DCL-23-020, Responses to NRC Questions Regarding License Renewal Efforts

Responses to NRC Questions Regarding License Renewal Efforts

ML23076A210
Person / Time
Site:	Diablo Canyon
Issue date:	03/17/2023
From:	Gerfen P Pacific Gas & Electric Co
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
DCL-23-020
Download: ML23076A210 (1)

Text

Paula Gerfen Senior Vice President and Chief Nuclear Officer Diablo Canyon Power Plant Mail code 104/6/602 P.O. Box 56 Avila Beach, CA 93424 805.545.4596 Fax: 805.545.4234 Paula.Gerfen@pge.com A member of the STARS Alliance Callaway

• Diablo Canyon

• Palo Verde

• Wolf Creek PG&E Letter DCL-23-020 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 Diablo Canyon Units 1 and 2 Docket No. 50-275, OL-DPR-80 Docket No. 50-323, OL-DPR-82 Responses to NRC Questions Regarding Diablo Canyon Power Plant License Renewal Efforts

Reference:

1. Nuclear Regulatory Commission Letter to Pacific Gas and Electric Company, "Request for Information Regarding Diablo Canyon Power Plant, Units 1 and 2 - December 8, 2022, Public Meeting," dated February 17, 2023 (ML23041A186)

Dear Commissioners and Staff:

In Reference 1, the Nuclear Regulatory Commission (NRC) asked Pacific Gas and Electric Company (PG&E) to provide input regarding ongoing license renewal efforts discussed during the public meeting on December 8, 2022. The Enclosure to this letter provides PG&E responses to the NRC requests. To facilitate license renewal and safe outage planning activities, PG&E is requesting any feedback from the NRC, within 30 days of the submission of this letter, on the implementation plans and schedules contained in the Enclosure. This will allow PG&E to consider any necessary planning adjustments as soon as possible.

PG&E makes no new or revised regulatory commitments (as defined in NEI 99-04) in this letter.

If you have any questions or require additional information, please contact Mr. Philippe Soenen at (805) 459-3701.

Sincerely, Paula Gerfen Date March 17, 2023 m

Pacific Gas and Electric Company*

Document Control Desk PG&E Letter DCL-23-020 Page 2 A member of the STARS Alliance Callaway

• Diablo Canyon

• Palo Verde

• Wolf Creek Enclosure cc:

Diablo Distribution cc/enc:

Christian Arechavaleta, Department of Water Resources Lauren Gibson, License Renewal Branch Chief Brian Harris, NRC Senior Project Manager Mahdi O. Hayes, NRC Senior Resident Inspector Samson S. Lee, NRC Senior Project Manager Robert J. Lewis, NRC Acting Region IV Administrator Nicholas Taylor, NRC Inspector Region IV

Enclosure PG&E Letter DCL-23-020 Page 1 of 5 Responses to NRC Request for Information Regarding Diablo Canyon Power Plant, Units 1 and 2 - December 8, 2022, Public Meeting (Reference 1)

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Background===

As documented in Reference 1, Pacific Gas and Electric Company (PG&E) had a public meeting with the Nuclear Regulatory Commission (NRC) on December 8, 2022, to discuss ongoing plans for Diablo Canyon Power Plant (DCPP) license renewal (LR).

After the public meeting, the NRC issued a letter to PG&E (Reference 2) containing the Staff's decision not to resume review of the withdrawn license renewal application (LRA). As a result of this decision, PG&E is proceeding with developing a new LRA. As discussed further below in response to the NRC questions included in Reference 1, PG&E is proactively implementing the aging management programs (AMPs) and commitments included in the DCPP LRA at the time of withdrawal (Reference 4) and will reconcile any differences as the new LRA is developed and submitted to the NRC.

Updates regarding the status of implementing the commitments included in the Enclosure will be available for NRC inspection.

In Reference 3, the NRC issued PG&E an exemption to allow DCPP Units 1 and 2 to continue operating past the expiration date of the licenses while the LRA is under review, provided PG&E submits a sufficient LRA by December 31, 2023. PG&E will submit a new LRA by December 31, 2023, which will contain the official updated commitment list for the new DCPP LRA. Additional changes to commitments that may occur during the NRC review of the LRA will be addressed in accordance with the request for additional information process.

NRC Staff Requested:

The current schedule for AMP-related activities in the October 2023 Unit 1 refueling outage.

PG&E Response to Staff Request:

PG&E is proceeding with implementing the AMP inspections as documented in the DCPP LRA and related correspondence at the time of withdrawal. The inspections that are currently planned for the upcoming DCPP Unit 1 refueling outage are documented in Attachment 1.

NRC Staff Requested:

The AMP-required commitments (including but not limited to inspections) that PG&E was committed to perform by the withdrawn license renewal application (dated November 23, 2009) prior to entering the [period of extended operations] PEO.

Enclosure PG&E Letter DCL-23-020 Page 2 of 5 PG&E Response to Staff Request:

PG&E is proactively implementing the commitments included in the DCPP LRA at the time of withdrawal. PG&E plans to implement the commitments as documented in. Implementation dates have been revised to reflect current timeframes, with additional details provided below for commitments with revised completion dates that extend past the expiration date of the operating licenses. PG&E is planning to implement the commitments at the earliest opportunity at which they can be performed consistent with industry standards and NRC expectations for management of shutdown risk through outage planning, personnel training, and procurement of necessary materials. Attachment 2 includes a column with the implementation schedule that was included in the withdrawn LRA and a column with new implementation dates proposed for planning purposes. As noted, several of the commitments are already complete.

As documented further below, the commitments with revised completion dates that extend past the expiration dates of the operating licenses require extensive planning for their safe and effective implementation, including training, procurement, and development of work packages. For each commitment, there are existing operating programs or other aging management activities that will continue after the expiration of the operating licenses that provide reasonable assurance the systems are adequately managed prior to full implementation of the program. Further, any aging management issues identified by these existing programs or other surveillance activities will be entered into and addressed by the DCPP corrective action program. These considerations demonstrate that PG&E's proposed implementation plan presents no significant risk to public health and safety or the environment.

PG&E does not currently have any commitments on the docket with the NRC for the DCPP LR. PG&E is using the previously withdrawn commitments for planning purposes.

PG&E plans to implement all previous commitments in accordance with the proposed implementation schedule included in Attachment 2, however unforeseen circumstances may arise which necessitates modification to commitments or implementation dates.

The official updated commitment list including implementation dates for the new DCPP LRA will be submitted with the application by December 31, 2023.

Specific License Renewal Commitments to be Implemented at the Earliest Opportunity Commensurate with Safety Commitment Number 6 For implementing the Selective Leaching of Materials Program, PG&E proposes completing the initial sample size inspections as defined in the AMP prior to the expiration of the current operating licenses, with any follow-up or expansion inspections being completed within approximately 5 years of the LRA submittal (i.e., December 1, 2028). As this is a new program, the 5-year timeframe to complete the follow-up inspections allows for adequate time to plan, prepare, and execute the follow-up or expansion inspections on various plant systems. Any issues identified as part of the

Enclosure PG&E Letter DCL-23-020 Page 3 of 5 initial inspections will be entered into the DCPP corrective action program and will be prioritized and resolved in accordance with plant procedures.

The 5-year follow-up/expansion selective leaching inspection period equates to a small portion of the initial licensed operating period and a minimal increase in service time for structures, systems, and components (SSCs) potentially susceptible to selective leaching. Some SSCs within the scope of this program are managed by other AMPs, that will be implemented prior to the license expiration dates and that provide reasonable assurance for continued functionality (e.g., Water Chemistry, Open Cycle Cooling Water, and Closed Cycle Cooling Water Programs). Further, PG&E plans to use the initial inspection results to prioritize the follow-up inspections.

