ML17054D687

Fourth 10-Year Interval Pump and Valve Inservice Testing Program Relief Requests GRR-01, GRR-02, PRR-01, PRR-02, PRR-03, PRR-04, PRR-05, and PRR-06

ML17054D687
Person / Time
Site:	Palo Verde
Issue date:	02/23/2017
From:	Lacal M Arizona Public Service Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
102-07436-MLL/TNW
Download: ML17054D687 (37)

Text

10 CFR 50.55a MARIA L. LACAL Senior Vice President, Nuclear Regulatory & Oversight Palo Verde Nuclear Generating Station 102-07436-MLL/TNW P.O. Box 52034 February 23, 2017 Phoenix, AZ 85072 Mail Station 7605 Tel 623.393.6491 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001

Subject:

Palo Verde Nuclear Generating Station (PVNGS)

Units 1, 2, and 3 Docket Nos. STN 50-528/529/530 Fourth 10-Year Interval Pump and Valve Inservice Testing Program Relief Requests GRR-01, GRR-02, PRR-01, PRR-02, PRR-03, PRR-04, PRR-05, and PRR-06 Pursuant to 10 CFR 50.55a, Arizona Public Service Company (APS) has revised the Palo Verde Nuclear Generating Station (PVNGS) pump and valve inservice testing (IST) program for the fourth 10-year interval for Units 1, 2, and 3, which begins on January 15, 2018. The Enclosure contains the relief requests required for the fourth 10-year interval. The majority of these relief requests were previously authorized for the PVNGS third 10-year interval by the NRC in Safety Evaluation dated April 24, 2008 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML081050003). The relief requests that were not previously authorized are GRR-01, GRR-02, and PRR-06. Relief request GRR-01 proposes the use of the 2012 edition of the ASME OM Code, which is in the final rulemaking process and is expected to be incorporated into 10 CFR 50.55a in the second quarter of 2017. Relief Request GRR-02 proposes the adoption of Code Case OMN-20, Inservice Test Frequency, which is an alternative to the frequency specifications of the ASME OM Code.

PRR-06 requests an alternative vibration measuring method from the requirement of the ASME OM Code.

APS requests approval of the relief requests prior to the start of the fourth 10-year inservice testing interval which will begin on January 15, 2018.

No new commitments are being made in this submittal.

If you have any questions about this request, please contact Michael D. DiLorenzo at (623) 393-3495.

Sincerely, MLL/TNW/MSC/af A member of the STARS Alliance LLC Callaway Diablo Canyon Palo Verde Wolf Creek

102-07436-MLL/TNW ATTN: Document Control Desk U. S. Nuclear Regulatory Commission Fourth 10 Year Interval Pump and Valve Inservice Testing Program Relief Requests Page 2

Enclosure:

Fourth 10-Year Interval Pump and Valve Inservice Testing Program Relief Requests cc: K. M. Kennedy NRC Region IV Regional Administrator S. P. Lingam NRC NRR Project Manager for PVNGS M. M. Watford NRC NRR Project Manager C. A. Peabody NRC Senior Resident Inspector for PVNGS

Enclosure Fourth 10-Year Interval Pump and Valve Inservice Testing Program Relief Requests GRR-01, GRR-02, PRR-01, PRR-02, PRR-03, PRR-04, PRR-05, and PRR-06

Enclosure Fourth 10-Year Interval Pump and Valve Inservice Testing Program Relief Requests Summary Section 50.55a of Title 10 of the Code of Federal Regulations (10 CFR), requires that inservice testing (IST) of certain American Society of Mechanical Engineers (ASME) Code Class 1, 2, and 3 pumps and valves be performed at 10-year IST program intervals in accordance with the specified ASME Code incorporated by reference in the regulations, except where an alternative has been authorized or relief has been requested by the licensee and granted by the Nuclear Regulatory Commission (NRC or the Commission) pursuant to paragraphs (z)(1), (z)(2), or (f)(5)(iii) of 10 CFR 50.55a. In accordance with 10 CFR 50.55a(f)(4)(ii), Arizona Public Service Company (APS) is required to comply with the requirements of the latest edition and addenda of the ASME Code incorporated by reference in the regulations 12 months prior to the start of each 10-year IST program interval. In accordance with 50.55a(f)(4)(iv),

inservice tests of pumps and valves may meet the requirements set forth in subsequent editions and addenda that are incorporated by reference in 10 CFR 50.55a(a)(1)(iv), subject to the conditions in 10 CFR 50.55a(b).

The Palo Verde Nuclear Generating Station (PVNGS) Fourth Interval Pump and Valve Inservice Testing Program has been developed in accordance with the 2012 Edition of the ASME OM Code. The PVNGS fourth 10-year IST interval for all three units begins on January 15, 2018.

This Enclosure contains the relief requests required for the fourth interval.

Relief Requests GRR-01, GRR-02, and PRR-06 are being submitted under the provision of 10 CFR 50.55a(z)(1), wherein the proposed alternative will provide an acceptable level of quality and safety.

Relief Requests PRR-01, PRR-03, PRR-04, and PRR-05 are being submitted under the provision of 10 CFR 50.55a(z)(2), wherein ASME Code requirements present a hardship.

Relief Request PRR-02 is being submitted under the provision of 10 CFR 50.55a(f)(5)(iii), wherein compliance with the ASME OM Code requirements is impractical for pump testing.

Relief Requests PRR-01, PRR-02, PRR-03, PRR-04, and PRR-05 were previously authorized for the PVNGS third interval by the NRC Safety Evaluation dated April 24, 2008. Relief Request GRR-01 is being requested to allow the use of ASME OM Code 2012 Edition. This Code is in the final rulemaking process and is expected to be issued in the second quarter of 2017. Relief Request GRR-02 requests the application of surveillance frequency extensions to IST frequency per Code Case OMN-20. Relief Request PRR-06 requests the use of alternate vibration instrumentation as required by ISTB-3510(e).

The attached APS requests demonstrate that: (1) the proposed alternatives provide an acceptable level of quality and safety, (2) ASME OM Code requirements pose a hardship without a compensating increase in quality and safety, or (3) conformance is impractical for the facility.

APS requests approval of the relief requests prior to the start of the fourth 10-year IST interval which will begin on January 15, 2018.

Arizona Public Service Company (APS)

Palo Verde Nuclear Generating Station - Units 1, 2 and 3 GENERAL RELIEF REQUEST GRR-01 Proposed Alternative In Accordance with 10 CFR 50.55a(z)(1)

Use of ASME OM Code 2012 Edition ASME Components Affected:

All pumps and valves contained in the Palo Verde Nuclear Generating Station (PVNGS), Units 1, 2 and 3 Inservice Testing (IST) Program scope.

Applicable Code Edition and Addenda

ASME OM Code 2004 Edition with 2006 Addenda Applicable Code Requirements:

This request applies to the edition of the American Society of Mechanical Engineers (ASME) Operation and Maintenance (OM) Code.

Subsection ISTA, General Requirements Subsection ISTB, Inservice Testing of Pumps Subsection ISTC, Inservice Testing of Valves Mandatory Appendix I, Inservice Testing of Pressure Relief Devices Mandatory Appendix II, Check Valve Condition Monitoring Program

Reason for Request

Pursuant to 10 CFR 50.55a, Codes and standards, paragraph (z)(1), an alternative of acceptable level of quality and safety is requested to the edition of the ASME OM Code. The basis of this request is that the ASME OM Code 2012 Edition requirements are an improvement upon the ASME OM Code 2004 Edition with 2006 Addenda and will provide an acceptable level of quality and safety. In addition, during the third 10-year interval PVNGS has already implemented ASME OM Code Case OMN-1, Revision 0, Alternative Rules for Preservice and Inservice Testing of Certain Electric Motor-Operated Valve Assemblies in Light-Water Reactor Power Plants (Palo Verde Third 10-Year Interval NRC Safety Evaluation Report ADAMS Accession No. ML081050003), which is the predecessor to ASME OM Code Mandatory Appendix III, Preservice and Inservice Testing of Active Electric Motor Operated Valve Assemblies in Light Water Reactor Power Plants, in the ASME OM Code 2012 Edition.

The Nuclear Regulatory Commission (NRC) is currently in the process of finalizing a revision to 10 CFR 50.55a, which is expected to approve use of the ASME OM Code 2012 Edition with conditions. The expected publication of the revised 10 CFR 50.55a is in the first half of 2017 and prior to the start of the PVNGS fourth 10-year interval on January 15, 2018.

1

Arizona Public Service Company (APS)

Palo Verde Nuclear Generating Station - Units 1, 2 and 3 GENERAL RELIEF REQUEST GRR-01 Proposed Alternative In Accordance with 10 CFR 50.55a(z)(1)

Use of ASME OM Code 2012 Edition Proposed Alternative and Basis:

APS proposes the use of the ASME OM Code 2012 Edition as an alternative to the latest approved edition of the ASME OM Code listed in 10 CFR 50.55a: ASME OM Code 2004 Edition with 2006 Addenda. This alternative edition of the ASME OM Code will provide an acceptable level of quality and safety.

The ASME OM Code 2012 Edition contains the following requirements for inservice testing Pumps and Valves:

Subsection ISTA, General Requirements Subsection ISTB, Inservice Testing of Pumps Subsection ISTC, Inservice Testing of Valves Mandatory Appendix I, Inservice Testing of Pressure Relief Devices Mandatory Appendix II, Check Valve Condition Monitoring Program Mandatory Appendix III, Preservice and Inservice Testing of Active Electric Motor Operated Valve Assemblies in Light Water Reactor Power Plants Mandatory Appendix V, Pump Periodic Verification Test Program The ASME OM Code 2004 Edition with 2006 Addenda requirements do not contain Mandatory Appendix III or Mandatory Appendix V.

On September 18, 2015, in the Federal Register Vol. 80, No. 181, the NRC proposed to amend 10 CFR 50.55a to incorporate by reference recent editions of the American Society of Mechanical Engineers (ASME) codes (one of which is the ASME OM Code 2012 Edition) with conditions on use. In this announcement, the NRC also proposed to incorporate by reference ASME OM Code Case OMN-20, Inservice Test Frequency.

Based upon the Federal Register Vol. 80, No. 181, the conditions on the ASME OM Code are summarized as follows:

Clarification that Subsections ISTA, ISTB, ISTC, ISTD, ISTE, and ISTF; Mandatory Appendices I, II, III, and V; and Non-mandatory Appendices A through H and J through M of the ASME OM Code would be incorporated by reference in §50.55a. Clarification that the non-mandatory appendices which are incorporated by reference are approved for use but not mandated.

