ML16182A270

Relief Request PRR-WF3-2016-1, Alternative to the Inservice Testing Program

ML16182A270
Person / Time
Site:	Waterford
Issue date:	07/06/2016
From:	Shaun Anderson Plant Licensing Branch IV
To:	Entergy Operations
Pulvirenti A, NRR/DORL 415-1390
References
CAC MF7485, PRR-WF3-2016-1
Download: ML16182A270 (8)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 July 6, 2016 Site Vice President Entergy Operations, Inc.

Waterford Steam Electric Station, Unit 3 17265 River Road Killona, LA 70057-3093

SUBJECT:

WATERFORD STEAM ELECTRIC STATION, UNIT 3 - RELIEF REQUEST PRR-WF3-2016-1, ALTERNATIVE TO THE INSERVICE TESTING PROGRAM (CAC NO. MF7485)

Dear Sir:

By letter dated March 17, 2016 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML16077A376), as supplemented by letter dated May 26, 2016, (ADAMS Accession No. ML16154A115), Entergy Operations, Inc. (the licensee), submitted Relief Request PRR-WF3-2016-1, which proposed an alternative to the requirements of the American Society of Mechanical Engineers (ASME) Code for Operation and Maintenance of Nuclear Power Plants (OM Code), Section ISTB-6200, associated with pump inservice testing at Waterford Steam Electric Station, Unit 3 (Waterford 3).

Specifically, pursuant to Title 10 of the Code of Federal Regulations (10 CFR),

Section 50.55a(z)(2), the licensee requested authorization for the alternative in Relief Request PRR-WF3-2016-1 on the basis that the ASME OM Code requirements present an undue hardship without a compensating increase in the level of quality and safety.

The NRC staff has reviewed the subject request and has determined, as set forth in the enclosed safety evaluation, that compliance with the ASME OM Code corrective action requirement of ISTB-6200(a) would result in hardship or unusual difficulty without increase in the level of quality and safety, and that the alternative proposed in Relief Request PRR-WF3-2016-1 provides reasonable assurance that the High-Pressure Safety Injection Pump AB (Sl-MPMP-0002AB) is operationally ready.

Accordingly, the U.S. Nuclear Regulatory Commission (NRC) staff concludes that the licensee has adequately addressed all of the regulatory requirements set forth in 10 CFR 50.55a(z)(2) for this proposed alternative. Therefore, the NRC staff authorizes the use of the alternative in Relief Request PRR-WF3-2016-1 for Waterford 3 until the end of Operating Cycle 21, which began in December 2015 and is scheduled to last for approximately 18 months.

All other ASME OM Code requirements for which relief was not specifically requested and approved in the subject request remain applicable.

If you have any questions, please contact the Project Manager, April Pulvirenti at 301-415-1390 or via e-mail at April.Pulvirenti@nrc.gov.

Sincerely,

/~

Shaun M. Anderson, Acting Chief Plant Licensing 4-2 and Decommissioning Transition Branch Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-382

Enclosure:

Safety Evaluation cc w/encl: Distribution via Listserv

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, O.C. 20555-0001 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELIEF REQUEST PRR-WF3-2016-1 ALTERNATIVE TO THE INSERVICE TESTING PROGRAM ENTERGY OPERATIONS. INC.

WATERFORD STEAM ELECTRIC STATION. UNIT 3 DOCKET NO. 50-382

1.0 INTRODUCTION

By letter dated March 17, 2016 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML16077A376), as supplemented by letter dated May 26, 2016 (ADAMS Accession No. ML16154A115), Entergy Operations, Inc. (the licensee), submitted an alternative to the requirements of the American Society of Mechanical Engineers (ASME) Code for Operation and Maintenance of Nuclear Power Plants (OM Code), associated with pump inservice testing (IST) at Waterford Steam Electric Station, Unit 3 (Waterford 3).

Specifically, pursuant to Title 10 of the Code of Federal Regulations (10 CFR),

Section 50.55a(z)(2), the licensee requested authorization for the alternative in Relief Request PRR-WF3-2016-1 on the basis that the ASME OM Code requirements present an undue hardship without a compensating increase in the level of quality and safety.

2.0 REGULATORY EVALUATION

The regulation in 10 CFR 50.55a, "Codes and standards," paragraph (f), "lnservice testing requirements," states, in part, that IST of certain ASME Code Class 1, 2, and 3 pumps and valves be performed in accordance with the specified ASME OM Code and applicable addenda incorporated by reference in the regulations.

Section 50.55a(z) of 10 CFR states, in part, that alternatives to the requirements of 10 CFR 50.55a(f) may be used, when authorized by the U.S. Nuclear Regulatory Commission (NRC), if the licensee demonstrates (1) the proposed alternatives would provide an acceptable level of quality and safety or (2) compliance with the specified requirements would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety.