Commitment Numbers 52 and 53 PG&E proposes to complete the initial (baseline) inspections for the Buried Piping and Tanks Inspection Program and install cathodic protection for the buried Auxiliary Saltwater Water (ASW) piping as soon as this work can be safely implemented, but no later than December 1, 2028. The proposed 5-year period (December 2023 through December 2028) for implementation allows for at least three outages for each unit in which to perform the specified inspections, some of which may require an outage, significant excavation work, and design and installation of cathodic protection. The scope of an outage is normally established over a year in advance to allow for adequate planning and coordination with system and train outages, etc. This 5-year window also allows for design change package development and adequate planning and scheduling around and within outage windows to ensure effective and safe implementation. The timing of baseline inspections identified in LR-ISG-2015-01 is tied to the 10-year period before a particular unit will enter the PEO. For both DCPP units, completing baseline inspections and cathodic protection installation prior to the expiration date of the licenses is not a realistic date for implementing changes from the Interim Staff Guidance (ISG) document. Indian Point was approved to extend the implementation schedule for a LR commitment with a similar rationale (Reference 5).

PG&E has an existing Buried Piping and Tanks Program designed to provide reasonable assurance of structural and leakage integrity for systems within the scope of the program. This program aligns with Nuclear Energy Institute (NEI) 09-14, "Guideline for the Management of Underground Piping and Tank Integrity." Portions of systems such as the ASW system are within the scope of this existing program, which will continue past the expiration date of the operating licenses. Any issues identified as part of this program will be entered into the DCPP corrective action program, prioritized, and resolved in accordance with plant procedures.

Enclosure PG&E Letter DCL-23-020 Page 4 of 5 Commitment Number 74 PG&E proposes to complete the initial (baseline) inspections for the Internal Coatings/Linings for In-Scope Piping, Piping Components, Heat Exchangers, and Tanks program by December 1, 2028. The 5-year period (December 2023 through December 2028) allows for at least three outages for each unit in which to perform the specified inspections, some of which may necessitate an outage. The scope of an outage is normally established over a year in advance to allow for adequate planning and coordination with system and train outages, etc. This 5-year window allows for adequate planning and scheduling around and within outage windows. The proposed approximate 5-year period (December 2023 through December 2028) to perform the initial inspections, which extends past the expiration date of the licenses, aligns with industry experience. Specifically, Indian Point was approved for a greater than 5-year timeframe during the PEO to implement the changes associated with LR-ISG-2013-01 (Reference 5).

Some SSCs within the scope of this program are also managed by other AMPs, that will be implemented prior to the license expiration date and that provide reasonable assurance for continued functionality (e.g., Water Chemistry, Open Cycle Cooling Water, and Closed-Cycle Cooling Water Programs). Further, PG&E plans to complete a majority of the inspections prior to the expiration date of the operating licenses, including inspections of components within risk significant systems.

Commitment Number 75 PG&E proposes to replace portions of the domestic water system piping by December 1, 2028. The 5-year period (December 2023 through December 2028) allows for adequate planning and preparations, including design change packages for safely conducting replacement piping design and installation.

The 5-year period equates to a small portion of the initial licensed operating period and a minimal increase in service time for the SSCs. Some SSCs are also managed by other AMPs, that will be implemented prior to the license expiration date, that provide reasonable assurance for continued functionality (e.g., One-Time Inspection). In addition, routine plant walkdowns will identify domestic water leakage which, if identified, would be entered into the DCPP corrective action program, prioritized, and resolved in accordance with plant procedures.

References

1. NRC Letter to PG&E, "Request for Information Regarding Diablo Canyon Power Plant, Units 1 and 2 - December 8, 2022, Public Meeting," dated February 17, 2023 (ML23041A186)

2. NRC Letter to PG&E, Diablo Canyon Power Plant, Units 1 and 2 - Staff Decision to Not Resume Review of Withdrawn License Renewal Application, dated January 24,

Enclosure PG&E Letter DCL-23-020 Page 5 of 5 2023 (ML22343A179)

3. NRC Letter to PG&E, Diablo Canyon Power Plant, Units 1 and 2 - Exemption From The Requirements Related to Submission of a License Renewal Application, dated March 2, 2023 (ML23026A102)

4. NRC Letter to PG&E, Response to Request to Withdraw the Diablo Canyon Power Plant, Unit Nos. 1 and 2, License Renewal Application, dated April 16, 2018 (ML18093A114)

5. NUREG-1930, Safety Evaluation Report Related to the License Renewal of Indian Point Nuclear Generating Plant, Units 2 and 3, Supplement 3, dated August 2018 (ML18200A333)

PG&E Letter DCL-23-020 1 of 10 Current Inspections Planned for the Upcoming Diablo Canyon Power Plant Unit 1 Twenty-Fourth Refueling Outage (1R24)

AMP No.

AMP Name AMP Description1 Inspection/Activity Description During 1R24 B2.1.1 ASME Section XI, Subsections IWB, IWC and IWD Perform periodic visual, surface and/or volumetric examinations and leakage tests of Class 1, 2 and 3 pressure-retaining components, and their integral attachments, including welds, pump casings, valve bodies, and pressure-retaining bolting to monitor for and manage the aging effects of cracking, loss of material, and reduction of fracture toughness.

PG&E will inspect the U1 Pressurizer Spray Line Weld WIB-378.

B2.1.3 Reactor Head Closure Studs Manages cracking and loss of material by providing periodic ASME Section XI inspections of reactor vessel flange stud hole threads, reactor head closure studs, nuts, and washers.

Existing program; typical outage activities to be performed (no additional scope to support license renewal).

B2.1.4 Boric Acid Corrosion Manages loss of material due to boric acid leakage. The program monitors mechanical, electrical, and structural components within the scope of license renewal that are susceptible to boric acid corrosion from systems that contain reactor coolant or treated borated water Existing program; typical outage activities to be performed (no additional scope to support license renewal).

PG&E Letter DCL-23-020 2 of 10 AMP No.

AMP Name AMP Description1 Inspection/Activity Description During 1R24 B2.1.5 Nickel-Alloy Penetration Nozzles Welded To The Upper Reactor Vessel Closure Heads of Pressurized Water Reactors Manages cracking due to Primary Water Stress Corrosion Cracking (PWSCC) and loss of material due to boric acid wastage in nickel-alloy vessel head penetration nozzles and includes the reactor vessel closure head, upper vessel head penetration nozzles, and associated welds.

Existing program; typical outage activities to be performed (no additional scope to support license renewal).

B2.1.6 Flow-Accelerated Corrosion Manages wall thinning due to FAC on the internal surfaces of carbon steel piping, elbows, reducers, expanders, and valve bodies which contain high energy fluids (both single phase and two phases).

Existing program; typical outage activities to be performed (no additional scope to support license renewal).

B2.1.8 Steam Generator Tube Integrity Manages the aging of steam generator tubes, plugs, and tube supports. The scope of the program includes the preventive measures, inspections, degradation assessment, condition monitoring, operational assessment, tube plugging, and leakage monitoring activities necessary to manage potential steam generator tube degradation, including mechanically induced phenomena, such as wear and impingement damage.

Existing program; typical outage activities to be performed (no additional scope to support license renewal).

B2.1.9 Open Cycle Cooling Water System Manages cracking, loss of material, and reduction of heat transfer for components exposed to the raw water of the DCPP auxiliary saltwater (ASW) system. The program includes surveillance and control techniques to manage aging effects caused by biofouling, corrosion, erosion, protective coating failures, and silting in components of the ASW system or structures and components serviced by the Existing program; typical outage activities to be performed and CCW heat exchanger performance testing.

PG&E Letter DCL-23-020 3 of 10 AMP No.

AMP Name AMP Description1 Inspection/Activity Description During 1R24 ASW system that are within the scope of license renewal.

The program also includes periodic visual inspections and non-destructive examinations to detect biofouling, defective coatings and degraded piping and components of, systems and components, and component cooling water (CCW) heat exchanger performance testing, to ensure that the effects of aging on components are adequately managed for the period of extended operation.