Revise §50.55a(b)(3)(ii) to reflect the new Mandatory Appendix III, Preservice and Inservice Testing of Active Electric Motor Operated Valve Assemblies in Light Water Reactor Power Plants. Appendix III reflects the incorporation of the ASME OM Code Cases OMN-1, Alternative Rules for Preservice and Inservice Testing of Active Electric Motor-Operated Valve Assemblies in Light-Water Reactor Power Plants, and OMN-11, Risk-Informed Testing for Motor-Operated Valves. NRC proposes the addition of four conditions in new §50.55a(b)(3)(ii)(A), (B), (C), and (D) to address periodic verification of MOV design-basis capability.

o 50.55a(b)(3)(ii)(A), MOV Diagnostic Interval, to require licensees evaluate adequacy of the diagnostic test interval for each MOV and adjust the interval as necessary, but not later than 5 years or three refueling outages (whichever is longer) from initial implementation of ASME OM Code, Appendix III.

2

Arizona Public Service Company (APS)

Palo Verde Nuclear Generating Station - Units 1, 2 and 3 GENERAL RELIEF REQUEST GRR-01 Proposed Alternative In Accordance with 10 CFR 50.55a(z)(1)

Use of ASME OM Code 2012 Edition o 50.55a(b)(3)(ii)(B), MOV Testing Impact on Risk, to require licensees ensure that the potential increase to core damage frequency (CDF) and large early release frequency (LERF) associated with the extension is acceptably small when extending exercise test intervals for high risk MOVs beyond quarterly frequency.

o 50.55a(b)(3)(ii)(C), MOV Risk Categorization, to require, when applying Appendix III to the ASME OM Code, that licensees categorize MOVs according to their safety significance using the methodology described in ASME OM Code Case OMN-3, Requirements for Safety Significance Categorization of Components Using Risk Insights for Inservice Testing of LWR Power Plants, subject to the conditions discussed in Regulatory Guide (RG) 1.192, or using an MOV risk ranking methodology accepted by the NRC on a plant-specific or industry-wide basis in accordance with the conditions in the applicable safety evaluation.

o 50.55a(b)(3)(ii)(D), MOV Stroke Time, to require that when a licensee applies Paragraph III-3600, MOV Exercising Requirement, of Appendix III to the OM Code, the licensee verify that the stroke time of the MOV satisfies the assumptions in the plant safety analyses. Paragraph III-3600 of Appendix III in the OM Code 2012 Edition does not require the verification of MOV stroke timing during periodic exercising, however, this condition will require MOV stroke timing during periodic exercising.

Clarifications of Mandatory Appendix II, Check Valve Condition Monitoring Program, that (1) the maximum test interval allowed by Appendix II for individual check valves in a group of two valves or more must be supported by periodic testing of a sample of check valves in the group during the allowed interval and (2) the periodic testing plan must be designed to test each valve of a group at approximate equal intervals not to exceed the maximum requirement interval.

Revise §50.55a(b)(3) to add a new §50.55a(b)(3)(vii) to prohibit the use of Subsection ISTB in the 2011 Addenda of the ASME OM Code because it did not include the Mandatory Appendix V, Pump Periodic Verification Test Program. ASME OM Code 2012 Edition does include Mandatory Appendix V.

Revise §50.55a(b)(3) to add a new §50.55a(b)(3)(xi) to require licensees implementing the ASME OM Code 2012 Edition or later Editions and Subsection ISTC-3700, Position Verification Testing, to supplement the ASME OM Code provisions as necessary to verify that valve operation is accurately indicated. This condition specifies that licensees shall develop and implement a method to verify operation is accurately indicated by supplementing valve position indicating lights with other indications, such as flow meters or other suitable instrumentation, to provide assurance of proper obturator position. The NRC position is further elaborated in NUREG-1482, Revision 2, paragraph 4.2.7.

In addition to the conditions on the ASME OM Code summarized above, the NRC also proposed in Federal Register Vol. 80, No. 181 the following additional changes:

10 CFR 50.55a(f)(3)(iii)(A), Class 1 Pumps and Valves: First Provision, revise to ensure paragraph is applicable to pumps and valves that are within the scope of the ASME OM Code.

This is to align scope of pumps and valves for inservice testing with the scope defined in the ASME OM Code and in Standard Review Plan (SRP) Section 3.9.6, Functional Design, Qualification, and Inservice Testing Programs for Pumps, Valves, and Dynamic Restraints.

10 CFR 50.55a(f)(3)(iii)(B), Class 1 Pumps and Valves: Second Provision, revise to ensure paragraph is applicable to pumps and valves that are within the scope of the ASME OM Code.

3

Arizona Public Service Company (APS)

Palo Verde Nuclear Generating Station - Units 1, 2 and 3 GENERAL RELIEF REQUEST GRR-01 Proposed Alternative In Accordance with 10 CFR 50.55a(z)(1)

Use of ASME OM Code 2012 Edition This is to align scope of pumps and valves for inservice testing with the scope defined in the ASME OM Code and in Standard Review Plan (SRP) Section 3.9.6.

10 CFR 50.55a(f)(3)(iv)(A), Class 2 and 3 Pumps and Valves: First Provision, revise to ensure paragraph is applicable to pumps and valves that are within the scope of the ASME OM Code and not covered by paragraph (f)(3)(iii)(A) for Class 1 pumps and valves. This is to align scope of pumps and valves for inservice testing with the scope defined in the ASME OM Code and in SRP Section 3.9.6.

10 CFR 50.55a(f)(3)(iv)(B), Class 2 and 3 Pumps and Valves: First Provision, revise to ensure paragraph is applicable to pumps and valves that are within the scope of the ASME OM Code and not covered by paragraph (f)(3)(iii)(B) for Class 1 pumps and valves. This is to align scope of pumps and valves for inservice testing with the scope defined in the ASME OM Code and in SRP Section 3.9.6.

10 CFR 50.55a(f)(4), Inservice Testing Standards Requirement for Operating Plants, revise to clarify that this paragraph is applicable to pumps and valves that are within the scope of the ASME OM Code. This is to align scope of pumps and valves for inservice testing with the scope defined in the ASME OM Code and in SRP Section 3.9.6.

APS will implement the conditions cited in the final version of the 10 CFR 50.55a as published, except where specific relief may be requested per the provisions of 10 CFR 50.55a(z) and 10 CFR 50.55a(f)(5).

In conclusion, 10 CFR 50.55a(a)(1)(iv), ASME Operation and Maintenance Code, does not currently list ASME OM Code 2012 Edition as approved for use. Using the provisions of ASME OM Code 2012 Edition, in conjunction with the conditions stipulated when 10 CFR 50.55a is revised in 2017, will provide an acceptable level of quality and safety. Therefore, pursuant to 10 CFR 50.55a(z)(1), PVNGS requests approval to use ASME OM Code 2012 Edition as an alternative to ASME OM Code 2004 Edition with 2006 Addenda during the fourth 10-year IST interval.

Duration:

The proposed alternative identified in this 10 CFR 50.55a request shall be utilized during the fourth 10-year IST interval beginning January 15, 2018 and ending January 14, 2028.

Precedence:

None known.

References:

1) 10 CFR 50.55a, Codes and standards

2) ASME OM Code 2004 Edition with 2006 Addenda

3) ASME OM Code 2012 Edition

4) NUREG 1482, Revision 2, Guidelines for Inservice Testing at Nuclear Power Plants: Inservice Testing of Pumps and Valves and Inservice Examination and Testing of Dynamic Restraints (Snubbers) at Nuclear Power Plants, Table 3.2, ASME OM Code Terms for Inservice Testing Activities, dated October 2013 (ADAMS Accession No. ML13295A020)

5) Palo Verde Third 10-Year Interval NRC Safety Evaluation (SE) (ADAMS Accession No. ML081050003) 4

Arizona Public Service Company (APS)

Palo Verde Nuclear Generating Station - Units 1, 2 and 3 GENERAL RELIEF REQUEST GRR-02 Proposed Alternative In Accordance with 10 CFR 50.55a(z)(1)

Inservice Test Frequency per Code Case OMN-20 ASME Components Affected:

All Pumps and Valves contained in the Palo Verde Nuclear Generating Station (PVNGS), Units 1, 2 and 3 Inservice Testing (IST) Program scope.

Applicable Code Edition And Addenda:

ASME OM Code 2012 Edition Applicable Code Requirements:

This request applies to the frequency specifications of the American Society of Mechanical Engineers (ASME) Operation and Maintenance (OM) Code. The frequencies for tests given in the ASME OM Code include the following, but do not include a tolerance band:

ISTA-3120, Inservice Examination and Test Interval, paragraph (a), states, "Examination and test frequency shall be in accordance with the requirements of Section IST."

ISTB-3400, Frequency of Inservice Tests, states, An inservice test shall be run on each pump as specified in Table ISTB-3400-1.

Table ISTB-3400-1, Inservice Test Frequency, notes that Group A and Group B pump tests are to be conducted quarterly. Comprehensive pump tests and applicable pump periodic verification tests are to be conducted biennially.

ISTB-6200, Corrective Action, paragraph (a), states If measured test parameter values fall within the alert range the frequency of testing specified in para. ISTB-3400 shall be doubled ISTC-3510, Exercising Test Frequency, states, in part, that Active Category A, Category B, and Category C check valves shall be exercised nominally every 3 mo, ISTC-3540, Manual Valves, states, in part, that Manual Valves shall be full-stroke exercised at least once every 2 yr, except where adverse conditions may require the valve to be tested more frequently to ensure operational readiness.

ISTC-3630, Leakage Rate for Other Than Containment Isolation Valves, (a) Frequency, states, Tests shall be conducted at least once every 2 yr.

ISTC-3700, Position Verification Testing, states, in part, that Valves with remote position indicators shall be observed locally at least once every 2 yr to verify that valve operation is accurately indicated.

ISTC-5221, Valve Obturator Movement, subparagraph (c)(3) states, "At least one valve from each group shall be disassembled and examined at each refueling outage; all valves in each group shall be disassembled and examined at least once every 8 yr."

Mandatory Appendices:

Appendix I, Inservice Testing of Pressure Relief Devices in Light-Water Reactor Nuclear Power Plants, I-1320, Test Frequencies, Class 1 Pressure Relief Valves, (a) 5-Yr Test Interval, states, in part, that Class 1 pressure relief valves shall be tested at least once every 5 yr, 1

Arizona Public Service Company (APS)

Palo Verde Nuclear Generating Station - Units 1, 2 and 3 GENERAL RELIEF REQUEST GRR-02 Proposed Alternative In Accordance with 10 CFR 50.55a(z)(1)

Inservice Test Frequency per Code Case OMN-20 Applicable Code Requirements (continued):

Appendix I, I-1330, Test Frequency, Class 1 Nonreclosing Pressure Relief Devices, states, in part, that Class 1 nonreclosing pressure relief devices shall be replaced every 5 yr Appendix I, I-1340, Test Frequency, Class 1 Pressure Relief Valves That Are Used for Thermal Relief Application, states, Tests shall be performed in accordance with para. I-1320, Test Frequencies, Class 1 Pressure Relief Valves.

