Palo Verde, Units 1, 2 and 3 - Responses to Follow-up

ALS A subsidiary of Pinnacle West Capital Corporation

Dwight C. Mims Mail Station 7605Palo Verde Nuclear Vice President Tel. 623-393-5403 P.O. Box 52034Generating Station Regulatory Affairs and Plant Improvement Fax 623-393-6077 Phoenix, Arizona 85072-2034

102-06205-DCM/GAMJune 21, 2010

ATTN: Document Control DeskU.S. Nuclear Regulatory CommissionWashington, DC 20555-0001

Dear Sirs:

Subject: Palo Verde Nuclear Generating Station (PVNGS)Units 1, 2, and 3Docket Nos. STN 50-528, 50-529 and 50-530Responses to Follow-up Requests for Additional InformationRegarding Buried Piping, Elastomers, Compressed Air, ContainmentLiner, Spray Ponds, and Supports, for the Review of the PVNGSLicense Renewal Application, and License Renewal ApplicationAmendment No. 17

By letter no. 102-06134, dated February 19, 2010, Arizona Public Service Company(APS) submitted responses to requests for additional information (RAIs) B2.1.18-1,B2.1.20-1, and B2.1.20-3 regarding buried piping, elastomers, and compressed air,respectively, for the review of the PVNGS license renewal application (LRA). By letterno. 102-06160, dated April 1, 2010, APS submitted responses to RAIs 4.6-1 andB2.1.33-2 regarding the containment liner and spray pond walls, respectively, for thereview of the PVNGS LRA. By letter no. 102-06194, dated May 21, 2010, APSsubmitted a response to RAI 3.5.2.3-4 regarding ASME Class 2 and 3 supports for thereview of the PVNGS LRA. The NRC staff has requested follow-up informationregarding these RAI responses.

Enclosure 1 contains responses to the follow-up RAIs. Enclosure 2 contains PVNGSLRA Amendment No. 17 to reflect changes made as a result of the follow-up RAIresponses. In addition, LRA Amendment No. 17 includes a revision to LRA SectionA1.6, Flow Accelerated Corrosion, to include a reference to the EPRI recommendationsin NSAC-202L.

Commitment no. 20 in LRA Table A4-1 for the buried piping and tanks inspectionprogram has been revised as shown in LRA Amendment No. 17 in Enclosure 2. Inaddition, a new commitment no. 56 for spray pond wall repairs has been added to TableA4-1 as shown in LRA Amendment No. 17 in Enclosure 2.

A member of the STARS (Strategic Teaming and Resource Sharing) Alliance

Callaway • Comanche Peak • Diablo Canyon - Palo Verde - San Onofre • South Texas - Wolf Creek / I •

141e

ATTN: Document Control DeskU.S. Nuclear Regulatory CommissionResponses to Follow-up Requests for Additional Information Regarding Buried Piping,Elastomers, Compressed Air, Containment Liner, Spray Ponds, and Supports, for theReview of the PVNGS License Renewal Application, and License Renewal ApplicationAmendment No. 17Page 2

Should you need further information regarding this submittal, please contact Russell A.

Stroud, Licensing Section Leader, at (623) 393-5111.

I declare under penalty of perjury that the foregoing is true and correct.

Executed on 6 ; /Z /(date)

Sincerely,

DCM/RAS/GAM

Enclosures:

1. Responses to Follow-up Requests for Additional Information Regarding BuriedPiping, Elastomers, Compressed Air, Containment Liner, Spray Ponds, andSupports, for the Review of the PVNGS License Renewal Application

2. Palo Verde Nuclear Generating Station License Renewal ApplicationAmendment No. 17

cc: E. E. Collins Jr. NRC Region IV Regional AdministratorJ. R. Hall NRC NRR Project ManagerL. K. Gibson NRC NRR Project ManagerR. I. Treadway NRC Senior Resident Inspector for PVNGSL. M. Regner NRC License Renewal Project ManagerG. A. Pick NRC Region IV (electronic)

ii-.,

ENCLOSURE 1

Responses to Follow-up Requests for Additional InformationRegarding Buried Piping, Elastomers, Compressed Air,Containment Liner, Spray Ponds, and Supports, for the

Review of the PVNGS License Renewal Application

Follow-up RAI 3.5.2.3-4Follow-up RAI 4.6-1

Follow-up RAI B2.1.18-1

Follow-up RAI B2.1.20-1.......... F -up '- . -. ........SFollow-up RAI 132.1.20-2