B2.1.10 Closed Cycle Cooling Water System Manages loss of material, cracking and reduction of heat transfer for components in the closed-cycle cooling water systems. The program provides for: (1) preventive measures to minimize corrosion including maintenance of corrosion inhibitor, pH buffering agent, and biocide concentrations, and (2) periodic system and component performance testing and inspection.

PG&E will inspect the component cooling water supply isolation check valve to the reactor coolant pumps (valve CCW-1-585).

B2.1.11 Inspection of Overhead Heavy Load and Light Load (Related to Refueling) Handling Systems Manages the loss of material for all cranes, trolley and hoist structural components, fuel handling equipment, and applicable rails within the scope of license renewal. The program is implemented through periodic visual inspections of components.

PG&E will perform visual inspections for corrosion of structural members of the containment dome service crane and special service hoists, jib cranes, and monorails.

PG&E Letter DCL-23-020 4 of 10 AMP No.

AMP Name AMP Description1 Inspection/Activity Description During 1R24 B2.1.13 Fire Water System Manages loss of material due to corrosion, MIC, or biofouling for water-based fire protection systems. Internal and external inspections and tests of fire protection equipment are performed in accordance with applicable National Fire Protection Association (NFPA) codes and standards.

Existing program; typical outage activities to be performed (no additional scope to support license renewal).

B2.1.14 Fuel Oil Chemistry Manages loss of material due to general, pitting, crevice and microbiological influenced corrosion on the internal surface of components in the emergency diesel fuel oil storage and transfer system, portable diesel fire pump fuel oil tanks, and portable caddy fuel oil tanks.

PG&E plans to inspect the unit common diesel fuel oil storage tanks.

B2.1.15 Reactor Vessel Surveillance Manages loss of fracture toughness due to neutron embrittlement in reactor materials exposed to neutron fluence exceeding 1.0E17 n/cm2 (E>1.0 MeV). Neutron embrittlement is evaluated through surveillance capsule testing and evaluation, ex-vessel neutron fluence calculations, and monitoring of reactor vessel neutron fluence.

Upon NRC approval, PG&E plans to remove reactor vessel surveillance Capsule B during 1R24. In parallel, contingency planning for removal of capsule B during the Unit 1 Twenty-Fifth Refueling Outage is underway, in the event the capsule cannot be removed during 1R24.

PG&E Letter DCL-23-020 5 of 10 AMP No.

AMP Name AMP Description1 Inspection/Activity Description During 1R24 B2.1.16 One Time Inspection Conducts one-time inspections of plant system piping and components to verify the effectiveness of the Water Chemistry program, Fire Water System program, Fuel Oil Chemistry program, and Lubricating Oil Analysis program.

The aging effects to be evaluated by the One-Time Inspection program are loss of material, cracking, and reduction of heat transfer.

One-time NDE inspections are planned for selected components within scope with environments of secondary water, lubricating oil, reactor coolant borated water, and sodium hydroxide.

B2.1.17 Selective Leaching of Materials Manages loss of material due to selective leaching for gray cast iron and copper alloys (except for inhibited brass) containing greater than 15 percent zinc or greater than 8 percent aluminum components within the scope of license renewal that are exposed to raw water, including condensation, treated water, closed cooling water, ground water, water-contaminated fuel oil, or water-contaminated lube oil. The program provides measures for detecting the aging effects prior to loss of intended function, but does not prevent degradation due to aging effects.

PG&E plans to inspect selected components within the scope of this program; specific component selection is in progress.

B2.1.19 One Time Inspection of ASME Code Class 1 Small-Bore Piping Program Manages cracking of ASME Code Class 1 piping less than or equal to four inches nominal pipe size (NPS 4). This program is implemented as part of the fourth interval of the DCPP Inservice Inspection (ISI) program.

PG&E plans to inspect approximately 25 socket welds and 13 butt welds.

PG&E Letter DCL-23-020 6 of 10 AMP No.

AMP Name AMP Description1 Inspection/Activity Description During 1R24 B2.1.20 External Surfaces Monitoring Program Manages loss of material for external surfaces of steel, stainless steel, aluminum, and copper alloy components and elastomers, and hardening and loss of strength for elastomers. The program is a visual monitoring program that includes those systems and components within the scope of license renewal.

PG&E plans to utilize the System Engineering walkdowns of select components within the scope of this program.

B2.1.21 Flux Thimble Inspection Manages loss of material by performing wall thickness eddy current testing of all flux thimble tubes that form part of the reactor coolant system pressure boundary. The pressure boundary includes the length of the tube inside the reactor vessel out to the seal fittings outside the reactor vessel. Eddy current testing is performed on the portion of the tubes inside the reactor vessel.

Existing program; typical outage activities to be performed (no additional scope to support license renewal).

B2.1.22 Inspection of Internal Surfaces in Miscellaneous Piping and Ducting Components Manages cracking, loss of material, change in material properties and hardening and loss of strength of the internal surfaces of piping, piping components, ducting and other components that are not within the scope of other aging management programs. The program will also address the management of aging internal surfaces of miscellaneous piping and ducting components that are inaccessible during both normal operations and refueling.

PG&E plans to inspect the Refueling Water Storage Tank.2 PG&E Letter DCL-23-020 7 of 10 AMP No.

AMP Name AMP Description1 Inspection/Activity Description During 1R24 B2.1.24 (E1) Electrical Cables and Connections Not Subject to 10 CFR 50.49 Environmental Qualification Requirements Manages the aging effects demonstrated by cable and connection jacket surface anomalies, such as embrittlement, melting, cracking, swelling, surface contamination, or discoloration to ensure that electrical cables, connections and terminal blocks not subject to the environmental qualification (EQ) requirements of 10 CFR 50.49 and within the scope of license renewal are capable of performing their intended function.

PG&E plans to conduct walkdowns of in-scope cables (not accessible at power) in the Pressurizer and Steam Generator Cubicles.

B2.1.25 (E2) Electrical Cables and Connections Not Subject to 10 CFR 50.49 Environmental Qualification Requirements Used in Instrumentation Circuits Program includes the cables and connections used in instrumentation circuits with sensitive, high voltage, low-level signals within the nuclear instrumentation system and radiation monitors. Provides reasonable assurance that the intended function of cables and connections used in instrumentation circuits with sensitive, high voltage, low-level signals that are not subject to the environmental qualification requirements of 10 CFR 50.49 and are exposed to adverse localized environments caused by heat, radiation, or moisture are maintained consistent with the current licensing basis through the period of extended operation.

PG&E plans to perform testing on the in-scope Nuclear Instrument cables.

B2.1.26 (E3) Inaccessible Cables Not Subject to 10 CFR 50.49 Environmental Qualification Requirements Manages the aging effects of inaccessible medium-voltage cables located in conduit, duct banks, and pull boxes exposed to adverse localized environments caused by significant moisture simultaneously with significant voltage to ensure that inaccessible medium voltage cables not subject to the EQ requirements of 10 CFR 50.49 and within the scope of license renewal are capable of performing their intended function.

Majority of in-scope E3 cable testing will be performed.

Majority of in-scope pull boxes will be inspected.

PG&E Letter DCL-23-020 8 of 10 AMP No.

AMP Name AMP Description1 Inspection/Activity Description During 1R24 B2.1.27 ASME Section XI, Subsection IWE Manages loss of material and loss of sealing: leakage through containment and provides aging management of the steel liner of the concrete containment building. IWE inspections are performed in order to identify and manage containment liner aging effects that could result in loss of intended function. Included in this inspection program are the containment liner plate and its integral attachments, containment hatches and airlocks, and pressure-retaining bolting.

Existing program; typical outage activities to be performed (no additional scope to support license renewal).

B2.1.28 ASME Section XI, Subsection IWL Manages cracking due to expansion, loss of bond, and loss of material (spalling, scaling), increase in porosity and permeability, increase in porosity, permeability and cracking and provides aging management of the concrete containment building, which is conventionally reinforced Existing program; typical outage activities to be performed (no additional scope to support license renewal).

