetration was performed using the 60-year projected number of transients and that the results for the Unit 1 pressurizer lower head heater penetration demonstrated that the CUF for 60 years is less than 1.0.

However, LRA Section 4.3.2.4 does not describe the revised CUF value of the Unit 1 lower head heater penetration and the CUF values of the other limiting components of the pressurizer and pressurizer nozzle.

1. Describe the CUF values of the Unit 1 pressurizer lower head heater penetration and other limiting pressurizer components to confirm that the CUF values are less than the fatigue design limit. If the previous CUF calculations have been updated based on component modifications or updated cycle data, provide the latest CUF values of the limiting pressurizer components.

7 4.3.2.4 4.3-9 LRA Section 4.3.2.4 addresses the fatigue TLAA for the pressurizer and pressurizer nozzle components.

Specifically, the LRA section discusses the fatigue analysis for the Unit 2

1. With respect to the CUF calculation for the Unit 2 pressurizer relief valve support bracket fillet weld, describe the following items: (1) the transients and their cycles evaluated in the CUF calculation due to the loads of the design specification; and (2) the

Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request pressurizer relief valve support bracket fillet weld.

LRA Section 4.3.2.4 indicates that the fatigue usage factor due to the loads required by the design specification is much less than 0.1 and maintaining the CUF below 1.0 is controlled by the permitted number of valve operating cycles. The applicant further explained that the limit for the valve operation cycles is above 9,000 operations, far in excess of the expected number of valve operations in the design life because (1) the 60 years of operation would require approximately 150 valve operations per year to reach 9,000 and (2) based on DCPP operating history, the Unit 2 pressurizer relief valves are operated less than 10 times per year (not exceeding 600 operation cycles for 60 years).

However, the LRA does not clearly discuss the following items: (1) the transients and their cycles evaluated in the CUF calculation due to the loads of the design specification; and (2) the 60-year projected cycles related to the loads of the design specification.

60-year projected cycles related to the loads of the design specification.

8 4.3.2.5 4.3-11 LRA Section 4.3.2.4 addresses the fatigue TLAAs for the replacement steam generator components and feedwater nozzle fatigue analyses.

1. Clarify the specific Code provisions, approaches and acceptance criteria of ASME Code Section III that are used for the qualification of the steam generator components by using fatigue tests. As

Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request The LRA also addresses the fatigue qualification tests for the following components: (1) primary manway drain hole; (2) primary manway studs; (3) 6-inch handhole studs; (4) 2.5-inch inspection port gasket seal bolts; and (5) diaphragm seal bolts.

The LRA explains that these components were qualified by fatigue tests in accordance with ASME Code Section III, for the number of cycles required by the design specification.

However, the LRA does not clearly describe specific Code provisions, approaches and acceptance criteria of ASME Code Section III that are used for the qualification by using fatigue tests. In addition, the LRA does not clearly describe the transients and cycles evaluated in the tests in comparison with the corresponding 60-year projected cycles to confirm that the evaluated cycles are bounding for the 60-year projected cycles.

The staff also needs the information on the periodic inspections for these components and the inspection results (e.g., absence of cracking in these components).

part of the discussion, provide the transients and their cycles evaluated in the fatigue tests in comparison with the corresponding 60-year projected cycles to confirm that the evaluated cycles are bounding for the 60-year projected cycles.

2. Describe the periodic inspections for the components subject to the fatigue qualification tests and the inspection results (e.g., absence of cracking in these components).

Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 9

4.3.2.7 4.3-9 LRA Section 4.3.2.7 addresses the fatigue TLAA for the reactor coolant pressure boundary piping.

LRA Section 4.3.2.7 indicates that full structural weld overlays (Alloy 52M) were completed on the Unit 1 suction pipe-to-elbow weld (WIB-228) in 2019 and on the Unit 2 suction pipe-to-elbow weld (WIB-245) in 2018 to provide long-term mitigation of future crack growth in the original stainless steel welds. The LRA section also explains that the CUF analysis and fatigue crack growth analysis were performed on these welds.

However, LRA Section 4.3.2.7 does not describe the CUF values of the repaired welds. In addition, the LRA section does not describe the following items regarding the fatigue crack growth analysis; (1) the initial crack size; (2) the final crack size and allowable crack size; (3) ASME Code provision or guidance used for the crack growth rate; and (4) ASME Code provisions used in the analysis (e.g.,

acceptance criteria for cracks).

1. Describe the CUF values of the repaired welds (WIB-228 and WIB-245 welds).

2. Provide the following information regarding the fatigue crack growth analysis: (1) initial crack size; (2) final crack size and allowable crack size; (3)

ASME Code provision or guidance used for the crack growth rate; and (4) ASME Code provisions used in the analysis (e.g., acceptance criteria for cracks).

Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 10 4.3.2.11 4.3-17 LRA Section 4.3.2.11 addresses the absence of a cumulative fatigue usage factor TLAA to determine high energy line break (HELB) locations.

With respect to the Westinghouse-scope piping (i.e., reactor coolant loop and connected piping), the LRA section explains that, since the Westinghouse generic design used the BTP (Branch Technical Position) MEB 3-1 fatigue criterion (ML052340555), the analysis of these generic break locations and types was a time-dependent fatigue analysis.

The LRA section also explains that however, the later application of a leak-before-break (LBB) analysis eliminated dynamic effects (jet and pipe whip loads) of the reactor coolant loop breaks from the design and licensing basis so that there is no longer a CUF TLAA to determine HELB locations for this piping.

With the other high energy line piping (also called DCPP design piping), LRA Section 4.3.2.11 indicates that the break locations were determined by BTP MEB 3-1 stress criteria and by other criteria independent of time.

In relation to the Westinghouse-scope piping (i.e., reactor coolant loop and connected piping), the LRA does not

1. Clarify whether the reactor coolant loop connected piping such as pressurizer surge line is subject to the HELB location postulation based on the CUF criterion (i.e., CUF exceeding 0.1). If not, provide the technical basis for the reactor coolant loop connected piping is not subject to the HELB location postulation based on the CUF criterion. If so, revise the LRA to identify the reactor coolant loop connected piping (e.g., pressurizer surge line) as a piping line subject to the TLAA based on the CUF criterion for HELB postulation.

2. Clarify whether the HELB location postulation for the non-Class 1 piping, which involves SA, is a basis for identifying the HELB analysis as a TLAA.

If not, provide the technical basis of the determination. If so, revise the LRA and related UFSAR supplement to identify the TLAA on HELB location postulation based on the cycle-dependent stress criterion involving SA.

Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request clearly discuss whether the reactor coolant loop connected piping such as pressurizer surge line, which is not part of the reactor coolant primary loop, is subject to the HELB location postulation based on the CUF criteria (i.e., CUF exceeding 0.1).

In comparison, UFSAR Section 3.6.1.6 also indicates that the postulation of HELB locations other than the reactor coolant line is in part, based on the allowable stress range for expansion stress (SA), consistent with BTP MEB 3-1 (ML052340555). SA may need to be adjusted by a stress range reduction factor that is determined by the number of thermal cycles, as addressed in the implicit fatigue analysis in LRA Section 4.3.5.

However, LRA Sections 4.3.2.11 and 4.3.5 and the associated UFSAR supplement do not clearly discuss whether the HELB location postulation for the non-Class 1 piping, which involves SA, is a basis for identifying the HELB analysis as a TLAA.

Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 11 4.3.2.7 4.3.2.10 4.3.2.12 A.3.2.1.6 A.3.2.1.8 A.3.2.1.9 A.3-5 A.3-6 LRA Section A.3.2.1.6 addresses the UFSAR supplement for the fatigue TLAA for the reactor coolant pressure boundary piping. The LRA section includes the fatigue monitoring for the residual heat removal (RHR) suction pipe-to-elbow structural weld overlays fatigue and fatigue crack growth analyses.

Similarly, LRA Section A.3.2.1.8 addresses the UFSAR supplement for the fatigue TLAA for the cast austenitic stainless steel reactor coolant pumps.

The LRA section includes the fatigue monitoring for the fatigue crack growth analysis for the pump casing outlet nozzle.

In addition, LRA Section A.3.2.1.9 addresses the UFSAR supplement for the fatigue crack growth analysis for the leak-before-break elimination of dynamic effects of primary loop piping failures.

However, these UFSAR supplements do not clearly describe whether the action limits for the fatigue monitoring and initiation of corrective actions will be established to ensure the validity of the fatigue and fatigue crack growth analyses.

1. With respect to the UFSAR supplements in LRA Sections A.3.2.1.6, A.3.2.1.8, A.3.2.1.9, clarify whether the action limits for the fatigue monitoring and initiation of corrective actions will be established to ensure the validity of the fatigue (CUF) and fatigue crack growth analyses. If so, discuss a potential need to revise the LRA sections for the UFSAR supplements accordingly. If not, provide justification for why such action limits are not necessary for the fatigue monitoring and initiation of corrective action.

Diablo Canyon Power Plant LRA: Breakout Questions LRA Section 4.3.3, Fatigue Analyses of the Reactor Pressure Vessel Internals Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 1

4.3.3 4.3-19 LRS Section 4.3.3 addresses the fatigue TLAA for the reactor vessel internal (RVI) components. The applicant dispositioned the TLAA in accordance with 10 CFR 54.21()(1)(iii) and proposed to use the Fatigue Monitoring AMP.

However, LRA Section 4.3.3 does not provide the limiting (highest) CUF values for these components to confirm the effectiveness of the Fatigue Monitoring AMP and timeliness of potential corrective actions.

Describe the limiting CUF values and associated components and time period (e.g., CUF based on 50-year design cycles) of the fatigue analysis for the RVI components to confirm the effectiveness of the fatigue monitoring and the timeliness of potential corrective actions.

2 4.3.3 4.3-19 LRS Section 4.3.3 addresses the fatigue TLAA for the reactor vessel internal (RVI) components.

The LRA section also indicates that the CUF of the baffle-former bolts was originally shown to be less than 1.0 based on evaluation of test data which demonstrated acceptable performance for a set of bolt displacements.

However, the LRA does not clearly describe the following items: (1) the Describe the following information related to the fatigue tests for the qualification of the baffle-former bolts: (1) the transients and their cycles evaluated in the fatigue tests; (2) the basis of the selection of the evaluated transients; (3) the 60-year projected cycles of the evaluated transients; and (4) the Code provisions or other standards used in the fatigue tests and related evaluation.

Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request transients and their cycles evaluated in the fatigue tests; (2) the basis of the selection of the evaluated transients; (3) the 60-year projected cycles of the evaluated transients; and (4) the Code provisions or other standards used in the fatigue tests and related evaluation.

Diablo Canyon Power Plant LRA: Breakout Questions LRA Section 4.3.4, Environmentally-Assisted Fatigue Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 1

4.3.4 4.3-24 LRA Section 4.3.4 addresses the environmentally-assisted fatigue (EAF) time-limited aging analysis (TLAA) for the reactor coolant pressure boundary components and piping.

LRA Section 4.3.4 indicates that the applicant commits to perform an additional review to determine whether there are more limiting locations than the NUREG/CR-6260 components for DCPP (LRA Commitment 1, item (a) as described in LRA Table A-3). The commitment is also identified as Enhancement 1 of the Fatigue Monitoring AMP.

However, the LRA section does not clearly discuss whether the screening CUFen values are refined after the screening evaluation in relation to Commitment 1, item (a) (i.e.,

determination of the more limiting locations than the NUREG/CR-6260 locations) and, if so, how the screening CUFen values are refined to reduce the conservatisms associated with the screening CUFen values.

6. Clarify the following in relation to LRA Commitment 1, item (a): (1) whether the screening CUFen values are refined after the screening evaluations and (2) If so, how the screening CUFen values are refined to reduce the conservatisms associated with the screening CUFen values.

7. Clarify whether the maximum service temperature used in the screening evaluation for EAF is the component-specific maximum service temperature or the generic maximum temperature bounding for all the components evaluated in the EAF analysis.

Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request LRA Section 4.3.4 also indicates that the maximum service temperature is used in the screening evaluation for EAF.

However, the LRA does not clearly discuss whether the maximum service temperature is the component-specific maximum service temperature or the generic maximum temperature bounding for all the components evaluated in the EAF analysis.

3 4.3.4 4.3-23 LRA Section 4.3.4 addresses the EAF TLAA for the reactor coolant pressure boundary components and piping. LRA Table 4.3.4-1 summarizes the CUFen values for the NUREG/CR-6260 locations applicable to DCPP Units 1 and 2 before the refinement of the CUFen values (e.g.,

refinement using the more realistic strain rates).

However, the LRA does not clearly discuss whether the calculations of the CUFen values in LRA Table 4.3.4-1 use the 60-year projected cycles or based on 50-year design cycles.

3. Clarify whether the calculations of the CUFen values in LRA Table 4.3.4-1 use the 60-year projected cycles or 50-year design cycles. If the CUFen calculations use the 50-year design cycles, clarify whether the 50-year design cycles are bounding for the 60-year projected cycles.

4 4.3.4 4.3-22 LRA Section 4.3.4 addresses the EAF TLAA for the reactor coolant pressure boundary components and piping.

1. Clarify whether the augmented inspections will be performed to manage the aging effect of EAF for the hot-leg surge nozzle safe-end. If so, discuss the following items: (1) the inspection frequency; (2) the technical basis of the inspection frequency

Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request LRA Section 4.3.4 and Table 4.3.4-2 indicate that the 60-year CUFen value of the hot-leg surge nozzle safe-end is greater than 1.0. The LRA also explains that the aging effect of EAF in this component will be managed by performing repair, replacement or augmented periodic inspections.

However, the LRA does not clearly discuss the frequency of the augmented periodic inspections and the associated technical basis (e.g., flaw tolerance analysis to determine an adequate inspection frequency).

(e.g., flaw tolerance analysis and its results); and (3) the previous inspections and their results.

Diablo Canyon Power Plant LRA: Breakout Questions LRA Section 4.3.5, Assumed Thermal Cycle Count for Allowable Secondary Stress Range Reduction Factor in ANSI B31.1 Piping Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 1

4.3.5 4.3-24 LRA Section 4.3.5 addresses the time-limited aging analysis (TLAA) on the allowable stresses for the ANSI B31.1 piping.

With respect to the piping lines not affected by the reactor coolant system (RCS) transients, the applicant indicated that the thermal cycles for the piping lines are not more than 3 cycles per week so that the total cycle number is less than 7000 cycles for 60 years of operation.

However, the staff needed clarification on whether the applicants discussion is intended to mean the weekly thermal cycles not more than 2 cycles per week rather than 3 cycles per week because 2 cycles per week result in approximately 6240 cycles for 60 years and the 3 cycles per week result in approximately 9360 cycles for 60 years exceeding the 7000 cycle threshold.

The staff also needs clarification on how the applicant determined the weekly cycles for the piping lines (e.g., by using piping design information, transient definitions, plant operation data, operation procedures, test requirements,

1. Clarify whether the applicants discussion regarding the total cycle estimation is intended to mean the weekly thermal cycles not more than 2 cycles per week instead of 3 cycles per week given that 2 cycles per week result in approximately 6240 cycles for 60 years and the 3 cycles per week result in approximately 9360 cycles for 60 years exceeding the 7000 cycle threshold.

2. Discuss how the applicant determined the weekly cycles for the piping lines (e.g., by using piping design information, transient definitions, plant operation data, operation procedures, test requirements, UFSAR information, and specific system-level knowledge).

3.

Clarify which specific piping lines are evaluated by using the weekly thermal cycles discussed in the background section.

Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request UFSAR information, and specific system-level knowledge).

In addition, the staff needs which specific piping lines are evaluated by using the weekly thermal cycles discussed above.

2 4.3.5 4.3-24 LRA Section 4.3.5 addresses the time-limited aging analysis (TLAA) on the allowable stresses for the ANSI B31.1 piping.

For the piping lines affected by the reactor coolant system (RCS) transients, the applicant explained that the total count of all design basis events (UFSAR Table 5.2-4) is estimated as 4665 cycles and that this is a reliable indication of the number of thermal cycles for most in-scope balance-of-plant support systems, as well as the chemical volume control system (CVCS) and emergency core cooling system (ECCS) piping more directly connected to the RCS.

However, the LRA does not clearly discuss the following items: (1) specific in-scope balance-of-plant support systems, for which the cycle estimation based on the design transient cycles is applicable; and (2) whether piping-

2. Clarify the following items: (1) specific in-scope balance-of-plant support systems, for which the cycle estimation based on the RCS design cycles is applicable; and (2) whether piping-specific transients need to be added to the cycle estimation that is based on the RCS design transients and, if not, the technical basis for why piping-specific transient cycles do not need to be considered in the total cycle estimation.

Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request specific transients need to be added to the cycle estimation that is based on the RCS design transients and, if not, the technical basis for why piping-specific transient cycles do not need to be considered in the total cycle estimation.

Diablo Canyon Power Plant LRA: Breakout Questions LRA Section B.2.3.21, One-Time Inspection of ASME Code Class 1 Small-Bore Piping Question Number LRA/SLRA Section LRA/SLRA Page Background / Issue (As applicable/needed)

Discussion Question /

Request 1

LRA Section B.2.3.21 LAR Section B.2.3.21 states that, A recent DCPP OE search was performed for LR which covered a date range of March 1994 through February 2023. The results of the DCPP OE search did not identify applicable examples of cracking in ASME Code Class 1 small-bore piping greater than or equal to NPS 1 inch and less than NPS 4 inches.

Please provide files which document the subject OE search results 2

LRA Section B.2.3.21 LRA Section B.2.3.21 states that, The one-time inspections will be completed prior to November 2, 2024 and August 26, 2025, for Units 1 and 2 respectively. It also provides inspection sample sizes as follows: Unit 1, 17 butt welds and 25 socket welds; Unit 2, 16 butt welds and 25 socket welds.

Confirm that the inspection schedule is still on track. If credits are taken for inspections performed within six years prior to entering the PEO, provide dates when the inspections were performed.

Diablo Canyon Power Plant LRA: Breakout Questions LRA Section 2.5 and TRP 53 Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 1

2.5.1.4 Appendix B, B.2.3.42 2.5-5 B.2-192 LRA section 2.5.1.4 states: The electrical interconnection between DCPP and the offsite transmission network and the offsite power recovery paths following an SBO are shown in Figure 2.5-1. These commodities are included in the DCPP Transmission Conductor and Connections, Switchyard Bus and Connections, and High-Voltage Insulators AMP (B.2.3.42).

LRA Figure 2.5-1 shows auxiliary transformers between the 4.16-kV buses and the main transformers.

The staff notes that the LRA Appendix B section B.2.3.42 does not include auxiliary transformers and cables between the 4.16-kV buses and the main transformers.

Clarify which component commodity group includes the cables and connections associated with the auxiliary transformers?

2 2.5 SRP-LR section 2.5.2.1.1 states that the portion of the offsite power system which is used to connect the plant to the offsite power source meeting the requirements under 10 CFR 54.4(a)(3) includes the circuit breakers that connect to the offsite system power transformers (startup transformers), the transformers themselves, the intervening overhead or underground circuits Are the control circuits associated with the components in the portion of the offsite power system used for restoration of SBO included in LR and subject to AMR? If not, please explain the basis for this decision.

between circuit breaker and transformer and transformer and onsite electrical distribution system, and the associated control circuits and structures.

LRA section 2.5.1.4, Switchyard Bus and Connections, Transmission Conductors and Connections, High-Voltage Electrical Insulators Commodity groups do not include the control circuits associated with the components in the portion of the offsite power system used for restoration of SBO.

3 2.5.2 2.5-9 Section 2.5.1.1 of the NRC staffs 2011 Safety Evaluation Report for DCPP previous LRA provides the list of commodity groups requiring AMR and their intended functions that includes:

-lightning rods (those mounted on the reactor containment building) protect the containment structure, and personnel and components within, from lightning strikes LRA Table 2.5-2 does not include lightning rods.

Also, DCPP UFSAR, Rev. 27, Chapter 3, Table 3.2-3 references grounding, lightning protection, and cathodic protection systems.

a-Explain why the lightning rods (those mounted on the reactor containment building) are not included in the electrical and I&C commodity groups subject to AMR.

b-Discuss why the lightning protection on main and auxiliary transformers are not included in the electrical and I&C commodity groups subject to AMR.

DCPP UFSAR, Rev. 20, Chapter 8 indicated that there are lightning arrestors on the phases of the main and auxiliary transformers.

LRA Table 2.5-2 does not include lightning arrestors/protection.

4 2.5.1.3 3.6.2.3 Table 3.6-1 2.5-3 3.6-6 GALL-LR identifies fatigue due to thermal cycling, electrical transients as aging effects for fuse holders.

LRA section 2.5.1.3 states that the fuse holders are not subject to AMR because they are not subject to applicable stressors, and do not experience aging mechanisms /

effects. LRA section 2.5.1.3 does not discuss the effect of fatigue due to thermal cycling, electrical transients on the fuse holders.

a-Discuss the aging effects due to thermal cycling and electrical transients on the fuse holders.

b-Describe the circuits /systems in which these fuse holders are installed and the environment (indoor and/or outdoor, cooling systems etc...) for the fuse holders.

5 2.5.1.4 2.5.2 3.6.2.3 Table 3.6-1 2.5-4 2.5-8 3.6-6 LRA section 2.5.1.4 identifies insulating portions of fuse holders as components in the Insulated Electrical Cables and Connections commodity. These insulated cables and connections that perform an intended function within the scope of LR but are not included in the DCPP Environmental Qualification of Electric Equipment AMP (B.2.2.2),

meet the criterion of 10 CFR 54.21(a)(1)(ii) and are subject to an AMR.

LRA Table 2.5-2 does not include fuse holders having insulating Clarify whether the insulating portions of fuse holders (outside of active equipment) are subject to AMR.

functions in the list of commodity groups subject to AMR.

Diablo Canyon LRA: Breakout Questions LRA Section: B.2.3.38; B.2.3.36 Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 1

B.2.3.38; 2.5.1.3 B.2-173; LRA Section 2.5.1.3 eliminates cable tie-wraps from the scope of license renewal, cable tie-wraps are not credited in the DCPP design basis and have no license renewal intended functions as defined in 10 CFR 54.4(a).

Therefore, cable tie-wraps are not within the scope of license renewal and therefore, are not subject to AMR.