Based on the above, and subject to the following technical evaluation, the NRC staff finds that regulatory authority exists for the licensee to request and the Commission to authorize the alternatives requested by the licensee.

Enclosure

=

Applicable Code Edition and Addenda===

The applicable ASME OM Code edition and addenda for the Waterford 3 third 10-year IST program interval is the 2001 Edition through the 2003 Addenda.

Applicable Code Requirements

• ISTB-3300, "Reference Values," (e)(1 ), states, "Reference values shall be established within +/-20% of pump design flow rate for the comprehensive test."

• ISTB-3300(e)(2), states, "Reference values shall be established within +/-20% of pump design flow for the Group A and Group B tests, if practicable. If not practicable, the reference point flow rate shall be established at the highest practicable flow rate."

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

• Table ISTB-3400-1, "lnservice Test Frequency," requires Group A and Group B tests to be performed quarterly, and Comprehensive tests to be performed biennially.

• Table ISTB-3500-1, "Required Instrument Accuracy," specifies the instrument accuracies for Group A, Group B, Comprehensive, and Preservice tests.

• Table ISTB-5100-1, "Centrifugal Pump Test Acceptance Criteria," defines the required acceptance criteria for Group A, Group B, and Comprehensive tests for centrifugal pumps.

• ISTB-6200, "Corrective Action," (a), "Alert Range," states, "If the measured test parameter values fall within the alert range of Table ISTB-5100-1, Table ISTB-5200-1, Table ISTB-5300-1, or Table ISTB-5300-2, as applicable, the frequency of testing specified in ISTB-3400 shall be doubled until the cause of the deviation is determined and the condition is corrected."

Reason for Request

During refueling outages, a comprehensive pump test (CPT) is performed on High-Pressure Safety Injection (HPSI) Pump AB. The pump flow rate is approximately 405 gallons per minute (gpm), and inboard and outboard pump bearing vibration and pump differential pressure (DP) data are verified to be within the acceptable range criteria in Table ISTB-5100-1.

On November 3, 2015, a CPT was performed on HPSI Pump AB, and two of the vibration readings were in the alert range. The licensee also performed a vibration frequency spectrum analysis. Based on the current pump vendor's (Flowserve) recommendation, the licensee realigned the pump and motor and inspected the pump foundations for voids. On November 23, 2015, a post-maintenance CPT was performed and elevated vibration levels were detected.

The same two vibration readings were in the alert range. Per ISTB-6200(a), "Alert Range," the

frequency of the CPT shall be doubled until the cause of the high vibration readings is determined and the condition is corrected.

The licensee performed a cause evaluation and determined that the pump is in the beginning stages of end of life. In order to avoid further pump wear, the licensee is utilizing the following recommendations to the extent practical: (1) avoid using the pump for non-accident, non-surveillance scenarios/tasks that can be accomplished with other pumps, (2) use HPSI Pump A (which has an upgraded rotating assembly), as the preferred pump, (3) minimize the pump stop/start cycles as much as possible, and (4) minimize the pump operation above 120 percent of the best efficiency point.

In its letter dated March 17, 2016, the licensee stated that the following information demonstrates that the HPSI AB Pump is capable of performing its safety function:

• Bearing vibrations do not improve or worsen with higher flow rates and longer periods of operation [approximately 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> on November 23, 2015);

• Pump discharge flow has consistently achieved TS [Technical Specification] 4.5.2(h) flow requirements during each refueling outage;

• Pump differential pressure has achieved TS 4.5.2(f)(1) DP requirements during each quarterly surveillance during Operating Cycle 20 prior to RF [Refueling Outage) 20;

• The pump has [remained] within IST Comprehensive [pump] test differential pressure acceptance criteria with no degrading trend in pump hydraulic performance.

The licensee provided data from CPTs performed since RF16 on October 28, 2009. Using the DP value from the CPT performed on October 28, 2009, as the reference value, the data shows that the DP has consistently been in the acceptable range for the five CPTs performed since the test during RF16, and there has been no evidence of a degrading trend on pump hydraulic performance.

Proposed Alternative The Waterford 3 third 10-year IST program interval began on December 1, 2007 and is scheduled to end on November 30, 2017.

The licensee requested to use an alternative to the applicable ASME OM Code requirements for HPSI Pump AB (Sl-MPMP-0002AB). The licensee requested to not double the CPT test frequency as per ISTB-6200(a), because in order to perform an additional CPT, a mid-cycle shutdown is required and the reactor pressure vessel head must be removed.