B2.1.29 ASME Section XI, Subsection IWF Manages loss of material, cracking, and loss of mechanical function that could result in loss of intended function for supports for Class 1, 2, and 3 piping and components Existing program; typical outage activities to be performed (no additional scope to support license renewal).

B2.1.30 10 CFR Part 50, Appendix J Manages loss of sealing, leakage through containment, loss of leak tightness, and loss of material. The program detects pressure boundary degradation in the reactor containment and all systems and components penetrating primary containment that are covered under the Appendix J program.

The program includes the steel liner of the concrete containment and its integral attachments, as well as welds, gaskets, seals, and bolted connections for the primary containment pressure boundary access points.

Existing program; typical outage activities to be performed (no additional scope to support license renewal).

PG&E Letter DCL-23-020 9 of 10 AMP No.

AMP Name AMP Description1 Inspection/Activity Description During 1R24 B2.1.31 Masonry Wall Program Manages cracking of masonry walls that are within scope of license renewal based on guidance provided in NRC Bulletin 80-11, Masonry Wall Design and NRC Information Notice 87-67, Lessons Learned from Regional Inspections of Licensee Actions in Response to NRC IE Bulletin 80-11. The Structures Monitoring Program manages cracking and loss of material for the structural steel restraint systems of the masonry walls.

The inspections performed for this program are performed as part of the Structural Monitoring Program (refer to B2.1.32).

B2.1.32 Structures Monitoring Program Manages cracking, loss of material, and change in material properties by monitoring the condition of structures and structural supports that are in the scope of license renewal.

The program implements the requirements of 10 CFR 50.65, the Maintenance Rule, which is consistent with the guidance of NUMARC 93-01, Industry Guidelines for Monitoring the Effectiveness of Maintenance at Nuclear Power Plants, Revision 2 and Regulatory Guide 1.160, Monitoring the Effectiveness of Maintenance at Nuclear Power Plants, Revision 2.

PG&E plans to inspect areas not accessible at power (i.e.,

intake, discharge, and containment).

B2.1.33 RG 1.127, Inspection of Water-Control Structures Associated with Nuclear Power Plants Manages cracking, loss of material, loss of form, loss of bond, loss of strength, and increase in porosity and permeability due to extreme environmental conditions and the effects of natural phenomena.

The inspections performed for this program are performed as part of the Structural Monitoring Program (refer to B2.1.32).

B2.1.37 Nickel-Alloy Aging Management Program Manages cracking due to primary water stress corrosion cracking (PWSCC) in reactor coolant system (RCS) locations that contain Alloy 600.

Existing program; typical outage activities to be performed (no additional scope to support license renewal).

PG&E Letter DCL-23-020 10 of 10 AMP No.

AMP Name AMP Description1 Inspection/Activity Description During 1R24 B2.1.38 Transmission Conductor and Connections, Insulators, and Switchyard Bus and Connections The components inspected during these inspections include transmission line towers, conductors, connectors, splices and insulators. The condition of inspected equipment is evaluated for acceptability.

Existing program; typical outage activities to be performed (no additional scope to support license renewal).

B2.1.40 Protective Coating Monitoring and Maintenance Program Manages the condition of Service Level I coatings, including cracking, blistering, flaking, peeling, and delamination, subjected to indoor air in the containment structure.

Existing program; typical outage activities to be performed (no additional scope to support license renewal).

B2.1.42 Internal Coatings/Linings for In-Scope Piping, Piping Components, Heat Exchangers, and Tanks Manages loss of coating integrity for piping, tanks, and heat exchangers fabricated from concrete, nickel alloy, carbon steel, and stainless steel with an internal coating/lining. The program consists of periodic visual inspections of internal coatings/linings exposed to closed-cycle cooling water, raw water, demineralized water, treated borated water, fuel oil, and lubricating oil.

PG&E plans to inspect select components within the scope of this program.

Notes:

1. AMP descriptions are from Appendix B of the withdrawn LRA.

2. The DCPP Inspection of Internal Surfaces in Miscellaneous Piping and Ducting Components AMP also manages some in-scope tanks.

PG&E Letter DCL-23-020 1 of 25 Current Implementation Schedule for DCPP Commitments Included in Withdrawn License Renewal Application (LRA)

Commitment Implementation Schedule in Withdrawn LRA2 Current Proposed Implementation Schedule 1

Enhance the Closed-Cycle Cooling Water program to:

• Utilize inspections of the CCW supply isolation check valves to the reactor coolant pumps (valves CCW-1-585 and CCW-2-585) as a leading indicator of the condition of the interior of piping components otherwise inaccessible for visual inspection. This periodic internal inspection will detect loss of material and fouling. The inspections are scheduled to be performed for Unit 1 and for Unit 2 at least once every five years. Plant procedures will be enhanced to include the acceptance criteria.

Prior to the Period of Extended Operation 11/02/2024 2

Enhance the Fire Protection program procedures to:

• Include inspection of all fire rated doors listed in the DCPP Fire Hazards Analysis, and

• Include qualification criteria for individuals performing inspections of fire dampers and fire doors Prior to the Period of Extended Operation 11/02/2024 PG&E Letter DCL-23-020 2 of 25 3

Enhance the Fire Water System program:

(a) Sprinkler heads in service for 50 years will be replaced or representative samples from one or more sample areas will be tested consistent with NFPA 25, Inspection, Testing and Maintenance of Water-Based Fire Protection Systems, 2011 Edition guidance. Test procedures will be repeated at 10-year intervals during the period of extended operation, for sprinkler heads that were not replaced prior to being in service for 50 years, to ensure that signs of degradation, such as corrosion, are detected prior to the loss of intended function, and (b) To perform non-intrusive follow-up volumetric examinations if internal visual inspections detect surface irregularities to determine if wall thickness is within acceptable limits. Visual inspections will evaluate for the presence of sufficient foreign material to obstruct fire water pipe or sprinklers (c) To be in conformance with LR-ISG-2012-02, Section C as discussed in PG&E Letter DCL-14-103, Enclosure 1, Attachment 7C.

(d) To be in conformance with LR-ISG-2013-01 as discussed in PG&E Letters DCL 15 027, Enclosure 1, and DCL-16-023 in response to RAI 3.0.3.2.6-2a.

(e) Test deluge system nozzles in accordance with the 2011 Edition of NFPA 25, Section 10.3.4.3.1.

(f) Conduct augmented inspections to address recurring internal corrosion as discussed in PG&E Letter DCL 023 Program is implemented 5 years before the period of extended operation.

Augmented inspections to address recurring internal corrosion and inspections of wetted normally dry piping segments that cannot be drained or that allow water to collect begin 5 years before the period of extended operation.

Internal linings inspections begin no later than the last refueling outage before the period of extended operation.

The programs remaining inspections begin during the period of extended operation Program is implemented by 11/02/2024.

Augmented inspections to address recurring internal corrosion and inspections of wetted normally dry piping segments that cannot be drained or that allow water to collect begin prior to U1: 11/02/2024 U2: 8/26/2025 Internal lining baseline inspections begin no later than U1: 11/02/2024 U2: 8/26/2025 The programs remaining inspections begin after U1: 11/02/2024 U2: 8/26/2025 4

Enhance the Fuel Oil Chemistry program to:

• Include the periodic draining, cleaning, and visual inspection of the diesel generator day tanks, the Prior to the period of extended operation Enhance procedures by 11/02/2024 PG&E Letter DCL-23-020 3 of 25 Commitment Implementation Schedule in Withdrawn LRA2 Current Proposed Implementation Schedule portable diesel-driven fire pump fuel oil tanks, and portable caddy fuel oil tanks, and

• Include sampling of the new fuel oil prior to introduction into the portable diesel-driven fire pump tanks and portable caddy fuel oil tanks, and

• Provide for one-time supplemental ultrasonic thickness measurements of accessible portions of fuel oil tank bottoms, and

• State that trending of water and particulate levels is controlled in accordance with DCPP Technical Specifications and plant procedures for the diesel fuel oil storage tanks and the diesel generator day tanks, and

• Include monitoring and trending of water and sediment levels of new fuel oil for the portable diesel driven fire pump fuel oil tank and portable caddy fuel oil tanks, and

• State acceptance criteria for new fuel oil being introduced into the portable diesel driven fire pump fuel oil tanks or portable caddy fuel oil tanks.