Enclosure 1Responses to Follow-up Requests for Additional Information Regarding

Buried.Piping, Elastomers, Compressed Air, Containment Liner, Spray Ponds,and Supports, for the Review of the PVNGS License Renewal Application

NRC Follow-up RAI 3.5.2.3-4

The applicant's response to RAI 3.5.2.3-4 in their letter dated May 21,.2010, stated thatthe Palo Verde ASME Class 2 and 3 supports in a fuel oil environment are ASME Class3 supports located in the diesel fuel oil storage tanks for support of the diesel fuel oiltransfer pump. Supports for the diesel fuel oil transfer pump are within the scope of theASME Section Xl Subsection IWF (B2.1.29) AMP, but exempt from examinationrequirements.

What is the basis for the diesel fuel oil transfer pump supports to be exempt from

examination requirements?

APS Response to Follow-up RAI 3.5.2.3-4

(This response supplements the RAI 3.5.2.3-4 response provided in APS letter no.102-06194, dated May 21, 2010)

The ¾ inch diesel fuel discharge line in the diesel fuel oil tank is restrained by a carbonsteel Class 3 support assembly which also supports the diesel fuel oil transfer pump.Supports and their examination requirements are based on the process piping size. Inthis case, these supports are exempted from examination based on the size of the pipe(ASME Section XI Subarticle IWF-1230).

NRC Follow-up RAI 4.6-1

In response to RAI 4.6-1, the applicant stated the following in the April 1, 2010, letter:

"The containment liner design documents have been revised to include theevaluation described above. In addition, PVAR 3451141 has been initiated to clarifyUFSAR Section 3.8.1.5.4.B."

This change to the UFSAR appears to also affect the UFSAR supplement in LRASection A3.5. Please provide a revision to LRA Section A3.5, or provide justification fornot revising this section.

APS Response to Follow-up RAI 4.6-1

(This response supplements the RAI 4.6-1 response provided in APS letter no.102-06160, dated April 1, 2010)

LRA Section A3.5 has been revised, as shown in LRA Amendment No. 17 inEnclosure 2, to reflect the revisions to the containment liner design documents.

1

Enclosure IResponses to Follow-up Requests for Additional Information Regarding

Buried Piping, Elastomers, Compressed Air, Containment Liner, Spray Ponds,and Supports, for the Review of the PVNGS License Renewal Application

NRC Follow-up RAI B2.1.18-1

1. Provide a list and brief summary of any leaks or adverse conditions discovered duringinspections (e.g., coating damage that directly exposes the piping or tank to theenvironment, presence of any coarse material in backfill within 6 inches of the pipe ortank, unexpected corrosion or damage to piping walls or component pressureboundaries) which have occurred, in buried or underground piping or tanks at the stationin the past five years that were entered in your corrective action program but are notincluded in your LRA.

2. Discuss the number of planned inspections that will be conducted in the ten year periodprior to extended operation where the in-scope buried pipe is excavated and visuallyinspected around the circumference of the pipe.

3. For in-scope buried piping that is not.protected by a cathodic protection system, whatpercentage of this piping will have been or will be exposed and visually, inspected duringthe inspections in 1 and 2 above?

4. To what extent has in scope buried piping been protected by the existing cathodicprotection system over the past five years?

APS Response to Follow-up RAI B2.1.18-1

(This response supplements the RAI B2.1.18-1 response provided in APS letterno. 102-06134, dated February 19, 2010)

1. The following leaks or adverse conditions were discovered and corrected in buriedpiping within the scope of license renewal within the last five years:

" March 2005: Fire Protection Piping 1 PFPNL282

A water leak was identified in the Unit 1 firewater loop. The condition wascorrected.

* January 2006: Fire Protection Piping APFPNL228

Water was leaking near the retention basins on the west side of Unit 3. Theleaking piping was replaced.

* March 2006: Fire Protection Piping APFPNL209

The south loop of the fire protection system was not leaking but was determinedto be potentially degraded. This piping was proactively replaced with fiberglass

2



reinforced plastic (FRP) as part of the on-going fire protection system piping

upgrades.

" August 2006: Compressed Air Piping 1 PGANL0O1

The high pressure nitrogen header was corroded and missing wrapping where itextends out of the ground. The corrosion was cleaned-up and missing bitumastictape wrap was restored.

* July 2009: Fire Protection Piping APFPNL210

There was a fiberglass reinforced plastic pipe failure of the fire main between theUnit 3 Turbine Building and the Unit 3 Spray Pond. The piping was replaced.