In lieu of the additional CPT, the licensee proposes to perform Group A tests during Operating Cycle 21 using the pre-October 2013 HPSI Pump AB quarterly test flow rate and flow path. The pre-October 2013 HPSI Pump AB quarterly test flow rate was approximately 250 gpm, and the flow path was the hot leg injection line back to the refueling water storage pool (RWSP). The 250 gpm flow rate is approximately 62 percent of the HPSI Pump AB comprehensive pump test flow rate, which is the highest practicable flow rate for online testing. The 250 gpm flow rate is

located on a sloped portion of the pump curve where pump degradation can be detected. The test data will be compared to the Group A vibration and DP acceptance criteria that were established when the pump was known to be operating acceptably prior to the third IST interval, and analyzed to ensure there are no indications of unacceptable pump performance.

ISTB-6200 shall remain applicable to the Group A quarterly tests. The vibration, flow, and pressure instrumentation used during the Group A tests shall meet the instrumentation accuracy requirements stated in Table ISTB-3500-1.

The licensee states that this proposed alternative is a one-time request until pump refurbishment is performed during RF21. Therefore, the duration of the proposed alternative is for Operating Cycle 21, which began in December 2015 and will continue until RF21. RF21 is scheduled to begin in April 2017.

3.2 NRC Staff Evaluation The licensee requests an alternative to the ASME OM Code corrective action requirement of ISTB-6200(a) for the HPSI Pump AB, which is classified as a Group B pump. ISTB-6200(a) requires that if a measured test parameter falls within the alert range, the frequency of testing shall be doubled until the cause of the deviation is determined and the condition is corrected.

Vibration measurements at two locations were in the alert range when a CPT was performed on HPSI Pump AB on November 3, 2015. The pump and motor were realigned, and a CPT was performed again on November 23, 2015, and the vibration measurements at the same two locations were still in the alert range. Doubling the frequency of the CPT would require a mid-cycle shutdown and removal of the reactor pressure vessel head, which is a hardship. In lieu of doubling the frequency of the CPT, the licensee proposes to perform Group A quarterly tests on the pump instead of Group B quarterly tests until RF 21, which is when the pump will be repaired. The differences between Group A and Group B tests are that the Group A test is performed at a higher flow rate (approximately 250 gpm versus approximately 30 gpm), and vibration measurements are required for a Group A test and not for a Group B test. The flow path will be the hot leg injection line to the RWSP, which will allow for the higher flow rate of 250 gpm. The 250 gpm flow rate is located on a sloped portion of the pump curve, which will allow the monitoring of pump degradation.

The licensee determined that HPSI Pump AB is in the beginning stages of end of life, and is limiting operation of the pump, to the extent practical, in order to avoid further wear on the pump. The licensee avoids using the pump for non-accident, non-surveillance scenarios/tasks that can be accomplished with other pumps, uses HPSI Pump A as the preferred pump, minimizes the pump stop/start cycles as much as possible, and minimizes the operation of the pump above 120 percent of the best efficiency point.

The licensee provided CPT and TS surveillance data back to 2009 that indicates that HPSI Pump AB has not shown any degradation in flow or differential pressure since that time. Also, bearing vibrations do not improve or worsen with higher flow rates and longer periods of pump operation (approximately 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />.)

Based on the above, the NRC staff finds that the proposed alternative provides reasonable assurance that HPSI Pump AB will remain operationally ready until RF 21.

4.0 CONCLUSION

As set forth above, the NRC staff determines that compliance with the ASME OM Code corrective action requirement of ISTB-6200(a) would result in hardship or unusual difficulty without increase in the level of quality and safety, and that the alternative proposed in Relief Request PRR-WF3-2016-1 provides reasonable assurance that the HPSI Pump AB (Sl-MPMP-0002AB) is operationally ready.

Accordingly, the NRC staff concludes that the licensee has adequately addressed all of the regulatory requirements set forth in 10 CFR 50.55a(z)(2) for this proposed alternative.

Therefore, the NRC staff authorizes the use of the alternative in Relief Request PRR-WF3-2016-1 at Waterford 3 until the end of Operating Cycle 21, which began in December 2015. The Operating Cycle 21 duration is approximately 18 months.

All other ASME OM Code requirements for which relief was not specifically requested and approved in the subject request remain applicable.

Principal Contributor: R.Wolfgang Date: July 6, 2016

If you have any questions, please contact the Project Manager, April Pulvirenti at 301-415-1390 or via e-mail at April.Pulvirenti@nrc.gov.

Sincerely, IRA/

Shaun M. Anderson, Acting Chief Plant Licensing 4-2 and Decommissioning Transition Branch Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-382

Enclosure:

Safety Evaluation cc w/encl: Distribution via Listserv DISTRIBUTION:

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DATE 7/1/16 7/1/16 06/12/2016 OFFICE DORL/LPL4-2/BC(A)

NAME SAnderson DATE 7/6/16 OFFICIAL RECORD COPY