5 Implement the One-Time Inspection (OTI) program as described in LRA Section B2.1.16 During the 10 years prior to the period of extended operation U1: 11/02/2024 U2: 8/26/2025 6

Implement the Selective Leaching of Materials program as described in LRA Section B2.1.17.

During the 5 years prior to the period of extended operation Complete initial sample size inspections by U1: 11/02/2024 U2: 8/26/2025 Complete follow-up or expansion inspections by 12/01/2028 PG&E Letter DCL-23-020 4 of 25 Commitment Implementation Schedule in Withdrawn LRA2 Current Proposed Implementation Schedule 7

Deleted N/A N/A 8

Implement the External Surfaces Monitoring Program as described in LRA Section B2.1.20 and to be in conformance with LR-ISG-2012-02, Section E as discussed in PG&E Letter DCL-14-103, Enclosure 1, E.

Six months prior to the period of extended operation Program is implemented by 05/02/2024; Inspections begin after U1:11/02/20244 U2: 8/26/20254 9

Implement the Inspection of Internal Surfaces in Miscellaneous Piping and Ducting Components program as described in LRA Section B2.1.22 and to be in conformance with LR-ISG-2012-02 as discussed in PG&E Letters DCL-14-103, Enclosure 1, Attachments 7A, 7B, 7D, 7F, 7G, and 7H, and DCL-15-121 respectively.

Six months prior to the period of extended operation Program is implemented by 05/02/2024; Inspections begin after U1:11/02/20244 U2: 8/26/20254 PG&E Letter DCL-23-020 5 of 25 Commitment Implementation Schedule in Withdrawn LRA2 Current Proposed Implementation Schedule 10 Enhance the Lubricating Oil Analysis program to:

• Developed a new procedure to govern the Lubricating Oil Analysis program testing, evaluation, and disposition for in scope equipment, and

• Include procedural guidance for oil sampling and analysis for chemical and physical properties, and

• Specify standard analyses that will be performed on oils in a new procedure, and

• Include in a new procedure acceptance criteria for each of the lubricating oils commonly used on-site, including the oils associated with the equipment within the scope of the Lubricating Oil Analysis program. DCPP acceptance criteria for lubricating oil analysis will be derived from original equipment manufacturer (OEM) vendor manuals, industry guidance, and the advice of qualified offsite laboratories, and

• Include trending in a new procedure, and

• Address conditions where action limits are reached or exceeded.

Prior to the period of extended operation 11/02/2024 11 Implement the Electrical Cables and Connections Not Subject to 10 CFR 50.49 EQ Requirements program as described in LRA Section B2.1.24.

Prior to the period of extended operation U1: 11/02/2024 U2: 8/26/2025 PG&E Letter DCL-23-020 6 of 25 Commitment Implementation Schedule in Withdrawn LRA2 Current Proposed Implementation Schedule 12 Enhance the Electrical Cable and Connections Not Subject to 10 CFR 50.49 Environmental Qualification Requirements Used in Instrumentation Circuits program to:

• Identify license renewal scope and require an engineering evaluation of the calibration results when the loop fails to meet acceptance criteria.

Prior to the period of extended operation U1: 11/02/2024 U2: 8/26/2025 13 Enhance the Inaccessible Medium Voltage Cables Not Subject to 10 CFR 50.49 Environmental Qualification Requirements program to:

• Implement the aging management program for testing of the medium voltage cables not subject to 10 CFR 50.49 EQ requirements and enhance the periodic inspections and removal of water from the cable pull boxes containing in scope medium voltage cables not subject to 10 CFR 50.49 EQ requirements.

Prior to the period of extended operation U1: 11/02/2024 U2: 8/26/2025 14 Enhance the Structures Monitoring program procedures to:

• Monitor groundwater samples every five years for pH, sulfates and chloride concentrations, including consideration for potential seasonal variations, and

• Specify inspections of bar racks and associated structural components in the intake structure.

• Inspect the administration building, the elevated walkway connecting the turbine building to the administration building, and the structural members that support the walkway.

Prior to the period of extended operation U1: 11/02/2024 U2: 8/26/2025 15 Deleted N/A N/A PG&E Letter DCL-23-020 7 of 25 Commitment Implementation Schedule in Withdrawn LRA2 Current Proposed Implementation Schedule 16 Implement the Electrical Cable Connections Not Subject to 10 CFR 50.49 Environmental Qualification Requirements program as described in LRA Section B2.1.35.

Prior to the period of extended operation U1: 11/02/2024 U2: 8/26/2025 17 Enhance the Metal Enclosed Bus program:

• The existing bus work order inspection activities for inspection and testing of the MEBs will be proceduralized to include specific inspection scope, frequencies and actions to be taken when acceptance criteria are not met.

Prior to the period of extended operation U1: 11/02/2024 U2: 8/26/2025 18 Enhance the Transmission Conductor, Connections, Insulators and Switchyard Bus and Connections program procedures to:

• Identify components required to support station blackout recovery which are in the scope of license renewal aging management. In the 230 kV switchyard, these are the components between the startup transformers and disconnects 217 and 219. In the 500 kV switchyard these are the components between the main transformers and switchyard breakers 532/632 in Unit 1 and 542/642 in Unit 2, and

• Include gathering and reviewing completed maintenance and inspection results, by the plant staff, to identify adverse trends, and

• Identify that an engineering evaluation will be conducted when a degraded condition is detected that considers the extent of the condition, reportability of the event, potential root causes, probably of recurrence, and the corrective actions required.

Prior to the period of extended operation U1: 11/02/2024 U2: 8/26/2025 PG&E Letter DCL-23-020 8 of 25 Commitment Implementation Schedule in Withdrawn LRA2 Current Proposed Implementation Schedule 19 Implement the Thermal Aging Embrittlement of Cast Austenitic Stainless-Steel program as described in LRA Section B2.1.39.

During the 10 years prior to the period of extended operation 11/02/2024 20 DCPP procedures will be enhanced and implemented to conform to LR-ISG-2011-05, Ongoing Review of Operating Experience, as discussed in PG&E Letter DCL-14-103, Enclosure 1, Attachment 5.

Upon receipt of the renewed operating licenses 11/02/2024 21 Enhance the Metal Fatigue of Reactor Coolant Pressure Boundary program to:

• Include additional locations which are not covered by the current Metal Fatigue of Reactor Coolant Pressure Boundary program. Additional locations will include the NUREG/CR 6260 locations for the effects of the reactor coolant environment on fatigue. Usage factors in the NUREG/CR 6260 sample locations will include the environmental factors, F(en), calculated by NUREG/CR 6583 and NUREG/CR 5704 or appropriate alternative methods, and

• Include additional transients that contribute to fatigue usage and those transients used in fatigue flaw growth analyses supporting the leak-before-break analysis, ASME Section XI tolerance evaluations, and relief from ASME Section XI inspections, which are not covered by the current Metal Fatigue of Reactor Coolant Pressure Boundary program. Usage factors in the NUREG/CR 6260 sample locations will include the environmental factors, F(en), calculated by NUREG/CR 6583 and NUREG/CR 5704 or appropriate alternative methods, and Prior to the period of extended operation 11/02/2024 PG&E Letter DCL-23-020 9 of 25 Commitment Implementation Schedule in Withdrawn LRA2 Current Proposed Implementation Schedule

• Include additional cycle count and fatigue usage action limits, which will invoke appropriate corrective actions if a component approaches a cycle count action limit or a fatigue usage action limit. Action limits permit completion of corrective actions before the design limits are exceeded.