Appendix I, I-1350, Test Frequency, Classes 2 and 3 Pressure Relief Valves, (a) 10-Yr Test Interval, states, in part, that Classes 2 and 3 pressure relief valves, with the exception of PWR main steam safety valves, shall be tested every 10 yr, Appendix I, I-1360, Test Frequency, Classes 2 and 3 Nonreclosing Pressure Relief Devices, states, in part, that Classes 2 and 3 nonreclosing pressure relief devices shall be replaced every 5 yr, Appendix I, I-1370, Test Frequency, Classes 2 and 3 Primary Containment Vacuum Relief Valves, states, in part, that (a) Tests shall be performed on all Classes 2 and 3 containment vacuum relief valves at each refueling outage or every 2 yr, whichever is sooner, Appendix I, I-1380, Test Frequency, Classes 2 and 3 Vacuum Relief Valves, Except for Primary Containment Vacuum Relief Valves, states, in part, that All Classes 2 and 3 vacuum relief valves shall be tested every 2 yr, Appendix I, I-1390, Test Frequency, Classes 2 and 3 Pressure Relief Devices That Are Used for Thermal Relief Application, states, in part, that Tests shall be performed on all Classes 2 and 3 relief devices used in thermal relief application every 10 yr, Appendix II, Check Valve Condition Monitoring Program, II-4000, Condition-Monitoring Activities, (a)

Performance Improvement Activities, (4) states, in part, "Perform these activities at their associated intervals" Appendix II, II-4000, (b), Optimization of Condition-Monitoring Activities, Subparagraph (1)(e) states, in part, Identify the interval for each activity.

Appendix III, Preservice and Inservice Testing of Active Electric Motor Operated Valve Assemblies in Light-Water Reactor Power Plants, paragraph III-3310, Inservice Test Interval, (b) states, in part, that If insufficient data exist to determine the inservice test interval in accordance with para. III-6400, then MOV inservice testing shall be conducted every two refueling cycles or 3 yr (whichever is longer)

Appendix III, III-3310(c), states, in part, that The maximum inservice test interval shall not exceed 10 yr.

Appendix III, III-3610, Normal Exercising Requirements, states, in part, that All MOVs, within the scope of this Mandatory Appendix, shall be full cycle exercised at least once per refueling cycle with the maximum time between exercises to be not greater than 24 mo.

2

Arizona Public Service Company (APS)

Palo Verde Nuclear Generating Station - Units 1, 2 and 3 GENERAL RELIEF REQUEST GRR-02 Proposed Alternative In Accordance with 10 CFR 50.55a(z)(1)

Inservice Test Frequency per Code Case OMN-20 Applicable Code Requirements (continued):

Appendix III, III-3620, Additional Exercising Requirements, states, in part, that The Owner shall consider more frequent exercising requirements for MOVs with high risk significance, adverse or harsh environmental conditions, and abnormal characteristics such as operational, design or maintenance conditions.

Appendix III, III-3721, HSSC MOVs, states, in part, that HSSC MOVs shall be tested in accordance with para. III-3300 and exercised in accordance with para. III-3600. HSSC MOVs that can be operated during plant operation shall be exercised quarterly, Appendix III, III-3722, LSSC MOVs, subparagraph (c) states, in part, that LSSC MOVs that are not associated with an established group shall be inservice tested, in accordance with para. III-3300, using an initial test interval of three refueling cycles or 5 yr (whichever is longer)

Appendix III, III-3722(d) states, LSSC MOVs shall be inservice tested at least every 10 yr in accordance with para. III-3310.

Appendix V, Pump Periodic Verification Test Program, V-3000, General Requirements, states, the Owner shall (b) perform the pump periodic verification test at least once every 2 yr.

Reason for Request

Pursuant to 10 CFR 50.55a, Codes and standards, paragraph (z)(1), an alternative is requested to the frequency specifications of the ASME OM Code. The basis of this request is that the alternative represents an acceptable level of quality and safety.

The ASME OM Code Section IST establishes the inservice test frequencies for all components within the scope of the Code. The frequencies (e.g., quarterly) have always been interpreted as "nominal" frequencies (generally as defined in Table 3.2 of NUREG 1482, Revision 2) and licensees routinely applied the surveillance extension time period (i.e., grace period) contained in the plant Technical Specification (TS) Surveillance Requirements (SRs). The TS typically allow for a less than or equal to 25 percent extension of the surveillance test interval to accommodate plant conditions that may not be suitable for conducting the surveillance (SR 3.0.2). However, regulatory issues have been raised concerning the applicability of the TS "grace period" to ASME OM Code-required IST frequencies irrespective of allowances provided under TS Administrative Controls (i.e., TS 5.5.8, Inservice Testing Program, invokes SR 3.0.2 for various OM Code frequencies of 2 years or less).

The lack of a tolerance band on the ASME OM Code IST frequencies restricts operational flexibility.

There may be a conflict where a code required test is required (i.e., its frequency could expire), but where it is not possible or not desired that the test be performed until some time after a plant condition or associated Limiting Condition for Operation (LCO) is within its applicability. Therefore, to avoid this conflict, the code required test should be performed when plant conditions allow (i.e., when it can be and should be performed).

The NRC recognized this potential issue in the TS by allowing a frequency tolerance as described in TS SR 3.0.2. The lack of a similar tolerance applied to the ASME OM Code testing, places an unusual hardship on the plant to adequately schedule work tasks without operational flexibility.

3

Arizona Public Service Company (APS)

Palo Verde Nuclear Generating Station - Units 1, 2 and 3 GENERAL RELIEF REQUEST GRR-02 Proposed Alternative In Accordance with 10 CFR 50.55a(z)(1)

Inservice Test Frequency per Code Case OMN-20 Reason for Request (continued):

Thus, just as with TS-required surveillance testing, some tolerance is needed to allow adjusting ASME OM Code testing intervals to suit the plant conditions and other maintenance and testing activities. This assures operational flexibility when scheduling code required tests that would minimize the conflicts between the need to complete the testing and plant conditions.

Proposed Alternative and Basis:

APS proposes the use of the allowance of grace as stipulated in ASME OM Code Case OMN-20, Inservice Test Frequency, for flexibility in IST scheduling for applicable code requirements noted in Requirements above.

The ASME OM Code specifies component test frequencies that are based either on elapsed time periods (e.g., quarterly, 2 years, etc.) or on the occurrence of plant conditions or events (e.g., cold shutdown, refueling outage, upon detection of a sample failure, following maintenance, etc.).

1) Components, whose test frequencies are based on elapsed time periods, shall be tested at the frequencies specified in OM Code Section IST with a specified time period between tests as shown in Table 1. The specified time period between tests may be reduced or extended as follows:

i) For periods specified as fewer than 2 years, the period may be extended by up to 25% for any given test.

ii) For periods specified as greater than or equal to 2 years, the period may be extended by up to 6 months for any given test.

iii) All periods specified may be reduced at the discretion of the owner (i.e., there is no minimum period requirement).

Table 1: Specified Test Frequencies Frequency Specified Time Period Between Tests Quarterly 92 Days (or every 3 months)

Semiannually 184 Days (or every 6 months)

Annually 366 Days (or every year) x calendar years x Years

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Period extension is used to facilitate test scheduling and considers plant operating conditions that may not be suitable for performance of the required testing (e.g., performance of the test would cause an unacceptable increase in the plant risk profile due to transient conditions or other ongoing surveillance, test or maintenance activities). Period extensions are not intended to be used repeatedly merely as an operational convenience to extend test intervals beyond those specified.

Period extensions may also be applied to accelerated test frequencies (e.g., pumps in Alert Range) and other fewer than two-year test frequencies not specified in Table 1.

4

Arizona Public Service Company (APS)

Palo Verde Nuclear Generating Station - Units 1, 2 and 3 GENERAL RELIEF REQUEST GRR-02 Proposed Alternative In Accordance with 10 CFR 50.55a(z)(1)

Inservice Test Frequency per Code Case OMN-20 Proposed Alternative and Basis (continued):

Period extensions may not be applied to the test frequency requirements specified in Subsection ISTD, Preservice and Inservice Examination and Testing of Dynamic Restraints (Snubbers) in Light-Water Reactor Nuclear Power Plants, as Subsection ISTD contains its own rules for period extensions.

2) Components whose test frequencies are based on the occurrence of plant conditions or events (e.g.,

cold shutdown, refueling outage, upon detection of a sample failure, following maintenance, etc.) may not have their period between tests extended except as allowed by the ASME OM Code.

This alternative is requested citing the above guidance found in ASME-approved Code Case OMN-20 for determining acceptable tolerances for pump and valve test frequencies. The ASME OM Code Standards Committee approved this Code Case in February 2012. Code Case OMN-20 was subsequently published in conjunction with the ASME OM Code, 2012 Edition.

On September 18, 2015, in the Federal Register Vol. 80, No. 181, the NRC proposed to amend 10 CFR 50.55a to incorporate by reference ASME OM Code Case OMN-20, Inservice Test Frequency.

In conclusion, as currently written, the ASME OM Code requirements do not allow testing period extensions that provide an allowance for operational flexibility for the performance of ASME OM Code testing. As a result, this places a hardship on the ability for PVNGS to schedule and perform ASME OM Code testing without a compensating increase in level of quality and safety. Using the provisions of this request as an alternative to the specific frequency requirements of the OM Code identified above will provide operational flexibility and still continue to provide an acceptable level of quality and safety.

Therefore, pursuant to 10 CFR 50.55a(z)(1), PVNGS requests approval of the alternative, which is consistent with ASME-approved Code Case OMN-20, to the specific ASME OM Code frequency requirements identified in this request.

Duration:

The proposed alternative identified in this 10 CFR 50.55a request shall be utilized during the fourth 10-year IST interval beginning January 15, 2018, and ending January 14, 2028.