2. The visual inspections noted below of piping in a soil environment within the scopeof license renewal will be conducted within the ten-year period prior to entering theperiod of extended operation, and again within the first ten years after entering theperiod of extended operation. Each inspection will:

* select accessible locations where degradation is expected to be high;* excavate and visually inspect the circumference of the pipe; and* examine at least ten feet of pipe.

a. Metallic Piping not Cathodically-Protected

At least two excavations and visual inspections of stainless steel piping will beconducted in each unit. Stainless steel piping within the scope of license renewalexists in the following systems:

o Chemical and Volume Control (CH),o Condensate Transfer and Storage (CT), ando Fire Protection (FP).

b. Steel Piping Cathodically-Protected

At least two excavations and visual inspections of cathodically-protected steelpiping will be conducted in each unit.

c. Steel Piping with Potentially Degraded Cathodic Protection

An investigation of Palo Verde's common fire protection water piping identifiedpotentially degraded cathodic protection for sections of this piping. This condition isdue to degraded bonding straps between piping sections. This condition is being

3

• Enclosure IResponses to Follow-up Requests for Additional Information Regarding

Buried Piping, Elastomers, Compressed Air, Containment Liner, Spray Ponds,and Supports, for the Review'of the PVNGS License Renewal Application

addressed in the Palo Verde corrective action program, and corrective actionsinclude on-going fire protection system piping upgrades.

At least three excavations and visual inspections of fire protection steel piping withpotentially degraded bonding straps will be conducted at the Palo Verde site.

3. The following percentages of piping that are not cathodically protected will be

inspected:


At least two visual inspections of stainless steel will be conducted in each unit.Based on each inspection examining at least ten feet of pipe with approximately1200 feet of stainless steel pipe installed per unit (including common piping),approximately 1.7% of the stainless steel pipe will be inspected in each unit.

Stainless Steel piping has the following functions:

" CH - Reactor makeup water to the auxiliary feedwater pumps(approximately 633 feet).

o CT - Condensate storage tank to the spent fuel pool (approximately 512feet).

o CT - Condensate storage tank to the 'N' auxiliary feedwater pump(approximately 40 feet).

o FP - Fire pump recirculation to the fire water tank (approximately 17 feet- common piping).

b. Steel Piping with Potentially Degraded Cathodic Protection

At least three excavations and visual inspections of fire protection steel pipingwith potentially degraded bonding straps will be conducted at the Palo Verde site.Based on each inspection examining at least ten feet of pipe with approximately14,000 feet of fire protection steel piping with potentially degraded bonding strapsat the Palo Verde station, less than 1% of the fire protection steel piping withpotentially degraded bonding straps will be inspected.

In addition to these inspections, on-going fire protection system piping upgradesare being implemented.

4. The systems listed below contain carbon steel piping in a soil environment within thescope of license renewal. The carbon steel piping in a soil environment within thescope of license renewal is designed to be cathodically protected. There is nocopper or aluminum piping in a soil environment within the scope of license renewal.

4



, Diesel Fuel Storage and Transfer (DF)* Domestic Water (DS)* Fire Protection (FP)* Station Blackout Generator (SBOG) Fuel System (FS)* Service Gas (nitrogen) System (GA)* Essential Spray Pond (SP)

Except during outages or due to degraded conditions, cathodic protection has beenapplied over the past five years. Annually, Palo Verde replaces depleted anodebeds and degraded rectifiers based on the survey results to optimize cathodicprotection performance.

To assess the performance of the cathodic protection system within the protectedarea, Palo Verde uses an outside National Association of Corrosion Engineers(NACE) certified corrosion specialist to perform annual surveys and makerecommendations. Systems outside the protected area such as the FS lines in theWater Reclamation Facility have also been surveyed separately by a NACE certifiedcorrosion specialist.

LRA Sections A1.18 and B2.1.18, and Item No. 20 in Table A4-1, have been revised, asshown in LRA Amendment No. 17 in Enclosure 2, to reflect the planned inspectionsdescribed in responses 2 and 3 above.


Revise the aging management program (AMP) in LRA Sections A1.20 and B2.1.20,External Surfaces Monitoring Program, to require physical manipulation of elastomercomponents, or provide justification for not requiring physical manipulation of elastomercomponents.



LRA Sections A1.20 and B2.1.20 have been revised, as shown in LRA AmendmentNo. 17 in Enclosure 2, to require physical manipulation of elastomer components toverify absence of hardening or loss of strength.