Pull box BPZ44 contains safety-related cables for Auxiliary Saltwater Pump Cross-tie MOVs on DCPP Unit 2 and these cables are supported to the side of the pull box with tie-wraps and not by any support structure.

Applicant generated SAPN 51242057 to replace the missing cable supports at the earliest opportunity.

Provide a current copy of the SAPN 51242057 Provide the expected date of cable support replacement (i.e., from cable tie-wraps to an appropriate structural support), or if not known at this time, provide assurance that a suitable cable support will be installed prior to entering the period of extended operation for DCPP Unit 2.

2 B.2.3.36 B.2-166 B.2.3.36 describes an Adverse Local Environment (ALE) as a condition in a limited plant area that is significantly more severe than the plant design basis environment for the cable or connections insulation material that could increase the rate of aging of a component or have an adverse effect on operability.

The applicant informed the NRC of two different sections of direct current power SAPN 51205737 evaluated the oil on the cables from a limited inspection distance (below the cable tray). Did the inspection include a tactile inspection to check for softening/swelling?

What is the current condition of the cables in this area?

Have measurements been taken to track the condition of these cables? If so, provide the results of the last several tests.

cables that were covered in oil due to in leakage from an air intake.

The particular cables, while apparently oil resistant, are not expected to have long-term exposure to/coverage in oil (e.g., industry guidance does not endorse long-term exposure to oil on cables and exposure to oil is not identified as an aging effect/mechanism in LRA Tables 3.6-1 or 3.6.2-1).

The concern is with potential degradation of the cables over time due to long-term contact with oil.

Has a decision been made on the final corrective actions to prevent the oil mist from being entrained into the ventilation system or to prevent oil from dripping onto the cables? If so, provide the result of that decision.

3 B.2.3.38 B.2-175 Justification for Exception 1 for inspecting intake structure pull boxes relies on automatic pumping and alarm functions.

GALL-LR XI.E3, Inaccessible Power Cables Not Subject to 10 CFR 50.49 Environmental Qualification Requirements, states that The inspection should include direct observation that cables are not wetted or submerged, that cables/splices and cable support structures are intact, and that dewatering/drainage systems (i.e.,

sump pumps) and associated alarms operate properly.

Provide a full version of SAPN 51242056.

How are these local alarms/panel lights monitored so that the AMP credited scope of program, preventive actions, and corrective actions program elements can be achieved (i.e., prevent cables from being exposed to significant moisture (e.g., submerged) for long periods of time (i.e., more than a few days))?

Diablo Canyon LRA: Breakout Questions LRA Section B.2.3.7 AMP: PWR Vessel Internals Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 1

Table 3.1.2-1 3.1-82 Three of the four rows of Table 3.1.2-1 of the Diablo Canyon LRA identifying BMI:

flux thimble tube evaluations refer to NUREG-1801 (or SLR-ISG-2021 PWRVI) item numbers assigned to other components. Presumably, this is because the guidance only lists flux thimble tubes for the loss of material aging effect managed by the Flux Thimble Tube Inspection AMP and Diablo Canyon is managing the other aging effects by the PWR Vessel Internals AMP Item IV.B2.R-424 refers generically to reactor vessel internal components and item IV.B2.RP-345a refers to the core barrel flange which is inspected by VT per MRP-227-1A. Note 2 of Table 3.1.2-1 of the Diablo Canyon LRA states that flux thimble tubes are existing program components for Diablo Canyon. For change in dimension, loss of fracture toughness, and cracking, are the flux thimble tubes being inspected by VT or by ET?

2 Table 3.1.2-5 3.1-129 Two rows in Table 3.1.2-5 of the LRA list RV Bottom Mounted Instrument Guide Tubes as components with a Pressure Boundary function subject to the PWR Vessel Internals AMP. The item numbers identified are IV.B2.RP-292 and IV.B2.RP-293 which refer to the BMI column bodies in SLR-ISG-2021-01-PWRVI.

MRP-227-1A discusses instrument guide tubes which are generally applicable to CE plant designs and not Westinghouse designs.

Additionally, the PWR Vessel Internals AMP generally doesnt manage pressure boundary inspections. Clarify what component is being managed and by what inspection practices, with respect to the IV.B2.RP-292 and IV.B2.RP-293 line items in Table 3.1.2-5 of the LRA.

Diablo LRA: Breakout Questions LRA Section TLAA: 4.2.2 (PTS) and 4.2.3 (USE)

Question Number LRA Section SLRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 1

4.2.2 DCPP Unit 1 - LRA Table 4.2.2-1 identifies material property values for the following materials:

Upper Shell Long.Welds 1-442 A Upper Shell Long.Welds 1-442 B Upper Shell Long.Welds 1-442 C Foot note a indicates that the Chemistry values are reported in DCPP UFSAR.

The staff noted FSAR Table 5.2-21A identifies the initial RTNDT for this material - however, the Cu and Ni does not appear to be in the DCPP FSAR.

The staff noted that this information was provided by letter dated January 17, 1986 from DCPP to the NRC - see ML16342B173 and ML16341D574). However, it was not readily apparent if there was an NRC SE documenting this letter.

If the material property information for Upper Shell Long.Welds 1-442 A, B and C - is documented with the DCPP FSAR - Identify the specific section/page/reference Otherwise, provide CMTRs for these materials or other design documentation identifying the material properties of Cu % and Ni %.

2 4.2.2 LRA Table 4.2.2-2 identifies material property values for the following materials:

Lower Shell Long.Welds 3-201C The staff noted FSAR Table 5.2-21B identifies the initial RTNDT for Lower Shell Long.Welds 3-201A and Lower Shell Long.Welds 3-201B (two times)

Confirm that the second Lower Shell Long.Welds 3-201B is supposed to be Lower Shell Long.Welds 3-201C in the FSAR If not - provide the basis for the initial RTNDT for the Lower Shell Long.Welds 3-201C 3

4.2.2 DCPP Unit 2 - LRA Table 4.2.2-2 identifies material property values for the following materials:

If the material property information for Upper Shell Long.Welds 1-201 A, B and C - is documented with

Upper Shell Long.Welds 1-201 A Upper Shell Long.Welds 1-201 B Upper Shell Long.Welds 1-201 C Foot note a indicates that the Chemistry values are reported in DCPP UFSAR.

The staff noted FSAR Table 5.2-21B identifies the initial RTNDT for this material - however, the Cu and Ni does not appear to be in the DCPP FSAR.

The staff noted that this information was provided by letter dated January 17, 1986 from DCPP to the NRC - see ML16342B173 and ML16341D574). However, it was not readily apparent if there was an NRC SE documenting this letter.

The staff noted that Cu. % reported in the LRA and referenced letters are the same. In addition, the staff noted that the Ni % reported in the LRA and referenced letters are NOT the same (0.87 vs 0.85).

the DCPP FSAR - Identify the specific section/page/reference Otherwise, provide CMTRs for these materials or other design documentation identifying the material properties of Cu % and Ni %.

4 4.2.2 FSAR 5.2-21A provides information for Upper Shell to Intermediate Shell Circumferential Weld 8-442.

Specifically, the initial USE is annotated with footnote (g) - WCAP 10492, Analysis of Capsule T, Salem 2 Surveillance Program, March 1984.

Based on the footnote and review of all available capsule reports for Salem Unit 2 - it appears that there is a match for Weld Heat No. 13253 between the reactors pressure vessels (e.g., DCPP, Unit 2 and Salem, Unit 2).

Discuss whether the available surveillance data for Weld Heat No. 13253 from Salem, Unit 2 is applicable to DCPP, Unit 1 If yes - was this surveillance data taken into consideration when assessing RPV integrity (i.e.,

ART for PT limits and PTS) - Provide documentation of this evaluation/assessment.

If not - provide the basis that the surveillance data from Salem, Unit 2 for Weld Heat No. 13253 is not relevant.

50.61(c)(2) states, To verify that RTNDT for each vessel beltline material is a bounding value for the specific reactor vessel, licensees shall consider plant-specific information that could affect the level of embrittlement. This information includes but is not limited to the reactor vessel operating temperature and any related surveillance program5 results.

Foot note 5 clarifies that Surveillance program results means any data that demonstrates the embrittlement trends for the limiting beltline material, including but not limited to data from test reactors or from surveillance programs at other plants with or without surveillance program integrated per 10 CFR part 50, appendix H.

Section 5 and Appendix A of WCAP-17315-NP - provide assessments of sister-plant data from various other relevant plants with heat-to-heat match for certain RPV weld materials; however, Weld Heat No. 13253 does not appear to be addressed.

Discuss whether there is other relevant sister-plant data for other RPV materials at DCPP Units 1 and 2 that were not already addressed in the LRA and WCAP 17315-NP.

5 4.2.3 LRA Section 4.2.3. states that for DCPP Unit 2, the USE data from Unit 2 surveillance Capsule V were determined to be credible for determining the EOLE USE projections in accordance with RG 1.99, Revision 2.

USE values were projected to 54 EFPY of operation using RG 1.99 Position 1.2 because these results were more limiting than the Position 2.2 result.

Based on the information in LRA Table 4.2.3-2 for Unit 2, it appears that the of Clarify and explain the discrepancy between the statement in LRA Section 4.2.3 that is cited and the information in LRA Table 4.2.3-2.

RG 1.99, Position 2.2 is more limiting than Position 1.2 for particular RPV material.1

Diablo Canyon LRA: Breakout Questions LRA Section /TLAA: 4.1 Identification of TLAAs Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 1

4.1 4.8-1 Section 4.8 of the LRA states, in part, the following:

If PG&E chooses to use the ASME Code Case N-514 exemption during the PEO, the LTOP pressure lift setpoint must be established based on the use of updated P-T curves for the PEO. Furthermore, these updated P-T curves must be generated using the methodology in the version of the ASME Code,Section XI, Appendix G that was approved in the NRC safety evaluation dated May 3, 1999, which accepted the 12 EFPY and 16 EFPY curves because this was the methodology in effect at that time and was approved by the NRC when this exemption was granted.

Otherwise, PG&E may use the LTOP system pressure lift setpoint and enable temperature setpoint methodologies in ASME Section XI, as endorsed by 10 CFR 50.55a, for the DCPP PTLR, as the basis for establishing the LTOP system pressure lift and enable temperature setpoints during the PEO.

TS 5.6.6 states the following:

The analytical methods used to determine the RCS pressure and temperature and Provide discussion on why the previously approved exemption in the SE dated May 3, 1999, which includes the use of ASME Code Case N-514 to establish the LTOP system setpoints, is still in effect for the PEO, given that ASME Code Case N-514 has been annulled and incorporated in ASME Section XI.

Provide clarity on the use of ASME Code Case N-514 as a previously approved exemption rather than through DCPP Tech Specs (i.e., PTLR).

Clarify whether the applicant is indicating that it may use any edition of ASME Section XI that is endorsed by 10 CFR 50.55a for the DCPP PTLR for establishing the LTOP system pressure lift setpoint and enable temperature setpoint. If so, provide the basis that the applicant may deviate from the approved methodologies for P-T Limits and LTOP setpoints in TS 5.6.6 (i.e., WCAP 14040-NP-A and WCAP-15958).

LTOP limits shall be those previously reviewed and approved by the NRC, specifically those described in the following documents:

WCAP 14040-NP-A, Methodology Used to Develop Cold Overpressure Mitigating System Setpoints and RCS Heatup and Cooldown Limit Curves.

Chapter 6.0 of WCAP-15958, Analysis of Capsule V from Pacific Gas and Electric Company Diablo Canyon Unit 1 Reactor Vessel Radiation Surveillance Program.

DCPP PTLR (ML23298A107) Section 2.2.1 states, The LTOP lift setpoint and arming temperature are based on the methodology established in the Westinghouse WCAP - 14040 - NP - A, "Methodology Used to Develop Cold Overpressure Mitigating System Setpoints and RCS Heatup and Cooldown Limit Curves," Revision 2, January 1996.

RG 1.147, Revision 20, Table 3 indicates NRC Annulled Unconditionally Approved Section XI Code Cases and includes ASME Code Case N-514 (that has been incorporated into Section XI). The staff noted ASME Code Case N-514 was an annulled on 4/19/2002.

Diablo Canyon LRA: Breakout Questions LRA Section: B.2.3.10 and 3.1 Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 1

Table 3.1-1 Table 2.3.1-4 B.2.3.10 3.1-31 2.3-11 B.2-53 The Steam Generators AMP description states on LRA page B.2-53 that the tube-to-tubesheet welds are addressed by this AMP. In addition, the discussion for AMR item 3.1-1, 025 in LRA Table 3.1-1 states that cracking of the tube-to-tubesheet welds is managed by the Water Chemistry and Steam Generator AMPs.

These welds were inspected in the most recent (1R24) SG inspections at Diablo Canyon.

However, the tube-to-tubesheet welds are not listed as a steam generator component subject to aging management review in SLR Table 2.3.1-4, and it is not clear that they are included in LRA Table 3.1.2-4. In addition, these welds do not appear to be addressed explicitly in the implementing documents.

Consistency with the guidance and AMP description in LR-ISG-2016-01 includes visual inspection of the tube-to-tubesheet welds.

Please address the following:

a. Clarify the scoping and aging management plans for the SG tube-to-tubesheet welds.

b. Describe any changes needed in the SLR and implementing documents to make them consistent with the intended scoping and aging management plans.

2 N/A N/A The staff observed that the EPRI PWR Steam Generator Examination Guidelines are not mentioned or referenced in the Please discuss the differences between the Steam Generators AMP basis document and LR-ISG-2016-01 AMP description in terms of:

Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request AMP basis document (DCM No. T-43, AMP B.2.3.10 - Steam Generators).

The staff also observed that the scope of Section 4.4 (Detection of Aging Effects) of the AMP basis document is significantly less than the corresponding section of the AMP description in the GALL report (as modified by LR-ISG-2016-01).

Specifically, this section of the AMP basis document has no discussion of tube inspection, such as the Steam Generator Program in the technical specifications and the EPRI PWR Steam Generator Examination Guidelines.

The omission of the EPRI examination guidelines document is notable because it is a key part of the Steam Generator Program guidelines (NEI 97-06) and part of the basis for Elements 4 (Detection of Aging Effects) and 6 (Acceptance Criteria) in Section XI.M19 (Steam Generators) of the GALL report.

a. The omission of the EPRI PWR Steam Generator Examination Guidelines.

b. The reduced scope of the Detection of Aging Effects section in the AMP basis document.

3 N/A N/A DCPP Surveillance Test Procedure STP M-SGTI (Rev. 25) instructs in Section 9.3 that the following documents be reviewed, approved, and consistent with one another:

Degradation Assessment report Condition Monitoring and Operational Assessment report Please describe the guidance and requirements at DCPP for reviewing and approving:

Degradation Assessment reports Condition Monitoring and Operational Assessment reports Site Technique Validation reports Examination Technique Specification Sheets

Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request Site Technique Validation report Examination Technique Specification Sheets It is not clear if there are additional DCPP procedures that provide guidance on how to review these reports (e.g., scope of review, level of detail, acceptance criteria.)

If this guidance is in contained in written procedures, please identify them and make them available for audit

Diablo Canyon LRA: Breakout Questions LRA Sections: 3.5 and B.2.3.2 Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 1

N/A N/A In Table 5 of CAP A-2 Secondary Cycle Sampling Schedule, the sampling interval for Feedwater Copper and Total Iron is stated as weekly which appears to be a deviation from the EPRI Guidelines.

However, in attachment 2 of the same document it states that these parameters have continuous monitoring via integrated sampling which aligns with Table 5-6 of the EPRI Guidelines. Therefore, the sampling interval for feedwater total iron and copper is unclear to the staff.

Please clarify the sampling interval for feedwater total iron and copper.

If there are any deviations from the EPRI Guidelines, please explain the technical basis for these deviations.

2 B.2.3.2 B.2-15 In LRA Section B.2.3.2, the program description for the Water Chemistry program, states, The primary water chemistry program is consistent with the guidelines of EPRI Report 3002000505, "PWR Primary Water Chemistry Guidelines," Revision 7 and, The secondary water chemistry program is consistent with the guidelines of EPRI Report 3002010645, "PWR Secondary Water Chemistry Guidelines," Revision 8.

It also states that the program is consistent with the GALL report, NUREG-1801,Section XI.M2, Water Chemistry.

However,Section XI.M2 of the GALL report refers to revision 6 of the EPRI guidelines for primary water chemistry and revision 7 of the EPRI guidelines for secondary water chemistry. Therefore, for Please address the deviation between the water chemistry guidelines referenced in the LRA and the statement of consistency with NUREG-1801.

initial license renewal, the water chemistry guidelines referenced in the LRA represent an exception to the program described in the GALL report.

3 LRA Table 3.5.2-1 3.5-86 LRA Table 3.5.2-1 includes stainless steel Liner Refueling in a Submerged (Structural) (Ext) environment. The nature of the environment is unclear in the application because it is not defined in NRC Guidance, such as Table IX.D of the GALL report, Rev. 2.

Please clarify the nature of the submerged (Structural) (Ext) environment that is cited in this AMR item.

4 LRA Table 3.5.2-1 and LRA Table 3.5.1 3.5-67 and 3.5-86 In LRA Table 3.5.2-1, the AMR item that refers to the loss of material for stainless steel Liner Refueling in a Submerged (Structural) (Ext) environment cites Table 1 item 3.5.1-078. In LRA Table 3.5.1 item 3.5.1-078 identifies both cracking and loss of material as aging effects. In addition, the previous Diablo Canyon LRA identifies only cracking as an aging effect for this component. The basis for excluding cracking as an aging effect in the current LRA is unclear to the staff.

Please explain the exclusion of cracking as an aging effect needing to be managed for the stainless steel liner refueling exposed to a Submerged (Structural) (Ext) environment.

5 LRA Table 3.5.2-1 3.5-83 LRA Table 3.5.2-1 has an AMR item relating to the stainless steel Fuel Transfer Tube exposed to treated borated water. For that component, loss of material is the only aging effect identified for that environment. The staff is unclear as to why cracking was excluded as aging effect for this component in the treated borated water environment.

Please explain the exclusion of cracking as an aging effect needing to be managed for the stainless steel fuel transfer tube exposed to a treated borated water environment.

Diablo Canyon LRA: Breakout Questions LRA Section B.2.3.27, Internal Coatings/Linings for In-Scope Piping, Piping Components, Heat Exchangers, and Tanks Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 1

N/A N/A The staff reviewed DCM T-43, Appendix B, Section B.2.3.27 Internal Coatings/Linings on In-Scope Piping, Piping Components, Heat Exchangers, and Tanks, Revision 2, and noted that plant-specific operating experience included inspections of ASW piping revealed areas where paraliner holidays were observed. Subsequent inspections were performed to confirm that there are no degrading trends in the base ASW piping metal thickness.

The staff also noted that in its October 21, 2015 response to a previous request for additional information (RAI) B2.1.9-2 (see ADAMS ML15294A437), the applicant described the inspection procedure and inspection interval for auxiliary saltwater (ASW) System piping with plastic pipe-liner (paraliner).

The staff requests a discussion on the timing of the subsequent inspections of ASW piping discussed in DCM T-43, and how it was determined that there are no degrading trends.

The staff also requests either confirmation or clarification as to whether the inspections that were discussed in DCM T-43 were performed consistent with the previous inspections that were described in the applicants response to RAI B2.1.9-2 (see ADAMS ML15294A437).

2 B.2.3.27 B.2-130 LRA Section B.2.3.27 (Exception No. 1) states LR-ISG-2013-01 recommends that baseline coating/lining inspections occur in the 10-year period prior to the PEO.

DCPP will complete the baseline coating/lining inspections and/or external wall thickness measurements no later than December 1, 2028.

Due to the timing of the LRA, there will be overlap between the 1st inspection interval (2023-2028) and the subsequent inspection interval required by GALL XI.M42 to be performed during the PEO. The staff requests a discussion with respect to if inspections in one interval can be credited towards inspections in another interval.

Diablo Canyon LRA: Breakout Questions LRA Section: B.2.3.14 Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 1

3.3, Appendix B

3.3-56, 3.3-

304, B.2-71 Revision 2 of NUREG-1800 includes AMR item 3.3-1, 058 for managing loss of material of steel carbon dioxide fire suppression system piping, piping components, and piping elements exposed externally to indoor uncontrolled air by the Fire Protection program.

The discussion of AMR item 3.3-1, 058 in LRA Table 3.3-1 states, Consistent, with exception, with NUREG-1801.

Loss of material of steel carbon dioxide fire suppression system piping and piping components, as well as carbon dioxide tanks, exposed to plant indoor air is managed by the DCPP Fire Protection AMP (B.2.3.14),

which takes exception to NUREG-1801.

LRA Table 3.3.2-12 cites AMR item 3.3-1, 058 for managing loss of material of carbon steel piping, piping components, and carbon dioxide tanks exposed Please discuss whether the Fire Protection program or the External Surfaces Monitoring of Mechanical Components program manages the external surfaces of the steel carbon dioxide fire suppression system piping, piping components, tanks.

externally to plant indoor air by the Fire Protection program.

This seems to be in conflict with LRA Section B.2.3.14 which states, Visual inspections are performed through the DCPP External Surfaces Monitoring of Mechanical Components AMP (B.2.3.22) to identify conditions of corrosion and mechanical damage in the CO2 flow path, and Sections 4.3 and 4.4 of the AMP basis document (Appendix B of DCM T-43) which state, Periodic visual inspections of the CO2 fire suppression system external surfaces are managed by XI.M36, External Surfaces Monitoring of External Components.

2 2.3, 3.3 2.3-53, 3.3-233 LRA Tables 2.3.3-8 and 3.3.2-8 include piping, piping components with a fire barrier intended function. LRA Section 2.1.5.5 defines the fire barrier intended function as Provide rated fire barrier to confine or retard a fire from spreading between adjacent areas of the plant.

LRA Table 3.3.2-8 cites AMR items 3.3-1, 078 and 3.2-1, 044 for managing loss of material of carbon steel piping, piping Please provide additional information regarding the piping, piping components in the Chemical and Volume Control System with a fire barrier intended function.

components exposed externally and internally to plant indoor air by the External Surfaces Monitoring of Mechanical Components and Inspection of Internal Surfaces in Miscellaneous Piping and Ducting Components, respectively.