Precedence:

Similar requests were approved for the following utilities:

1) Byron Station, Unit Nos. 1 and 2 - Relief [RG-1] from the Requirements of the ASME Code, dated February 26, 2016 (ADAMS Accession No. ML16022A135)

2) Fort Calhoun Station, Unit No. 1 - Requests for Relief G-1, P-1 and P-2 for the Fifth Inservice Testing Interval, dated February 19, 2016 (ADAMS Accession No. ML16041A308)

3) Callaway Plant, Unit 1 - Requests for Relief [PR-04], Alternatives to ASME OM Code Requirements for Inservice Testing for the Fourth Program Interval, dated July 15, 2014 (ADAMS Accession No. ML14178A769) 5

Arizona Public Service Company (APS)

Palo Verde Nuclear Generating Station - Units 1, 2 and 3 GENERAL RELIEF REQUEST GRR-02 Proposed Alternative In Accordance with 10 CFR 50.55a(z)(1)

Inservice Test Frequency per Code Case OMN-20 Precedence (continued):

4) Dresden Nuclear Power Station, Units 2 and 3 - Safety Evaluation in Support of Request for Reliefs

[RR RV-01] Associated with the Fifth 10-Year Interval Inservice Testing Program, dated October 31, 2013 (ADAMS Accession No. ML13297A515)

5) Quad Cities Nuclear Power Station, Units 1 and 2 - Safety Evaluation in Support of Request for Relief

[RV-01] Associated with the Fifth 10-Year Interval Inservice Testing Program, dated February 14, 2013 (ADAMS Accession No. ML13042A348)

6) Three Mile Island Nuclear Station, Unit 1 - Relief Request [VR-02] Associated with the Fifth 10-Year Inservice Test Interval, dated August 15, 2013 (ADAMS Accession No. ML13227A024)

References:

1) NRC Regulatory Issue Summary 2012-10, NRC Staff Position on Applying Surveillance Requirements 3.0.2 and 3.0.3 to Administrative Controls Program Tests

2) ASME OM Code Case OMN-20, Inservice Test Frequency

3) PVNGS Technical Specifications

4) NUREG 1482, Revision 2, Guidelines for Inservice Testing at Nuclear Power Plants: Inservice Testing of Pumps and Valves and Inservice Examination and Testing of Dynamic Restraints (Snubbers) at Nuclear Power Plants, Table 3.2, ASME OM Code Terms for Inservice Testing Activities, dated October 2013 (ADAMS Accession No. ML13295A020) 6

Arizona Public Service Company (APS)

Palo Verde Nuclear Generating Station - Units 1, 2 and 3 PUMP RELIEF REQUEST PRR-01 Relief Request in Accordance with 10 CFR 50.55a(z)(2)

Essential Auxiliary Feedwater Pump Flow Rate Measurement ASME Components Affected:

The affected Palo Verde Nuclear Generating Station (PVNGS) essential Auxiliary Feedwater (AF) pumps are identified in the table below:

Pump ID Pump Description Code Pump Group Class 1MAFAP01 Unit 1 Essential Auxiliary 3 B Feedwater Pump (Turbine-Driven) 1MAFBP01 Unit 1 Essential Auxiliary 3 B Feedwater Pump (Motor-Driven) 2MAFAP01 Unit 2 Essential Auxiliary 3 B Feedwater Pump (Turbine-Driven) 2MAFBP01 Unit 2 Essential Auxiliary 3 B Feedwater Pump (Motor-Driven) 3MAFAP01 Unit 3 Essential Auxiliary 3 B Feedwater Pump (Turbine-Driven) 3MAFBP01 Unit 3 Essential Auxiliary 3 B Feedwater Pump (Motor-Driven)

Component/System Function:

The essential AF pumps supply water to the steam generators during an accident. They also may be used to supply feedwater to the steam generators during plant startup and shutdown, although the non-class AF pump normally fulfills that function.

Applicable Code Edition and Addenda

ASME OM Code 2012 Edition Applicable Code Requirements:

ISTB-3300, Reference Values, paragraph (e)(2), states, "Reference values shall be established at the comprehensive pump test flow rate for the Group A and Group B tests, if practicable. If not practicable, the reference point flow rate shall be established at the highest practical flow rate."

ISTB-5122, Group B Test Procedure, states, in part, that "Group B tests shall be conducted with the pump operating as close as practical to a specified reference point and within the variances from the reference point as described in this paragraph. The test parameter value identified in Table ISTB-3000-1 shall be determined and recorded as required by this paragraph. "

ISTB-5122(b), states, "The differential pressure or flow rate shall be determined and compared to its reference value."

Reason for Request

Pursuant to 10 CFR 50.55a, Codes and standards, paragraph (z)(2), an alternative is being requested from the requirement of the ASME OM Code for measurement of the flow rate for Group 1

Arizona Public Service Company (APS)

Palo Verde Nuclear Generating Station - Units 1, 2 and 3 PUMP RELIEF REQUEST PRR-01 Relief Request in Accordance with 10 CFR 50.55a(z)(2)

Essential Auxiliary Feedwater Pump Flow Rate Measurement Reason for Request (continued):

B testing of the six Essential Auxiliary Feedwater (AF) Pumps. The basis of this request is that the ASME OM Code requirements present an undue hardship without a compensating increase in the level of quality and safety.

This relief request is a resubmittal of NRC approved third 10-year interval PRR-01, which was based on the ASME OM Code-2001 Edition through the OMB 2003 addenda. This fourth 10-year interval request is based on the ASME OM Code 2012 Edition. There have been no substantive changes to this alternative, to the OM Code requirements or to the basis for use, which would alter the previous NRC Safety Evaluation conclusions.

The ASME OM Code requires the establishment of Group B reference point flow rate at the comprehensive test flow rate or at the highest practical flow rate and to operate the pump at a specified reference point (i.e., fix the flow to a specified value). Measurement of flow is considered a hardship since this is a fixed resistance recirculation path with no flow instrumentation provided.

When the pump operates on minimum flow recirculation (approximately 260 gallons per minute (gpm)), the specified reference point is essentially achieved by the recirculation lines fixed resistance. To establish the fixed resistance, the minimum flow recirculation line contains an administratively controlled locked-throttled drag valve and a locked open manual isolation valve. The drag valve is entirely passive and treated as an orifice. The hand wheels are removed and the valves are locked in position. There are no operations procedures that manipulate the valve. There are no maintenance tasks associated with the valve. The use of an ultrasonic flowmeter was evaluated and determined nonviable due to the difficulty in establishing an application-specific 2%

calibration on the AF mini-flow piping. Allowing the flow to remain fixed by the locked-in resistance increases the potential for repeatable test results and degradation monitoring rather than changing the resistance based on the ultrasonic flow meter readout fluctuations. With this understanding, there is little value added by installing ISTB-3510 compliant flow instrumentation in the minimum flow recirculation line to measure flow. This fixed resistance methodology is repeatable from test to test and accomplishes the same result as if flow were being measured and recorded.

To comply with the ASME OM Code there are only two practical flow paths available for testing each essential AF pump. The primary flow path is into the main feedwater lines to the steam generators.

The other flow path is the minimum flow recirculation line that recirculates back to the condensate storage tank. The flow path to the steam generators is equipped with flow instrumentation, but the recirculation line is a fixed resistance circuit with no provisions for flow indication.

Use of the primary flow path at power would inject cold AF into the main feedwater lines. The resulting temperature perturbations could lead to thermal shock/fatigue damage to the feedwater piping and steam generators, and the cooldown of the reactor coolant system could cause undesirable reactivity variations and power fluctuations.

Modifying the minimum flow recirculation line to provide flow indication that meets the +/- 2%

accuracy requirement (as specified in Table ISTB-3510-1, Required Instrument Accuracy) adds little value since the flow is fixed at approximately 260 gpm and differential pressure is used to monitor degradation. Use of an ultrasonic flow meter and possible adjustment of the fixed resistance introduces the potential for less accurate degradation monitoring than currently employed.

2

Arizona Public Service Company (APS)

Palo Verde Nuclear Generating Station - Units 1, 2 and 3 PUMP RELIEF REQUEST PRR-01 Relief Request in Accordance with 10 CFR 50.55a(z)(2)

Essential Auxiliary Feedwater Pump Flow Rate Measurement Proposed Alternative and Basis for Use:

The essential AF pumps are standby pumps that are normally idle during plant operation, except for testing. During plant operation, quarterly Group B pump testing for each pump shall be conducted at mini-flow conditions using the minimum flow recirculation line fixed resistance to establish the specified reference point. ISTB-5100(b)(2) allows the use of bypass test loops to be used for Group B tests. The PVNGS minimum flow recirculation line is designed to meet the pump manufacturers operating specifications of approximately 260 gpm. Flow rate will not be measured or recorded. To monitor for degradation, pump differential pressure shall be determined and compared to its reference value and the associated Acceptance, Alert and Required Action Ranges as specified in Table ISTB-5121-1, Centrifugal Pump Test Acceptance Criteria.

Each essential AF pump will be comprehensively tested in accordance with ISTB-5123, Comprehensive Test Procedure, on a biennial (2-year) frequency as specified in Table ISTB-3400-1, Inservice Test Frequency, and meet the requirements of Mandatory Appendix V, Pump Periodic Verification Test Program, as specified in ISTB-1400(d).

Since these are standby pumps, little degradation is expected during plant operation when the pumps are idle except for testing. Testing the pumps at the comprehensive pump test flow rate on a 2-year frequency, while satisfying Mandatory Appendix V, provides additional information regarding the condition of the pumps.

Duration of Proposed Alternative:

The proposed alternative identified in this 10 CFR 50.55a request shall be utilized for the duration of the fourth 10-year IST interval beginning January 15, 2018, and ending January 14, 2028.

Precedence:

The NRC previously authorized pump relief request PRR-01 for the third 10-year IST Program interval at PVNGS Units 1, 2 and 3 in the following safety evaluation:

Letter from the NRC (T. G. Hiltz) to Arizona Public Service Company (R. K. Edington), Palo Verde Nuclear Generating Station, Units 1, 2, and 3 - Relief Request for the Third 10-Year Interval Pump and Valve Inservice Testing, dated April 24, 2008 (ADAMS Accession No. ML081050003)

In addition, this proposed alternative complies with NRC Generic Letter 89-04, Guidance on Developing Acceptable Inservice Testing Programs, Position 9, dated April 3, 1989.

References:

1) 10 CFR 50.55a, Codes and standards

2) ASME OM Code 2012 Edition 3

Arizona Public Service Company (APS)

Palo Verde Nuclear Generating Station - Units 1, 2 and 3 PUMP RELIEF REQUEST PRR-02 Relief Request in Accordance with 10 CFR 50.55a(f)(5)(iii)

Diesel Fuel Oil Transfer Pump Suction Pressure Measurement ASME Components Affected:

The affected Palo Verde Nuclear Generating Station (PVNGS) Diesel Generator Fuel Oil (DGFO) transfer pumps are identified in the table below:

Code Pump Pump ID Pump Description Class Group 1MDFAP01 Unit 1 Diesel Generator 3 B Fuel Oil Transfer Pump A 1MDFBP01 Unit 1 Diesel Generator 3 B Fuel Oil Transfer Pump B 2MDFAP01 Unit 2 Diesel Generator 3 B Fuel Oil Transfer Pump A 2MDFBP01 Unit 2 Diesel Generator 3 B Fuel Oil Transfer Pump B 3MDFAP01 Unit 3 Diesel Generator 3 B Fuel Oil Transfer Pump A 3MDFBP01 Unit 3 Diesel Generator 3 B Fuel Oil Transfer Pump B Component/System Function:

The DGFO transfer pumps transfer diesel fuel from the fuel oil storage tank to the Emergency Diesel Generator (EDG) day tank.

