ML24165A123

Proposed Alternative Relief Request P-1, P-2 Inservice Testing of Residual Heat and Containment Spray Pumps (EPID l-2023-LLR-0058)

ML24165A123
Person / Time
Site:	Surry
Issue date:	07/17/2024
From:	Markley M Plant Licensing Branch II
To:	Carr E Virginia Electric & Power Co (VEPCO)
Klos, J
References
EPID l-2023-LLR-0058
Download: ML24165A123 (1)

Text

July 17, 2024

Eric S. Carr President - Nuclear Operations and Chief Nuclear Officer Innsbrook Technical Center 5000 Dominion Boulevard Glen Allen, VA 23060-6711

SUBJECT:

SURRY POWER STATION, UNITS 1 AND 2 - PROPOSED ALTERNATIVE RELIEF REQUESTS P-1 AND P-2 FOR INSERVICE TESTING OF RESIDUAL HEAT AND CONTAINMENT SPRAY PUMPS (EPID l-2023-LLR-0058)

Dear Eric Carr:

By letter dated October 12, 2023 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML23285A092) with supplements dated March 26, 2024 (ML24088A248), and July 8, 2024 (ML24190A419), (Virginia Electric and Power Company (Dominion Energy Virginia, licensee) submitted R elief Requests P-1 and P-2 to the U.S. Nuclear Regulatory Commission (NRC) requesting autho rization of proposed alternatives to certain inservice testing (IST) Code requirements in the 2020 Edition of the American Society of Mechanical Engineers (ASME) Operation and Maintenance of Nuclear Power Plants, Division 1, OM Code: Section IST (OM Code) as incorporated by reference in Part 50 of Title 10 of the Code of Federal Regulations (10 CFR) for Sixth IST Program Interval at Surry Power Station (SPS), Units 1 and 2.

Specifically, pursuant to 10 CFR 50.55a(f)(5)(iii), the licensee submitted Relief Requests P-1 and P-2 on the basis that conformance with certain IST Code requirements is impractical for SPS, Units 1 and 2. The licensee proposed alternatives to the IST requirements for certain residual heat removal (RHR) and containment spray (CS) pumps at SPS, Units 1 and 2.

Accordingly, the NRC staff concludes that confor mance with certain OM Code requirements is impractical, and the licensee has adequately addressed the regulatory requirements set forth in 10 CFR 50.55a(f)(5)(iii). Therefore, the NRC staff authorizes Relief Requests P-1 and P-2 for the Sixth Interval IST Program at SPS, Units 1 and 2, which will begin on May 10, 2025, and ends May 9, 2034.

All other ASME OM Code requirements for which r elief or an alternative was not specifically requested and granted or authorized (as applicable) in the subject requests remain applicable.

E. Carr

If you have any questions, please contact me at (301) 415-5136, or via email at John.Klos@nrc.gov.

Sincerely,

Michael Markley, Chief Plant Licensing Branch II-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation

Docket Nos. 50-280 and 50-281

Enclosure:

Safety Evaluation

cc: Listserv SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION

RELIEF REQUESTS P-1 AND P-2

FOR THE SIXTH INTERVAL INSERVICE TESTING PROGRAM

VIRGINIA ELECTRIC AND POWER COMPANY

SURRY POWER STATION, UNITS 1 AND 2

DOCKET NOS. 50-280 AND 281

EPID L-2023-LLR-0058

1.0 INTRODUCTION

By letter dated October 12, 2023 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML23285A092) with supplements dated March 26, 2024 (ML24088A248), and July 8, 2024 (ML24190A419) Virginia Electric and Power Company (Dominion Energy Virginia, licensee) submitted R elief Requests P-1 and P-2 to the U.S. Nuclear Regulatory Commission (NRC, Commission) req uesting authorization of proposed alternatives to certain inservice testing (IST) Code requirements in the 2020 Edition of the American Society of Mechanical Engineers (ASME) Operation and Maintenance of Nuclear Power Plants, Division 1, OM Code: Section IST (OM Code) as incorporated by reference in Part 50 of Title 10 of the Code of Federal Regulations (10 CFR) for the Sixth IST Program Interval at Surry Power Station (SPS), Units 1 and 2.