The Discussions of AMR items 3.3-1, 078 and 3.2-1, 044 in LRA Tables 3.3-1 and 3.2-1, respectively, do not provide additional insight on this piping, piping components in the Chemical and Volume Control System that have a fire barrier intended function.

3 2.3, 3.3 2.3-56, 2.3-59, 2.3-63, 3.3-

258, 3.3-

267, 3.3-278 LRA Tables 2.3.3-9, 2.3.3-10, 2.3.3-11, 3.3.2-9, 3.3.2-10, and 3.3.2-11 include dampers with intended functions (i.e.,

pressure boundary, structural integrity (attached), and structural support), in addition to the fire barrier intended function.

Using LRA Table 3.3.2-9, all the carbon steel dampers are fire dampers, the carbon steel fire dampers have fire barrier, pressure boundary, and structural support intended functions, and the effects of aging for the carbon steel fire Please confirm the staffs understanding of how dampers are represented in LRA Tables 3.3.2-9, 3.3.2-10, and 3.3.2-11. In addition, discuss whether there should be rows with a fire barrier intended function for the carbon steel (galvanized) dampers exposed externally to encased concrete and plant indoor air, and internally to plant indoor air in LRA Table 3.3.2-10.

dampers are managed by the Fire Protection, External Surfaces Monitoring of Mechanical Components, and Inspection of Internal Surfaces in Miscellaneous Piping and Ducting Components programs.

The carbon steel (galvanized) dampers are not fire dampers.

Only the carbon steel (galvanized) dampers are fire dampers in LRA Table 3.3.2-10, and only the carbon steel and carbon steel (galvanized) dampers are fire dampers in LRA Table 3.3.2-11.

The staff noted that in LRA Table 3.3.2-10 only a ventilation atmosphere (int) was given for the carbon steel (galvanized) where the Fire Protection program is cited. However, there appears to be other environments associated with the carbon steel (galvanized) dampers in the table.

4 2.3, 3.3 2.4-7, 2.4-11, 2.4-13, 2.4-17, LRA Tables 2.4-1, 2.4-2, 2.4-3, 2.4-4, 2.4-7, 2.4-9, 2.4-10, 3.5.2-1, 3.5.2-2, 3.5.2-3, 3.5.2-4, 3.5.2-7, 3.5.2-9, and 3.5.2-10 include concrete components with intended functions (i.e.,

direct flow, flood barrier, HELB shielding, missile barrier, Please discuss how the programs other than the Fire Protection program will manage aging effects associated with the fire barrier intended function.

2.4-23, 2.4-28, 2.4-31, 3.5-76, 3.5-92, 3.5-96, 3.5-

108, 3.5-

119, 3.5-

131, 3.5-139 shelter, protection, shielding, structural pressure boundary, and structural support), in addition to the fire barrier intended function. However, the Fire Protection program is not credited for managing the effects of aging associated with the fire barrier intended function for the following components:

Concrete (accessible areas):

Dome, Wall, Basemat Concrete (inaccessible areas): dome, wall, basemat Concrete (Accessible Areas): Interior and Above-Grade Exterior Concrete (Inaccessible Areas): All Concrete: Interior; Above-Grade Exterior Concrete (Accessible Areas): All Concrete (Inaccessible Areas):

Exterior Above-and Below-Grade; Foundation Concrete (Accessible Areas): Exterior Above-and Below-Grade; Foundation; Interior Slab It is unclear to the staff whether the programs credited to manage the applicable aging

effects are capable of ensuring the fire barrier intended function is maintained during the period of extended operation.

Specifically, it is unclear whether the inspections and acceptance criteria for the credited programs are equivalent to those in the Fire Protection program; the credited programs perform inspections on the same frequency as required by the Fire Protection program; and the credited programs procedures have been updated, if necessary, to ensure the fire barrier intended function is maintained during the period of extended operation.

5 3.3 3.3-57, 3.3-58, 3.5-112 LRA Table 3.5.2-4 cites AMR items 3.3-1, 060 and 062 for component type structural fire barriers: curbs (diesel rooms).

However, the Discussions of AMR items 3.3-1, 060 and 062 do not include this component type. The staff notes that the Discussions do include hatches and plugs.

Please discuss whether component type structural fire barriers:

curbs (diesel rooms) should be included in the Discussions of AMR items 3.3-1, 060 and 062 in LRA Table 3.3.1.

6 Appendix B

B.2-72 The Detection of Aging Effects program element in AMP XI.M26 in Revision 2 of NUREG-1801 states, If any sign of degradation is detected within that sample [10 percent of each type of penetration seal],

Please discuss whether a new sample population will be inspected if a seal is found to be nonfunctional, or a new sample population will be inspected if an engineering evaluation makes that determination. If it is the later, please discuss the criteria that will be used to determine whether a new sample population will be inspected if a nonfunctional seal is found.

the scope of the inspection is expanded to include additional seals.

LRA Section B.2.3.14 includes an exception to the Parameters Monitored/Inspected and Detection of Aging Effects program elements. The justification for the exception states, in part, If any degradation is identified within the sample, an engineering evaluation of the degraded condition is performed and documented in the corrective action program to determine if the degraded penetration seal is still capable of performing its intended function and if a new sample population of penetration seals is required to be inspected.

Section 4.4 of DCM T-43, Appendix B (basis document) states that an evaluation is performed to determine if the seal is still capable of performing its safety function and if a seal is determined to be nonfunctional, then a new sample population of penetration seals shall be inspected, and the inspections

continue until there are no additional nonfunctional seals.

The basis document where RAI B.2.3.15-3 for the Point Beach SLRA is discussed, it states, If the seal is deemed to be nonfunctional, an engineering evaluation will be performed to determine whether a new sample population of penetration seals shall be inspected.

The staff notes that the initial LRA stated, The results of the evaluation are used to determine if the degraded penetration seal is still capable of performing its intended function. If the seal is deemed to be nonfunctional, a new sample population of penetration seals shall be inspected.

Therefore, the staff is unclear whether the exception is that if a seal is found to be nonfunctional, then a new sample population shall be inspected, or an engineering evaluation will be performed to determine whether a new sample population of seals will be inspected.

7 Appendix A,

Appendix B

A.2-7, B.2-71 The Monitoring and Trending program element for AMP XI.M26 in Revision 2 of NUREG-1801 states, The results of inspections of the aging effects of cracking, spalling, and loss of material on fire barrier penetration seals, fire barriers, and fire doors are used to trend future actions. It also states that These periodic tests

[periodic tests of the halon/CO2 fire suppression system] provide data necessary for trending.

LRA Sections A.2.2.14 and B.2.3.14 do not address trending of inspection and test results. However, the staff notes that Section 4.5 of the basis document states the language in Revision 2 of NUREG-1801 noted above.

While the staff recognizes that the language in the basis document is consistent with the language in Revision 2 of NUREG-1801, there are aging effects in the LRA in addition to cracking, spalling, and loss of material. For example, change in material properties, increased hardness, shrinkage, loss of strength, and delamination.

Please discuss whether results of inspections and tests of all applicable aging effects will be trended, including whether changes to the program are required to account for inspection for and trending of all applicable aging effects.

8 N/A N/A Section 5.12 of STP M-70D states stainless steel banding secures fire wraps.

Section 6.1 of EPRI 3002013084, Long-Term Operations: Subsequent License Renewal Aging Effects for Structures and Structural Components (Structural Tools),

November 2018, states, in part, wire and other appurtenances used to secure fire wrap to the item being protected - is considered to be part of the fire wrap itself. Therefore, the effects of aging of the stainless steel banding should be managed.

Please identify where the stainless steel banding is addressed in the LRA.

9 N/A N/A The staff noted that most Fire Protection program procedures on the portal include the frequency, however the following procedures do not:

STP M-70.CRD, Control Room ECG Door Inspection STP M-70-ROL, Inspection of ECG Roll-up Doors and Doors on Rollers STP M-70.SWG, Inspection of ECG Swing Type Doors The Detection of Aging Effects and Acceptance Criteria program elements for AMP Please discuss why STP M-70.CRD, STP M-70-ROL, and STP M-70.SWG do not state the frequency for the inspections. In addition, please discuss whether other fire door components could experience wear, other than those noted in the procedures, and why STP M-70.CRD does not appear to address wear for any fire door components.

XI.M26 in Revision 2 of NUREG-1801 state, Visual inspection by fire protection qualified personnel detects any sign of degradation of the fire doors, such as wear and missing parts, and (c) no visual indications of missing parts, holes, and wear; and (d) no deficiencies in the functional tests of fire doors, respectively.

The staff noted that STP M ROL and STP M-70.SWG include checking for wear of hinges, moving parts, and hand chains. STP M-70.CRD does not appear to address wear.

10 2.1 2.1-23 The staff noted that LRA Table 2.1-1 identifies the intended function of Structural Pressure Barrier. However, it appears that Structural Pressure Boundary is consistently used in the rest of the LRA.

Please discuss updating LRA Table 2.1-1 to be consistent with the rest of the LRA which uses Structural Pressure Boundary.

11 3.3 3.2-162 SLR-ISG-2021-02-Mechanical, Updated Aging Management Criteria for Mechanical Portions of Subsequent License Renewal Guidance (ML20181A434) added GALL-SLR Items 3.3-1, 267, 3.3-1, 268, and 3.3-1, 269.

The aging effects for subliming compounds, cementitious coatings, and silicates used as fireproofing/fire barriers exposed Please discuss why separation was not cited as an applicable aging effect for the grout fire barrier seals; cementitious coating, subliming, and ceramic fiber fireproofing; and gypsum and plaster barriers in LRA Table 3.5.2-14.

to air are loss of material, cracking/delamination, change in material properties, and separation. These aging effects are consistent with Section 6, Fire Barriers, of EPRI 3002013084, Long-Term Operations: Subsequent License Renewal Aging Affects for Structures and Structural Components (Structural Tools),

November 2018.

LRA Table 3.5.2-14 includes loss of material, change in material properties, and cracking/delamination for grout fire barrier seals; cementitious coating, subliming, and ceramic fiber fireproofing; and gypsum and plaster barrier. The plant-specific notes reference SLR-ISG-2021-02-MECHANICAL.

However, separation was not cited as an applicable aging effect.

12 2.3, 3.3 2.4-42, 3.5-161 LRA Tables 2.4-14 and 3.5.2-14 include the following fire barriers with intended functions other than the fire barrier intended function:

Fire Barrier Seals -

Structure Pressure Boundary Please discuss whether it would be appropriate to credit a program in addition to the Fire Protection program to manage the effects of aging associated with the intended functions other than the fire barrier intended function.

Gypsum & Plaster Barrier -

Shelter, Protection and Structural Pressure Boundary The staff noted that for some component types with intended functions in addition to the fire barrier intended function (e.g.,

cable trays and supports, and fire barrier doors), the Structures Monitoring program was also credited for managing the effects of aging.

Diablo Canyon LRA: Breakout Questions LRA Section: B.2.3.15 Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 1

2.3, 3.3 2.3-66, 3.3-92, 3.3-300 The staff notes that the LRA and Revision 3 of DCM No. T-43, Appendix B (AMP basis document), refers to both spray nozzles and sprinklers.

However, LRA Tables 2.3.3-12 and 3.3.2-12 do not include sprinklers. These tables do include spray nozzles.

Specifically, LRA Table 3.3.2-12 includes copper alloy (>15%

Zinc) spray nozzles.

The staff also notes that the Discussion of AMR 3.3-1, 130 in LRA Table 3.3-1 refers only to the copper alloy (>15% Zinc) spray nozzles.

Please discuss whether sprinklers should also be included in LRA Tables 2.3.3-12, 3.3-1, and 3.3.2-12.

2 3.3 3.3-310 LRA Table 3.3.2-12 cites AMR item 3.3-1, 116 (no aging effects or AMP) for the carbon steel (galvanized) RCP oil collection reservoir exposed externally to plant indoor air.

While this is consistent with GALL, in the 2009 LRA, AMR item 3.3.1.58 was cited to managed loss of material of the carbon steel (galvanized) RCP oil collection reservoir exposed If loss of material was previously identified as an applicable aging effect for the carbon steel (galvanized) RCP oil collection reservoir, then please discuss the basis for now citing AMR item 3.3-1, 116 (no aging effects or AMP) in the current LRA.

Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request externally to plant indoor air by the External Surfaces Monitoring Program.

It is unclear to the staff why loss of material was not identified as an applicable aging effect in the current LRA, even though it was in the 2009 LRA.

3 2.1, 3.3 2.1-27, 3.3-44, 3.3-79, 3.3-303 LRA Section 2.1.6.1 states that NUREG-2191 and NUREG-2192 were considered to be operating experience evaluated for applicability to Diablo Canyon.

The Discussion for AMR item 3.3-1, 032 in LRA Table 3.3-1 states, Cracking and changes in material properties of the asbestos cement piping and piping components exposed to raw water is managed by the DCPP Fire Water System AMP (B.2.3.15), which takes exception to NUREG-1801.

The Discussion for AMR item 3.3-1, 103 in LRA Table 3.3-1 states, Cracking and changes in material properties of buried asbestos cement piping and piping components is managed Please discuss whether loss of material and flow blockage should be applicable aging effects for the asbestos cement piping and piping components exposed to buried (ext) and raw water (int) in LRA Tables 3.3.2-5 and 3.3.2-12.

Is the asbestos cement exposed to buried (ext) in the FPS coated? If not, should there be an exception similar to that in SLRA Section B.2.3.26 in SLRA Section B.2.3.15?

Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request by the DCPP Buried and Underground Piping and Tanks AMP (B.2.3.26), which takes exception to NUREG-1801.

LRA Table 3.3.2-5 cites AMR item 3.3-1, 103 for managing cracking and changes in material properties of the asbestos cement piping and piping components exposed to buried (ext) by the Buried Piping and Tanks Inspection program.

LRA Table 3.3.2-12 cites AMR item 3.3-1, 103 for managing cracking and changes in material properties for asbestos cement piping and piping components exposed to buried (ext) by the Buried and Underground Piping and Tanks program. It cites AMR item 3.3-1, 032, with Notes E, 4, for managing cracking and change in material properties of the asbestos cement piping and piping components exposed internally to raw water by the Fire Water System program.

The staff notes that loss of material was also managed for

Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request the asbestos cement piping exposed to buried (ext) and raw water (int) by the Buried Piping and Tanks Inspection and Inspection of Internal Surfaces in Miscellaneous Piping and Ducting Components programs, respectively, for both the MWS and FPS in the 2009 LRA. It appears that the staff agreed in the 2011 SER that cracking, loss of material, and change in material properties were the applicable aging effects for asbestos cement. Therefore, it is unclear why loss of material is not identified as an applicable aging effect in the current LRA.

NUREG-2191, Revision 0, includes AMR item 3.3-1, 195 for managing cracking, loss of material, and flow blockage of asbestos cement piping and piping components exposed to raw water by the Fire Water System Program; and AMR item 3.3-1, 103 for managing cracking and loss of material of asbestos cement piping and piping components exposed to soil by the Buried and

Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request Underground Piping and Tanks program. Therefore, it is unclear to the staff how the AMR items in NUREG-2191 for asbestos cement were considered, especially, loss of material and flow blockage (raw water only).

The staff notes that the Justification for Exception 1 states, Therefore, the performance testing and flushes performed by the program are acceptable methods to detect aging and manage loss of material for fire water system components fabricated of ACP. This appears to indicate that flow blockage and loss of material would be managed.

The staff notes that LRA Section B.2.3.26 states in Exception 2 that the asbestos cement piping in the MWS is not coated as recommended by LR-ISG-2015-01, Table XI.M41-1. It is unclear to the staff whether the asbestos cement exposed to buried (ext) in the FPS is coated. If not, should there be a similar

Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request exception in SLRA Section B.2.3.15.

4 2.1.6.1, 3.3.2.2.8 2.1-25, 3.3-31, LRA Section 2.1.6.1 states that the updated guidance in LR-ISG-2012-02 has been considered and reflected in AMR results and LRA Section B.2.3.15.

LRA Section 3.3.2.2.8 states that the Fire Water System will be enhanced to manage loss of material due to RIC of steel and gray cast iron piping, piping components, and tanks in the FPS.

LR-ISG-2012-02 states that the applicant states the following:

(a) why the programs examination methods will be sufficient to detect the recurring aging effect before affecting the ability of a component to perform its intended function, (b) the basis for the adequacy of augmented or lack of augmented inspections, (c) what parameters will be trended as well as the decision points where increased inspections would be implemented (e.g., the extent Please discuss how the Fire Water System program will inspect components that are not easily accessed (i.e., buried, underground), and how leaks in buried or underground components will be identified.

Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request of degradation at individual corrosion sites, the rate of degradation change),

(d) how inspections of components that are not easily accessed (i.e., buried, underground) will be conducted, and (e) how leaks in any involved buried or underground components will be identified.

The enhancement in LRA Section B.2.3.15 does not appear to clearly address (d) and (e) noted above.

5 2.1.6.1, Appendix A,

Appendix B 2.1-25, A.2-8, A.4-11, B.2-75 LRA Section 2.1.6.1 states that the updated guidance in LR-ISG-2012-02 has been considered and reflected in AMR results and LRA Section B.2.3.15.

Table 4a in Appendix L of LR-ISG-2012-02 recommends sprinkler testing in accordance with Section 5.3.1 of NFPA 25.

The periodicity for replacement or testing depends on the type of sprinkler (i.e., standard, fast-response, or dry sprinkler).

The staff notes that LRA Sections A.2.2.15 and B.2.3.15 Please discuss the following:

Are there fast-response and/or dry sprinklers used at Diablo Canyon?

If so, please discuss how the LRA would be updated to reflect the different replacement/test periodicities.

What exception is being taken to replacing/testing sprinklers in accordance with NFPA Section 5.3.1?

Should the enhancement to Test/replace sprinkler heads in accordance with NFPA 25, Section 5.3.1 be revised to include Sprinklers that have been in service for greater than 50 years prior to the program implementation date will be replaced or tested consistent with NFPA 25 prior to the program being implemented?

Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request refer to the 50 year replacement/testing periodicity (NFPA 25, Section 5.3.1.1, standard sprinklers). Therefore, it is unclear whether there are fast-response and/or dry sprinklers used at Diablo Canyon.

LRA Section A.2.2.15 states, Testing or replacement of sprinklers that have been place for 50 years is performed in accordance with NFPA 25 (2011 Edition) with exceptions.

However, there does not appear to be an exception in LRA Section B.2.3.15 associated with testing and replacing sprinklers in accordance with NFPA Section 5.3.1.

LRA Table A.4 and Section B.2.3.15 include an enhancement to the Fire Water System program to Test/replace sprinkler heads in accordance with NFPA 25, Section 5.3.1.

LRA Section B.2.3.15 states, Sprinklers that have been in service for greater than 50

Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request years prior to the program implementation date will be replaced or tested consistent with NFPA 25 prior to the program being implemented.

This appears to be a commitment but there is no specific commitment in LRA Table A.4 or LRA Section B.2.3.15.

6 2.1.6.1, Appendix A,

Appendix B 2.1-25, A.2-8, B.2-75 LRA Section 2.1.6.1 states that the updated guidance in LR-ISG-2013-01 has been considered and reflected in AMR results and LRA Section B.2.3.27, Internal Coatings/Linings for In-Scope Piping, Piping Components, Heat Exchangers, and Tanks.

The Scope of Program in Appendix C of LR-ISG-2013-01 states, The aging effects associated with fire water tank internal coatings/linings are managed by GALL Report AMP XI.M27, Fire Water System, instead of this AMP.

However, where the fire water storage tank internals are coated, the Fire Water System Program and FSAR Summary Description of the Program should be enhanced to include Please address the following:

Why the corrective actions from LR-ISG-2013-01, Appendix C are not included in LRA Section A.2.2.15?

What version of ASTM D4537?

What is meant by will include the relevant recommendations in this instance. If there are training and qualification, acceptance criteria and/or corrective actions from LR-ISG-2013-01 that will not be incorporated into the Fire Water System program, then please identify them.

Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request the recommendations associated with training and qualification of personnel and the corrective actions program element. The Fire Water System Program should also be enhanced to include the recommendations from the acceptance criteria program element.

LRA Section A.2.2.15 states, Individuals responsible for conducting coating inspections will be qualified in accordance with ASTM D4537, which is endorsed by RG 1.54. The individuals responsible for assessing the type and extent of coating degradation will be qualified in accordance with ASTM D7108-05, which is also endorsed by RG 1.54.

However, the FSAR summary does not appear to include the recommendations from the Corrective Actions program element. In addition, the staff notes that the specific version of ASTM D4537 is not identified.

Enhancement (g)(3) for No. 17 in LRA Table A.4 and the

Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request enhancement to the Detection of Aging Effects, Acceptance Criteria, and Corrective Actions program elements in LRA Section B.2.3.15 states, Inspections of FWST coatings will include the relevant recommendations associated with training and qualification of personnel, acceptance criteria, and corrective actions from LR-ISG-2013-01, Appendix C.

Individuals responsible for conducting coating inspections will be qualified in accordance with ASTM D4537. Individuals responsible for assessing the type and extent of coating degradation will be qualified in accordance with ASTM D7108-

05.

LRA Section A.2.3.15 states, With respect to internal coatings, training and qualification of personnel, acceptance criteria, and corrective actions will be in accordance with LR-ISG-2013-01, Appendix C.

The staff notes that there is a difference between in accordance with and will

Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request include the relevant recommendations.

7 2.1.6.1, Appendix B 2.1-25, B.2-77 LRA Section 2.1.6.1 states that the updated guidance in LR-ISG-2012-02 has been considered and reflected in AMR results and LRA Section B.2.3.15.

The Acceptance Criteria program element in Appendix L of LR-ISG-2012-02 states, The acceptance criteria are: (a) the water-based fire protection system is able to maintain required pressure and flow rates, (b) minimum design wall thickness is maintained, and (c) no fouling exists in the sprinkler systems that could cause corrosion in the sprinklers.

LRA Section B.2.3.15 states, The DCPP Fire Water System AMP acceptance criteria are:

(1) The ability of the fire protection system to maintain required pressure; (2) No unacceptable signs of degradation, such as loss of material due to corrosion, are observed during visual assessment of internal system conditions; and (3) No fouling Please discuss why LRA Section B.2.3.15 does not include the systems ability to maintain required flow rates or that minimum wall thickness is maintained in the acceptance criteria.

Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request exists in the sprinkler system that could cause blockage in the sprinkler heads.

The staff notes that the acceptance criteria stated in LRA Section B.2.3.15 do not refer to the systems ability to maintain required flow rates or that minimum wall thickness is maintained.

8 Appendix A,

Appendix B A.4-17, B.2-85 The Parameters Monitored/Inspected program element in Appendix L of LR-ISG-2012-02 states, When visual inspections are used to detect loss of material, the inspection technique is capable of detecting surface irregularities that could indicate wall loss to below nominal pipe wall thickness due to corrosion and corrosion product deposition. Where such irregularities are detected, follow-up volumetric wall thickness examinations are performed. In addition, the Detection of Aging Effects program element states, Internal visual inspections used to detect loss of material are capable of detecting surface irregularities that could Please discuss whether Enhancement (n) to No. 17 in LRA Table A-3 and the enhancement to the Detection of Aging Effects, Acceptance Criteria, and Corrective Actions program elements in LRA Section B.2.3.15 should be updated to better reflect the guidance in LR-ISG-2012-02 (i.e., inspection technique capable of detecting surface irregularities, follow-up volumetric wall thickness examinations when irregularities are detected).

Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request be indicative of wall loss below nominal pipe wall thickness due to corrosion and corrosion product deposition. Where such irregularities are detected, follow-up volumetric examinations are performed.

Enhancement (n) to No. 17 in LRA Table A.4 and the enhancement to the Detection of Aging Effects, Acceptance Criteria, and Corrective Actions program elements in LRA Section B.2.3.15 state, Update existing procedures to require supplemental volumetric testing when early indications of aging effects that could lead to wall thinning are identified to ensure that minimum wall thickness is maintained.

It states in the Operating Experience portion of LRA Section B.2.3.15 that PG&E will make enhancements to the DCPP Fire Water System AMP, including ensuring follow-up volumetric examinations are conducted whenever internal visual inspections detect surface irregularities indicative

Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request of material loss below nominal wall thickness.

In the discussion of previous LRA RAI responses and supplements/amendments in the AMP basis document, it states, Plant procedures will be enhanced to ensure that visual inspections for loss of material use inspection techniques capable of detecting surface irregularities that could indicate an unexpected level of degradation due to corrosion and corrosion product deposition. Where such irregularities are detected, follow-up volumetric wall thickness examinations will be performed.

The staff notes that PG&E Letter DCL-14-103 included language like the language in the ISG.

9 Appendix A A.4-11 Enhancement (k)(1) for No. 17 in LRA Table A.4 and the Enhancement to the Detection of Aging Effects program element in LRA Section B.2.3.15 state, Prior to November 2, 2024, after Please clarify the implementation schedule for the augmented inspections/tests for portions of water-based fire protection system components that have been wetted but are normally dry for Unit 2.

Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request identifying any portions of the fire water deluge system piping that are normally dry and periodically subject to flow, but are unable to be drained, perform either: (a) a flow test or flush sufficient to detect potential flow blockage, or (b) an inspection of 100 percent of the internal surface on those portions unable to be drained.

This activity shall be conducted in each 5-year period during the PEO. If the results of a 100 percent internal visual inspection are acceptable, and the segment is not subsequently wetted, no further augmented tests or inspections are necessary.

However, the Implementation Schedule in LRA Table A.4 states, Augmented inspections to address recurring internal corrosion and inspections (identification, visual inspections, and flow tests) of wetted normally dry piping segments that cannot be drained or that allow water to collect begin prior to Unit 1: 11/02/2024 Unit 2: 8/26/2025

Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request It is unclear to the staff when portions of water-based fire protection system components that have been wetted but are normally dry will be identified and inspections/tests begin for Unit 2 (11/2/2024 or 8/26/2025).

10 2.4.13 2.4-37 LRA Section 2.4.13 states, The FWST steel liner is evaluated with the Fire Protection System Section 2.3.3.12. It was the staffs understanding that the FWST is coated with an epoxy paint-based system.

Please discuss whether the FWST has a steel liner.

11 3.2.2.2.9 3.2-10 LRA Section 3.2.2.2.9 states, As such, the DCPP Fire Water System (B.2.3.15), DCPP Inspection of Internal Surfaces in Miscellaneous Piping and Ducting Components (B.2.3.24), and DCPP Open-Cycle Cooling Water (B.2.3.11), do not require enhancements to address RIC in DCPP ESF Systems.

The staff notes that LRA Section 3.3.2.2.8 addresses enhancing the Fire Water System program to manage RIC.

Please discuss why the Fire Water System program is discussed in LRA Section 3.2.2.2.9.

Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 12 N/A N/A Section 4.3 in DCM No. T-43, Appendix B, states Other components in the long term cooling paths will be evaluated to ensure additional components and intended functions are managed by the DCPP Fire Water System AMP.

Please discuss whether this evaluation is complete and that all components and their intended functions have been identified in the LRA.

13 Appendix A,

Appendix B A.4-17, B.2-85 Enhancement (m) for No. 17 in LRA Table A.4 and the Enhancement to the Monitoring and Trending program element in LRA Section B.2.3.15 states, Update inspection and test procedures to require trending of data. The staff notes that Section 4.5 in the AMP basis document states, This enhancement includes maintenance of the documentation above for comparing and trending inspection/test results using the DCPP corrective action program to drive improvement.

Please discuss why the language in Section 4.5 in the AMP basis document, which appears to be providing additional details on the enhancement, was not included in the enhancement language in the LRA.

14 N/A N/A In the discussion of previous LRA RAI responses and supplements/amendments in the AMP basis document, it states, The DCPP Fire Water System AMP will be enhanced to trend deposits associated with flushing-related testing Please discuss whether trending deposits associated with flushing-related testing and inspections should be included as an enhancement in the LRA.

Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request inspections. However, trending deposits associated with flushing-related testing and inspections does not appear to be included in the LRA as an enhancement.

Diablo Canyon LRA: Breakout Questions LRA Section B.2.3.20, Selective Leaching Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 1

B.2.3.20 B.2-101 LRA Section B.2.3.20, Selective Leaching, states the program manages the effects of aging for copper alloys containing greater than 8 percent aluminum.

The staff requests a discussion with respect to why this material is listed in LRA Section B.2.3.20. It is the staffs understating that loss of material due to selective leaching for this material will be managed using the Periodic Inspections for Selective Leaching program (LRA Section B.2.3.41).

2 N/A N/A DCM T-43, License Renewal Appendix B Diablo Canyon Aging Management Program Evaluation Report B.2.3.20 -

Selective Leaching, includes a discussion on excluding buried components from inspection based on the performance of the cathodic protection system.

The only buried components within the scope of the Selective Leaching program are ductile iron components in the fire protection system. A review of the program basis document for the Buried and Underground Piping and Tanks program indicates that these components are not provided with cathodic protection. The staff requests a discussion with respect to why cathodic protection is discussed in DCM T-43.

3 N/A N/A Draft NUREG-2221, Revision 0, Supplement 1, Technical Bases for Changes in the Subsequent License Renewal Guidance Documents, Draft NUREG-2191, Revision 1, and Draft NUREG-2192, Revision 1, Draft Report for Comment, documents recent SLRA plant-specific operating experience as a basis for the inclusion of malleable iron as a material susceptible to selective leaching.

The staff requests a discussion with respect to if there are mechanical malleable iron components in-scope for license renewal (the LRA shows malleable iron for electrical insulators only).

Diablo Canyon LRA: Breakout Questions LRA Section B.2.3.26, Buried and Underground Piping and Tanks Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 1

N/A N/A The staff reviewed PGEDCROLI00007-REPT-078, License Renewal Aging Management Program Basis Document Buried and Underground Piping and Tanks, Revision 1 in early February 2024.

On 02/20/2024, the staff noted the above document was replaced with DCM T-43, License Renewal Appendix B Diablo Canyon Aging Management Program Evaluation Report B.2.3.26 Buried and Underground Piping and Tanks, Revision 3 on the ePortal.

The staff requests a discussion with respect to why this change occurred and which program basis document is the appropriate one for the staff to review.

2 N/A N/A The staff reviewed PEP 72.1, Annual Survey of ASW Pipe Cathodic Protection, and noted that it does not include the -1,200 mV limiting critical potential to prevent damage to coatings or base metals.

The staff requests a discussion with respect to if the limiting critical potential is identified in another procedure (or if there should be an enhancement associated with this GALL Report recommendation).

3 N/A N/A The staff reviewed PGEDCROLI00007-REPT-078 and noted steel firewater piping is coated in accordance with AWWA C203, Coal-Tar Protective Coatings And Linings For Steel Water Pipes. The staff notes that buried metallic fire protection system piping is constructed from steel, ductile iron, and gray cast iron.

The staff requests a discussion with respect to if ductile iron and gray cast iron are coated in accordance with AWWA C203, or if another specification covers these materials.

4 B.2.3.26 B.2-123 LRA Section B.2.3.26, Buried and Underground Piping and Tanks, states

[t]he DCPP Buried and Underground Piping and Tanks AMP is an existing program that manages cracking, loss of material, and change in surface conditions of buried and underground components in the auxiliary saltwater (ASW) system, diesel generator fuel transfer system, fire protection system, and the makeup water system.

LRA Table 3.3.2-3, Saltwater and Chlorination System - Summary of Aging Management Evaluation, states elastomeric expansion joints exposed to a buried environment will be managed for hardening and loss of strength using the Buried and Underground Piping and Tanks program.

The staff requests a discussion with respect to why the subject sentence from LRA Section B.2.3.26 does not include hardening and loss of strength.

5 B.2.3.26 B.2-123 LRA Section B.2.3.26 states [t]he number of inspections for the buried and underground auxiliary saltwater system piping, buried makeup water system piping and valves, and underground diesel fuel oil piping, will be consistent with LR-ISG-2015-01, Table XI.M41-2, as modified for a two-unit site The number of inspections identified in LRA Section B.2.3.26 are consistent with GALL Report recommendations; however, the staff could not identify in the LRA or procedures on the ePortal that one inspection consists of a 10-foot segment of piping.

The staff requests a discussion on this topic.

6 B.2.3.26 B.2-124 LRA Section B.2.3.26 (Exception No. 4) states NUREG-1801,Section XI.M41 states that inspections of buried and underground piping and tanks will commence 10 years prior to the PEO.

Due to the expedited timeframe to implement the DCPP Buried and Underground Piping and Tanks AMP, Due to the timing of the LRA, there will be overlap between the 1st inspection internal (2023-2028) and the 2nd inspection interval (2024-2034 (Unit 1), 2025-2035 (Unit 2)). The staff requests a discussion with respect to if inspections in one interval can be credited towards inspections in another interval.

initial inspection will be completed by December 1, 2028.

7 N/A N/A DA50513038 notes (a) a failure of buried ductile iron fire protection system piping in 2012 due to general corrosion on the external surfaces; (b) the damaged pipe had a light external coating, which was added for aesthetic reasons and affords negligible corrosion protection; and (c) another plant specific operating experience event (A0369216) related to a broken makeup water pipe due to external corrosion, where the cause was determined to be uncoated pipe directly exposed to soil.

The staff requests a discussion with respect to the subject operating experience, specifically related to the extent of in-scope buried piping that is (a) not coated in accordance with required specifications; or (b) not provided with a coating intended for long-term corrosion protection.

8 N/A N/A DN51050775 discusses a buried makeup water leak.

The staff requests a discussion with respect to (a) if the piping is constructed from asbestos cement (as shown in LRA Table 3.3.2-5, Makeup Water System

- Summary of Aging Management Evaluation); and (b) the cause of the leak (i.e., was this due to age-related degradation).

9 N/A N/A GALL Report AMP XI.M41 (as amended by LR-ISG-2015-01) includes the following acceptance criteria (in part):

b. Cracking is absent in rigid polymeric components. Blistering, gouges, or wear of non-metallic piping is evaluated.

c. The measured wall thickness projected to the end of the period of extended operation meets minimum wall thickness requirements.

The staff requests a discussion with respect to where these acceptance criteria are accounted for in current procedures.

d. Indications of cracking in metallic pipe are managed in accordance with the corrective actions program element.

e. Cementitious piping may exhibit minor cracking and spalling provided there is no evidence of leakage, exposed or rust staining from rebar or reinforcing hoop bands.

10 B.2.3.26 Table 3.3.2-13 B.2-124 3.3-322 LRA Section B.2.3.26, Buried and Underground Piping and Tanks, states

[t]he buried DFOSTs are double walled steel LRA Table 3.3.2-13, Diesel Fuel Oil System - Summary of Aging Management Evaluation, states loss of material for diesel engine generator fuel oil tanks exposed to plant indoor air (internal and external) will be managed by the Buried and Underground Piping and Tanks program.

The staff requests a discussion with respect to (a) if the subject tanks are exposed to a buried or underground environment; and (b) why the Buried and Underground Piping and Tanks program is managing the effects of aging for an internal environment.

11 Table 3.3.2-3 3.3-119 LRA Table 3.3.2-3, Saltwater and Chlorination System - Summary of Aging Management Evaluation, states loss of material for copper alloy piping exposed to plant indoor air will be managed by the Buried and Underground Piping and Tanks program.

The staff requests a discussion with respect to if underground copper alloy piping in the saltwater and chlorination system is externally coated in accordance with GALL Report Table XI.M41-1, Preventive Actions for Buried and Underground Piping and Tanks. The staff could not identify where this information is discussed on the ePortal.

12 B.2.3.26 B.2-124 Exception No. 2 states [a]sbestos cement piping (ACP) and cast iron valves in the makeup water system are not coated as recommended by LR-ISG-2015-01 Table XI.M41-1.

The staffs understanding is that in-scope buried stainless steel in not coated; however, it is not included in this exception because it is a super austenitic stainless steel (e.g., AL-6XN). The staff requests a discussion with respect to if this is an accurate assessment.

GALL Report AMP XI.M41 recommends external coatings for buried stainless steel, but not buried super austenitic stainless steel.

13 Table 3.3.2-3 3.3-113 LRA Table 3.3.2-3 states buried elastomeric expansion joints will be managed for hardening and loss of strength using the Buried and Underground Piping and Tanks program.

GALL Report AMP XI.M41 (as amended by LR-ISG-2015-01) includes loss of material due to wear as an aging effect requiring management for polymeric materials. The staff requests a discussion with respect to why loss of material due to wear is not cited for the subject components. In addition, the staff noted these aging effects for elastomeric materials are not included in LRA Section A.2.2.26, Buried and Underground Piping and Tanks (FSAR Supplement).

14 A.2.2.26 A.2-14 SRP-LR Table 3.0-1, FSAR Supplement for Aging Management of Applicable Systems, for AMP XI.M41 (as amended by LR-ISG-2015-01) includes the following:

Annual cathodic protection surveys are conducted. For steel components, where the acceptance criteria for the effectiveness of the cathodic protection is other than -850 mV instant off, loss of material rates are measured.

Inspections are conducted by qualified individuals. Where the coatings, backfill or the condition of exposed piping does not meet acceptance criteria such that the depth or extent of degradation of the base metal could have resulted in a loss of pressure boundary function when the loss of material rate is extrapolated to the end of the period of extended operation, an increase in the sample size is conducted.

The staff requests a discussion with respect to why the subject text is not included in LRA Section A.2.2.26.

If a reduction in the number of inspections recommended in GALL Report, AMP XI.M41, Table XI.M41-2 is claimed based on a lack of soil corrosivity as determined by soil testing, then soil testing is conducted once in each 10-year period starting 10 years prior to the period of extended operation.

15 B.2.3.26 B.2-124 B.2-125 Exception Nos. 1 and 2 to LRA Section B.2.3.26 relate to not providing cathodic protection (Exception No. 1) and external coatings (Exception No. 2) for specific components. The staff has a few discussion topics related to these exceptions.

The justification for Exception Nos. 1 and 2 address piping and tanks but not the makeup water system cast iron valves. The staff requests a discussion with respect to the basis for not providing cathodic protection or external coatings for these valves.

Does buried in-scope asbestos cement piping have steel reinforcement? Please upload any relevant information (e.g., piping specification for this material) to the ePortal.

The justification for Exception No. 1 states [n]on-cathodically protected buried steel (including cast iron makeup water valves) will be inspected in accordance with LR-ISG-2015-01, Appendix B, Table XI.M41-2, Preventive Action Category F. It is unclear to the staff why non-cathodically protected buried steel piping and valves are grouped together for aging management.

The buried steel piping is externally coated; however, the buried steel valves are not externally coated.

The staff reviewed groundwater sampling results from 2008 to 2009 (ML102080385) showing pH greater than 6.8, chlorides less than 215 ppm (parts per million), and sulfates less than 602 ppm. Can more recent groundwater sampling data be uploaded to the ePortal? In addition, where is this data collected in relation to buried in-scope asbestos cement piping?

Diablo Canyon LRA: Breakout Questions Corrosion Material 1

Table 3.4.2-5 3.4-145 LRA Table 3.4.2-5, Auxiliary Feedwater System - Summary of Aging Management Evaluation, states carbon steel valve bodies exposed to raw water will be managed for loss of material using the Inspection of Internal Surfaces in Miscellaneous Piping and Ducting Components program.

The staff requests a discussion with respect to why fouling is not cited in addition to loss of material.

Diablo Canyon LRA: Breakout Questions Non-metallic Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 1

2.1, 3.3 2.1-27, 3.3-117 LRA Section 2.1.6.1 states that NUREG-2191 and NUREG-2192 were considered to be operating experience evaluated for applicability to Diablo Canyon.

LRA Table 3.3.2-3 cites no aging effects or aging management programs for fiberglass piping and piping components exposed to closed-cycle cooling water (internal) and plant indoor air (external),

and fiberglass reinforced plastic pump casing (circulating water top cover sump pumps) exposed to plant indoor air (external) and raw water (internal).

NUREG-2191 includes several AMR items associated with fiberglass exposed to air, treated water, and raw water (e.g.,

3.3-1, 159, 176, and 082).

It is unclear to the staff how the AMR items in NUREG-2191 for fiberglass were considered, especially, loss of material and flow blockage (raw water only).

Please discuss how the AMR items in NUREG-2191 for fiberglass exposed to air, treated water, and raw water were considered for the fiberglass piping and piping components and for the fiberglass reinforced plastic pump casing in LRA Table 3.3.2-3.

2 2.1, 3.3 2.1-27, LRA Section 2.1.6.1 states that NUREG-2191 and NUREG-2192 were considered to be operating experience evaluated for applicability to Diablo Canyon.

Please discuss how the AMR items in NUREG-2191 for PVC exposed to soil, treated water, and raw water were considered for the PVC piping, piping components, and valve bodies in LRA Tables 3.3.2-3 and 3.3.2-12.

Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request The LRA cites no aging effects or aging management programs for the following:

Table 3.3.2-3, PVC piping, piping components, and valve bodies exposed internally to closed-cycle cooling water and raw water.

Table 3.3.2-12, PVC piping and piping components exposed externally to buried (soil).

NUREG-2191 includes several AMR items associated with PVC exposed to treated water, soil, and raw water (e.g.,

3.3-1, 253 and 194, 3.4-1, 125).

The staff notes that plant-specific note 2 for the PVC conduit and supports exposed externally to buried states, Consistent with guidance in NUREG-2191, buried PVC is susceptible to loss of material. The DCPP Structures Monitoring AMP (B.2.3.33) will be used to manage buried PVC conduit. Unclear why this approach was not applied to the PVC piping and piping components exposed externally to buried in LRA Table 3.3.2-12.

The staff notes that flow blockage and loss of material is being managed by the Fire Water System program for the PVC piping and piping components in LRA Table 3.3.2-12. Unclear why loss of material and flow blockage is not similarly

Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request managed for the PVC piping, piping components, and valve bodies exposed internally to raw water in LRA Table 3.3.2-

3.

It is unclear to the staff how the AMR items in NUREG-2191 for PVC were considered, especially, loss of material and flow blockage (raw water only).

Diablo Canyon LRA: Breakout Questions LRA Sections 3.2.2.2.3.2, 3.2.2.2.6, 3.3.2.2.3, 3.3.2.2.5, 3.4.2.2.2, 3.4.2.2.3 Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 1

3.2.2.2.3.2, 3.2.2.2.6, 3.3.2.2.3, 3.3.2.2.5, 3.4.2.2.2, 3.4.2.2.3 3.2-7 3.2-8 3.3-28 3.3-29 3.4-7 3.4-8 In NUREG-1800, Rev. 2 (the SRP),

stainless steel Further Evaluation Sections 3.2.2.2.3.2, 3.2.2.2.6, 3.3.2.2.3, 3.3.2.2.5, 3.4.2.2.2, 3.4.2.2.3 state that for loss of material due to pitting corrosion, and for cracking due to stress corrosion cracking, applicable outdoor air environments (and associated indoor air environments) include, but are not limited to, those within approximately five miles of a saltwater coastline.

Several of the corresponding sections of the LRA state that,

a. Cracking or loss of material of stainless steel components are managed conservatively.

b. The environment for these further evaluation sections is atmosphere/weather. (LRA Table 3.0-1 states that this environment corresponds to Air -outdoor and Condensation in the GALL report.)

The staff seeks clarity about the meaning of these statements.

Please address the following:

a. Relative to the guidance in the SRP, explain what is meant by the statement that these components are managed conservatively.

b. Explain how the atmosphere/weather environment compares to the environments described in the guidance for these further evaluation sections (outdoor air, including air recently introduced into buildings, in which condensation or deliquescence is assumed to be possible).

2 3.2.2.2.3.2, 3.2.2.2.6, 3.2-7 3.2-8 LRA sections 3.2.2.2.3.2, 3.2.2.2.6, 3.3.2.2.3, 3.3.2.2.5, 3.4.2.2.2, and Please clarify the aging management plans for loss of material and stress corrosion cracking of stainless

Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 3.3.2.2.3, 3.3.2.2.5, 3.4.2.2.2, 3.4.2.2.3 3.3-28 3.3-29 3.4-7 3.4-8 3.4.2.2.3 propose the External Surfaces Monitoring of Mechanical Components program for managing cracking due to stress corrosion cracking and loss of material for stainless steel in atmosphere/weather. (Section 3.2.2.2.6 also proposes the Structures Monitoring program.) This is consistent with the SRP guidance in the corresponding sections.