Applicable Code Edition and Addenda

ASME OM Code 2012 Edition Applicable Code Requirements:

ISTB-3510, General, paragraph ISTB-3510(a), Accuracy, states, in part, that "Instrument accuracy shall be within the limits of Table ISTB-3510-1."

Table ISTB-3510-1, Required Instrument Accuracy, provides the accuracy limits for Comprehensive and Preservice Tests, percent for pressure is +/- 1/2% [+/- 0.5%].

Reason for the Request:

Pursuant to 10 CFR 50.55a, Codes and standards, paragraph (f)(5)(iii), an alternative is being requested from the requirement of the ASME OM Code relative to the DGFO transfer pumps suction pressure instruments accuracy.

1

Arizona Public Service Company (APS)

Palo Verde Nuclear Generating Station - Units 1, 2 and 3 PUMP RELIEF REQUEST PRR-02 Relief Request in Accordance with 10 CFR 50.55a(f)(5)(iii)

Diesel Fuel Oil Transfer Pump Suction Pressure Measurement Reason for the Request (continued):

The basis of this request is that compliance with the ASME OM Code requirements is impractical for pump testing and would present a burden if those requirements were imposed, without providing significantly more accurate suction pressure data for the evaluation of pump degradation.

This relief request is a resubmittal of NRC-approved third 10-year interval PRR-02, which was based on the ASME OM Code-2001 Edition through the OMB 2003 addenda. This fourth 10-year interval request is based on the ASME OM Code 2012 Edition. There have been no substantive changes to this proposed alternative, to the OM Code requirements or to the basis for use, which would alter the previous NRC safety evaluation conclusions.

Impracticality of Compliance There are no inlet pressure gauges installed for this pump configuration. Specifically, the pumps are horizontal, centrifugal type with an integral motor. They operate submerged in the diesel fuel oil storage tank. The pump and drive motor are completely housed in an enclosed steel casing with no shaft penetrations requiring seals or packing. The casing has a hermetically sealed compartment for the stator windings of the motor to prevent entrance of pumped liquid or vapor. Pump bearings are cooled by recirculation of pumped fluid. The entire assembly is suspended from a cover plate, which is bolted to a nozzle on the tank.

The DGFO storage tank is equipped with level instrumentation (DFN-LI-33 and DFN-LI-34) having a calculated loop accuracy of +/- 1.5%. The instrument reads out in percent of tank level, which is converted to suction pressure during pump Inservice tests. The calibrated instrument range results in a suction pressure span of 0.2 pounds per square inch gauge (psig) to 4.4 psig.

This instrument accuracy is acceptable for use during Group B pump testing but does not meet the +/- 0.5% accuracy as required by Table ISTB-3510-1 for comprehensive pump testing performed every 2 years, or preservice pump testing performed as required.

Burden Caused by Compliance Compliance with ISTB-3510 accuracy requirements during comprehensive and preservice pump testing measurement of suction pressure would require re-design and installation of more accurate instrumentation with minimal benefit.

The installed instrumentation converts to a full-scale range of 4.4 psig, which only slightly exceeds the pump suction reference (Pr) value of 3.8 psig (full scale equals 1.15 times reference).

Considering the existing 1.5% accuracy of the level instrument, the reading could be as high as 3.85 psig or as low as 3.74 psig. This results in less than a 0.11 psig difference in the readings and is considered insignificant when monitoring for degradation. Also, there is an essentially equivalent variance for the ISTB-3510 allowed combination of range and accuracy for 2

Arizona Public Service Company (APS)

Palo Verde Nuclear Generating Station - Units 1, 2 and 3 PUMP RELIEF REQUEST PRR-02 Relief Request in Accordance with 10 CFR 50.55a(f)(5)(iii)

Diesel Fuel Oil Transfer Pump Suction Pressure Measurement Reason for the Request (continued):

comprehensive and preservice pump testing, as compared to the installed instrumentation. The table below illustrates.

Range Accuracy Range x Accuracy Maximum Variance Instrument (R) (A) (R x A) R x A x Pr ISTB-3510 allowed 3 x Pr +/- 0.5% 1.5%Pr 1.5% (3.8) = .057 psig Installed 1.15 x Pr +/-1.5% 1.7%Pr 1.7% (3.8) = .065 psig instruments The current DGFO pump differential pressure reference value (DPr) varies from 27.7 to 29.1 pounds per square inch differential (psid), with an average of 28.4 psid. The difference between the ISTB-3510 allowed variance in pressure measurement, compared with the variance in the installed instruments, is insignificant when monitoring for pump degradation. The difference is 0.008 psig, where 0.008 psig = 0.065 psig - 0.057 psig.

Another consideration is that the existing DGFO storage tank level is essentially constant, thus assuring a constant suction pressure for the DGFO transfer pumps. Technical Specification (TS) 3.8.3.1 requires that the DGFO storage tank be maintained at 80%, which is verified every 31 days to assure sufficient supply for 7 days of full-load Diesel Generator operation. The difference between minimum allowable tank level and the top of the tank is only 26.4 inches.

The suction pressure is essentially fixed by the TS level requirements, allowing for minimal variation in suction pressure. Due to strict controls placed on fuel oil level, the suction pressure does not vary by more than 0.7 psig. APS reviewed the previous two years of test history. The data shows essentially constant suction pressure for each of the pumps with a maximum recorded variance of 0.5 psig.

Proposed Alternative and Basis for Use:

Comprehensive and preservice tests for each DGFO transfer pump will measure and record pump suction pressure using the installed plant instruments (DFN-LI-33 and DFN-LI-34). Use of these instruments provides reasonable assurance that DGFO transfer pumps are operationally ready since 1) the instruments yield a reading that is essentially equivalent to that achieved using an instrument meeting the ASME OM Code range and accuracy requirements and 2) the TS requirements limit DGFO tank level variations, thus suction pressure is essentially constant.

Based on the determination that compliance with the ASME OM Code requirements is impractical for pump testing, Code compliant instrumentation would provide insignificantly more accurate data for evaluation of pump degradation, and the burden caused if the Code requirement was imposed, the proposed alternative is requested pursuant to 10 CFR 50.55a(f)(5)(iii).

3

Arizona Public Service Company (APS)

Palo Verde Nuclear Generating Station - Units 1, 2 and 3 PUMP RELIEF REQUEST PRR-02 Relief Request in Accordance with 10 CFR 50.55a(f)(5)(iii)

Diesel Fuel Oil Transfer Pump Suction Pressure Measurement Duration of Proposed Alternative:

The proposed alternative identified in this 10 CFR 50.55a request shall be utilized during the fourth 10-year IST Interval beginning January 15, 2018, and ending January 14, 2028.

Precedent:

The NRC previously authorized pump relief request PRR-02 for the third 10-year IST program interval at PVNGS Units 1, 2 and 3 in the following safety evaluation:

• Letter from the NRC (T. G. Hiltz) to Arizona Public Service Company (R. K. Edington), Palo Verde Nuclear Generating Station, Units 1, 2, and 3 - Relief Request for the Third 10-Year Interval Pump and Valve Inservice Testing Program, dated April 24, 2008 (ADAMS Accession No. ML081050003)

Reference:

NUREG 1482, Revision 2, Guidelines for Inservice Testing at Nuclear Power Plants: Inservice Testing of Pumps and Valves and Inservice Examination and Testing of Dynamic Restraints (Snubbers) at Nuclear Power Plants, Section, 5.5.3, Use of Tank or Bay Level to Calculate Differential Pressure, dated October 2013 (ADAMS Accession No. ML13295A020) 4

Arizona Public Service Company (APS)

Palo Verde Nuclear Generating Station - Units 1, 2 and 3 PUMP RELIEF REQUEST PRR-03 Relief Request in Accordance with 10 CFR 50.55a(z)(2)

Low Pressure Safety Injection (LPSI) Pump Flow Rate Measurement ASME Components Affected:

The affected Palo Verde Nuclear Generating Station (PVNGS) Low Pressure Safety Injection (LPSI) pumps are identified in the table below:

Code Pump Pump ID Pump Description Class Group 1MSIAP01 Unit 1 Low Pressure Safety Injection A Pump 2 A 1MSIBP01 Unit 1 Low Pressure Safety Injection B Pump 2 A 2MSIAP01 Unit 2 Low Pressure Safety Injection A Pump 2 A 2MSIBP01 Unit 2 Low Pressure Safety Injection B Pump 2 A 3MSIAP01 Unit 3 Low Pressure Safety Injection A Pump 2 A 3MSIBP01 Unit 3 Low Pressure Safety Injection B Pump 2 A Component/System Function:

The LPSI pumps provide low-pressure coolant injection of borated water into the reactor coolant system (RCS) under accident conditions. They also provide shutdown cooling flow post-accident and during normal reactor startup and shutdown.

Applicable Code Edition and Addenda

ASME OM Code 2012 Edition Applicable Code Requirements:

ISTB-3300, Reference Values, paragraph ISTB-3300(e)(2), states, "Reference values shall be established at the comprehensive pump test flow rate for the Group A and Group B tests, if practicable. If not practicable, the reference point flow rate shall be established at the highest practical flow rate.

ISTB-5121, Group A Test Procedure, states, in part, "Group A tests shall be conducted with the pump operating as close as practical to a specified reference point and within the variances from the reference point as described in this paragraph. The test parameters shown in Table ISTB-3000-1 shall be determined and recorded as required by this paragraph. "

ISTB-5121(b), states, "The resistance of the system shall be varied until the flow rate is as close as practical to the reference point with the variance not to exceed +2% or -1% of the reference point. The differential pressure shall then be determined and compared to its reference value.

1

Arizona Public Service Company (APS)

Palo Verde Nuclear Generating Station - Units 1, 2 and 3 PUMP RELIEF REQUEST PRR-03 Relief Request in Accordance with 10 CFR 50.55a(z)(2)

Low Pressure Safety Injection (LPSI) Pump Flow Rate Measurement Applicable Code Requirements (continued):

Alternatively, the flow rate shall be varied until the differential pressure is as close as practical to the reference point with the variance not to exceed +1% or -2% of the reference point and the flow rate determined and compared with the reference flow rate."

ISTB-5121(c), states, Where it is not practical to vary system resistance, flow rate and pressure shall be determined and compared to their respective reference values."

Reason for Request

Pursuant to 10 CFR 50.55a, Codes and standards, paragraph (z)(2), an alternative is being requested from the ASME OM Code requirement for the flow rate measurement during Group A testing of the LPSI Pumps. The basis of this request is that the ASME OM Code requirements present an undue hardship without a compensating increase in the level of quality and safety.

This relief request is a resubmittal of NRC approved third 10-year interval PRR-03, which was based on the ASME OM Code-2001 Edition through the OMB 2003 addenda. This fourth 10-year interval request is based on the ASME OM Code 2012 Edition. There have been no substantive changes to this alternative, to the OM Code requirements or to the basis for use, which would alter the previous NRC safety evaluation conclusions.