5




Are the instrument air solenoid valves full port?



The instrument air solenoid valves within the scope of license renewal are full portedinstrument air solenoid valves.


Background

By letter dated April 1, 2010, the applicant responded to RAI B2.1.33-2 regardingdegradation of the spray ponds of all three Units.

Issue

In response to RAI B2.1.33-2, the applicant explained that the condition of the structures"has been assessed and will be reworked prior to the Period of Extended Operation." Theapplicant further stated that Work Orders have been initiated and are being tracked in theCorrective Action Program. However, the applicant did not clearly explain what was meantby 'rework,' the criteria used to identify degradation which requires reworking, nor thetimeframe of the reworking.

Request

1. Explain specifically what is meant by 'rework'.

2. Provide a summary of the extent of the degradation and the planned repairs. Explainwhich locations of degradation are being reworked and the criteria used to select thelocations.

3. Provide the schedule for the work, as well as a justification for the appropriatetimeliness of the schedule.

6

L ~




(This response supplements the RAI B2.1.22-2 response provided in APS letterno. 102-06160, dated April 1, 2010)

Spray pond material condition has been added to the Palo Verde Site Top TenTechnical Issues list. A recovery team has been formed under the guidance of amanagement sponsor to develop the plan and schedule for spray pond rework and, ifneeded, repair. Team membership includes System Engineering, Design CivilEngineering, Project Management, and Planning.

1. In this case, rework means restoration that can be completed using existingapproved engineering specifications for concrete work. Repair means that furtherengineering direction is needed to develop a method to correct the degradedcondition.

2. Spray pond concrete condition monitoring has identified degradation on the surfaceof the spray pond walls and delamination in the top 6 to 8 inches of the spray pondconcrete walls. Corrective actions are being developed. One of the correctiveactions being considered is to remove and re-pour the top of the concrete walls andrework or repair reinforcement, if needed. The concrete degradation along theperimeter (surface) of each spray pond will be corrected. No prioritization will berequired to select specific degraded locations to be reworked or repaired becausethe full scope of rework and repairs will be completed for each spray pond, withpriority for the spray pond with the most degradation.

3. The effect of the spray pond wall degradation has been evaluated in an operabilitydetermination, as documented in the Palo Verde corrective action program, with theconclusion that the structural integrity of the spray ponds is not challenged and thespray ponds remain operable. The spray pond wall rework/repair methods arecurrently being determined, and the rework/repair is planned to begin in 2011. AsUnit 1 spray ponds have the most degradation, work is planned to start therefollowed by Units 2 and 3. It is expected that the work will be completed in all threeunits in 2015.

Item No. 56 has been added to the commitment list in LRA Table A4-1, as shown in LRAAmendment No. 17 in Enclosure 2, to reflect the spray pond wall rework/repair plan describedin response 3 above.

7

ENCLOSURE 2

Palo Verde Nuclear Generating StationLicense Renewal Application Amendment No. 17

LRA Section Page Nos. RAI No.

A1.6* A-4 See cover letter

A1.18* A-11, 11A Follow-up RAI B2.1.18-1

A1.20* A-12 Follow-up RAI B2.1.20-1

A3.5* A-38, 39, 39A Follow-up RAI 4.6-1

Table A4-1, Item 20 A-48, 48A Follow-up RAI B2.1.18-1

Table A4-1, Item 56 A-59 Follow-up RAI B2.1.33-2

B2.1.18* B-60, 61, 61A Follow-up RAI B2.1.18-1

B2.1.20* B-64, 65 Follow-up RAI B2.1.20-1

* The complete Appendix A and B aging management program sectionsare provided for reviewer convenience when there is any change to thesections.

Appendix AUpdated Final Safety Analysis Report Supplement

A1.6 FLOW-ACCELERATED CORROSION

The Flow-Accelerated Corrosion (FAC) program manages wall thinning due to FAC onthe internal surfaces of carbon or low alloy steel piping, elbows, reducers, expanders,and valve bodies which contain high energy fluids (both single phase and two phases).

The objectives of the FAC program are achieved by (a) identifying system componentssusceptible to FAC, (b) an analysis using a predictive code such as CHECWORKS todetermine critical locations for inspection and evaluation, (c) providing guidance offollow-up inspections, (d) repairing or replacing components, as determined by theguidance provided by the program, and (e) continual evaluation and incorporation of thelatest technologies, industry and plant in-house operating experience.