Specifically, pursuant to 10 CFR 50.55a(f)(5)(iii), the licensee submitted Relief Requests P-1 and P-2 on the basis that conformance with certain IST Code requirements is impractical for SPS, Units 1 and 2. The licensee proposed alternatives to the IST requirements for certain residual heat removal (RHR) and containment spray (CS) pumps at SPS, Units 1 and 2.

2.0 REGULATORY EVALUATION

The NRC regulations in 10 CFR 50.55a(f)(4), Inservice testing standards requirement for operating plants, state, in part, that throughout the service life of a boiling or pressurized water-cooled nuclear power facility, pumps and valves that are within the scope of the ASME OM Code must meet the IST requirements (except design and access provisions) set forth in the ASME OM Code and addenda that become effective subsequent to editions and addenda specified in 10 CFR 50.55a(f)(2) and that are incorporated by reference in 10 CFR 50.55a(a)(1)(iv) of this section, to the extent practical within the limitations of design, geometry, and materials of construction of the components.

Enclosure

The NRC regulations in 10 CFR 50.55a(f)(5), Requirements for updating IST programs, state in part:

(iii) IST program update: Notification of impractical IST Code requirements. If the licensee has determined that conformance with certain Code requirements is impractical for its facility, the licensee must notify the Commission and submit, as specified in § 50.4, information to support the determination.

(iv) IST program update: Schedule for completing impracticality determinations.

Where a pump or valve test requirement by the Code or addenda is determined to be impractical by the licensee and is not included in the revised inservice test program (as permitted by paragraph (f)(4) of this section), the basis for this determination must be submitted for NRC review and approval not later than 12 months after the expiration of the initial 120-month interval of operation from the start of facility commercial operation and each subsequent 120-month interval of operation during which the test is determined to be impractical.

The NRC regulations in 10 CFR 50.55a(f)(6), Actions by the Commission for evaluating impractical and augmented IST Code requirements, state in part:

(i) Impractical IST requirements: Granting of relief. The Commission will evaluate determinations under paragraph (f)(5) of this section that code requirements are impractical. The Commission may grant relief and may impose such alternative requirements as it determines are authorized by law, will not endanger life or property or the common defense and security, and are otherwise in the public interest, giving due consideration to the burden upon the licensee that could result if the requirements were imposed on the facility.

3.0 TECHNICAL EVALUATION

The information provided by the licensee in support of Relief Requests P-1 and P-2 has been evaluated and the bases for disposition are documented below.

3.1 Licensees Relief Request P-1

Applicable ASME OM Code Edition

The IST Code of Record for the Sixth Interval IST Program at SPS, Units 1 and 2, is the 2020 Edition of the ASME OM Code as incorporated by reference in 10 CFR 50.55a. The Sixth Interval IST Program at SPS, Units 1 and 2, will begin on May 10, 2025, and end May 9, 2034.

ASME OM Code Components Affected

The following plant equipment within the scope of this request are:

Component ID Component Description ASME Pump Class Group 1-RH-P-1A Unit 1 Residual Heat Removal Pump 1A 2 A

1-RH-P-1B Unit 1 Residual Heat Removal Pump 1B 2 A

2-RH-P-1A Unit 2 Residual Heat Removal Pump 1A 2 A

2-RH-P-1B Unit 2 Residual Heat Removal Pump 1B 2 A

Applicable ASME OM Code Requirements

ASME OM Code, Subsection ISTB, Inservice Testing of Pumps in Water-Cooled Reactor Nuclear Power Plants - Pre-2000 Plants, paragraph ISTB-3400, Frequency of lnservice Tests, states in part:

An inservice test shall be run on each pump as specified in Table ISTB-3400-1.

ASME OM Code, Subsection ISTB, Table ISTB-3400-1, lnservice Test Frequency, requires an inservice test be run on each Group A pump nominally every 3 months.