The ASME OM Code requires the establishment of the Group A reference point flow rate at the comprehensive test flow rate or at the highest practical flow rate, and to operate the pump at a specified reference point (i.e., fix the flow to a specified value). It is considered a hardship to meet this requirement since this is a fixed resistance recirculation path of approximately 180 gallons per minute (gpm) with limited capability permanent plant flow instrumentation. The installed flowmeter is on a common recirculation line to the refueling water tank. The instrumentation is a 0-5000 gpm ultrasonic flowmeter with +/- 5% accuracy that does not meet the +/- 2% instrument accuracy requirements of Table ISTB-3510-1, Required Instrument Accuracy, for pump testing. The use of an ultrasonic flowmeter with 2% accuracy was evaluated and determined nonviable due to the difficulty in establishing an application specific 2%

calibration on the safety injection mini-flow piping. To establish the fixed resistance, the minimum flow recirculation line contains a flow orifice and a normally open motor-operated valve and solenoid isolation valve. Allowing the flow to remain fixed by the orifice resistance increases the potential for repeatable test results and degradation monitoring rather than attempting to change the resistance based on ultrasonic flowmeter readout fluctuations. When the pump operates on minimum flow recirculation, the specified reference point is essentially achieved by the fixed resistance. With this understanding, there is little value added in replacing the existing 0-5000 gpm, +/- 5% ultrasonic flowmeter, or adding instrumentation that meets ISTB-3510 requirements. The fixed resistance methodology is repeatable from test to test and accomplishes the same result as if flow were being measured and recorded.

During normal plant operation, the LPSI pumps cannot develop sufficient discharge pressure to overcome RCS pressure and allow flow through the safety injection headers. Thus, during quarterly testing, LPSI flow is routed through a minimum flow recirculation line to the refueling 2

Arizona Public Service Company (APS)

Palo Verde Nuclear Generating Station - Units 1, 2 and 3 PUMP RELIEF REQUEST PRR-03 Relief Request in Accordance with 10 CFR 50.55a(z)(2)

Low Pressure Safety Injection (LPSI) Pump Flow Rate Measurement Reason for Request (continued):

water tanks. The minimum-flow recirculation flow path is a fixed resistance circuit containing a flow-limiting orifice capable of passing only a small fraction (approx. 180 gpm) of the design flow (4200 gpm). The permanent plant 0-5000 gpm, +/- 5% accuracy, flow instrumentation (permanently mounted ultrasonic flowmeter) has only limited capability, and its accuracy does not meet Table ISTB-3510-1, Required Instrument Accuracy, flow rate +/- 2% accuracy requirements.

The LPSI pumps are categorized as Group A since they are normally used to provide shutdown cooling flow during shutdown operations, and occasionally for recirculating the refueling water tank when the unit is at power. This infrequent use is expected to result in minimal degradation during plant operation. Thus, the alternate testing will adequately monitor these pumps to ensure continued operability and availability for accident mitigation.

Modifying the minimum flow recirculation line to provide flow indication to meet the +/- 2%

accuracy requirement as specified in Table ISTB-3510-1 adds little value since the flow is fixed and differential pressure is used to monitor degradation.

Proposed Alternative and Basis for Use:

During plant operation, quarterly Group A pump testing for the LPSI pumps shall be conducted at mini-flow conditions using the minimum flow recirculation line fixed resistance of approximately 180 gpm to establish the specified reference point.

Subsection ISTB, paragraph ISTB-5100(b), Bypass Loops, subparagraph (1) allows the use of bypass test loops for Group A tests. The flow rate through the loop is established at the highest practical flow rate of approximately 180 gpm in accordance with ISTB-3300(e)(2). Flow rate will not be measured or recorded. To monitor for degradation, pump differential pressure shall be determined and compared to its reference value and the associated Acceptable and Required Action Ranges as specified in Table ISTB-5121-1, Centrifugal Pump Test Acceptance Criteria.

Vibration measurement will be conducted quarterly in accordance with ISTB-3540, Vibration.

The LPSI pumps will be comprehensively tested in accordance with ISTB-5123, Comprehensive Test Procedure, on a biennial (2-year) frequency as specified in Table ISTB-3400-1, Inservice Test Frequency, and meet the requirements of Mandatory Appendix V, Pump Periodic Verification Test Program, as specified in ISTB-1400(d).

The LPSI pumps are used infrequently. Little degradation is expected during plant power operation when the pumps are idle except for limited operations and testing. Testing the pumps at the comprehensive pump flow rate on a 2-year frequency while satisfying Mandatory Appendix V provides additional information regarding the condition of the pumps.

Based on the determination that compliance with the ASME OM Code requirement results in a hardship without a compensating increase in the level of quality and safety, this proposed alternative is requested pursuant to 10 CFR 50.55a(z)(2).

3

Arizona Public Service Company (APS)

Palo Verde Nuclear Generating Station - Units 1, 2 and 3 PUMP RELIEF REQUEST PRR-03 Relief Request in Accordance with 10 CFR 50.55a(z)(2)

Low Pressure Safety Injection (LPSI) Pump Flow Rate Measurement Duration of Proposed Alternative:

The proposed alternative identified in this 10 CFR 50.55a request shall be utilized during the fourth 10-year inservice test interval beginning January 15, 2018, and ending January 14, 2028.

Precedence:

The NRC previously authorized pump relief request PRR-03 for the third 10-year IST program interval at PVNGS Units 1, 2 and 3 in the following safety evaluation:

• Letter from the NRC (T. G. Hiltz) to Arizona Public Service Company (R. K. Edington), Palo Verde Nuclear Generating Station, Units 1, 2, and 3 - Relief Request for the Third 10-Year Interval Pump and Valve Inservice Testing Program, dated April 24, 2008 (ADAMS Accession No. ML081050003)

In addition, this proposed alternative complies with NRC Generic Letter 89-04, Guidance on Developing Acceptable Inservice Testing Programs, Position 9, dated April 3, 1989.

References:

1) 10 CFR 50.55a, Codes and standards

2) ASME OM Code 2012 Edition 4

Arizona Public Service Company (APS)

Palo Verde Nuclear Generating Station - Units 1, 2 and 3 PUMP RELIEF REQUEST PRR-04 Relief Request in Accordance with 10 CFR 50.55a(z)(2)

HPSI Pump Flow Rate Measurement ASME Components Affected:

The affected Palo Verde Nuclear Generating Station (PVNGS) High Pressure Safety Injection (HPSI) pumps are identified in the table below:

Code Pump Pump ID Pump Description Class Group 1MSIAP02 Unit 1 High Pressure Safety Injection Pump A 2 B 1MSIBP02 Unit 1 High Pressure Safety Injection Pump B 2 B 2MSIAP02 Unit 2 High Pressure Safety Injection Pump A 2 B 2MSIBP02 Unit 2 High Pressure Safety Injection Pump B 2 B 3MSIAP02 Unit 3 High Pressure Safety Injection Pump A 2 B 3MSIBP02 Unit 3 High Pressure Safety Injection Pump B 2 B Component/System Function:

The HPSI pumps provide high-pressure coolant injection of borated water into the reactor coolant system (RCS) under accident conditions. They also provide flow for long-term cooling and flushing to prevent boron precipitation.

Applicable Code Edition and Addenda

ASME OM Code 2012 Edition Applicable Code Requirements:

ISTB-3300, Reference Values, paragraph ISTB-3300(e)(2), states, "Reference values shall be established at the comprehensive pump test flow rate for Group A and Group B tests, if practicable. If not practicable, the reference point flow rate shall be established at the highest practical flow rate."

ISTB-5122, Group B Test Procedure, states, in part, that "Group B tests shall be conducted with the pump operating as close as practical to a specified reference point and within the variances from the reference point as described in this paragraph. The test parameter value identified in Table ISTB-3000-1 shall be determined and recorded as required by this paragraph. "

ISTB-5122(c), states, System resistance may be varied as necessary to achieve a point as close as practical to the reference point. If the reference point is flow rate, the variance from the UHIHUHQFHSRLQWVKDOOQRWH[FHHGRUí...

1

Arizona Public Service Company (APS)

Palo Verde Nuclear Generating Station - Units 1, 2 and 3 PUMP RELIEF REQUEST PRR-04 Relief Request in Accordance with 10 CFR 50.55a(z)(2)

HPSI Pump Flow Rate Measurement

Reason for Request

Pursuant to 10 CFR 50.55a, Codes and standards, paragraph (z)(2), an alternative is being requested from the requirement of the ASME OM Code for measurement of the flow rate for Group B testing of the HPSI Pumps. The basis of this request is that the ASME OM Code requirements present an undue hardship without a compensating increase in the level of quality and safety.

This relief request is a resubmittal of NRC approved third 10-year interval PRR-04, which was based on the ASME OM Code-2001 Edition through the OMB 2003 addenda. This fourth 10-year interval request is based on the ASME OM Code 2012 Edition. There have been no substantive changes to this alternative, to the OM Code requirements or to the basis for use, which would alter the previous NRC safety evaluation conclusions.

The ASME OM Code requirements to establish the Group B reference point flow rate at the highest practical flow rate and operate the pump at a specified reference point (i.e., fix the flow to a specified value) is considered a hardship since this is a fixed resistance recirculation path of approximately 170 gallons per minute (gpm), which is measured by limited capability permanent plant flow instrumentation. The installed flowmeter is on a common recirculation line to the Refueling Water Tank. This instrumentation is a 0-5000 gpm ultrasonic flowmeter with +/- 5%

accuracy and does not meet the +/- 2% instrument requirements of Table ISTB-3510-1, Required Instrument Accuracy, for pump testing. The use of an ultrasonic flowmeter with 2% accuracy was evaluated and determined to be nonviable due to the difficulty in establishing an application specific 2% calibration on the SI mini-flow piping. To establish the fixed resistance, the minimum flow recirculation line contains a flow orifice and a normally open motor-operated valve and solenoid isolation valve. Allowing the flow to remain fixed by the orifice resistance increases the potential for repeatable test results and degradation monitoring rather than attempting to change the resistance based on ultrasonic flowmeter readout fluctuations. When the pump operates on minimum flow recirculation, the specified reference point is essentially achieved by the fixed resistance.

With this understanding, there is little value added in replacing the existing 0-5000 gpm, +/- 5%

ultrasonic flowmeter, or adding instrumentation that meets ISTB-3510(a), Accuracy, requirements. The fixed resistance methodology is repeatable from test to test and accomplishes the same result as if flow were being measured and recorded.