However, the first bullet in Section 4.1 of PGEDCROLI00007-REPT-005 Rev.1 (Operating Experience Report) states that Ambient air is considered mild to stainless steel, nickel-alloy, and aluminum alloy components.

Aging management reviews will evaluate cracking and loss of material in uncontrolled or outdoor air environments using the One-Time Inspection program.

The examples above indicate a potential discrepancy between the LRA and Operating Experience Report with respect to the aging management program used for managing loss of material and cracking for stainless steel in outdoor air environments and indoor environments with recently introduced outdoor air.

steel in outdoor air environments and indoor environments with recently introduced outdoor air (LRA Sections 3.2.2.2.3.2, 3.2.2.2.6, 3.3.2.2.3, 3.3.2.2.5, 3.4.2.2.2, 3.4.2.2.3).

Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 3

3.2.2.2.6 Table 3.2-1 3.2-8 3.2-15 LRA further evaluation sections 3.2.2.2.6, 3.3.2.2.3, and 3.4.2.2.2 address the potential for cracking due to stress corrosion cracking of stainless steel components exposed to outdoor air.

Sections 3.3.2.2.3, and 3.4.2.2.2 state that cracking of piping and piping components is managed by the DCPP External Surfaces Monitoring of Mechanical Components AMP.

Section 3.2.2.2.6, however, states that cracking of certain components (siding, doors, support instruments, and structural bolting) is managed by the DCPP Structures Monitoring Program. In addition, the discussions in Section 3.2.2.2.6 and for item 3.2-1, 007 in Table 3.2-1 do not address piping and piping components other than insulated piping and piping components managed by another AMR item.

Therefore, it is not clear if cracking for stainless steel piping and piping components in the engineered safety features (ESF) systems is managed with the same approach as for the auxiliary and steam and power conversion systems.

Please clarify the aging management plans for cracking of stainless steel piping and components in the ESF systems (Section 3.2.2.2.6 and item 3.2-1, 007) compared to the approach for the auxiliary and steam and power conversion systems, and provide the basis for any differences.

Diablo Canyon LRA: Breakout Questions Steel-other Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 1

The Discussion of AMR item 3.3-1, 112 in LRA Table 3.3.1 indicates that electrical penetrations are covered by this AMR item. The staff notes that no electrical penetrations in the auxiliary system were assigned to AMR item 3.3-1, 112.

Please discuss if there are any electrical penetrations associated with AMR item 3.3-1, 112.

2 AMR item 3.3-1, 121 is for managing steel piping, piping components, and piping elements per NUREG-1800, Rev 2. AMR item 3.3-1, 121 is cited for carbon steel tanks in LRA Tables 3.3.2-4 and 3.3.2-12 with a Standard Note A. The staff noted that AMR item 3.3-1, 121 is cited with a Standard Note C for carbon steel tanks in LRA Tables 3.3.2-7, 3.3.2-14, and 3.3.2-

16.

Additionally, AMR item 3.3-1, 121 is cited for carbon steel compressor housing with a Standard Note A in LRA Tables 3.3.2-9 and 3.3.2-10.

Given the components are different, please discuss the use of Standard Note A where AMR item 3.3-1, 121 is cited for the carbon steel tanks in LRA Tables 3.3.2-4 and 3.3.2-12, and for the carbon steel compressor housing in LRA Tables 3.3.2-9 and 3.3.2-10 3

AMR item 3.4-1, 059 is for managing Steel piping, piping components, and piping elements exposed to Air - indoor controlled (External), Gas per NUREG-1800, Rev 2. AMR item 3.4-1, 059 is cited for the carbon steel Heat Exchanger (Gas Dryer Water Gas) Tube Side Components and Heat Exchanger (Gas Dryer) Shell Side Components with Standard Note A in Given the components are different, please discuss the use of Standard Note A where AMR item 3.4-1, 059 is cited for carbon steel heat exchanger components in 3.3.2-24, and carbon steel tanks in LRA Table 3.3.2-24.

Please discuss whether the dry gas environment for the carbon steel (coated/lined) piping and piping elements in LRA Table 3.4.2-1 is external or internal.

LRA Table 3.3.2-24. The staff notes that Standard Note C is cited for heat exchanger components in the same table, LRA Table 3.3.2-24, and in LRA Table 3.4.2-4.

Additionally, AMR item 3.4-1, 059 with a Standard Note A is cited for carbon steel Tank (Gas Dryer Skid Water Gas Separator Tanks) in LRA Table 3.3.2-24 under.

AMR item 3.4-1, 059 is cited for carbon steel (coated/lined) piping and piping components exposed externally to dry gas in LRA Table 3.4.2-1. Plant-specific notes 2 and 3 appear to indicate that the dry gas environment is internal.

Diablo Canyon LRA: Breakout Questions Titanium Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 1

Table 3.3.2-3 3.3-124 LRA Table 3.3.2-3, Saltwater and Chlorination System - Summary of Aging Management Evaluation, cites no aging effects requiring management for titanium tubing exposed to raw water.

As noted in SRP-LR Table 3.3-1, Summary of Aging Management Programs for Auxiliary Systems Evaluated in Chapter VII of the GALL Report, item 123, no aging effects are cited for specific grades of titanium exposed to raw water (i.e., ASTM Grades 1,2, 7, 11, or 12 that contains greater than 5 percent aluminum or more than 0.20 percent oxygen or any amount of tin). The staff requests a discussion with respect to the specific grade of titanium used for the tubing exposed to raw water.

2 N/A N/A UFSAR Section 10.4.1, Main Condenser, includes a reference to titanium tubes.

The staff requests a discussion with respect to if the subject tubes are in-scope for license renewal (and if so, how they are accounted for in the LRA).

Diablo Canyon LRA: Breakout Questions LRA Section B.2.3.41, Periodic Inspections for Selective Leaching Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 1

B.2.3.41 B.2-191 LRA Section B.2.3.41, Periodic Inspections for Selective Leaching, states

[t]he DCPP Periodic Inspection of Selective Leaching AMP is a new plant-specific AMP that will have the 10-elements defined specific to DCPP.

Therefore, the AMP is not compared for consistency with NUREG-1801.

Although the program is not compared for consistency with NUREG-1801, the program elements described in LRA Section B.2.3.41 appear to be consistent with the SLR version (NUREG-2191) of the Selective Leaching program. The staff requests a discussion to confirm that this is an accurate assessment.

In addition, the staff requests a discussion with respect to if there are any differences between the Periodic Inspections for Selective Leaching program and the NUREG-2191 version of AMP XI.M33, Selective Leaching.

2 B.2.3.41 B.2-187 The parameters monitored or inspected program element in LRA Section B.2.3.41 states [t]his monitoring will be performed where feasible based on form and configuration.

The staff requests a discussion with respect to why this statement is included. The NUREG-2191 version of AMP XI.M33 does not include this statement.

3 A.2.2.41 A.2-22 GALL-SLR Report Table XI-01, FSAR Supplement Summaries for GALL-SLR Report Chapter XI Aging Management Programs, includes the following for AMP XI.M33:

[i]nspections are conducted in accordance with plant-specific procedures including inspection parameters such as lighting, distance, offset and surface conditions. When the acceptance criteria are not met such that it is determined that the affected component should be The staff noted that the subject statement is not included in LRA Section A.2.2.41, Periodic Inspections for Selective Leaching. The staff requests a discussion with respect to why this statement is not included.

replaced prior to the end of the subsequent [deleted since this is an LRA not SLRA] period of extended operation, additional inspections are performed.

4 B.2.3.41 B.2-190 B.2-191 The plant-specific operating experience discussion in LRA Section B.2.3.41 states the following:

[i]n 1997, two aluminum-bronze valves in the Auxiliary Saltwater System showed signs of selective leaching. Polishing of the counterweight housings was performed and incorporated into normal maintenance work instructions to slow the rate of dealloying. Since implementation of the polishing of the counterweight housings in 1997, preventive maintenance inspections, performed every 18 months, have shown no issues associated with selective leaching.

The staff requests a discussion with respect to how polishing slows the rate of dealloying in aluminum-bronze (e.g., is polishing removing deposits from saltwater exposure that were causing accelerated rates of selective leaching?).

In addition, it appears that this activity is minimizing the potential for and rate of selective leaching; however, it is not included in the preventive actions program element of LRA Section B.2.3.41. The staff requests a discussion with respect to why this activity is not included in the preventive actions program element of LRA Section B.2.3.41.

5 N/A N/A DN50416947 discusses the failure of a buried cast iron fire water line in 2011 due to selective leaching.

The staff requests a discussion with respect to if selective leaching was identified on the internal or external surfaces of the pipe (or both surfaces).

6 N/A N/A DN50123904 states the most likely cause for the observed failure [referring to an event in 2008] is graphitization of the cast iron pipe, which lead to a catastrophic failure. Long-term plans for providing cathodic protection for this section of pipe and others in similar applications is prudent in preventing or reducing the occurrence of this problem.

The staff requests a discussion with respect to why it was subsequently determined that cathodic protection was not necessary for buried fire protection system piping.

7 B.2.3.41 B.2-188 NUREG-2222, Disposition of Public Comments on the Draft Subsequent License Renewal Guidance Documents NUREG-2191 and NUREG-2192, Based on plant-specific operating experience noted in breakout questions Nos. 5 and 6 above, the staff requests a discussion with respect to using the reduced

provides the basis for reducing the extent of inspections for selective leaching during the subsequent period of extended operation (i.e., 3 percent with a maximum of 10 components per GALL-SLR guidance) when compared to the extent of inspections for selective leaching during the initial period of extended operation (i.e., 20 percent with a maximum of 25 components per GALL Report, Revision 2 guidance). Part of the basis for reducing the extent of inspections is that industry OE had not identified instances of loss of material due to selective leaching which had resulted in a loss of intended function for the component.

LRA Section B.2.3.41 states [t]he visual/mechanical periodic inspections will consist of a sample of 3 percent of the population or a maximum of 10 components per population at each Unit.

sample size (i.e., 3 percent with a maximum of 10 components) for gray cast iron piping exposed to soil.

Diablo Canyon LRA: Breakout Questions LRA Sections A.2.2.28 and B.2.3.28 AMP: ASME Section XI, Subsection IWE Question Number SLRA Section SLRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 1

B.2.3.28 &

Table A-3, Items 30(a)

& 30(c)

B.2-134 &

A.4-24 Consistency of preventive actions element:

To establish consistency with the GALL-LR Report AMP XI.S1, the LRA AMP includes the following two enhancements to the preventive actions program element:

Bolting practice procedures will be enhanced to explicitly identify that NUREG-1339 (June 1990), EPRI NP-5769, and EPRI TR 104213 form a portion of the basis for the DCPP bolting program.

Ensure replacement and maintenance activities for structural bolting include appropriate preload and proper tightening (torque or tension) as recommended in EPRI documents, ASTM standards, AISC Specifications, and in Section 2 of RCSC publication "Specifications for Structural Joints Using ASTM A325 or A490 Bolts," as applicable.

The preventive actions program element of the GALL-LR AMP XI.S1 states, in part: The program is also augmented to require that the selection a) Discuss potential revised language to the enhancements and related LR commitments that provides specific clarity of actions and objective in a manner that demonstrates consistency with the preventive actions program element of the GALL-LR AMP XI.S1.

b) Update the LRA as necessary consistent with response to the above

of bolting material, installation torque or tension and the use of lubricants and sealants are in accordance with the guidelines of EPRI NP-5769, EPRI TR-104213, and the additional recommendations of NUREG-1339 to prevent or mitigate degradation and failure of structural bolting. If the structural bolting consists of ASTM A325, ASTM F1852, and/or ASTM A490 bolts, the preventive actions for storage, lubricants, and stress corrosion cracking potential discussed in Section 2 of RCSC (Research Council for Structural Connections) publication Specification for Structural Joints Using ASTM A325 or A490 Bolts, need to be considered.

The language of the referenced LRA enhancements and related LR commitments appear to be very general and non-specific, lacks clarity with regard to the specific objective of the enhancements, and it is unclear how it would make the program element consistent with the GALL-LR.

2 B.2.3.28 &

Table A-3, Item 31(b)

B.2-134 &

A.4-24 In consideration of operating experience and laboratory examinations that show that the use of molybdenum disulfide (MoS2) and other products containing sulfur as a lubricant is a potential contributor to stress corrosion cracking (SCC) especially in high-strength a) Confirm or clarify whether or not MoS2 or other lubricants containing sulfur have been or will be used prior to the PEO for high-strength bolting (actual tensile strength greater than 150 ksi) within the scope of the LRA B.2.3.28 (IWE) AMP.

bolting, the LRA includes the following enhancement to the preventive actions program element: Prohibit the use of molybdenum disulfide as a lubricant for structural bolts to prevent SCC.

It is not clear if MoS2 or other lubricants containing sulfur have been or will used in structural bolting in the scope of the LRA AMP prior to entering the period of extended operation (PEO). If so, it is not clear how the potential for SCC in such bolting be adequately managed during the PEO.

b) If used in response to a), discuss how the potential for SCC in such bolting will be adequately managed during the PEO as required by 10 CFR 54.21(a)(3).

c) Update LRA as necessary consistent with the responses to the above requests.

3 PBD Section 4.4 for LRA AMP B.2.3.28 PBD pages 10-11 Program Basis Document (PBD) in the ERR AMP Evaluation Report for AMP B.2.3.28, Section 4.4, states on page 10

&11: The frequency of the examinations on the containment liner is specified in the 2007 edition through 2008 addenda of ASME Section XI, Subsections IWE

[Ref. 7.9, Section 5.1.5.1].

Contrary to the above statement in the PBD, the GALL-LR AMP XI.S1 requires the examination methods, frequency and scope to be consistent with the code edition(s) during the PEO in accordance with 10 CFR 50.55a, and therefore appears inconsistent with the GALL-LRA AMP XI.S1. There is no a) Discuss how the Detection of Aging Effects program element of the LRA AMP described in the PBD is consistent with GALL-LR AMP XI.S1, as claimed, when the code edition used during the PEO will not be the 2007 Edition with 2008 addenda. Also, discuss the changes that may need to be made to the PBD to achieve consistency.

mention of 10 CFR 50.55a in Section 4.4 of the PBD.

4 B.2.3.28 &

Table A-3, Item 30(f)

B.2-134 &

A.4-25 The detection of aging effects program element includes an enhancement as below to confirm the absence of SCC.

A supplemental one-time inspection will be performed by qualified personnel using methods capable of detecting cracking due to SCC, comprising a representative sample (2 penetrations) of the stainless steel penetrations or DMWs associated with high-temperature (temperatures above 140°F) stainless steel piping systems in frequent use. These inspections are intended to confirm the absence of SCC aging effects. If cracking is detected as a result of the supplemental one-time inspections, additional inspections will be conducted in accordance with the sites corrective action process. Periodic inspection of subject penetrations with dissimilar metal welds for cracking will be added to the ASME Section XI, Subsection IWE AMP if necessary, depending on the inspection results.

The enhancement does not state the method(s) capable of detecting cracking that will used for the inspection.

a) Clearly state in the enhancement the method(s) capable of detecting cracking that will be for the one-time inspection.

b) Discuss and justify the adequacy of the proposed representative sample for discussing the total number of the population of penetrations/DMWs it represents and clarify if it applies to each unit.

Further, clarify if the fuel transfer tube/bellows should also be included in the sample.

c) Discuss and include in the enhancement the frequency of periodic inspections if the absence of SCC is not confirmed or if SCC is detected from the one-time examination and clarify if the enhancement should also apply to the corrective actions program element.

d) Discuss whether DCPP has had any operating experience of cracking due to SCC or due to cyclic loading in penetrations with DMWs and clarify if these penetrations are subject to Type B leak rate testing.

e) Revise the LRA consistent with the responses to the above

There is no information provided of the adequacy of the representative sample, especially considering the population of SS penetrations or DMWs associated with high temperature piping it represents and whether the sample size applies to each of the two units. Also, it is not clear why the fuel transfer tube and bellows are not included in the sample.

The enhancement does not address the frequency of periodic inspections if the absence of SCC is not confirmed or if SCC is detected from the one-time examination, and it is unclear if the enhancement should also apply to the corrective actions program element.

5 Table 3.5-1, item 3.5-1, 027; ERR PBD DCM T-43, Appendix B, Rev 3 3.5-41, PBD p10 LRA Table 3.5-1, item 3.5-1, 027 states the AMR line item is not applicable because All penetrations are covered by a fatigue waiver, fatigue analysis, or 3.5-1, 009.

The above AMR item corresponds to GALL-LR item II.A3.CP-37 for penetration sleeves and bellows of steel, stainless steel and dissimilar metal welds to manage cracking due to cyclic loading when CLB fatigue analysis does not exist for the component.

a) Justify the non-applicability claim for LRA AMR item 3.5-1, 027 when penetration sleeves components with DMWs and stainless steel fuel transfer tube/bellows exist for which there is no CLB fatigue analyses b) Explain how cracking due to cyclic loading will be adequately managed consistent with 10 CFR 54.21(a)(3) for the containment penetration components with DMWs or of stainless steel material for which there is no CLB fatigue analyses c) Revise the LRA as necessary consistent with responses to the above requests.

Contrary to the non-applicability claim for item 3.5-1, 027, the staff notes from LRA Section 3.5.2.2.1.6 that penetration components (e.g., sleeves fuel transfer tube and bellows) exist at DCPP with no CLB fatigue analyses. Further, noting that SCC is not addressed by fatigue analyses, Section 4.3 of program basis document for the IWE AMP, DCM T-43, Appendix B, Rev 3, on page 10 states:

In addition to stainless steel piping lines that penetrate containment and contain borated water at greater than 140o F are welded to carbon steel penetration sleeves. The CLB fatigue analyses did not include the resulting DMWs that could be susceptible to SCC.

It is not clear if the non-applicability claim for item 3.5-1, 027 is justified and how cracking due to cyclic loading will be adequately managed for the penetration components that have no CLB fatigue analyses.

6 B.2.3.28 B.2-135 The fourth bullet under Industry Operating Experience states: RIS 2016-07, "Containment Shell or Liner Moisture Barrier Inspection," reiterated the NRC position regarding inservice inspection requirements for moisture barrier materials. This document is being re-evaluated by PG&E for applicability to the DCPP containment liners.

a) Discuss and update the LRA to reflect the results of PG&Es re-evaluation of applicability of RIS 2016-07.

b) Discuss and clarify if DCPP has had any OE of degradation of the containment liner due to potential intrusion of moisture into inaccessible areas at the interface of the containment liner with the concrete containment floor regardless of whether a moisture barrier exists or not.

It is not clear what the outcome of the re-evaluation and its impact on the IWE AMP.

Also, it is not clear if DCPP has had any OE of degradation of the containment liner due to potential intrusion of moisture into inaccessible areas at the interface of the containment liner with the concrete containment floor regardless of whether a moisture barrier exists or not; and whether any areas of the components under the IWE program have been identified for augmented examination.

c) Discuss what areas, if any, of metallic containment pressure-retaining boundary components have been identified for augmented examination in the current or past ISI intervals and results of findings if any.

7 B.2.3.28 ERR The staff understands from information in the ERR (e.g., Notifications A0554957, 50354177 etc) that DCPP has OE of instances of containment liner bulges in several areas in both units.

For clarity of the staffs understanding, the staff requests a discussion on the operating experience of discernible bulges of the containment liner at DCPP.

a) Discuss the extent of discernible containment liner bulges at DCPP.

b) Clarify whether there is any evidence of separation of the containment liner from an anchor point or anchor separating from the concrete at the locations of discernible bulges and explain how that was determined.

c) Clarify if existing containment liner bulges are monitored for changes or separation, and how that is included in the AMP.

d) Include a summary of the OE of containment liner bulges in the LRA as part of plant-specific OE.

8 A.2.2.28 A.2-14 The LRA FSAR description for the ASME Section XI, Subsection IWE does not appear to include Class MC Provide a revised FSAR supplement description that provides a clear and appropriate description of the

mechanical and electrical penetrations.

Also, the underlined phrase in the sentence The AMP consists of periodic visual, surface and volumetric inspection, as applicable, of pressure-retaining components of steel liner and concrete containments for signs of degradations, assessment of damage, and corrective actions, does not appear to provide an appropriate description of the containment pressure-retaining boundary metallic components intended to by managed by the AMP.

containment pressure-retaining boundary metallic components managed by the AMP.

9 3.5.2.2.2.4 and Table 3.5-1, AMR Item 3.5-1, 052 3.5-27, 3.5-55 The referenced AMR item and FE relates to cracking due to SCC, and loss of material due to pitting and crevice corrosion of stainless steel material components of Group 7 (concrete with liner) & Group 8 (steel) tanks in a water-standing environment.

The LRA Section 3.5.2.2.2.4 and Table 3.5-1, 052 line item states:

Not Used. The in-scope tank liners at DCPP were evaluated as tanks with their mechanical systems and assigned lines from NUREG-1801 Chapters VII and VIII. Therefore, the NUREG-1801 lines from Chapter III were not used.

From the above descriptions in the LRA, it is not clear what specific AMR line items from NUREG-1801 Chapters VII and VIII are used in a) Identify the specific LRA Table and AMR line items that are used in lieu of Table 3.5-1, item 3.5-1, 052 for each of the component, material, environment, and aging effect combination covered by the line item.

b) Provide the related further evaluation that justifies why the AMP credited in the alternate AMR item used is adequate to manage the related aging effects during the period of extended operation.

c) Update applicable portions of the LRA consistent with responses to the above.

lieu of item 3.5-1, 052 for each of the aging effects covered by the line item, and where in the LRA they are included.

Diablo Canyon LRA: Breakout Questions LRA Section: B.2.3.30 /A.2.2.30 ASME Section XI, Subsection IWF AMP Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 1

B.2.3.30; AMP Evaluation Report for B.2.3.30 (PBD),

Section 4.1 B.2-140; B.2-141; PBD p6-7 Consistency of scope of program element:

Scope of program element of GALL-LR AMP XI.S3 states, in part: The scope of the program includes support members, structural bolting, high strength structural bolting, support anchorage to the building structure,..