Procedures and methods used by the FAC program are consistent with APScommitments to NRC Bulletin 87-01, "Thinning of Pipe Wall in Nuclear Power Plants,"-and NRC Generic Letter 89-08, "Erosion/Corrosion-Induced Pipe Wall Thinning._"-

The program relies on implementation of the EPRI guidelines of NSAC-202L,"Recommendations for an Effective Flow Accelerated Corrosion Program."

Palo Verde Nuclear Generating StationLicense Renewal ApplicationAmendment 17

Page A-4


A1.18 BURIED PIPING AND TANKS INSPECTION

The Buried Piping and Tanks Inspection program manages loss of material of buriedcomponents in the chemical and volume control, condensate storage and transfer, dieselfuel storage and transfer, domestic water, fire protection, SBOG fuel system, service gasand essential spray ponds systems. Visual inspections monitor the condition ofprotective coatings and wrappings found on carbon steel, gray cast iron or ductile ironcomponents and assess the condition of stainless steel components with no protectivecoatings or wraps. The program includes opportunistic inspection of buried piping andtanks as they are excavated or on a planned basis if opportunistic inspections have notoccurred.

The Buried Piping and Tanks Inspection program is a new program that will beimplemented prior to the period of extended of operation. Within the ten year periodprior to entering the period of extended operation an opportunistic or planned inspectionof buried tanks at the Palo Verde site will be performed. Within the ten year period priorto entering the period of extended operation the buried piping inspections noted belowwill be performed. Upon entering the period of extended operation the buried pipinginspections noted below will be performed a plne inspection within ten years-wlA-erequired unless an ppoFtu•Ristic inspec*-tin has ocurred withiR this te I.-er priod.Industry and plant-specific operating experience will be evaluated in the developmentand implementation of this program.

The visual inspections noted below of piping in a soil environment within the scope oflicense renewal will be conducted within the ten-year period prior to entering the periodof extended operation, and again within the first ten years after entering the period ofextended operation. Each inspection will:

* select accessible locations where degradation is expected to be high:* excavate and visually inspect the circumference of the pipe; and* examine at least ten feet of pipe.






Palo Verde Nuclear Generating Station Page A-11License Renewal ApplicationAmendment 17


c. Steel Pioino with Potentiallv Dearaded Cathodic Protection

At least three excavations and visual inspections of fire protection steel pipingqwith potentially degraded bonding straps will be conducted at the Palo Verde site.


Page A-11A

Appendix AUpdated Final Safety Analysis Report

A1.20 EXTERNAL SURFACES MONITORING PROGRAM

The External Surfaces Monitoring Program manages loss of material for steel, aluminum,and copper alloy components and hardening and loss of strength for elastomer components.The program includes those systems and components within the scope of license renewalthat require external surface monitoring. Visual inspections conducted during engineeringwalkdowns will be used to identify aging effects and leakage. Physical manipulation duringthe visual inspections R6ay must also be used to verify absence of hardening or loss ofstrength for elastomers.

Loss of material for external surfaces is managed by the Boric Acid Corrosion program(A1.4) for components in a system with treated borated water or reactor coolant environmenton which boric acid corrosion may occur, Buried Piping and Tanks Inspection program(A1.18) for buried components, and Structures Monitoring Program (A1.32) for civilstructures, and other structural items which support and contain mechanical and electricalcomponents.

The External Surfaces Monitoring Program is a new program that will be implemented priorto the period of extended operation. Industry and plant-specific operating experience will beevaluated in the development and implementation of this program.


Page A-12


refurbished or replaced, or have their qualification extended prior to reaching the aging limitsestablished in the evaluation.

Continuing the existing 10 CFR 50.49 EQ program ensures that the aging effects will bemanaged and that the EQ components will continue to perform their intended functions forthe period of extended operation. The Environmental Qualification of Electrical Componentsprogram is described in Section A2.2.

A3.4 CONCRETE CONTAINMENT TENDON PRESTRESS

The PVNGS containment is a prestressed concrete, hemispherical-dome-on-a-cylinderstructure, with a steel membrane liner. Post-tensioned tendons compress the concrete andpermit the structure to withstand design basis accident internal pressures. The reinforcedconcrete basemat is conventionally reinforced.

To ensure the integrity of the containment pressure boundary under design basis accidentloads, design predictions of loss of prestress demonstrate that prestress will remainadequate for the design life. An inspection program confirms that the tendon prestressremains within design limits throughout the life of the plant [UFSAR Section 3.8.1, TechnicalSpecification Surveillance Requirement 3.6.200.1].