Cycle Count Action Limits:

An action limit initiates corrective action when the cycle count for any of the critical thermal or pressure transients is projected to reach the action limit defined in the program before the end of the next fuel cycle. In order to assure sufficient margin to accommodate occurrence of a low probability transient, corrective actions must be initiated before the remaining number of allowable cycles for any specified transient becomes less than one. Action limits will also be established based on the number of transients used in fatigue flaw growth analyses.

Cumulative Fatigue Usage (CUF) Action Limits:

An action limit requires corrective action when calculated cumulative usage factor (CUF) for any monitored location is projected to reach 1.0 within the next 3 fuel cycles, and

• The procedures governing the DCPP Metal Fatigue of Reactor Coolant Pressure Boundary program will be enhanced to specify the frequency of periodic reviews of the results of the monitored cycle count and cumulative usage factor data at least once per fuel cycle. This review will compare the results against the corrective PG&E Letter DCL-23-020 10 of 25 Commitment Implementation Schedule in Withdrawn LRA2 Current Proposed Implementation Schedule action limits to determine any approach to action limits and any necessary revisions to the fatigue analyses will be included in the corrective actions, and

• The procedures governing the DCPP Metal Fatigue of Reactor Coolant Pressure Boundary program will be enhanced to include appropriate corrective actions to be invoked if a component approaches a cycle count action limit or a fatigue usage action limit. The corrective action options for a component that has exceeded action limits include a revised fatigue analysis or repair or replacement of the component. Corrective actions for fatigue crack growth analysis action limits include re-analyzing the fatigue crack growth analysis consistent with or reconciled to the originally submitted analysis.

The reanalysis will receive the same level of regulatory review as the original analysis PG&E Letter DCL-23-020 11 of 25 Commitment Implementation Schedule in Withdrawn LRA2 Current Proposed Implementation Schedule 22 PG&E will:

A. For Reactor Coolant System Nickel-Alloy Pressure Boundary Components:

(1) Implement applicable NRC Orders, Bulletins and Generic Letters associated with nickel-alloys; (2) implement staff-accepted industry guidelines, (3) participate in the industry initiatives, such as owners group programs and the EPRI Materials Reliability Program, for managing aging effects associated with nickel-alloys, and (4) upon completion of these programs, but not less than 24 months before entering the period of extended operation, PG&E will submit an inspection plan for reactor coolant system nickel-alloy pressure boundary components to the NRC for review and approval.

Concurrent with industry initiatives and upon completion submit an inspection plan and not less than 24 months before entering the period of extended operation.

PG&E plans to replace this commitment with a commitment to implement the XI.M11B, Cracking of Nickel-Alloy Components and Loss of Material Due to Boric Acid-Induced Corrosion in Reactor Coolant Pressure Boundary Components program, prior to the expiration date of the operating licenses 23 DCPP will replace the current carbon steel with stainless steel clad CCP 2-2 pump casing in the CVCS with a completely stainless steel pump casing.

Completed. PG&E Letter DCL-11-136.

Complete1 24 Deleted N/A N/A 25 DCPP will re-evaluate the RCS Pressure-Temperature limits and COMS setpoints as necessary to comply with 10 CFR 50 Appendix G Prior to operation beyond 23 EFPY Complete3 26 The missile shield hoist crane will be removed from containment during the replacement reactor vessel closure head (RRVCH) project. The Unit 2 RRVCH project was completed during the fifteenth refueling outage beginning October 2009 and Unit 1 RRVCH project is planned during the sixteenth refueling outage beginning October 2010.

Completed. PG&E Letter DCL-10-158 Complete1 PG&E Letter DCL-23-020 12 of 25 Commitment Implementation Schedule in Withdrawn LRA2 Current Proposed Implementation Schedule 27 DCPP will repair or replace the hot leg surge nozzle, or augment the inservice inspection program to require ASME Section XI volumetric examination at regular intervals.

Prior to the period of extended operation 11/02/2024 28 The Unit 1 reactor pressure vessel (RPV) head is planned to be replaced during the 16th refueling outage beginning October 2010 and the Unit 2 RPV head was replaced during the 15th refueling outage in October 2009. All components penetrating the new reactor vessel closure heads and welded to the inner surfaces of the reactor vessel closure heads including the head vent piping and elbows will be replaced with Alloy 690.

Completed. PG&E Letter DCL-10-158.

Complete1 29 DCPP Unit 1 and 2 CRDM pressure housings, the core exit thermocouple nozzle assemblies (CETNAs), and the thermocouple nozzles will be replaced with the replacement reactor vessel closure heads (RRVCHs).

The Unit 2 RPV head was replaced during the fifteenth refueling outage beginning October 2009 and Unit 1 RPV head is planned to be replaced during the sixteenth refueling outage beginning October 2010. The replacement components will be qualified through the period of extended operation.

Completed. PG&E Letter DCL-10-158.

Complete1 PG&E Letter DCL-23-020 13 of 25 Commitment Implementation Schedule in Withdrawn LRA2 Current Proposed Implementation Schedule 30 DCPP will monitor the corrosion of closed cooling water components by inspecting the condition of corrosion coupons installed in the system and perform internal inspections of select components within the systems.

These methods will verify that wetted material exposed to the chemistry of the closed cooling water systems are not experiencing corrosion. The corrosion coupons are strips of metal (i.e. copper, carbon steel, stainless steel, etc.) that are installed in the closed cooling water systems in a manner such that they are exposed to the cooling water. Periodically these coupons are removed and their condition can be evaluated. This inspection will provide DCPP indication if significant corrosion is occurring in the system. The material of these corrosion coupons is representative of most of the materials that are used in the system. For those components that do not have material represented by the corrosion coupons, internal inspections will be performed on those components, or other component with similar material, in order to monitor for corrosion Prior to the period of extended operation U1: 11/02/2024 U2: 8/26/2025 31 The Unit 2 gap repair work will be completed prior to the period of extended operation.

Completed. PG&E Letter DCL-11-136 Complete1 32 DCPP plant procedures will be revised to perform concrete inspections per ASME Section XI Subsection IWL within a 5-year interval.

Completed. PG&E Letter DCL-14-103 Complete1 PG&E Letter DCL-23-020 14 of 25 Commitment Implementation Schedule in Withdrawn LRA2 Current Proposed Implementation Schedule 33 The plant procedure on work control will be revised to require that whenever an in-scope pullbox is going to be opened the Structural Monitoring Aging Management Aging Management program personnel be notified to allow them to determine whether an opportunistic inspection of the pull box should be performed.

Prior to the period of extended operation U1: 11/02/2024 U2: 8/26/2025 34 The DCPP work control procedure will be revised to include evaluation of reinforced concrete exposed during excavations.

Complete. PG&E Letter DCL-15-150.

Complete1 35 DCPP will revise the test procedure acceptance criteria to specifically preclude repositioning a tube more than once without capping or replacing. This will preclude repositioning a tube having chrome plated surfaces from the chrome being moved out of the areas of known wear.

Complete. PG&E Letter DCL-11-136.

Complete1 36 PG&E will revise plant procedures to specify visual inspections for corrosion of structural members of the containment dome service crane and special service hoists, jib cranes, and monorails.

Prior to the period of extended operation 11/02/2024 37 Deleted N/A N/A 38 The actual plant transient cycles related to the SWOL and Model 93A Reactor Coolant Pumps fatigue crack growth analyses will be included in the existing plant transient monitoring program by January 31, 2011 to ensure that the actual plant transients do not exceed the fatigue analysis limits.

Complete. PG&E Letter DCL-11-020.