From the description in Section 4.1 of the PBD, it is not clear if support anchorage to the building structure is included in the scope of the LRA B.2.3.30 AMP.

a) Clarify if and where support anchorage to the building structure is included in the scope of the LRA B.2.3.30 AMP.

b) If not included, please include to justify consistency with the scope of GALL-LR AMP; or justify the exception being taken in this regard.

c) Update the LRA (including the FSAR supplement) as necessary consistent with the response 2

B.2.3.30 &

Table A-3, Items 32(b) &

32(c)

B.2-141

& A.4-26 Consistency of preventive actions element:

To establish consistency with the GALL-LR Report AMP XI.S3, the LRA AMP includes the following two enhancements to the preventive actions program element:

Bolting practice procedures will be enhanced to explicitly identify that NUREG-1339 (June 1990), EPRI NP-5769, and EPRI TR 104213 a) Discuss potential revised language to the enhancements and related LR commitments that provides specific clarity of actions and objective in a manner that demonstrates consistency with the preventive actions program element of the GALL-LR AMP XI.S3.

b) Update the LRA as necessary consistent with response to the above

form a portion of the basis for the DCPP bolting program.

Ensure replacement and maintenance activities for high-strength structural bolting specify that the replaced bolting material has an actual measured yield strength less than 150 ksi or 1034 MPa and include appropriate preload and proper tightening (torque or tension) as recommended in EPRI documents, ASTM standards, AISC Specifications, and in Section 2 of RCSC publication "Specifications for Structural Joints Using ASTM A325 or A490 Bolts," as applicable.

The preventive actions program element of the GALL-LR AMP XI.S3 states, in part:

Selection of bolting material and the use of lubricants and sealants is in accordance with the guidelines of EPRI NP-5769, EPRI TR-104213, and the additional recommendations of NUREG-1339 to prevent or mitigate degradation and failure of safety-related bolting..

Preventive measures also include using bolting material that has an

actual measured yield strength less than 150 ksi or 1034 MPa.

Structural bolting replacement and maintenance activities include appropriate preload and proper tightening (torque or tension) as recommended in EPRI documents, ASTM standards, AISC Specifications, as applicable. If the structural bolting consists of ASTM A325, ASTM F1852, and/or ASTM A490 bolts, the preventive actions for storage, lubricants, and stress corrosion cracking potential discussed in Section 2 of RCSC (Research Council for Structural Connections) publication Specification for Structural Joints Using ASTM A325 or A490 Bolts, need to be used.

The language of the referenced LRA enhancements and related LR commitments (other than the part specifying bolting material strength less than 150 ksi) appear to be very general and non-specific, lacks clarity with regard to the specific objective of the enhancements, and it is unclear how it would make the program element consistent with the GALL-LR.

3 B.2.3.30 &

Table A-3, Item 31(a)

B.2-14`

& A.4-26 Use of MoS2 and other products containing sulfur as a lubricant:

In consideration of operating experience and laboratory examinations that show that the use of molybdenum disulfide (MoS2) and other products containing sulfur as a lubricant is a potential contributor to stress corrosion cracking (SCC) especially in high-strength bolting, the LRA includes the following enhancement to the preventive actions program element: Bolting procedures will be enhanced to explicitly prohibit the use of MoS2 as a lubricant for structural bolts to prevent SCC.

It is not clear if MoS2 or other lubricants containing sulfur have been or will used in structural bolting in the scope of the LRA AMP prior to entering the period of extended operation (PEO). If so, it is not clear how the potential for SCC in such bolting be adequately managed during the PEO.

d) Confirm or clarify whether MoS2 or other lubricants containing sulfur have been or will be used prior to the PEO for high-strength bolting (actual tensile strength greater than 150 ksi) within the scope of the LRA B.2.3.30 (IWF) AMP.

a) If used in response to a), discuss how the potential for SCC in such bolting will be adequately managed during the PEO as required by 10 CFR 54.21(a)(3).

b) Update the LRA as necessary consistent with the response to the above.

4 B.2.3.30 B.2-140, B.2-141 Justification for Exception:

The LRA AMP takes an exception to the preventive actions program element that, while the IWF AMP a) Explain, by sharing on the Teams screen the relevant documents, how and where lubricants using sulfur are recommended in the referenced documents and discuss how the

will prohibit the use of MoS2, it is taking exception to the recommendation to not use lubricants containing sulfur.

The related justification states, in part: This exception is consistent with NUREG-1339 (June 1990),

and industry recommendations delineated in the EPRI NP-5769, NP-5067, and TR-104213 for high-strength structural bolting. In addition, EPRI Materials Handbook for Nuclear Plant Pressure Boundary Application December 2019 (3002016000),

recommends use of alternative lubricants such as nickel-based anti-seize and graphite-alcohol to minimize the use of lubricants and sealants that may degrade to form aggressive species (such as MoS2-based lubricants) or have potentially aggressive impurities.

It is not made clear how the above explanation justifies the exception and how the AMP with the exception remains adequate to manage the related aging effects.

recommendation of use of nickel-based anti-seized and graphite alcohol lubricants recommended in EPRI materials handbook justify use of lubricants containing sulfur for which exception is being taken.

b) Provide a reasonable technical basis to justify how the AMP with the exception remains adequate to manage the applicable aging effects consistent with 10 CFR 54.21(a)(3).

c) Update the LRA, as necessary.

5 Table 3.5-1, Table 3.5.2-9 3.5-70, 3.5-136 AMR Item 3.5-1, 084 Issue:

LRA Table 3.5-1, AMR item 3.5-1, 084 addresses loss of material due a) Provide the technical bases as to why the LRA proposed alternate Structures Monitoring Program examination method(s), frequency,

to pitting and crevice corrosion for stainless steel (SS) structural bolting associated with the spent fuel pool (SFP) gates exposed to treated borated water. For the LRA Table 3.5.2-9 AMR item that cites generic note E, the LRA credits the Structures Monitoring AMP (B.2.3.30) in lieu of the Water Chemistry (XI.M2) and ASME Section XI, Subsection IWF(XI.S3)

AMPs recommended for the AMR item in SRP-LR Table 3.5-1 and GALL-LR to manage the effects of aging for loss of material.

This AMR item has a structural support function and cites plant specific note 1, which states: The DCPP Structures Monitoring AMP (B.2.3.33) will be used to manage loss of material for structural bolting associated with the spent fuel pool gates.

It is not made clear how the LRA credited single alternate Structures Monitoring Program is adequate and acceptable to manage the aging effect in lieu of the Water Chemistry and IWF AMPs recommended in the corresponding SRP-LR and GALL-LR for managing the aging effect.

and/or differences in program elements will be equally effective in managing the aging effect as the GALL-LR recommended combination of AMPs XI.M2 Water Chemistry and XI.S3 ASME Section XI, Subsection IWF.

b) Update the LRA as necessary consistent with the response to the above

Diablo Canyon LRA: Breakout Questions Structural Monitoring Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 1

B.2.3.33 B.2-152 LRA Section B.2.3.33 provides an enhancement to the DCPP Structures Monitoring AMP for revising procedures to require that whenever an in-scope pull box is going to be opened, the appropriate personnel will be notified to allow them to determine whether an opportunistic inspection of the pull box should be performed.

During the on-site audit, the staff observed that these in-scope pull boxes are reinforced concrete structures, which are directly buried in soil and potentially exposed to adverse localized environment caused by significant moisture.

The staff noted that LRA Sections 2.2, 2.4, and 3.5 lack the information of aging management for the in-scope pull boxes.

In addition, LRA does not make clear whether these in-scope pull boxes are inspected on the Scope of program:

1. Add pull boxes in LRA Sections 2.2, 2.4, and 3.5.

2. Clarify whether these in-scope pull boxed are inspected on the frequency not to exceed 5 years by the existing DCPP Structures Monitoring AMP. If not, provide the enhancement accordingly.

3. Clarify the criteria for whether an opportunistic inspection of the pull box should be performed when it is open.

frequency not to exceed 5 years by the existing AMP.

2 B.2.3.33 2.3.2.1 2.4.14 B.2-152 2.3-15 2.4-40 GALL-LR XI.S6 AMP includes the following SCs and structural commodities in the scope of program, such as trash racks, and tube tracks.

LRA Section 2.3.2.1 states, The containment sump screens, debris curb and trash racks prevent debris from entering the ECCS pump suctions to ensure adequate pump suction head.

LRA Section 2.4.14 states, The following structural supports for mechanical components are addressed: supports for HVAC ducts, tube track, instrument tubing, instruments, and non-ASME piping and components.

LRA does not make clear whether these SCs and structural commodities are already included in the existing DCPP Structures Monitoring AMP.

It appears that LRA does not include Tables 1 and 2 AMR items for the SCs and structural commodities mentioned above.

Scope of the Program:

1. Clarify whether trash racks and tube tracks are within the scope of existing DCPP Structures Monitoring AMP. If not, consider providing an enhancement to include these SCs and structural commodities.

2. Provide Tables 1 and 2 items for trash racks and tube tracks.

3 B.2.3.33 B.2-152 GALL-LR XI.S6 AMP states that the program should include preventive actions delineated in NUREG-1339 and in EPRI NP-5769, NP-5067, and TR-104213 to ensure structural bolting integrity, if applicable. These actions emphasize proper selection of bolting material, lubricants, and installation torque or tension to prevent or minimize loss of bolting preload and cracking of high-strength bolting. If the structural bolting consists of ASTM A325, ASTM F1852, and/or ASTM A490 bolts, the preventive actions for storage, lubricants, and stress corrosion cracking potential discussed in Section 2 of RCSC (Research Council for Structural Connections) publication Specification for Structural Joints Using ASTM A325 or A490 Bolts, need to be used.

The DCPP Structures Monitoring AMP provides an enhancement to include appropriate preload and proper tightening (torque or tension) for structural bolting replacement and maintenance activities, which is inconsistent with the GALL-LR XI.S6 AMP.

Preventive actions:

Address the inconsistency of the preventive actions between LRA and GALL-LR XI.S6 AMP.

4 B.2.3.33 B.2-152 B.2-154 The DCPP Structures Monitoring AMP provides an enhancement for conducting a one-time video inspection of the Unit 2 spent fuel pool leak chase within one year prior to August 26, 2025, and LRA states no SFP liner leaks at Unit 1 but describes the slight increases in leakage of the spent fuel pool at Unit 2. LRA does not make clear whether there are leakages in the leak chase channel in the refueling cavity and transfer canal.

EPRI 3002007348 report provides a template for an aging management program for managing boric acid attack on reinforced concrete in a SFP structure that has been exposed to leakage, which is consistent with the guidance in the Branch Technical Position RLSB-1 of the SRP-LR Appendix A.1.

The applicant is requested to follow the guidance in EPRI 3002007348 for adequately managing aging effects of boric attack on reinforced concrete in the SFP, the Transfer Canal, and the Refueling Cavity during the PEO.

Plant-specific AMP or enhancements to the Structures Monitoring AMP:

1. Evaluate Elements 1 through 7 in the EPRI 3002007348 report AMP template to determine which elements need to be enhanced to the DCPP Structures Monitoring AMP for managing aging effects of boric attack on reinforced concrete in the SFP, the Transfer Canal, and the Refueling Cavity, and provide enhancements if necessary.

2. Provide justifications (e.g. plant procedures, instructions, OE, and inspection and testing results, etc.) for why the enhancements to some of Elements 1 through 7 comparing with EPRI 3002007348 report AMP template are not necessary.

5 B.2.3.33 Table 3.5-1 B.2-152 3.5-63 GALL-LR XI.S6 AMP states in parameters monitored or inspected element that high strength (actual measured yield strength 150 ksi or 1,034 MPa) structural bolts greater than 1 inch (25 mm) in diameter are monitored for SCC.

GALL-LR XI.S6 AMP also states in detection of aging effects that visual inspection of high strength (actual measured yield strength 150 ksi or 1,034 MPa) structural bolting greater than 1 inch (25 mm) in diameter is supplemented with volumetric or surface examinations to detect cracking.

LRA Table 3.5-1 lists AMR item 3.5-1, 069 to be not used. It also states, Structural bolting within the scope of the DCPP Structures Monitoring AMP includes ASTM A490 material.

ASTM A490 bolts used in civil structures have not been shown to be prone to SCC, and SCC potential need not be evaluated for these bolts.

Therefore, cracking due to SCC is not an aging effect requiring management for structural bolting within the scope of the Parameters monitored or inspected, and detection of aging effects:

1. Clarify whether there are high-strength structural bolts greater than 1 inch in diameter that are monitored by the DCPP Structures Monitoring AMP. If yes, (a) provide Tables 1 and 2 AMR items; (b) discuss how the aging effect of cracking due to SCC will be adequately managed by the DCPP Structures Monitoring AMP during the PEO.

2. Evaluate whether enhancements to the DCPP Structures Monitoring AMP are needed to ensure the consistency with the GALL-LR XI.S6 AMP.

3. Evaluate the applicability of AMR item 3.5-1, 069.

DCPP Structures Monitoring AMP.

The staff notes that there is a difference between the terms not used and not applicable.

If Table 1 AMR item meets the following condition, Table 1 AMR item is not used:

The component, material, and aging effect combination are addressed by a different Table 1 AMR item.

LRA does not make clear whether there are high-strength structural bolts greater than 1 inch in diameter that are monitored by the DCPP Structures Monitoring AMP.

6 B.2.3.33 B.2-152 B.2-153 GALL-LR XI.S6 AMP states in parameters monitored or inspected element that elastomeric vibration isolators and structural sealants are monitored for cracking, loss of material, and hardening.

GALL-LR XI.S6 AMP also states in detection of aging effects that visual inspection of elastomeric vibration isolation elements should be supplemented by feel to detect Parameters monitored or inspected, detection of aging effects, and acceptance criteria:

1. Clarify whether there are elastomeric vibration isolators that are monitored by the DCPP Structures Monitoring AMP. If yes, provide Tables 1 and 2 AMR items.

2. Address the inconsistency between the DCPP Structures Monitoring AMP and the GALL-LR XI.S6 AMP.

hardening if the vibration isolation function is suspect.

GALL-LR XI.S6 AMP further states in acceptance criteria element that elastomeric vibration isolation elements are acceptable if there is no loss of material, cracking, or hardening that could lead to the reduction or loss of isolation function.

The DCPP Structures Monitoring AMP provides an enhancement to the acceptance criteria element for specifying that that structural sealants are acceptable if the observed loss of material, cracking, and hardening will not result in loss of sealing.

LRA does not make clear whether there are elastomeric vibration isolators that are managed by the DCPP Structures Monitoring AMP.

It appears that the DCPP Structures Monitoring AMP is inconsistent with the GALL-LR report.

7 B.2.3.33 B.2-152 The DCPP Structures Monitoring AMP provides an enhancement to the Parameters monitored or inspected:

Clarify whether the statement In addition, specify the acceptance criteria for sliding surfaces are no indications of

parameters monitored or inspected element for specifying the acceptance criteria for sliding surfaces no indications of excessive loss of material due to corrosion or wear and no debris or dirt that could restrict or prevent sliding of the surfaces as required by design, which is already included in the enhancement to the acceptance criteria element.

excessive loss of material due to corrosion or wear and no debris or dirt that could restrict or prevent sliding of the surfaces as required by design can be deleted in the enhancement to the parameters monitored or inspected element.

8 B.2.3.33 NA GALL-LR XI.S6 AMP states the detection of aging affects for inaccessible, below-grade concrete structural elements by the Structures Monitoring AMP.

For plants with non-aggressive ground water/soil (pH > 5.5, chlorides < 500 ppm, or sulfates <1500 ppm), the program recommends:

(a) evaluating the acceptability of inaccessible areas when conditions exist in accessible areas that could indicate the presence of, or result in, degradation to such inaccessible areas and (b) examining representative samples of the exposed portions of the below-grade concrete, when excavated for any reason.

Detection of aging effects:

Clarify whether the existing DCPP Structures Monitoring AMP implements (a) and (b) recommended by the GALL-LR XI.S6 AMP. If not, provide the enhancements to the DCPP Structures Monitoring AMP.

LRA claims that DCPP examines exposed portions of below-grade (inaccessible) concrete, when excavated for any reason.

However, the staff reviewed the MA1.NE1, Maintenance Rule Monitoring Program-Civil Implementation, Revision 7, MAI.ID 17, Maintenance Rule Monitoring Program, Revision 34, and AWP E - 016, Inspection Guide -

Maintenance Rule Structural Monitoring Program - Civil, Revision 12, and finds that these documents dont have information on (a) and (b) recommended by the GALL-LR XI.S6 AMP.

9 B.2.3.33 NA During the on-site walkdown, the staff noted cathodic protect system installed on the concrete deck of the intake structure. The staff observed some cracks and more concrete spalling and deterioration towards the waterfront.

LRA Table 2.2-1 lists the cathodic protection to be not within the scope of LR.

1. Clarify whether cathodic protection system is relied upon to manage the effects of aging. If yes, include provisions in the DCPP Structures Monitoring AMP to address cathodic protection system monitoring and maintenance and provide the corresponding Tables 1 and 2 AMR items.

2. Provide CRs and WOs and discuss corrective actions that will be taken for these degradations.

3. Evaluate the history of OE and determine whether an enhancement to the DCPP Structures Monitoring AMP is needed to include provisions for more frequent inspections of the reinforced concrete in the Intake Structure to ensure there is

Based on the applicants responses to the staffs on-site audit questions, the applicant used cathodic protection system to increase the service life of the concrete in the Intake Structure.

In addition, the staff noted that the applicant provides an enhancement to the Buried and Underground Piping and Tanks AMP for installing impressed current cathodic protection for remaining portions of the buried auxiliary saltwater system discharge and supply piping in contact with soil, etc.

GALL-LR XI.S6 AMP includes provisions for more frequent inspections of structures and components categorized as (a)(1) in accordance with 10 CFR 50.65 to ensure there is no loss of intended function between inspections.

LRA does not make clear whether cathodic protection system is credited for aging management in the DCPP Structures Monitoring AMP.

LRA does not make clear whether more frequent inspections are needed for the no loss of intended function between inspections. If yes, specify the inspection frequency.

concrete components in the Intake Structure to ensure there is no loss of intended function between inspections.

10 OE NA During the walkdown of the Turbine Building, the staff noted one offset pipe support at elevation 104 feet.

During the walkdown of the Intake Structure, the staff noted pipe leakage to the concrete floor.

1. Discuss corrective actions that will be taken for the observed offset pipe support and provide CRs and WOs if available.

2. Evaluate whether chemicals of the leaked fluid from pipe leakage will accelerate deterioration of the concrete floor in the Intake Structure and discuss corrective actions that will be taken.

11 Table 3.5.2-10 3.5-143 LRA Table 3.5.2-10 addresses loss of material due to pitting and crevice corrosion for the aluminum hatches and plugs exposed to encased in concrete environment.

Plant specific note 1 states, Concrete hatch covers and hatch openings are constructed with aluminum angles forming the corners and edges; used to prevent damage during maintenance. Portions of the aluminum angles are embedded in the concrete hatches. The DCPP Structures Monitoring AMP will inspect the accessible surfaces of the aluminum.

Explain how aging effects of the embedded aluminum hatches and plugs can be adequately managed by the DCPP Structures Monitoring AMP during the PEO.

GALL-LR XI.S6 AMP recommends: (a) evaluating the of inaccessible areas when conditions exist in accessible areas that could indicate the presence of, or result in, degradation to such inaccessible areas and (b) examining representative samples of the exposed portions of the below-grade concrete, when excavated for any reason.

LRA does not make clear how aging effects of the embedded aluminum can be adequately managed by the DCPP Structures Monitoring AMP during the PEO.

12 Table 3.5.2-14 3.5-160 LRA Table 3.5.2-14 addresses loss of material for the PVC conduit and supports exposed to buried environment.

Plant specific note 2 states, Consistent with guidance in NUREG-2191, buried PVC is susceptible to loss of material.

The DCPP Structures Monitoring AMP will be used to manage buried PVC conduit.

LRA does not make clear whether there are accessible

1. Clarify mechanism for the effects of aging.

2. Clarify whether there are accessible PVC conduit and supports requiring aging management. If yes, provide Tables 1 and 2 AMR items.

3. Explain how aging effects of the buried conduit and supports can be adequately managed by the DCPP Structures Monitoring AMP during the PEO.

PVC conduit and supports requiring aging management.

LRA does not make clear how aging effects of the buried PVC conduit and supports can be adequately managed by the DCPP Structures Monitoring AMP.

13 Table 3.5.2-4 3.5-111 LRA Table 3.5.2-4 addresses cracking/reduction of strength for the fiberglass roofing panel exposed to atmosphere/weather environment.

LRA does not make clear whether other aging effects (e.g.

loss of material, loss of sealing, etc) are applicable to the fiberglass roofing panel.

1. Clarify mechanism for the effects of aging.

2. Clarify whether other aging effects (e.g. loss of material, loss of sealing, etc) are applicable to the fiberglass roofing panel. If yes, provide Table 2 AMR items.

14 Table 3.5-1 Varies LRA Table 3.5-1 states in multiple locations that Group 8 structures are included in their respective mechanical systems.

LRA does not make clear how Tables 1 and 2 AMR items for structural components in the Group 8 structures are presented.

Clarify LRA Tables 1 and 2 AMR items for the structural components in the Group 8 structures.

15 Table 3.0-2 Table 3.5.2-3 3-10 3.5-97 3.5-105 LRA Table 3.0-2 lists structural service environments (atmosphere/weather, borated water leakage, buried, encased in concrete, plant indoor air, and submerged) along with description and corresponding NUREG-1801 environments.

For examples, LRA Table 3.5.2-3 lists Table 2 AMR item associated with AMR item 3.5-1, 065 for concrete component exposed to atmosphere/weather and buried environment, its corresponding NUREG-1801 item III.A3.TP-27 lists concrete component exposed to air-outdoor environment.

LRA Table 3.5.2-3 lists Table 2 AMR item associated with AMR item 3.5-1, 063 for concrete component exposed to atmosphere/weather and buried environment, its corresponding NUREG-1801 item III.A3.TP-24 lists concrete component exposed to air-indoor, uncontrolled environment.

LRA Table 3.5.2-3 lists Table 2 AMR item associated with AMR item 3.5-1, 080 for carbon steel structural bolting exposed to atmosphere/weather and plant Discuss structural service environments listed in LRA Table 3.0-2 to ensure consistency with NUREG-1801.

indoor air environment, its corresponding NUREG-1801 item III.A3.TP-248 lists steel structural bolting exposed to air-indoor, uncontrolled environment.