Original design predictions of prestress force were projected to the end of the period ofextended operation. The extended predicted force lines remain above minimum requiredvalues (MRVs) for the period of extended operation. Trend lines calculated by regressionanalyses of tendon surveillance data to date predict that the future performance of the post-tensioning system will remain above the minimum required values (MRV), and therefore thatthe assumptions of the containment vessel design will remain valid through the end of theperiod of extended operation.

Continuing the existing Concrete Containment Tendon Prestress program (A2.3) ensuresthat loss of prestress aging effects will be managed and that the containment tendons willcontinue to perform their intended functions for the period of extended operation.

A3.5 CONTAINMENT LINER PLATE, EQUIPMENT HATCHES,PERSONNEL AIR LOCKS, PENETRATIONS, AND POLARCRANE BRACKETS

NUREG-1800 Section 4.6.1 notes that in some designs "Fatigue of the liner plates or metalcontainments may be considered in the design based on an assumed number of loadingcycles for the current operating term."-

The PVNGS post-tensioned concrete containment vessels are designed to Bechtel TopicalReport BC-TOP-5-A Revision 3. The containment design report has been revised toaddress effects of power uprate and steam generator replacement.



At PVNGS the only metallic components of the containment pressure boundary that aredesigned for a specific number of load cycles in a design lifetime are-were the main steam,main feedwater, and recirculation sump suction penetrations (See Sections A3.5.1and A3.5.2). The remaining penetrations were designedl to stress limit criteria, independentof the number of load cycles, and with no fatigue analyses.

UFSAR Section 3.8.1.5.4, "Liner Plate System," item B, "Loads," describes annual, startup-shutdown., and loss-of-coolant-accident thermal cycles affecting the liner plate system.Containment liner design documents address these loads. Palo Verde has confirmed thatno significant fatigue effects would occur in the liner plate through the period of extendedoperation, and the design documents are therefore valid for the period of extendedoperation.

A3.5.1 Design Cycles for the Main Steam and Main FeedwaterPenetrations

The BC-TOP-1, "Containment Building Liner Plate Design Report", Part II Section 1.1,describes the main steam penetration design for cyclic loads. The design basis includes

* 100 lifetime steady state operating thermal gradient plus normal operating cyclicloads (Loading Condition V), and

* 10 steady state operating thermal gradient plus steam pipe rupture cyclic loads(Loading Condition IV).

The operating history to date indicates that the original design basis 100 operating cyclesassumed for main steam penetrations will be exceeded during the extended operatingperiod. However the number of Condition IV events assumed for design does not changewith an increase in the design life, and Condition V events do not contribute significantly tousage factor. Examination of possible changes to the BC-TOP-1 analysis for anyreasonably-expected increase in the number of Condition V events demonstrates adequatemargin to the stress limit determined by the elastic-plastic analysis. Design of the mainfeedwater penetrations is bounded by that of the main steam penetrations due to theirsmaller size, similar geometry and similar operating conditions. The design of the mainsteam and main feedwater penetrations is therefore valid for the period of extendedoperation.-

A3.5.2 Design Cycles for the Recirculation Sump Suction LinePenetrations

Recirculation sump suction line containment penetrations were evaluated for anNE-3222.4(d) exemption from fatigue analysis. The exemption criteria depend on thenumber of cycles for which loads are applied; therefore the exemption is supported by aTLAA.



The analysis of these penetrations was based on the alternating stress range for pressurecycles, and demonstrated that the allowable number of cycles is far greater than the numberexpected for the period of extended operation. There is sufficient margin in the design forany possible increase in operating cycles above the original estimate. The design of therecirculation penetrations is therefore valid for the period of extended operation.

[Remainder of this page intentionally left blank]


Page A-39A


I he nuried Hiping and I anKs Inspection program is a new program that willimplemented prior to the period of extended operation. Within the ten yearperiod prior to entering the period of extended operation an opportunistic orplanned inspection of buried tanks at the Palo Verde site will be performed.Within the ten year neriod nrior to enterina the neriod of extended onerntion

A1.18B2.1.18Buried Piping AndTanks Inspection

Within the ten yearperiod PQrior to the

period of extendedoperation1 .

the buried piping inspections noted below will be performed. The buriedpiping inspections noted below will be performed Bu•o•d Piping ,n TanksI

,nspoction program rguiros a plannod incpoGc'"n within the first ten years of

-*- -Ar~ r ... i+hi- +hic. +-- ~,--r -^r;-,rI

AND

Within the first tenyears after.enteringthe period of -extendedoperation.