Complete1 PG&E Letter DCL-23-020 15 of 25 Commitment Implementation Schedule in Withdrawn LRA2 Current Proposed Implementation Schedule 39 DCPP will volumetrically examine 10%, with a maximum of 25, of the small bore socket welds and 10%, with a maximum of 25, of the butt welds within the population of ASME Class-1 piping NPS less than 4-inches on each unit. Currently, DCPP has 696 socket welds in Unit 1, 841 socket welds in Unit 2, 134 butt welds in Unit 1, and 133 butt welds in Unit 2. Based on the current weld count, this would result in the examination of 25 socket welds for Unit 1, 25 socket welds for Unit 2, 13 butt welds for Unit 1 and 13 butt welds for Unit 2. DCPP may perform opportunistic destructive examination of welds in lieu of volumetric examination with 1 destructive examination being equivalent to 2 volumetric examinations.

During the 6 years prior to the period of extended operation U1: 11/02/2024 U2: 8/26/2025 40 Calculation No. 2305C will be revised by November 1, 2010 to be consistent with the latest revision of Procedure NDE VT 3C-1.

Complete. PG&E Letter DCL-10-158 Complete1 41 Calculation No. 2305C acceptance criteria will be consistent with the latest revision of Procedure NDE VT 3C-1. Any long term planning and decisions on potential repair will be made on a case by case basis and based on review of trends in the inspection findings and will be implemented via DCPP Corrective Action Program.

Complete. PG&E Letter DCL-10-158 Complete1 42 Procedure NDE VT 3C-1 acceptance criteria will be revised to be consistent with ACI 349.3R Chapter 5 detailed quantitative acceptance criteria.

Complete PG&E Letter DCL-13-119 Complete1 PG&E Letter DCL-23-020 16 of 25 Commitment Implementation Schedule in Withdrawn LRA2 Current Proposed Implementation Schedule 43 Prior to the period of extended operation, the acceptance criteria for concrete structural elements provided in the implementing procedures for the Structures Monitoring Program for both safety and non-safety-related structures will be revised to incorporate the quantitative evaluation criteria provided in ACI 349.3R, Evaluation of Existing Nuclear Safety Related Concrete Structures, Chapter 5, Evaluation Criteria Prior to the period of extended operation 11/02/2024 44 The Structures Monitoring Program inspection interval for safety related and non-safety related concrete structures will be revised to be aligned with the guidance in ACI 349.3R, Evaluation of Existing Nuclear Safety Related Concrete Structures, Chapter 6, Evaluation Frequency.

Prior to the period of extended operation 11/02/2024 45 A one-time video inspection of the Unit 2 leak chase will be performed within one year prior to the period of extended operation.

Within one year prior to the period of extended operation PG&E will inspect the Unit 2 spent fuel pool leak chase by 8/26/2025 46 The existing Structures Monitoring Program procedure will be revised prior to the period of extended operation to specify a five year maximum interval for inspection of water control structures.

Prior to the period of extended operation 11/02/2024 47 Aluminum tape currently installed on the seems of the Unit 1 RMI insulation panels of the pressurizer loop seals is currently scheduled to be removed during the Unit 1 sixteenth refueling outage (1R16), October 2010.

Complete. PG&E Letter DCL-10-158.

Complete1 48 Deleted N/A N/A PG&E Letter DCL-23-020 17 of 25 Commitment Implementation Schedule in Withdrawn LRA2 Current Proposed Implementation Schedule 49 DCPP will update the PM basis documents for strainers and screens in the makeup water system that support long term cooling and firewater inventory to require that they are cleaned and inspected on a 24 month frequency prior to the period of extended operation.

Prior to the period of extended operation 11/02/2024 50 Procedures will be enhanced to provide specific valves that need to be repositioned to provide Class I makeup to the spent fuel pool including the correct position of any normally open code break valves.

Complete. PG&E Letter DCL-11-020 Complete1 51 A one time UT examination of the firewater tank bottom will be performed as part of the One-Time Inspection aging management program, LRA Section B2.1.16.

During the 10 years prior to the period of extended operation 11/02/2024 52 The Buried Piping and Tanks Inspection Program will be implemented as described in LRA Section B2.1.18 and will conform to the specific additional guidance provided in LR ISG 2011 03 as discussed in PG&E Letter DCL-14-103, Enclosure 1, Attachment 3; the specific changes provided in draft LR-ISG-2015-01 as discussed in PG&E Letters DCL-15-121, Enclosures 1 and 2, and DCL 023; and the specific changes provided in LR ISG 2015 01 as discussed in PG&E Letter DCL-16-032, Enclosure

3.

Fire mains will be subject to a periodic flow test in accordance with NFPA 25 section 7.3 at a frequency of at least one test in each one year period. These flow tests will be performed in lieu of excavating buried portions of Fire Water pipe for visual inspections.

Within 10 years prior to the period of extended operation Program implemented by 11/02/2024; Initial inspections completed by 12/01/2028 PG&E Letter DCL-23-020 18 of 25 Commitment Implementation Schedule in Withdrawn LRA2 Current Proposed Implementation Schedule 53 PG&E will install impressed current cathodic protection for the buried ASW discharge and supply piping in contact with soil as described in PG&E Letter DCL 032 and will submit a final report to the NRC to confirm the completed scope.

During the 10 years prior to the period of extended operation 12/01/2028 54 The DCPP XI.E3 program will be revised to include in scope inaccessible underground 480 V power cables or higher power cables, regardless of the percentage of time the loads are energized. The program will require that in scope cable pull boxes will be inspected for water accumulation at least once every year. Detailed internal pull box inspections of cables and cable supports will be included in the structural monitoring program. Inspection criteria will be included in plant procedures. These are opportunistic inspections conducted when the pull boxes are opened for maintenance or other reasons. More frequent tests and inspections will be required when the current program identifies adverse trends indicating that in scope power cables insulation resistance is being reduced or the cables are being subjected to submergence or visible indications of cable aging or cable support degradation are observed. The DCPP corrective action program will drive any necessary changes. A corrective action document is required to be written when test or inspection requirements do not meet acceptance requirements or when adverse trends are noted when evaluating results over time.

Prior to the period of extended operation U1: 11/02/2024 U2: 8/26/2025 PG&E Letter DCL-23-020 19 of 25 Commitment Implementation Schedule in Withdrawn LRA2 Current Proposed Implementation Schedule 55 PG&E will conduct a baseline inspection of all safety and non-safety related structures concrete elements (in the scope of the Structures Monitoring Program) in accordance to ACI 349.3R acceptance criteria prior to entering the period of extended operation.

Prior to the period of extended operation U1: 11/02/2024 U2: 8/26/2025 56 Procedures will be implemented for:

A. Cable testing and periodic water accumulation inspections of the pull boxes for inscope 480V and higher power cables.

B. Pull box sump box and alarm features testing on an annual basis.

Prior to the period of extended operation 11/02/2024 57 In-scope 480V and higher power cables will be tested at a frequency of at least every 6 years with the first test completed prior to entering the period of extended operation.

Prior to the period of extended operation U1: 11/02/2024 U2: 8/26/2025 PG&E Letter DCL-23-020 20 of 25 Commitment Implementation Schedule in Withdrawn LRA2 Current Proposed Implementation Schedule 58 PG&E will perform a review of design basis ASME Class 1 component fatigue evaluations to determine whether the NUREG/CR-6260-based components that have been evaluated for the effects of the reactor coolant environment on fatigue usage are the limiting components for the DCPP plant configuration. If more limiting components are identified, the most limiting component will be evaluated for the effects of the reactor coolant environment on fatigue usage. The effect of the reactor coolant environment on DCPP fatigue usage will be evaluated using material-specific guidance presented in NUREG/CR-6583 for carbon and low alloy steels, NUREG/CR-5704 for stainless steels, and NUREG/CR-6909 for nickel alloys. This additional evaluation will be performed through the Metal Fatigue of Reactor Coolant Pressure Boundary Program in accordance with 10 CFR 54.21 (c)(1)(iii).