Licensees Proposed Alternative

In its letter dated October 12, 2023, the licensee states, in part, that:

The RHR pumps will be tested every cold shutdown and reactor refueling outage unless the pumps have been tested within the previous three months. For a cold shutdown or reactor refueling outage that extends longer than three months, the pumps will be tested every three months in accordance with Table ISTB 3400-1.

Licensees Reason for Request

In its letter dated October 12, 2023, the licensee stated, in part, that:

The RHR pumps are located inside the containment. The pumps are low-pressure pumps (600 psig [pounds per square inch gauge] design pressure) that take suction from and discharge to the RCS [reactor coolant system]. The RCS is maintained at 2235 psig, and the containment atmosphere is maintained at sub-atmospheric pressure during normal operation. The RHR motor-operated suction and discharge isolation valves are interlocked with an output signal from RCS pressure transmitters which prevent the valves from being opened. The motor-operated valves [MOVs] are closed whenever the RCS pressure and temperature exceed approximately 450 psig and 350

°F [Fahrenheit], respectively. Therefore, testing the RHR pumps during normal operation is impractical.

Licensees Basis for Use

In its letter dated October 12, 2023, the licensee stated, in part that:

Using the provisions of this relief request as an alternative to the specific requirements of Table ISTB-3400-1 identified above, which have been determined to be impractical, will provide adequate indication of pump perfo rmance. The RHR pumps will be tested using comprehensive test parameters biennially. These pumps are not subject to pump periodic verification testing requirements since there are no specific design basis accident flow rates credited in the safety analyses for these pumps. Therefore, the quarterly Group A test will not be performed.

Therefore, pursuant to 10 CFR 50.55a(f)(5)(iii), Relief Request P-1 identifies these quarterly test requirements as impractical an d requests relief from the specific ISTB Code requirements identified in this relief request.

NRC Staff Evaluation

The ASME OM Code, Subsection ISTB, Table ISTB-3400-1, requires that a Group A test be performed quarterly on each Group A pump. Based on review of the Table ISTB-3400-1 requirements, the NRC staff has determined that conformance with the quarterly testing requirements in the ASME OM Code for the RHR pumps 1-RH-P-1A, 1-RH-P-1B, 2-RH-P-1A, and 2-RH-P-1B within the scope of this request is impractical due to (1) the operational challenge of performing tests of pumps inside containment at-power, (2) the standby condition of the RHR pumps, and (3) the isolation of the RHR system during normal power operation.

Further, major plant and system modifications would be needed to implement the quarterly testing required by the ASME OM Code for thes e RHR pumps. Such plant modifications would be costly and burdensome and, therefore, are impractical.

As an alternative to the requirements in the ASME OM Code, Subsection ISTB, Table ISTB-3400-1, the licensee proposed to test RHR pumps 1-RH-P-1A, 1-RH-P-1B, 2-RH-P-1A, and 2-RH-P-1B every cold shutdown outage and reactor refueling outage, unless the pump has been tested within the previous 3 months. During back-to-back cold shutdown or refueling outages, the test period remains valid for 3 months following each test, and no additional periodic testing needs to be performed within this 3-month test period. For a cold shutdown or reactor refueling outage that extends longer than 3 months, the pumps will be tested every 3 months in accordance with the ASME OM Code, Subsection ISTB, Table ISTB-3400-1.

Based on the above, the NRC staff finds that the licensee's proposed alternative for testing the RHR pumps within the scope of relief request P-1 will provide reasonable assurance that the affected pumps are performing adequately and that conformance to certain ASME OM Code requirements is impractical as provided in 10 CFR 50.55a(f)(5)(iii).

3.2 Licensees Relief Request P-2

Applicable ASME OM Code Edition

The IST Code of Record for the Sixth Interval IST Program at SPS, Units 1 and 2, is the 2020 Edition of the ASME OM Code as incorporated by reference in 10 CFR 50.55a. The Sixth Interval IST Program at SPS, Units 1 and 2, will begin on May 10, 2025, and end May 9, 2034.