It appears that LRA Table 2 AMR item environments are inconsistent with NUREG-1801 environments.

Diablo Canyon LRA: Breakout Questions Concrete Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 1

3.5.2.2.1.7 3.5-21 LRA FE Section 3.5.2.2.1.7 states that DCPP is located in a negligible weathering region as determined by ASTM C33, Figure 1.

LRA does not make clear the version of ASTM C33.

Clarify the version of ASTM C33.

Note: this question also applies to LRA FE Sections 3.5.2.2.2.1, item 1 and 3.5.2.2.2.3, item 1.

2 3.5.2.2.1.8 3.5.2.2.2.1.2 3.5.2.2.2.3.2 Table 3.5-1 Table 3.5-1 3.5-21 3.5-23 3.5-26 3.5-48 3.5-53

1. ASR SRP-LR report states that a plant-specific aging management program is not necessary if (1) investigations, tests, and petrographic examinations of aggregates performed in accordance with ASTM C295 and other ASTM reactivity tests, as required, can demonstrate that those aggregates do not adversely react within concrete or (2) for potentially reactive aggregates, aggregate concrete reaction is not significant if the structure was constructed in accordance with ACI 318.

SRP-SLR report states visual indications of aggregate reactions in the accessible concrete areas, such as map or patterned cracking, alkali-

1. Provide petrographic test results to verify whether these patterned cracks are associated with expansion due to reaction with aggregates.

2. Provide the evaluation to determine the cause of these patterned cracks.

3. Provide plant-specific AMP if these patterned cracks are determined to be cracks due to ASR.

4. Clarify whether the DCPP Structures Monitoring AMP (TRP 046), the DCPP Inspection of Water-Control Structures (TRP-047), the DCPP ASME Section XI, Subsection IWL (TRP-042) will be enhanced to detect visual indications of aggregate reactions in the accessible concrete areas, such as map or patterned cracking, alkali-silica gel, exudations, surface staining, expansion causing structural deformation, relative movement or displacement, or misalignment/distortion of attached components during the PEO.

5. Explain how aging effect of the ASR in the inaccessible concrete areas can be adequately managed by the DCPP

silica gel, exudations, surface staining, expansion causing structural deformation, relative movement or displacement, or misalignment/distortion of attached components.

LRA FE sections state that cracking and other indications of ASR associated with expansion due to reaction with aggregates has not been observed on the DCPP containment and the DCPP concrete structures.

The staff reviewed Section 11, Inspection Guidelines for CIVIL SSCs of the AWP E-016, Inspection Guide -

Maintenance Rule Structural Monitoring Programs - Civil, Revision 12, on the Portal and finds that it does not contain information on visual indications of aggregate reactions.

During the on-site audit, the staff noted patterned cracks on the interior and exterior concrete walls in the Auxiliary Building. The staff also noted patterned cracks in the containment concrete walls (TRP 42) listed in the Units 1 AMPs during the PEO and ensure the consistency among LRA FE sections.

and 2 containment concrete visual inspection reports

(#VL_2007_0051322_Unit 1 and #VL_2007_051722_Unit 2).

LRA does not make clear whether these patterned cracks are associated with expansion due to reaction with aggregates. In addition, the current DCPP Structures Monitoring AMP and the ASME Section XI, Subsection IWL AMP lack procedures to detect these ASR -related indicators.

2. Inaccessible concrete areas GALL-LR XI.S6 AMP states the detection of aging affects for inaccessible, below-grade concrete structural elements by the Structures Monitoring AMP.

For plants with non-aggressive ground water/soil (pH > 5.5, chlorides < 500 ppm, or sulfates <1500 ppm), the program recommends:

(a) evaluating the acceptability of inaccessible areas when conditions exist in accessible areas that could indicate the presence of, or result in, degradation to such inaccessible areas and (b) examining representative

samples of the exposed portions of the below-grade concrete, when excavated for any reason.

LRA Table 3.5-1, AMR item 3.5-1, 043, states Consistent with the OE reflected in SLR-ISG-2021-03-STRUCTURES, a plant-specific AMP is not required. The DCPP Structures Monitoring AMP includes opportunistic examination of below-grade inaccessible concrete areas based on conditions in accessible areas.

LRA Table 3.5-1, AMR item 3.5-1, 050, states The DCPP Structures Monitoring AMP is credited with managing cracking due to expansion from reaction with aggregates in inaccessible areas of the intake and discharge structures based on conditions in accessible areas.

These FE sections do not make clear or be inconsistent for how aging effect of the ASR in the inaccessible concrete areas are adequately managed by the DCPP AMPs during the PEO.

3. Tri-bar

LRA Table 3.5.2-11 lists Table 2 AMR item associated with Table 1 AMR item 3.5-1, 050, citing Note E for the tri-bar, which its aging effect of the cracking due to expansion and reaction with aggregates will be managed by the DCPP Inspection of Water-Control Structures AMP instead of the DCPP Structures Monitoring AMP.

LRA does not make clear whether the DCPP Inspection of Water-Control Structures AMP is capable of detecting indications of aggregate reactions in the tri-bar.

Note: FE Sections 3.5.2.2.2.1.2 and 3.5.2.2.2.3.2 belong to TRP 087.

3 3.5.2.2.1.9 Table 3.5-1 Table 3.5.2-1 3.5-22 3.5-36 3.5-79

1. Evaluation SRP-LR Report Section 3.5.3.2.1.9 states that a plant-specific aging management program is not required, even if reinforced concrete is exposed to flowing water if (1) there is evidence in the accessible areas that the flowing water has not caused leaching and carbonation, or (2) evaluation determined that the observed

1. Provide an evaluation on the portal that demonstrates that the observed leaching of calcium hydroxide and carbonation in accessible areas has no impact on the intended function of the concrete structure.

2. Clarify the areas that the DCPP ASME Section XI, Subsection IWL AMP will monitor.

3. Clarify what AMP will be used to manage aging effects of the below-grade inaccessible concrete area.

leaching of calcium hydroxide and carbonation in accessible areas has no impact on the intended function of the concrete structure.

LRA FE Section 3.5.2.2.1.9 states that there has been no plant-specific OE indicating significant leaching of calcium hydroxide or carbonation that could affect the intended function of concrete in the containment.

LRA does not make clear whether evaluation determined that the observed leaching of calcium hydroxide and carbonation in accessible areas has no impact on the intended function of the concrete structure.

2. AMP for the inaccessible concrete area LRA FE Section 3.5.2.2.1.9 states, Normally inaccessible below grade concrete is visually examined when it is exposed by excavation (i.e., inspections of opportunity) for signs of degradation from aggressive chemical attack or corrosion of embedded steel. It also states, Increase in porosity

and permeability due to leaching of calcium hydroxide and carbonation of the containment exterior and below-grade concrete will be managed by the DCPP ASME Section XI, Subsection IWL AMP through the PEO.

LRA does not make clear what areas will be monitored by the DCPP ASME Section XI, Subsection IWL AMP and which DCPP AMP will be used to manage aging effects of the below-grade inaccessible concrete area.

4 3.5.2.2.2.2 3.5-25 LRA Section 3.5.2.2.2.2 states that the HVAC system is designed to maintain maximum design indoor room temperatures well below 150 oF, and penetrations for pipes carrying hot fluids are designed with insulation to maintain the temperature of the concrete adjacent to the sleeve below 200 F under normal operating conditions.

LAR does not make clear what AMPs are used for the HVAC system and Insulation.

1. Discuss AMPs used for managing aging effects of the HVAC system and Insulation.

2. Clarify temperatures for areas that bound high temperature considerations, such as the SFP bulk water and Primary Shield Wall (PSW) concrete.

LAR does not make clear what temperatures are maintained for areas that bound high temperature considerations, such as the SFP bulk water and Primary Shield Wall (PSW) concrete.

Diablo Canyon LRA: Breakout Questions Inaccessible Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 1

3.5.2.2.2.1.4 3.5-24 SRP-LR report states that a plant-specific aging management program is not required for the reinforced concrete exposed to flowing water if (1) there is evidence in the accessible areas that the flowing water has not caused leaching of calcium hydroxide and carbonation or (2) evaluation determined that the observed leaching of calcium hydroxide and carbonation in accessible areas has no impact on the intended function of the concrete structure.

LRA FE Section 3.5.2.2.1, item 4, states that there has been no plant-specific OE indicating significant leaching of calcium hydroxide or carbonation that could affect the intended function of concrete in the containment. However, this FE section addresses increase in porosity and permeability, and loss of strength due to leaching of calcium hydroxide and carbonation could occur in Provide an evaluation to demonstrate that the observed leaching of calcium hydroxide and carbonation in accessible areas has no impact on the intended function of the concrete structure.

below-grade inaccessible concrete areas of Groups 1-5 and 7-9 structures.

During the on-site audit, the staff observed the signs of leaching on some concrete walls, the applicant is requested to provide evaluation and clarify whether the observed leaching of calcium hydroxide and carbonation in accessible areas has impact on the intended function of the concrete structure.

2 3.5.2.2.2.3.3 Table 3.5.2-12 3.5-27 3.5-153

1. Evaluation SRP-LR report states that a plant-specific aging management program is not required for the reinforced concrete exposed to flowing water if (1) there is evidence in the accessible areas that the flowing water has not caused leaching of calcium hydroxide and carbonation or (2) evaluation determined that the observed leaching of calcium hydroxide and carbonation in accessible areas has no impact on the intended function of the concrete structure.

1. Provide an evaluation to demonstrate that the observed leaching of calcium hydroxide and carbonation in accessible areas has no impact on the intended function of the concrete structure.

2. Clarify how aging effects of the inaccessible concrete areas are adequately managed by the DCPP Structures Monitoring AMP and the DCPP Inspection of Water-Control Structures AMP during the PEO.

3. Clarify how aging effects of concrete components in the middle two segments (DS2 and DS3) of discharge structure will be adequately managed by the DCPP Structures Monitoring AMP and the Inspection of Water-Control Structures AMP during the PEO.

LRA FE Section 3.5.2.2.2.3, item 3, states that DCPP OE has not observed leaching in accessible areas of Group 6 Structures that impacted the intended function.

LRA does not make clear whether an evaluation has determined that the observed leaching of calcium hydroxide and carbonation in accessible areas has no impact on the intended function of the concrete structure.

2. Inaccessible concrete areas of Group 6 structures LRA does not make clear how aging effects of the inaccessible concrete areas are adequately managed by the Structures Monitoring AMP and the Inspection of Water-Control Structures AMP during the PEO.

3. Discharge Structure LRA Table 3.5.2-12 lists concrete components in the Discharge Structure to be managed by the DCPP Structures Monitoring AMP and the Inspection of Water-Control Structures AMP.

During the on-site walkdown, the staff noted that the Discharge Structure consists of four segments (DS1 to DS4) of concrete structures, and middle two segments (DS2 and DS3) are inaccessible for the inspection due to water flow.

Section 5.7.3f Permanent Inaccessible Areas of the MAI.NE1, Maintenance Rule Monitoring Program - Civil Implementation, Revision 7, states, The inspection of certain areas of the plant is not possible due to their location or environment conditions (e.g.

submergence, burial, radiation levels). The DE shall provide evaluation of such areas and justification for their adequacy.

LRA does not make clear how aging effects of concrete components in the middle two concrete segments (DS2 and DS3) of the Discharge Structure will be adequately managed by the DCPP Structures Monitoring AMP during the PEO.

Diablo Canyon LRA: Breakout Questions Settlement Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 1

3.5.2.2.1.1 Table 3.5-1 Table 3.5.2-1 3.5-15 3.5-30 3.5-81 LRA FE Section 3.5.2.2.1.1 states, Item Number 3.5-1, 002: This item number is not being used at DCPP. The aging mechanism of settling is evaluated and managed under Item 3.5-1, 001.

LRA Table 3.5-1 claims AMR item 3.5-1, 002 to be consistent with NUREG-1801. The staff noted Table 2 AMR item associated with Table 1 AMR item 3.5-1, 002 in LRA Table 3.5.2-1.

There is inconsistency for the LRA Table 1 AMR item 3.5-1, 002 between LRA FE section and Table 3.5.2-1.

Procedure STP M-90B Surveillance of Diablo Canyon Breakwaters Revision 6, shows settlements/displacements of the breakwaters over the year.

Does the DCPP have similar building settlement inspection results along with the

1. Address the noted inconsistency in Table 1 AMR item 3.5-1, 002.

2. Provide building settlement inspection results (except breakwaters) and their acceptance criteria.

settlement acceptance criteria for other buildings within the scope of LR?

Diablo Canyon LRA: Breakout Questions LRA Section: 4.2.1:

Question Number SLRA Section SLRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 1

4.2.1 4.2-3 In Section 4.2.1 of the LRA the licensee states that the reactor vessel beltline neutron fluence values for 60 years of operation were calculated for DCPP Units 1 and 2 reactor vessel beltline material in WCAP-17299-NP. It further states that the analysis methods used to calculate the predicted 60-year DCPP Units 1 and 2 vessel fluence have been approved by the NRC and are described in WCAP-14040-NP-A, Revision 4.

Based on the description provided in the LRA, the NRC staff would like to further discuss the fluence methodology discussed in Section 2.2 of the WCAP-14040-NP-A, Revision 4, specifically for the reactor pressure vessel (RPV) and well as reactor vessel internals (RVI). Provide a discussion on how the methodologies used for fluence evaluations for RPV and RVI adhere to the requirements set forth in RG 1.190 "Calculational and Dosimetry

Diablo Canyon LRA: Breakout Questions LRA Section: 2.3.3 Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 1

2.3.3.1 Cranes and Fuel Handling System 2.3.3.2 Spent Fuel Cooling System 2.3.3.3 Saltwater and Chlorination System 2.3.3.4 Component Cooling Water System 2.3.3.5 Makeup Water System 2.3.3.6 Nuclear Steam Supply System Sampling System 2.3.3.7 Compressed Air System 2.3.3.8 Chemical &

Volume Both DCPP LRA 2009, which was reviewed and approved by the NRC staff, and DCPP LRA 2023 consist of these systems Identify any changes made to these systems since the submittal of DCPP LRA 2009 that may affect the license renewal scoping and screening

Control System 2.3.3.9 Miscellaneous HVAC System 2.3.3.10 Control Room HVAC System 2

2.3.3.2 Spent Fuel Cooling System 2.3.3.3 Saltwater and Chlorination System 2.3.3.4 Component Cooling Water System 2.3.3.5 Makeup Water System 2.3.3.6 Nuclear Steam Supply System Sampling System 2.3.3.7 Compressed Air System 2.3.3.8 Chemical &

Volume A comparison of DCPP LRA 2023 (the current application) to DCPP LRA 2009 shows that some component types that were previously included as subject to AMR, as listed in Table 1, have been removed from the current application.

Explain the reasons for deletions.

Control System 2.3.3.9 Miscellaneous HVAC System 2.3.3.10 Control Room HVAC System Table 1. Component types subject to AMR that were included in DCPP LRA 2009 but are missing from DCPP LRA 2023 Table No.

Component Type Component Intended Function 2.3.3-2 Demineralizer Pressure Boundary Filter Leakage Boundary (spatial), Pressure Boundary Sight Gauge Leakage Boundary (spatial), Structural Integrity (attached)

Trap Pressure Boundary 2.3.3-3 Bellows Pressure Boundary Test Connection Pressure Boundary Thermowell Pressure Boundary 2.3.3-4 Slight Gauge Pressure Boundary Test Connection Pressure Boundary Thermowell Pressure Boundary 2.3.3-5 Eductor Leakage Boundary (spatial)

Orifice Leakage Boundary (spatial), Pressure Boundary Sample Vessel Leakage Boundary (spatial)

Test Connection Pressure Boundary Trap Leakage Boundary (spatial), Pressure Boundary 2.3.3-6 Switch Leakage Boundary (spatial) 2.3.3-7 Solenoid Valve Pressure Boundary

2.3.3-8 Demineralizer Leakage Boundary (spatial), Pressure Boundary Filter Leakage Boundary (spatial), Pressure Boundary Flow Indicator Structural Integrity (attached)

Orifice Leakage Boundary (spatial), Pressure Boundary, Structural Integrity (attached)

Pulsation Dampener Leakage Boundary (spatial)

Sensor Element Leakage Boundary (spatial)

Sight Gauge Leakage Boundary (spatial), Pressure Boundary, Structural Integrity (attached)

Test Connection Leakage Boundary (spatial), Pressure Boundary Trap Leakage Boundary (spatial) 2.3.3-9 Filter Structural Support Flow Element Pressure Boundary 2.3.3-10 Filter Structural Support

Diablo Canyon LRA: Breakout Questions LRA Section 2.3.3.21 Secondary Sampling Systems - License Renewal ID 28 Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 1

2.3.3.21, Secondary Sampling Systems The following LRBD Drawings have no apparent ties (i.e., System Identification - Offsheet Connectors) to System 28 (i.e., Secondary Sampling System) :

a. LR-DCPP-02-106702-08

b. LR-DCPP-02-107702-08

c. LR-DCPP-04-106704-05

d. LR-DCPP-04-106704-06 Please confirm that these LRBDs contain system components subject to Aging Management Review.

Diablo Canyon LRA: Breakout Questions LRA Section 2.3.3.22 Service Water Cooling - License Renewal ID 15 Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 1

2.3.3.22, Service Water Cooling Table 2.3.3 Service Cooling Water System Components Subject to Aging Management Review contains Component Type Expansion Joint and Pump Casing (Sample Circ Pump) with Component Intended Functions of Leakage Boundary (Spatial).

These two Component Type do not appear in the four LRBDs listed in LRA Section 2.3.3.22 Service Cooling Water.

1) On what LRBD(s) do these Component Types displayed?

2) Staff suggests this information (missing unknown LRBD) be added to LRA Section 2.3.3.22 or within notes of the cited LRBs for clarity.

Diablo Canyon LRA: Breakout Questions LRA Section 2.3.3.24 Turbine Generator Associated Systems - License Renewal ID 22 Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 1

2.3.3.24, Turbine Generator Associated Systems Unit 1 LRBDs LR-DCPP-22-106722-Sheets 02 through-06 and Unit 2 LRBDs LR-DCPP-22-107722-Sheets 02 through-06 displays many component types (e.g., filter housings; y-strainers; restricting orifices; flow elements; flow indicators/sight glass; thermowells; traps) subject to aging management review (AMR) because of 54.4(a)(2) intended functions [Leakage Boundary (Spatial)].

Table 2.3.3 Turbine Generator Associated Systems Components Subject to Aging Management Review does not list these component types.

Please confirm that these component types are contained within the Component Type Piping Elements of Table 2.3.3-24 Turbine Generator Associated Systems Components Subject to Aging Management Review.

Diablo Canyon LRA: Breakout Questions LRA Section 2.3.3.25 Oily Water And Turbine Sump Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 1

2.3.3.25, Oily Water And Turbine Sump The last sentence of LRA Section 2.3.3.25 Description reads The radioactive content of the liquids discharged from the turbine building is monitored by a radiation monitor and flow element in the process lines to the Oily Water Separator. LRA Section 2.2.6.2 Liquid Waste System reads in part The radiation concentration and flow of liquid from the turbine building drains are monitored at the oily water separator to verify that there are no unaccounted for or unexpected releases from the turbine building drains. If significant radioactivity is detected coming from the turbine building drains, the discharge can be routed to the LRS for treatment. The monitoring system is in conformance with Regulatory Guide 1.21, Revision

1.

From the Staffs review of LRA Sections:

2.3.3.17 Liquid Radwaste System 2.3.3.19 Radiation Monitoring System Justify these apparent discrepancies between the LRA and the Regulatory Requirements.

2.3.3.25 Oily Water and Turbine Sump it is not apparent that the regulatory guidance of RG 1.21 and regulatory requirements of 10 CFR 20, Standards for Protection Against Radiation & 10 CFR 50, Domestic Licensing of Production and Utilization Facilities (e.g., § 50.34a; § 50.36a; Appendix A GDC 60 & GDC 64; Appendix I) will continued to be met during the period of extended plant operations. For example, flow elements can be a fundamental component type in the measurement of radiation contained in plant effluents, but flow elements are not listed as a component type subject to aging management in either of the three LRA Sections listed above.

2 2.3.3.25, Oily Water And Turbine Sump LRA Section 2.3.3.25 reads in part Portions of the Oily Water and Turbine Sump System support FP requirements and are within the scope of LR.

The staff reviewed PEDCROLI00007

-REPT-041 Revision 1 - Aging Management Review Results (AMR)

Oily Water and Turbine Sump as provided by Applicant in the Certrec electronic portal and the staffs 2011 Safety Evaluation Report Related to the License Renewal of Please explain to the staff in detail which system components satisfy the regulatory requirements of 10 CFR 54.4(a)(3).

Please explain to the staff in detail whether the Oily Water And Turbine Sump system piping is connected to the equipment and/or floor drain lines of the Emergency Diesel Generator rooms. If so, are the passive parts (e.g., check valves and traps) of the components that prevent back flooding into these EDG rooms adequately managed for aging during the period of extended plant operations?

Diablo Canyon Nuclear Power Plant, Units 1 and 2 (ML11153A103).

What specific Oily Water And Turbine Sump system components serve this Fire Protection 54.4(a)(3) intended function. Do the component types consist of check valve(s), loop seal(s), or trap(s)?

How will the passive piece parts of these components be adequately managed for aging during the period of extended plant operations?

Diablo Canyon LRA: Breakout Questions LRA Section 2.3.4.1 Turbine Steam Supply System Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 1

2.3.4.1, Turbine Steam Supply System The original LRA (i.e., LRA1) as submitted in 2009 contained LRA Section 2.3.4.1 Turbine Steam Supply System. Table 2.3.4-1 Turbine Steam Supply System within LRA1 listed several Component Types not found in the Table 2.3.4 Turbine Steam Supply System Components Subject to Aging Management Review of the current LRA submittal (i.e., LRA2 as issued on November 7, 2023).

The following Component Types were listed in LRA1 but are not displayed in LRA2 Table 2.3.4-2.:

Demineralizer - Leakage Boundary (Spatial)

Filter - Leakage Boundary (Spatial)

Indicator Leakage Boundary (Spatial)

Orifice - Leakage Boundary (Spatial); Pressure Boundary; Structural Integrity (attached);

and Throttle.