Prior to the period of extended operation 11/02/2024 59 PG&E will revise the DCPP FSAR to include the basis for exclusion of unit loading and unloading transients from counting, and the transients and numbers of events related to the leak-before-break analysis, the ASME Section XI fatigue flaw growth analysis for auxiliary feedwater line 567, and the generic fatigue flaw growth analysis in WCAP-13045.

Prior to the period of extended operation 11/02/2024 60 PG&E will enhance provisions in the HVAC ducting from the 480V switchgear room that allow water to drain from the exhaust ducting so water cannot enter the 480V switchgear room.

Complete. PG&E Letter DCL-15-150.

Complete1 PG&E Letter DCL-23-020 21 of 25 Commitment Implementation Schedule in Withdrawn LRA2 Current Proposed Implementation Schedule 61 PG&E will close the isolation valve upstream of the water traps and drain the traps in the compressed air system.

Prior to the period of extended operation 11/02/2024 62 Implementation for all Unit 2 Diesel Generator Starting Air and Turbocharger Air Compressor upgrades is planned for April, 2011.

Complete. PG&E Letter DCL-11-136.

Complete1 63 PG&E will enhance the operating procedures to provide direction to evaluate and close valve MU-0-881 as appropriate.

Prior to the period of extended operation 11/02/2024 64 PG&E will perform a regularly scheduled lSI ultrasonic inspection of WIC-95 during the upcoming 1R17 refueling outage, scheduled for May 2012, to confirm the absence of service-related flaw growth. Should service-related flaw growth be identified in this inspection, the corrective action program will be entered and appropriate corrective action will be taken in accordance with ASME Section XI Code. In absence of flaw growth, WIC-95 will continue to be inspected at a frequency required by the lSI Program Plan.

Complete. PG&E Letter DCL-14-103.

Complete1 65 PG&E will revise the plant procedure on flux thimble tube inspections to reference this letter and WCAP-12866 to clarify the technical basis for an adequate margin of safety to ensure that the integrity of the reactor coolant system pressure boundary is maintained. This procedure revision is currently scheduled to be completed prior to December 2011, but will be completed prior to the period of extended operation.

Complete. PG&E Letter DCL-12-124.

Complete1 PG&E Letter DCL-23-020 22 of 25 Commitment Implementation Schedule in Withdrawn LRA2 Current Proposed Implementation Schedule 66 PG&E will revise its plant procedure to include a 5.1 percent allowance for predictability and a 10 percent allowance to account for instrument and wear scar uncertainty. This procedure will also be revised to include an 80 percent through wall acceptance criterion based upon its plant-specific FTT data wear and NRC acceptance of this 80 percent criterion. In conclusion, based on the WCAP-12866 80 percent acceptance criterion, including 5.1 percent predictability uncertainty and 10 percent for eddy current testing instrument and wear scar uncertainty, PG&E will use a net acceptance criterion of 64.9 percent. This procedure revision is currently scheduled to be completed prior to December 2011, but will be completed prior to the period of extended operation.

Complete. PG&E Letter DCL-12-124.

Commitment modified and completed per PG&E Letter DCL-14-103.

Complete1 67 PG&E will update the FSAR in accordance with 10 CFR 50.71(e) to include the flux thimble tube acceptance criterion. This update is currently scheduled to be included in the next FSAR update, but will be completed prior to the period of extended operation.

Complete. PG&E Letter DCL-12-124.

Complete1 PG&E Letter DCL-23-020 23 of 25 Commitment Implementation Schedule in Withdrawn LRA2 Current Proposed Implementation Schedule 68 PG&E will revise its plant procedure to require the actual plant FTT specific wear data versus wear projections be evaluated every refueling outage to ensure it remains consistent with a maximum non-conservative wear projection of 5.1 percent for wear above 40 percent. If the wear projection for a tube is determined to exceed the 5.1 percent under-prediction and has over 40 percent wear the previous cycle, PG&E will enter it into the corrective action program for evaluation and disposition. This procedure revision is currently scheduled to be completed prior to December 2011, but will be completed prior to the period of extended operation.

Complete. PG&E Letter DCL-12-124.

Commitment modified and completed per PG&E Letter DCL-14-103.

Complete1 69 Marine growth removal and subsequent inspection of all required areas of the Unit 2 discharge conduit will be completed prior to the period of extended operation. The Unit 2 discharge conduit is currently scheduled to be completed during 2R17 (2013). Reference PG&E Letter DCL-12-124 for Unit 1.

Complete. PG&E Letter DCL-13-119.

Complete1 70 The requirements for future discharge conduit inspections including those to be performed during the period of extended operation will be developed based on the findings from the 1R17 / 2R17 inspections. These requirements will address the following: (1) inspection interval (not to exceed 5 years); (2) extent and frequency of marine growth removal; and (3) inspection extent (100 percent vs. sampling).

Prior to the period of extended operation U1: 11/02/2024 U2: 8/26/2025 PG&E Letter DCL-23-020 24 of 25 Commitment Implementation Schedule in Withdrawn LRA2 Current Proposed Implementation Schedule 71 The Intake Structure will be returned to (a)(2) status prior to the period of extended operation. The Intake Structure is currently scheduled to be returned to (a)(2) status by the end of 2011 Complete. PG&E Letter DCL-11-136.

Complete1 72 Implement the PWR Vessel Internals Program to conform to LR-ISG-2011-04 as discussed in PG&E Letter DCL-14-103, Enclosure 1, Attachment 4, including the plant-specific action items, conditions, and limitations identified in the NRC Safety Evaluation, Revision 1, for MRP-227.

Prior to the period of extended operation Program is implemented by 11/02/2024 73 The NRC SE for MRP-227 contains eight action items for applicants/licensees to consider. Responses to the applicable aging management program plant-specific action items, conditions, and limitations identified in the NRC SE, Revision 1, on MRP-227 will be submitted to the NRC by December 2015. Reference DCL-14-103,, Attachment 4.

Complete. PG&E Letter DCL-15-150.

Complete 74 Implement the Internal Coatings/Linings for In-Scope Piping, Piping Components, Heat Exchangers, and Tanks program in conformance with LR-ISG-2013-01 as discussed in PG&E Letters DCL-15-027, Enclosure 1, DCL-15-121, and DCL-16-023.

No later than six months before the period of extended operation and inspections begin no later than the last refueling outage before the period of extended operation Program implemented by 11/02/2024; Initial inspections completed by 12/01/2028 PG&E Letter DCL-23-020 25 of 25 Commitment Implementation Schedule in Withdrawn LRA2 Current Proposed Implementation Schedule 75 For copper alloy piping portions of the domestic water system that are in the scope of license renewal, PG&E will replace the piping with a material that is more corrosion-resistant, or install pipe shielding to ensure that no adverse a(2) spatial interactions could occur.

Prior to the period of extended operation 12/01/2028 76 Pressurizer Spray Line Pipe Weld WIB-378 will be re-examined for the next three inservice inspection (ISI) periods as described in PG&E Letter DCL-16-043. If during the successive-inspection monitoring timeframe the flaw has reached 50 percent through wall depth, PG&E will reanalyze the current acceptability and projected flaw growth rate for the remainder of the period of extended operation and continue monitoring it on a periodic basis.

Prior to the period of extended operation 11/02/2024 Notes:

1. Some commitments labeled "Complete" may need minimal additional administrative work based on the previous decision not to pursue license renewal.

2. The implementation schedule included in this column corresponds to the implementation schedule included in the DCPP LRA at the time of withdrawal in April 2018.

3. This commitment was previously satisfied by submittal of PG&E Letter DCL-13-023 (ML13072A232), however the LRA was not officially updated to reflect completion.

4. The implementation schedule for initiating inspections is consistent with the AMP FSAR Supplements in LR-ISG-2012-02, Aging Management of Internal Surfaces, Fire Water Systems, Atmospheric Storage Tanks, and Corrosion Under Insulation.