VV II~lf. *t1

1JJ~fJ lAJIIJ J~J

] v•, i..v .....

The visual inspections noted below of pipincl in a soil environment within thescope of license renewal will be conducted within the ten-year period prior toentering the period of extended operation, and again within the first ten yearsafter entering the period of extended operation. Each inspection will:

* select accessible locations where degradation is expected to behigh:

" excavate and visually inspect the circumference of the pipe: and* examine at least ten feet of pipe.

a. Metallic PiDina not Cathodicallv-ProtectedAt least two excavations and visual inspections of stainless steel pipingwill be conducted in each unit. Stainless steel piping within the scopeof license renewal exists in the following systems:

0

0

0

h qteel

Chemical and Volume Control (CH),Condensate Transfer and Storacge (CT), andFire Protection (FP).

Pinina (athndicallv-ProtectedAt least two excavations and visual inspections of cathodically-nrotected steel ninina will be conducted in each unit.

______ I .-.---------- ----. I _______________________ j ____________________


Page A-48


c. Steel Piping with Potentially Degraded Cathodic ProtectionAt least three excavations and visual inspections of fire protection steelpiping with potentially degraded bonding straps will be conducted atthe Palo Verde site.

(RCTSAIs 3246909 [U1]; 3247263 [U2]; 3247264 [U3])


Page A-48A


The spray pond wall rework/repair methods are currently being determined, Follow-up 12/311and the rework/repair is planned to beqin in 2011. As Unit 1 spray ponds Response to RAIhave the most degradation, work is planned to start there followed by Units 2 B2.1.33-2 (letter no.and 3. It is expected that the work will be completed in all three units in 2015. 102-06205, dated(RCTSAI 3484623) June 21, 2010)


Page A-59

Appendix BAGING MANAGEMENT PROGRAMS

B2.1.18 Buried Piping and Tanks Inspection

Program Description

The Buried. Piping and Tanks Inspection program manages loss of material on externalsurfaces of buried components in the following systems: chemical and volume control,condensate storage and transfer, diesel fuel storage and transfer, domestic water, fireprotection, SBOG fuel system, service gas and essential spray ponds. Opportunistic visualinspections will monitor the condition of protective coatings and wrappings found on carbonsteel, gray cast iron or ductile iron components and assess the condition of stainless steelcomponents with no protective coatings or wraps. Any evidence of damaged wrapping orcoating defects is an indicator of possible corrosion damage to the external surface of thecomponents.

The Buried Piping and Tanks Inspection program is a new program that will be implementedprior to the period of extended operation. Within the ten year period prior to entering theperiod of extended operation an opportunistic or planned inspection of buried tanks at thePalo Verde site will be performed. Within the ten year period prior to entering the period ofextended operation the buried piping inspections noted below will be performed. The buriedpiping inspections noted below will be performed Buried ,Pipig and Tanks Inspectionprogram requires a planned in.pection within the first ten years of the period of extendedoperation if an oppo't•unit in.pection ha not been performed within this t. .year period.

The visual inspections noted below of piping in a soil environment within the scope oflicense renewal will be conducted within the ten-year period prior to entering the periodof extended operation, and again within the first ten years after entering the period ofextended operation. Each inspection will:

* select accessible locations where degradation is expected to be high:* excavate and visually inspect the circumference of the pipe: and" examine at least ten feet of pipe.






Palo Verde Nuclear Generating Station Page B-60License Renewal ApplicationAmendment 17


c. Steel Piping with Potentially Degraded Cathodic ProtectionAt least three excavations and visual inspections of fire protection steel piping

with potentially degraded bonding straps will be conducted at the Palo Verde site.

NUREG-1801 Consistency

The Buried Piping and Tanks Inspection program is a new program that, when implemented,will be consistent with exception to NUREG-1801, Section XI.M34, "Buried Piping and TanksInspection".

Exceptions to NUREG-1801

Program Elements Affected

Scope of Program - Element I and Acceptance Criteria- Element 6

NUREG-1801, Section XI.M34 scope only includes buried steel piping and components.However, PVNGS also includes stainless steel in their buried piping program that will bemanaged as part of this aging management program.

Scope of Program - Element 1, Preventive Actions - Element 2, and Acceptance Criteria-Element 6

NUREG-1801, Section XI.M34 relies on preventive measures such as coatings andwrappings. However, portions of buried stainless steel piping may not be coated orwrapped. Inspections of buried piping that is not wrapped will inspect for loss of materialdue to general, pitting, crevice, and microbiologically influenced corrosion.