During normal plant operation, the HPSI pumps cannot develop sufficient discharge pressure to overcome RCS pressure and allow flow through the SI headers. Thus, during quarterly testing, HPSI flow is routed through a minimum flow recirculation line to the refueling water tanks. The minimum-flow recirculation flow path is a fixed resistance circuit containing a flow-limiting orifice capable of passing only a small fraction (approximately 170 gpm) of the design flow (815 gpm).

The permanent plant 0-5000 gpm, +/- 5% accuracy, flow instrumentation (permanently mounted ultrasonic flowmeter) has only limited capability, and its accuracy does not meet Table ISTB-3510-1, Required Instrument Accuracy, flow rate 2% accuracy requirements.

The HPSI pumps are categorized as Group B. During normal operation, the HPSI pumps are generally in standby except for pump testing. Pumps 1MSIBP02, 2MSIBP02 and 3MSIBP02 are 2

Arizona Public Service Company (APS)

Palo Verde Nuclear Generating Station - Units 1, 2 and 3 PUMP RELIEF REQUEST PRR-04 Relief Request in Accordance with 10 CFR 50.55a(z)(2)

HPSI Pump Flow Rate Measurement Reason for Request (continued):

used occasionally to recharge the SI tanks. Minimal degradation is expected during plant operation with this limited use. Thus, the alternate testing will adequately monitor these pumps to ensure continued operability and availability for accident mitigation.

Modifying the minimum flow recirculation line to provide flow indication to meet the +/- 2%

accuracy requirement as specified in Table ISTB-3510-1 adds little value since the flow is fixed and differential pressure is used to monitor degradation.

Proposed Alternative and Basis for Use:

During plant operation, quarterly Group B pump testing for each HPSI pump shall be conducted at mini-flow conditions using the minimum flow recirculation line fixed resistance of approximately 170 gpm to establish the specified reference point.

ISTB-5100(b)(2) allows the use of bypass test loops to be used for Group B tests. The minimum flow recirculation line is designed to meet the pump manufacturers operating specifications. The flow rate through the loop is established at the highest practical flow rate of approximately 170 gpm in accordance with ISTB-3300(e)(2). Flow rate will not be measured or recorded. To monitor for degradation, pump differential pressure shall be determined and compared to its reference value and the associated Acceptable and Required Action Ranges as specified in Table ISTB-5121-1, Centrifugal Pump Test Acceptance Criteria.

The HPSI pumps will be comprehensively tested in accordance with ISTB-5123, Comprehensive Test Procedure, on a biennial (2-year) frequency as specified in Table ISTB-3400-1, Inservice Test Frequency, and meet the requirements of Mandatory Appendix V, Pump Periodic Verification Test Program, as specified in ISTB-1400(d).

The HPSI pumps are used infrequently. Minimal degradation is expected during plant power operation when the pumps are idle, except for limited operations and testing. Testing the pumps at the comprehensive pump test flow rate on a 2-year frequency, while satisfying Mandatory Appendix V, provides additional information regarding the condition of the pumps.

Based on the determination that compliance with the ASME OM Code requirement results in a hardship without a compensating increase in the level of quality and safety, this proposed alternative is requested pursuant to 10 CFR 50.55a(z)(2).

Duration of Proposed Alternative:

The proposed alternative identified in this 10 CFR 50.55a request shall be utilized during the Fourth 10-year IST interval beginning January 15, 2018, and ending January 14, 2028.

3

Arizona Public Service Company (APS)

Palo Verde Nuclear Generating Station - Units 1, 2 and 3 PUMP RELIEF REQUEST PRR-04 Relief Request in Accordance with 10 CFR 50.55a(z)(2)

HPSI Pump Flow Rate Measurement Precedence:

The NRC previously authorized pump relief request PRR-04 for the third 10-year IST Program interval at PVNGS Units 1, 2 and 3 in the following safety evaluation:

• Letter from the NRC (T. G. Hiltz) to Arizona Public Service Company (R. K. Edington), Palo Verde Nuclear Generating Station, Units 1, 2, and 3 - Relief Request for the Third 10-Year Interval Pump and Valve Inservice Testing Program, dated April 24, 2008 (ADAMS Accession No. ML0801050003)

In addition, this proposed alternative complies with NRC Generic Letter 89-04, Guidance on Developing Acceptable Inservice Testing Programs, Position 9, dated April 3, 1989.

References:

1) 10 CFR 50.55a, Codes and standards

2) ASME OM Code 2012 Edition 4

Arizona Public Service Company (APS)

Palo Verde Nuclear Generating Station - Units 1, 2 and 3 PUMP RELIEF REQUEST PRR-05 Relief Request In Accordance with 10 CFR 50.55a(z)(2)

Containment Spray Pump Flow Rate Measurement ASME Components Affected:

The affected Palo Verde Nuclear Generating Station (PVNGS) Containment Spray (CS) pumps are identified in the table below:

Code Pump Pump ID Pump Description Class Group 1MSIAP03 Unit 1 Containment Spray Pump A 2 A 1MSIBP03 Unit 1 Containment Spray Pump B 2 A 2MSIAP03 Unit 2 Containment Spray Pump A 2 A 2MSIBP03 Unit 2 Containment Spray Pump B 2 A 3MSIAP03 Unit 3 Containment Spray Pump A 2 A 3MSIBP03 Unit 3 Containment Spray Pump B 2 A Component/System Function:

The CS pumps deliver borated water to the containment spray headers, providing containment cooling and pressure control during accident conditions. The CS pumps can also be lined up to provide flow for shutdown cooling.

Applicable Code Edition and Addenda

ASME OM Code 2012 Edition Applicable Code Requirements:

ISTB-3300, Reference Values, paragraph ISTB-3300(e)(2), states, "Reference values shall be established at the comprehensive pump flow rate for Group A and Group B tests, if practicable. If not practicable, the reference point flow rate shall be established at the highest practical flow rate.

ISTB-5121, Group A Test Procedure, states, in part, "Group A tests shall be conducted with the pump operating as close as practical to a specified reference point and within the variances from the reference point as described in this paragraph. The test parameters shown in Table ISTB-3000-1 shall be determined and recorded as required by this paragraph. "

ISTB-5121(b), states in part, "The resistance of the system shall be varied until the flow rate is as close as practical to the reference point with the variance not to exceed +2% or -1% of the reference point. The differential pressure shall then be determined and compared to its reference value.

ISTB-5121(c), states, Where it is not practical to vary system resistance, flow rate and pressure shall be determined and compared to their respective reference values."

1

Arizona Public Service Company (APS)

Palo Verde Nuclear Generating Station - Units 1, 2 and 3 PUMP RELIEF REQUEST PRR-05 Relief Request In Accordance with 10 CFR 50.55a(z)(2)

Containment Spray Pump Flow Rate Measurement

Reason for Request

Pursuant to 10 CFR 50.55a, Codes and standards, paragraph (z)(2), an alternative is being requested from the requirement of the ASME OM Code for flow rate measurement for Group A testing of the CS Pumps. The basis of this request is that the ASME OM Code requirements present an undue hardship without a compensating increase in the level of quality and safety.

This relief request is a resubmittal of NRC approved third 10-year interval PRR-05, which was based on the ASME OM Code 2001 Edition through the OMB 2003 addenda. This fourth 10-year interval request is based on the ASME OM Code 2012 Edition. There have been no substantive changes to this alternative, to the OM Code requirements or to the basis for use, which would alter the previous NRC safety evaluation conclusions.

The ASME OM Code requires the Group A reference point flow rate to be established at the comprehensive pump test flow rate if practicable or at the highest practical flow rate, and to operate the pump at a specified reference point (i.e., fix the flow to a specified value). It is considered a hardship to meet this requirement since this is a fixed resistance recirculation path of approximately 190 gallons per minute (gpm) with limited capability permanent plant flow instrumentation.

The installed instrumentation is a 0-5000 gpm ultrasonic flowmeter with +/- 5% accuracy and does not meet the 2% instrument requirements of Table ISTB-3510-1, Required Instrument Accuracy, for pump testing. The use of an ultrasonic flowmeter with 2% accuracy was evaluated and determined nonviable due to the difficulty in establishing an application specific 2% calibration on the SI mini-flow piping.

To establish the fixed resistance the minimum flow recirculation line contains a flow orifice and a normally open motor-operated valve and solenoid isolation valve. Allowing the flow to remain fixed by the orifice resistance increases the potential for repeatable test results and degradation monitoring rather than attempting to change the resistance based on ultrasonic flowmeter readout fluctuations. When the pump operates on minimum flow recirculation, the specified reference point is essentially achieved by the fixed resistance. With this understanding, there is little value added in replacing the existing 0-5000 gpm, +/- 5% ultrasonic flowmeter, or adding instrumentation that meets ISTB-3510(a), Accuracy, requirements. The fixed resistance methodology is repeatable from test to test and accomplishes the same result as if flow were being measured and recorded.

The normal CS flow path cannot be used for testing the CS pumps without spraying down the inside of the containment building and risking damage to important equipment. The reactor coolant system (RCS) injection portion of the shutdown cooling flow path cannot be used for testing during plant operation because the CS pumps are unable to develop sufficient discharge pressure to overcome RCS pressure.

The minimum-flow recirculation flow path is a fixed resistance circuit containing a flow-limiting orifice capable of passing only a small fraction (approx. 190 gpm) of the design flow (3890 gpm).

The permanent plant 0-5000 gpm, +/- 5% accuracy, flow instrumentation (permanently mounted ultrasonic flowmeter) has only limited capability, and does not meet the Table ISTB-3510-1 flow rate accuracy requirement for +/-2%. This instrumentation is on a common recirculation line to the Refueling Water Tank. A larger recirculation flow path is available; however, this requires an 2

Arizona Public Service Company (APS)

Palo Verde Nuclear Generating Station - Units 1, 2 and 3 PUMP RELIEF REQUEST PRR-05 Relief Request In Accordance with 10 CFR 50.55a(z)(2)

Containment Spray Pump Flow Rate Measurement Reason for Request (continued):

alternate line up and the same limited capability flow instrument exists in this portion of the recirculation line.

The larger recirculation flow path is capable of carrying higher flow, but routine surveillance testing at less than the full flow reference value is not practical because of the pump rumble range (1800-2800 gpm). Testing in or near the rumble range is not practical because of the potential for equipment damage. Testing at flow rates above the rumble range (> 2800 gpm) is not practical because flow velocities in the recirculation piping would exceed the design criteria.

The CS pumps are categorized as Group A since they are normally used to provide shutdown cooling flow during shutdown operations. This infrequent use is expected to result in minimal degradation during plant operation. Thus, the alternate testing will adequately monitor these pumps to ensure continued operability and availability for accident mitigation.

Modifying the minimum flow recirculation line to provide flow indication to meet the +/- 2% accuracy requirement as specified in Table ISTB-3510-1 adds little value since the flow is fixed and differential pressure is used to monitor degradation.