Test Connection-Pressure Boundary Staff requests explanation of why these Component Types with respective Component Intended Function in LRA1 do not appear in LRA2.

Trap - Leakage Boundary (Spatial); Pressure Boundary; and Structural Integrity (attached).

2 2.3.4.1, Turbine Steam Supply System LRBD LR-DCPP-04-106704-05 displays the following Component Types: Resin Filter; Resin Trap; Pre-Filter; Dri-Breather (on Acid Day Tank); Pulsator (on two pump discharges); Level Indicator (on Caustic and Acid Day Tanks); In-line Electric Heater (Coordinate C-162) as being evaluated per 10 CFR 54.4(a)(2) and subject to AMR.

LRA Table 2.3.4 Turbine Steam Supply System Components Subject to Aging Management Review does not list these Component Types.

Staff requests confirmation that all Component Types are represented in LRA Table 2.3.4-1 and LRA Table 3.4.2-1: Turbine Steam Supply System -

Summary of Aging Management Evaluation with its respective internal and external environments and materials of fabrication.

3 2.3.4.1, Turbine Steam Supply System LRA Table 2.3.4 Turbine Steam Supply System Components Subject to Aging Management Review lists the Component Type Heat Exchanger (Abandoned Steam Purity Analyzer Sample Cooler) and Heat Exchanger (Abandoned Steam Purity Analyzer Sample Cooler) Tube Side Component with a Component Intended Function of Leakage Boundary (Spatial).

Staff requests further information about the abandoned in place status of the subject components and the specifics of how the Leakage Boundary (Spatial) will be maintained during the period of extended plant operations.

Diablo Canyon LRA: Breakout Questions LRA Section 2.3.4.2 Auxiliary Steam System Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 1

2.3.4.2, Auxiliary Steam System LRBD LR-DCPP-06-106707-07 (Coordinate E-70 through E-73) displays Auxiliary Steam Piping within Containment as being subject to AMR due to 54.4(a)(2) spatial or structural concerns. For this subject piing:

1) From review of this drawing, it is not apparent that the pipe anchors for the piping within Containment is in compliance with 10 CFR 54.4(a)(2) and follows the protocol of LRA Section 2.1.4.1.2 Nonsafety-Related Criteria Pursuant to 10 CFR 54.4(a)(2) [i.e., Nonsafety-Related SSCs Directly Connected to Safety-Related SSCs],

2) Coordinate E-73 displays an arrow entitled Tritium Control.

1) Staff request confirmation that the subject piping is in compliance with 10 CFR 54.4(a)(2) pertaining to structural integrity.

2) Staff request clarification of what is meant by the term Tritium Control and whether other regulatory requirements apply for this segment of piping.

2 2.3.4.2, Auxiliary Steam System The original LRA (i.e., LRA1) as submitted in 2009 contained LRA Section 2.2.4.2 Auxiliary Steam System.

Table 2.3.4-2 Auxiliary Steam System with LRA1 listed several Component Types not found in the Table 2.3.4 Auxiliary Steam System Components Subject to Aging Management Staff requests explanation of why the Component Types in LRA1 do not appear in LRA2.

Review of the current LRA submittal (i.e.,

LRA2 as issued on November 7, 2023).

The following Component Types had a Intended Function of Leakage Boundary (spatial) in LRA1 but are not displayed in LRA2 Table 2.3.4-2.:

Filter Orifice Sample Sink Sight Gauge Strainer Switch Test Connection Trap The Trap also listed an Intended Function of Structural Integrity (attached).

3 2.3.4.2, Auxiliary Steam System LRBD LR-DCPP-06-106706-05 Coordinate D-53 displays AUX STM DRN RECVR. VENT COND as subject to 10 CFR 54.4(a)(2) evaluation. LRA Table 2.3.4 Auxiliary Steam System Components Subject to Aging Management Review assigns the following Intended Functions to this component:

Leakage Boundary (Spatial)

Structural Integrity (Attached)

Structural Support Staff request clarification of how an abandoned in place component can still perform these three intended functions.

4 2.3.4.2, Auxiliary Steam System LRBD LR-DCPP-06-106706-05 Coordinate B-52 displays an arrow pointing to System 28 Coordinate 28-E

[LRBD LR-DCPP-28-106728-02]. LRA Table 2.3.4 Auxiliary Steam System Components Subject to Aging Management Review contains a line item for Component Type Heat Exchanger (Auxiliary Steam Drain Receiver Pump Discharge Sample Cooler) Shell Side Components. LR-DCPP-28-106728-02 displays the subject heat exchanger in an isothermal bath. There are other component types in the sample line to/from this subject heat exchanger all with intended functions under the purview of 10 CFR 54.4(a)(2).

This same issue pertains to the sampling line from the reboiler Coordinate C-85 on LRBD LR-DCPP-06-106706-05 and Component Type Heat Exchanger (Building Heating Reboiler Sample Cooler) Tube Side Components displayed in LRA Table 2.3.4-2.

The staff notes that LR-DCPP 106728-02 does not appear in LRA Section 2.3.4.2 listing of applicable drawings.

Staff requests verification that all the component types in the subject sample lines displayed on LR-DCPP-28-106728-02 and LRBD LR-DCPP 106706-05 will be adequately managed for aging during the period of extended operations per the requirements of 10 CFR 54.4(a)(2).

5 2.3.4.2, Auxiliary Steam System LRA Table 2.3.4 Auxiliary Steam System Components Subject to Aging Management Review lists the Component Type Heat Exchanger (Boric Evap Condenser Sample Cooler)

Tube Side Components. With a

1) Staff requests further information about the abandoned in place status of the subject components.

2) Staff requests verification that all the component types in the subject sample lines displayed on LR-

Component Intended Function of Leakage Boundary (Spatial).

LRBD LR-DCPP-06-106706-05 displays the two Boric Acid Evap. 1-1 and Boric Acid Evap. 2-1; respective Drip Pot(s);

and Sampling line Coordinate C-56) as being abandoned in place.

LR-DCPP-28-106728-02 displays the subject heat exchanger in an isothermal bath. There are other component types in the sample line to/from this subject heat exchanger all with intended functions under the purview of 10 CFR 54.4(a)(2).

DCPP-28-106728-02 and LRBD LR-DCPP 106706-05 will be adequately managed for aging during the period of extended operations per the requirements of 10 CFR 54.4(a)(2).

Diablo Canyon LRA: Breakout Questions LRA Section 2.3.4.3 Main Feedwater System Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 1

2.3.4.3, Main Feedwater System LRBD LR-DCPP-03-106703-02 (Coordinates B-28 through E-28) displays eight flow control valves (e.g., 1-FCV-510 & 1-FCV-1510) as evaluated as within the scope of license renewal for either 10 CFR 54.4(a)(1) or 54.4(a)(3).

1) What particular 54.4(a)(1) or 54.4(a)(3) function(s) do these valves perform?

2) Does the 10 CFR 54.4(a)(2) piping and structural supports for each valves connected piping satisfy the criteria of LRA Section 2.1.4.1.2 Nonsafety-Related Criteria Pursuant to 10 CFR 54.4(a)(2) --

Nonsafety-Related SSCs Directly Connected to Safety-Related SSCs?

3) For the feedwater lines to STM GEN 1-1 and STM GEN 1-2 what is the justification for not being subject to AMR: the vent and drain valves; bypass lines (e.g., containing valve 1-528); etc.?

2 2.3.4.3, Main Feedwater System LRA Table 2.3.4 Main Feedwater System Components Subject to Aging Management Review list the Component Type Flow Element with a Component Intended Functions of Throttle. The six LRBDs listed in LRA 2.3.4.3 contain at least 12 flow elements all parallel-connected to flow transmitters/indicators.

It appears that the calibration of the related flow transmitters would verify the internal flow element integrity of

1) Please discuss in detail with the staff this characterization of the Component Intended Function for Flow Element vs. Restricting Orifice.

2) Do any of the restricting orifices evaluated/identified as being within the domain of 10 CFR 54.4(a)(2) (i.e., leakage boundary or structural integrity concerns), have a component level intended function of restricting flow for overall 10 CFR 54.4(a)(2) system performance?

each flow element through routine testing (e.g., surveillance testing).

In contrast, on these same LRBDs there are many non-instrumented restricting orifices evaluated per 10 CFR 54.4(a)(2) (i.e., leakage boundary or structural integrity concerns) that may have a Throttle intended function but not listed as such in Table 2.3.4-3.

3 2.3.4.3, Main Feedwater System The six LRBDs listed in LRA 2.3.4.3 contain many component types not listed in Table 2.3.4 Main Feedwater System Components Subject to Aging Management Review. These include:

Temperature element (thermowell?);

filter housing; restricting orifices; pulsation chamber. Many other plant systems with components subject to AMR, contain a line item the respective LRA Table for Piping Elements exclusive of the component type Piping, Piping Components in the respective LRA AMR table assumed to envelope such miscellaneous component types.

1) Please discuss with the staff the lack of consistency in the approach between how such miscellaneous component types are captured for aging management during the period of extended operations.

2) Explain how such miscellaneous component types will be sufficiently captured in the DCPP data bases related to aging management programs during the period of extended operations.

3) Pulsation chamber is not clearly defined in the LRBD drawing LR-DCPP-01-106701-02 (i.e.,

valve, equipment symbols). It appears twice on LR-DCPP-01-106703-05 (Coordinates E-56 & C-56). Also T inside box on top of Main Feedwater Pumps LRBD LR-DCPP-01-106703-02 (Coordinates A-22 & C-22) is not clearly defined.

Please provide more LRA clarity for these component types.

4 2.3.4.3, Main Feedwater System LRA Table 3.4.2-3: Main Feedwater System - Summary of Aging Management Evaluation contains line items for Component Types such as Heat Exchanger (Sample Cooler) Shell Side Components and Pump Casing (Generic Secondary Water Pumps).

The staff could not identify these Component Types on the six LRBDs listed in LRA section 2.3.4.3.

Please identify the LRBDs.

Diablo Canyon LRA: Breakout Questions LRA Section 2.3.4.4 Condensate System Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 1

2.3.4.4, Condensate LRBD LR-DCPP-02-107702-03 display many piping interfaces that meet the criteria for evaluation per LRA Section 2.1.4.1.2 Nonsafety-Related Criteria Pursuant to 10 CFR 54.4(a)(2) (i.e.,

Nonsafety-related SSCs directly connected to safety-related SSCs).

From review of this LRBD alone it is not readily possible to confirm that protocol of LRA Section 2.1.4.1.2 has been satisfied.

The staff requests confirmation that the criteria of LRA Section 2.1.4.1.2 has been satisfied for all the SR/NSR interfaces on this LRBD.

2 2.3.4.4, Condensate LRBD LR-DCPP-02-107702-03 (Coordinate C-37) displays the HYDROGEN COOLER with only the heat exchanger shell side components as being within the scope of license renewal evaluated per 10 CFR 54.4(a)(2).

LRA Table 2.3.4 Condensate System Components Subject to Aging Management Review lists both Heat Exchanger (Hydrogen Cooler) Shell Side Components and Heat Exchanger (Hydrogen Cooler) Tube Side Components as being subject to the requirements of 10 CFR 54.4(a)(2) with Component Intended Functions of Leakage Boundary (Spatial).

1. Please reevaluate this apparent inconsistency or explain to the staff the differences between the LRBD and LRA Table 2.3.4-4.

2. Also evaluate the STATOR COIL CLG WTR HXs (Coordinate E-38) for this same inconsistency.

3 2.3.4.4, Condensate LRBD LR-DCPP-02-107702-03 (Coordinate E-34) displays Abandoned in Place piping components as being within the scope of license renewal evaluated per 10 CFR 54.4(a)(2). It is noted that the abandoned in place piping is connected to piping as being within the scope of license renewal evaluated per 10 CFR 54.4(a)(1). There are no (a)(2) Termination Symbols within the Abandoned in Place area pertaining to structural integrity.

Please provide the staff with additional information as to how the subject piping will be adequately managed for aging during the period of extended plant operations.

4 2.3.4.4, Condensate LRBD LR-DCPP-02-106702-14 displays CAUSTIC STG TK (Coord. E-123) as having internal heat exchanger coils.

LRA Table 2.3.4 Condensate System Components Subject to Aging Management Review does not list a Component Type that corresponds to this heat exchanger.

Please provide staff with additional information as to why LRA Table 2.3.4-4 does not list this heat exchanger within CAUSTIC STG TK.

5 2.3.4.4, Condensate LRBD LR-DCPP-02-106702-14 displays many component types as being within the scope of license renewal evaluated per 10 CFR 54.4(a)(2). Component Type displayed (while not all inclusive) consist of: Condensate Demineralizers; Resin Traps; Flow Elements; and Flow Indicators.

LRA Table 2.3.4 Condensate System Components Subject to Aging Management Review does not contain these Component Types Please provide staff with additional information as to why LRA Table 2.3.4-4 does not include these component types.

6 2.3.4.4, Condensate LRBD LR-DCPP-02-106702-05 and LRBD LR-DCPP-02-107702-05 both display Piping and Piping Components to the Abandoned in Place SEA WATER EVAPORATOR. The valves and piping segments to this evaporator are evaluated as being within the scope of license renewal evaluated per 10 CFR 54.4(a)(2) and subject of AMR.

Please provide the staff with additional information as to how the subject Abandoned in Place piping components will be adequately managed for aging during the period of extended plant operations.

Diablo Canyon LRA: Breakout Questions LRA Section 2.3.4.5 Auxiliary Feedwater System - License Renewal ID 03 Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 1

2.3.4.5, Auxiliary Feedwater System LRBD LR-DCPP-03-106703-03 displays three flow elements and three restricting orifices (e.g., FE-7 &

RO-63 @ Coordinates A-32 & A-33) for the two-motor driven and one turbine drive AFW PPs as evaluated as within the scope of license renewal for either 10 CFR 54.4(a)(1) or 54.4(a)(3). These components are located in pipelines that provide a minimum recirculation flow function for these AFW PPs back to the Condensate Storage Tank (CST) as evaluated per 54.4(a)(1) criterion. LRA Table 2.3.4-5 lists only a Throttle function for the Flow Element (i.e., no Pressure Boundary Intended Function) and does not list the Component Type This is the same issue as Breakout Issue Item 2 for the Main Feedwater System. Please ensure that the resolution for FW Breakout Issue Item 2 is addressed for the Auxiliary Feedwater System and holistically throughout the LRA.

Restricting Orifice with an Intended Function of Throttle.

It appears that the calibration of the related flow transmitters would verify the integrity of each internal flow element through routine testing (e.g.,

surveillance testing).

This same staff issue (sans the restricting orifices) would also apply to the four Flow Elements (with flow transmitters) that connect to the Main Feedwater System lines to the four steam generators (e.g., FE-215 @

Coordinate 38-D).

2 2.3.4.5, Auxiliary Feedwater System LRBDs LR-DCPP-03-106703-03 and LR-DCPP-03-107703-03 both display four Level Control Valves (e.g., 1-LCV-115 @ Coordinate B-38 for Unit 1) with what appears to be self-contained electro-hydraulic EH Fail Open actuators.

EH was not defined on LR-CCPP-01-106701-02.

If the EH actuators are not self-contained, do the hydraulic oil supplies to/from these actuators represent a 10 CFR 54.4(a)(2) spatial concern to any nearby 54.4(a)(1) components?

3 2.3.4.5, Auxiliary Feedwater System LRBDs LR-DCPP-03-106703-03 and LR-DCPP-03-107703-03 both display four Leak Detection system components (e.g., Unit 1 Flow switches FS4 & FS5 and Restricting Orifices RO53 & RO92 @

Coordinates C-34 through D-35) as Do these Restricting Orifices perform a component level Throttle intended function for leak detection such that 10 CFR 54.4(a)(2) function exists beyond spatial or structural concerns?

subject to AMR per 10 CFR 54.4(a)(2).

4 2.3.4.5, Auxiliary Feedwater System LRA Section 2.3.4.5 list six LRBDs.

These LRBDs contain several Component Types not listed in LRA Table 2.3.4 Auxiliary Feedwater System Components Subject to Aging Management Review as follows:

a) LR-DCPP-03-106703-03 and LR-DCPP-03-107703-03 both display a Vacuum Breaker 1-RV-537 and 2-RV-537 respectively @

Coordinate B-31.

b) LR-DCPP-03-106703-04 & 4A and LR-DCPP-03-106703-04 &

4A display Eductor; Level Indicators on all three tanks for each Unit; Portable Pump Hookup Disconnect Coupling; Vacuum Breaker on Measuring Tank; Flow Elements on discharge of pumps on both 4A drawings; Pulsation dampers; Measuring sticks to vent; strainers; five vacuum breakers/relief valves on drawing 4A; manual regulators on drawing 4A; pulsation dampers to five Pressure Indicators (e.g., Unit 1 PI 425 Coordinate C-40A).

Staff requests confirmation that all these Component Types are subject to AMR and enveloped by the Component Type Piping Elements in LRA Table 2.3.4-5.

5 2.3.4.5, Auxiliary Feedwater System LRA Section 2.3.4.5 System Intended Functions reads:

FP, EQ, PTS, ATWS, and SBO functions (10 CFR 54.4(a)(3)):

Staff requests that the 10 CFR 54.4(a)(3) Reports pertaining to the five regulated events be made available for review (i.e., on the Certrec Diablo Canyon LRAAPP electronic portal). These reports should optimally designate which components apply

(1) Portions of the AFWS support FP, EQ, ATWS and SBO requirements.

to each regulated event relevant to the Auxiliary Feedwater System.

Diablo Canyon LRA: Breakout Questions LRA Section B.2..1 ASME Section XI, Inservice Inspections, IWB, IWC, and IWD Question Number LRA Section LRA Page Background / Issue (As applicable/needed)

Discussion Question / Request 1

2.3.2.4, Containment HVAC A. DCPP LRA 2009 identified the containment hydrogen control system (CHCS) within the scope of license renewal, and DCPP LRA 2023, Table 2.2-1, Plant Level Scoping Results, lists the CHCS as a part of the containment HVAC system, which is in the scope of license renewal.

B. DCPP UFSAR, section 6.2.5.2.2, Electric Hydrogen Recombiner System, states that the hydrogen recombiner system (HRS) has a design life of 40 years. The renewal of this operating license would exceed the design life of the HRS.

A. Explain why DCPP LRA 2023 provides no information on the CHCS.

B. Explain how the HRS function will be maintained within the license renewal.

2 Section 2.3.3.20, Sanitary Sewage System DCPP LRA 2023, section 2.3.3.20 states the following: A portion of sanitary sewage drain piping extends down through the turbine building floor into the Unit 2 diesel generator area, which is the only portion of the Sanitary Sewage System that is in the scope of LR. A boundary drawing has not been created for the Sanitary Sewage System.

As a boundary drawing has not been created and the description provided does not specifically identify the portion of the system piping that is in the scope of license renewal, explain how aging management will be implemented on Piping, Piping Components as identified in table 2.3.3-20, Sanitary Sewage System Components Subject to Aging Management Review.

3 2.3.2.4 Containment Both DCPP LRA 2009, which was reviewed and approved by the NRC Identify any changes made to the these systems since the submittal of DCPP LRA 2009 that may affect the license renewal scoping and screening

HVAC System 2.3.3.11 Auxiliary Building HVAC System 2.3.3.13 Diesel Generator Fuel Oil System 2.3.3.14 Diesel Generator System 2.3.3.15 Lubricating Oil System 2.3.3.16 Gaseous Radwaste System 2.3.3.17 Liquid Radwaste System 2.3.3.19 Radiation Monitoring System staff, and DCPP LRA 2023 consist of these systems 4

2.3.2.4 Containment HVAC System A comparison of DCPP LRA 2023 (the current application) to DCPP LRA 2009 shows that some component types that were previously included as subject to Explain the reasons for deletions.

2.3.3.11 Auxiliary Building HVAC System 2.3.3.13 Diesel Generator Fuel Oil System 2.3.3.14 Diesel Generator System 2.3.3.15 Lubricating Oil System 2.3.3.16 Gaseous Radwaste System 2.3.3.17 Liquid Radwaste System AMR, as listed in Table 1, have been removed from the current application.

Table 1. Component types subject to AMR that were included in DCPP LRA 2009 but are missing from DCPP LRA 2023 Table No.

Component Type Component Intended Function 2.3.2-4 Filter Structural Integrity (attached)

Flow Element Pressure Boundary Heat Exchanger (lncore Instrument Room)

Leakage Boundary (spatial)

Structural Support Separator Structural Support 2.3.3-11 Filter Leakage Boundary (spatial)

Table No.

Component Type Component Intended Function Pressure Boundary Structural Support Flow Element Pressure Boundary Structural Integrity (attached)

Orifice Leakage Boundary (spatial)

Sight Gauge Leakage Boundary (spatial)

Strainer Leakage Boundary (spatial)

Test Connection Leakage Boundary (spatial)

Structural Integrity (attached)

Trap Structural Integrity (attached) 2.3.3-13 Filter Pressure Boundary 2.3.3-14 Filter Pressure Boundary Structural Integrity (attached)

Lubricator Pressure Boundary Orifice Pressure Boundary Throttle Solenoid Valve Pressure Boundary Thermowell Pressure Boundary 2.3.3-15 Sight Gauge Pressure Boundary 2.3.3-16 Instrument Leakage Boundary (spatial)

Instrument Bellows Leakage Boundary (spatial)

Structural Support Orifice Leakage Boundary (spatial)

Structural Integrity (attached)

Structural Support Sensor Element Leakage Boundary (spatial)

Sight Gauge Leakage Boundary (spatial)

Strainer Leakage Boundary (spatial)

Test Connection Leakage Boundary (spatial) 2.3.3-17 Demineralizer Leakage Boundary (spatial)

Filter Leakage Boundary (spatial)

Flow Element Leakage Boundary (spatial)

Table No.

Component Type Component Intended Function Structural Integrity (attached)

Flow Indicator Leakage Boundary (spatial)

Pressure Boundary Structural Integrity (attached)

Instrument Bellows Leakage Boundary (spatial)

Orifice Leakage Boundary (spatial)

Sample Cooler Leakage Boundary (spatial)

Structural Integrity (attached)

Sight Gauge Leakage Boundary (spatial)

Test Connection Leakage Boundary (spatial)

Trap Leakage Boundary (spatial)