Enhancements

None

Operating Experience

The Buried Piping and Tanks Inspection. program is a new program. Degradation ofburied components was addressed at PVNGS during an inspection program inSeptember 2002. Observations of this inspection program include:

During the past several years, leaks developed in various buried piping segments, whichpotentially threaten the continuous operation of PVNGS. These leaks collectivelyindicated a negative trend in the overall integrity of the buried pipe.

Inspection and maintenance activities were implemented in order to address overall integrityof the buried pipe. Determination of system priorities and development of a draft inspectionplan for each of the evaluated systems was developed.



The applicable systems with piping installed below grade were evaluated and assignedranking based on priority. The majority of these evaluated buried piping systems havevery little or no identified potential for degradation.

The majority of the systems evaluated in the inspection program are not within the scopeof license renewal. The PVNGS corrective action documentation to date has shownthat, for the systems within the scope of license renewal, degradation has been foundprimarily in the fire protection system. Fire protection system has had localizeddegradation in excess of the minimum wall requirement of 40% nominal wall thickness.The designated segments of the degraded ductile iron piping have been replaced byfiberglass reinforced plastic piping. The fire protection system has not experienced afailure that affected the ability of the plant to achieve and maintain safe shutdown in theevent of a fire. To date, the actual pipe failures of the underground fire protectionsystem have been isolated and repaired without adversely affecting any fire protectionwater suppression system.

Industry and plant-specific operating experience will be evaluated in the developmentand implementation of this program.

Conclusion

The implementation of the Buried Piping and Tanks Inspection program will providereasonable assurance that aging effects will be managed such that the systems andcomponents within the scope of this program will continue to perform their intendedfunctions consistent with the current licensing basis for the period of extended operation.


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B2.1.20 External Surfaces Monitoring Program

Program Description

The External Surfaces Monitoring Program manages loss of material for steel, aluminum,and copper alloy components, and hardening and loss of strength for elastomercomponents. The program includes those systems and components within the scope oflicense renewal that require external surface monitoring. Visual inspections of externalsurfaces conducted during engineering walkdowns will be used to identify aging effects andleakage. Physical manipulation during the visual inspections may must also be used toverify absence of hardening or loss of strength for elastomers.

The following aging management programs are used to manage aging for external surfacesthat are not in the scope of the external surfaces monitoring program.

1. Boric Acid Corrosion (B2.1.4) for components in a system with treated borated water orreactor coolant environment in which boric acid corrosion may occur.

2. Buried Piping and Tanks Inspection (B2.1.18) for buried components.

3. Structures Monitoring Program (B2.1.32) for civil structures, and other structural itemswhich support and contain mechanical and electrical components.

NUREG-1801 Consistency

The External Surfaces Monitoring Program is a new program that, when implemented, willbe consistent with exception to NUREG-1801, Section XI.M36, "External SurfacesMonitoring Program".

Exceptions to NUREG-1801

Program Elements Affected

Scope of Program - Element 1, Preventive Actions - Element 2, Detection of Aging Effects- Element ,4 Monitoring and Trending - Element 5, and Acceptance Criteria- Element 6

The exceptions to NUREG-1801, XI.M36 are an increase to the scope of the materialsinspected to include aluminum, copper alloy and elastomers and an increase to the scope ofaging effects to include hardening and loss of strength for elastomers. Additionally, visualinspections may must be augmented by physical manipulation to detect hardening and lossof strength of elastomers.

Enhancements

None



Operating Experience

The External Surfaces Monitoring Program is a new program, however, external surfacesinspections via system inspections and walkdowns have been in effect at PVNGS and haveproven effective in maintaining the material condition of, plant systems. The elements thatcomprise these inspections (e.g., the scope of the inspections and inspection techniques)are consistent with industry practice.

System engineering walkdowns require that aging effects are documented and that acorrective action be initiated for any deficiencies or adverse trends. A review of plant-specific operating experiences indicates that any documented aging has not caused thefailure of component's intended functions.

Industry and plant-specific operating experience will be evaluated in the development andimplementation of this program.

ConclusionThe implementation of the External Surfaces Monitoring Program will provide reasonableassurance that aging effects will be managed such that the systems and components withinthe scope of this program will continue to perform their intended functions consistent withthe current licensing basis for the period of extended operation.


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Documents

Palo Verde, Units 1, 2 and 3 - Responses to Follow-up