Proposed Alternative and Basis for Use:

During plant operation, quarterly Group A pump testing for the CS pumps shall be conducted at mini-flow conditions using the minimum flow recirculation line fixed resistance of approximately 190 gpm to establish the specified reference point. ISTB-5100(b), Bypass Loops, subparagraph (1) allows the use of bypass test loops for Group A tests. The flow rate through the loop is established at the highest practical flow rate of approximately 190 gpm in accordance with ISTB-3300(e)(2).

Flow rate will not be measured or recorded. To monitor for degradation, pump differential pressure shall be determined and compared to its reference value and the associated Acceptable and Required Action Ranges as specified in Table ISTB-5121-1, Centrifugal Pump Test Acceptance Criteria. Vibration measurement will be conducted quarterly in accordance with ISTB-3540, Vibration.

The CS pumps will be comprehensively tested in accordance with ISTB-5123, Comprehensive Test Procedure, on a biennial (2-year) frequency as specified in Table ISTB-3400-1, Inservice Test Frequency, and meet the requirements of Mandatory Appendix V, Pump Periodic Verification Test Program, as specified in ISTB-1400(d).

The CS pumps are infrequently used pumps. Little degradation is expected during plant power operation when the pumps are idle, except for limited operations and testing. Testing the pumps at the comprehensive pump test flow rate on a 2-year frequency, while satisfying Mandatory Appendix V, provides additional information regarding the condition of the pumps.

Based on the determination that compliance with the ASME OM Code requirement results in a hardship without a compensating increase in the level of quality and safety, this proposed alternative is requested pursuant to 10 CFR 50.55a(z)(2).

3

Arizona Public Service Company (APS)

Palo Verde Nuclear Generating Station - Units 1, 2 and 3 PUMP RELIEF REQUEST PRR-05 Relief Request In Accordance with 10 CFR 50.55a(z)(2)

Containment Spray Pump Flow Rate Measurement Duration of Proposed Alternative:

The proposed alternative identified in this 10 CFR 50.55a request shall be utilized during the Fourth 10-year IST interval beginning January 15, 2018, and ending January 14, 2028.

Precedence:

The NRC previously authorized pump relief request PRR-05 for the third 10-year IST Program interval at PVNGS Units 1, 2 and 3 in the following safety evaluation:

• Letter from the NRC (T. G. Hiltz) to Arizona Public Service Company (R. K. Edington), Palo Verde Nuclear Generating Station, Units 1, 2, and 3 - Relief Request for the Third 10-Year Interval Pump and Valve Inservice Testing Program, dated April 24, 2008 (ADAMS Accession No. ML0801050003)

In addition, this proposed alternative complies with NRC Generic Letter 89-04, Guidance on Developing Acceptable Inservice Testing Programs, Position 9, dated April 3, 1989.

References:

1) 10 CFR 50.55a, Codes and standards

2) ASME OM Code 2012 Edition 4

Arizona Public Service Company (APS)

Palo Verde Nuclear Generating Station - Units 1, 2 and 3 PUMP RELIEF REQUEST PRR-06 Relief Request in Accordance with 10 CFR 50.55a(z)(1)

Charging Pump Vibration Instrumentation ASME Components Affected:

The affected Palo Verde Nuclear Generating Station (PVNGS) Charging (CH) pumps are identified in the table below:

Code Pump Pump ID Pump Description Class Group 1MCHAP01 Unit 1 Charging Pump A 2 A 1MCHBP01 Unit 1 Charging Pump B 2 A 1MCHEP01 Unit 1 Charging Pump E 2 A 2MCHAP01 Unit 2 Charging Pump A 2 A 2MCHBP01 Unit 2 Charging Pump B 2 A 2MCHEP01 Unit 2 Charging Pump E 2 A 3MCHAP01 Unit 3 Charging Pump A 2 A 3MCHBP01 Unit 3 Charging Pump B 2 A 3MCHEP01 Unit 3 Charging Pump E 2 A Component/System Function:

The positive displacement CH pumps perform a safety function to provide charging flow from the volume control tank, refueling water tank, or spent fuel pool to the reactor coolant system (RCS) for emergency boration and RCS pressure control (with auxiliary pressurizer spray).

These pumps also provide flow for RCS makeup, RCS boron and chemical control, and reactor coolant pump seal injection (non-safety functions).

Applicable Code Edition and Addenda

ASME OM Code 2012 Edition Applicable Code Requirements:

ISTB-3510(e), Frequency Response Range, states, The frequency response range of the vibration-measuring transducers and their readout system shall be from one-third minimum pump shaft rotational speed to at least 1,000 Hz.

Reason for Request

Pursuant to 10 CFR 50.55a, Codes and standards, paragraph (z)(1), an alternative is being requested from the requirement of the ASME OM Code for use of vibration-measuring transducers with frequency response from one-third minimum pump shaft rotational speeds to at least 1,000 hertz (Hz) during Group A and Comprehensive pump inservice testing (IST). The basis for this request is that use of instrumentation with a frequency response range lower limit of 3 Hz versus the Code-required one-third shaft speed (or 1.1 Hz) will provide an acceptable level of quality and safety.

1

Arizona Public Service Company (APS)

Palo Verde Nuclear Generating Station - Units 1, 2 and 3 PUMP RELIEF REQUEST PRR-06 Relief Request in Accordance with 10 CFR 50.55a(z)(1)

Charging Pump Vibration Instrumentation Reason for Request (continued):

The CH pumps are of a single-acting reciprocating (three-piston) positive displacement design, model number NP18-3.1 TFS, manufactured by Gaulin Corporation. The nominal shaft rotational speed of the CH pumps is 199 revolutions per minute (rpm), which is equivalent to approximately 3.3 Hz. Based on this frequency and ISTB-3510(e), the required frequency response range of instruments used for measuring pump vibration is to be 1.1 to 1,000 Hz.

PVNGS has determined there are no mechanical degradation scenarios where only a sub-synchronous vibration component would develop on the CH pumps. Potential sub-synchronous and synchronous vibrations evaluated are as follows:

a) Oil whirl, which presents itself at frequencies below the rotational frequency of the pump (0.38X - 0.48X, where X equals the rotational frequency of the pump), is not applicable to the PVNGS horizontal, triplex, reciprocating charging pumps. These pumps have high reciprocating loads within their journal bearings, which prevents the oil whirl phenomena.

b) A light rub/impact could generate a vibrational component at a frequency below the pumps rotational frequency (e.g., 0.5X (99.5 rpm)), but would normally generate a harmonic vibrational component that would present either as an integer or half-integer multiple of the running speed of the pump. (e.g., a light rub vibration occurring at 0.5X, where X equals the rotational frequency of the pump, could also produce a vibrational component that could be measured at integer multiples of the original frequency (i.e., 1X, 1.5X, 2X, etc.), and would, thus, be identified in the calibrated range of the equipment.)

c) A heavy rub generates increased integer values of multiple running speed components, as well as processing the 1X phase measurement. In either case, the overall vibration level would still show an increase from both the attenuated sub-synchronous and 1X vibration components.

d) Looseness in the power train would likely be identified through the measurement of a vibrational component(s) found at frequencies that are multiples of the pumps rotational frequency. (i.e., 1X and 2X, where X equals the rotational frequency of the pump).

PVNGS has many years of CH pump operating experience (OE) that supports the preceding analysis that there is no mechanical degradation scenario where only a sub-synchronous vibration component would reveal pump degradation.

PVNGS has determined that relative to the charging pumps, the significant modes of vibration, with respect to equipment monitoring, are as follows:

2

Arizona Public Service Company (APS)

Palo Verde Nuclear Generating Station - Units 1, 2 and 3 PUMP RELIEF REQUEST PRR-06 Relief Request in Accordance with 10 CFR 50.55a(z)(1)

Charging Pump Vibration Instrumentation Reason for Request (continued):

1-Times Crankshaft Speed (1X) - An increase in vibration at this frequency may be an indication of rubbing between a single crankshaft cheek and rod end, cavitation at a single valve, or coupling misalignment.

2-Times Crankshaft Speed (2X) - An increase in vibration at this frequency may be an indication of looseness at a single rod bearing or crosshead pin, a loose valve seat in the fluid cylinder, a loose plunger crosshead stub connection, or coupling misalignment.

Other Multiples of Shaft Speed - An increase in vibration at other frequencies may be an indication of cavitation at several valves, looseness at multiple locations, or bearing degradation.

There are no probable sub-synchronous failure modes associated with these pumps under normal operating conditions. Furthermore, there are no known failure mechanisms that would be revealed by monitoring vibration at frequencies below those related to shaft speed (3.3 Hz.).

Based on the foregoing discussion, it is clear that monitoring pump vibration within the frequency range of 3 to 1000 Hz will provide adequate information for evaluating pump condition and ensuring continued reliability with respect to the pumps' function.

Proposed Alternative and Basis for Use:

Vibration levels of the CH pumps will be measured in accordance with the applicable portions of ISTB-3500 with the exception of the lower frequency response limit for the instrumentation (ISTB-3510(e)). In this case, the lower response limit for the vibration measuring equipment will be 3 Hz.

In addition to measurement of the Code-required normal CH pump IST peak vibration, PVNGS will routinely perform post spectral/waveform analysis of the vibration data to ensure no adverse trends toward mechanical degradation go undetected.

Based on the determination that the proposed alternative provides an acceptable level of quality and safety, this proposed alternative is requested pursuant to 10 CFR 50.55a(z)(1).

Duration of Proposed Alternative:

The proposed alternative identified in this 10 CFR 50.55a request shall be utilized during the Fourth 10-year IST Interval beginning January 15, 2018, and ending January 14, 2028.

3

Arizona Public Service Company (APS)

Palo Verde Nuclear Generating Station - Units 1, 2 and 3 PUMP RELIEF REQUEST PRR-06 Relief Request in Accordance with 10 CFR 50.55a(z)(1)

Charging Pump Vibration Instrumentation Precedence:

1. Duane Arnold Energy Center Relief Request PR-01: Letter from the NRC (David J. Wrona) to Duane Arnold Energy Center (Richard L. Anderson), Duane Arnold Energy Center -

Relief Request No. PR-01, PR-02, VR-01, VR-02, and VR-03 Related to the Inservice Testing Program for the Fifth 10-Year Interval, dated January 21, 2016 (ADAMS Accession No. ML16008A086)

2. Monticello Nuclear Generating Plant PR-05: Letter from the NRC (Istvan Frankl) to Northern States Power Company - Minnesota (Mark A. Schimmel), Monticello Nuclear Generating Plant - Relief from the Requirements of the American Society of Mechanical Engineers Code for Operation and Maintenance of Nuclear Power Plants for the Fifth 10-Year Inservice Testing Program Interval, dated September 26, 2012 (ADAMS Accession No. ML12244A272)

References:

1) 10 CFR 50.55a, Codes and standards

2) ASME OM Code 2012 Edition 4