ASME OM Code Components Affected

Component ID Component Description ASME Pump Class Group

1-CS-P-1A Unit 1 Containment Spray (CS) Pump 2 B

1-CS-P-1B Unit 1 CS Pump 2 B

2-CS-P-1A Unit 2 CS Pump 2 B

2-CS-P-1B Unit 2 CS Pump 2 B

Applicable ASME OM Code Requirements

ASME OM Code, Subsection ISTB, Inservice Testing of Pumps in Water-Cooled Reactor Nuclear Power Plants - Pre-2000 Plants, states, in part, that:

Paragraph ISTB-2000, Supplemental Definitions, defines pump periodic verification test as a test that verifies a pump can meet the required (differential or discharge, as applicable) pressure at its highest design-basis accident flow rate.

Paragraph ISTB-3400, Frequency of lnservice Tests, states:

An inservice test shall be run on each pump as specified in Table ISTB-3400-1.

For those pumps identified in ISTB-1400(d), a pump periodic verification test shall be performed biennially in accordance with this Subsection. The Owner is not required to perform a pump periodic verification test if the design-basis accident flow rate in the Owner's safety analysis is less than or equal to the comprehensive pump test flow rate or Group A test flow rate.

Paragraph ISTB-5110, Baseline Testing, in subparagraph (a) states:

In systems where resistance can be varied, flow rate and differential pressure shall be measured at a minimum of five points. If practicable, these points shall be from pump minimum flow to at least the comprehensive pump test flow rate, or, if a pump periodic verification test is required per ISTB-3400, the pump design-basis accident flow rate in the credited Owners safety analysis, whichever is higher. A pump curve sha ll be established based on the measured points. At least one point shall be designated as the reference point(s). Data taken at the reference point will be used to compare the results of inservice tests.

A pump curve need not be established for pumps in systems where resistance cannot be varied.

Paragraph ISTB-5124, Periodic Verification Test, states:

Tests shall be performed for pumps identified via ISTB-1400(d). If the required flow and differential pressure cannot be achieved, then the pump is in the action range, and corrective actions shall be ta ken in accordance with ISTB-6200(b).

Paragraph ISTB-6200, Corrective Action, subparagraph (b), Action Range, states:

If the pump periodic verification test flow or pressure parameter is not met or a measured test parameter value falls within the required action range of Table ISTB-5121-1, Table ISTB-5221-1, Table ISTB-5321-1, or Table ISTB-5321-2, as applicable, the pump shall be declared inoperable until either the cause of the deviation has been determined and the condition is corrected, or an analysis of the pump is performed in accordance with (c).

Licensees Proposed Alternative

In its letter dated October 12, 2023, the licensee stated that:

A comprehensive pump test (CPT) reference flow rate has been established for each of the four pumps at approximately 60 percent of the pump design-basis accident flow rate. This CPT will follow the guidance in ISTB-5123, Comprehensive Test Procedure, and will be performed on a quarterly basis.

The CS pumps will be subject to additional testing, trending, and diagnostic analysis per the Surry Predictive Maintenance Program.

Licensees Reason for Request

In its letter dated October 12, 2023, the licensee stated, in part, that:

The test loops for the CS pumps in shown in Figure P-2.1. The CS pumps take suction from the Refueling Water Storage Tank (RWST) and discharge back to the RWST.

With this test loop, it is not possible to achieve the design-basis accident flow rate required for the pump periodic verification (PPV) test. The PPV flow rate has been identified as 2605 gpm [gallons per minute]. Therefore, relief from the Code requirement is requested for Surry Units 1 and 2.

In relief request P-2, the licensee described its CS pump design-basis accident flow rate basis, CS pump preoperational testing, the SPS Predictive Maintenance Program, and detection of CS pump degradation. The licensee provides the minimum design-basis accident pump curve for pump 2-CS-P-1B, including a typical test point for each CS pump, and the corresponding minimum design-basis accident test point.

Licensees Basis for Use

In its letter dated October 12, 2023, the licensee stated, in part, that:

Using the provisions of this relief request as an alternative to the specific requirements of ISTB identified for Pump Periodic Verification (identified above) will provide adequate indication of pump performance and continue to provide an acceptable level of quality and safety. Therefore, pursuant to 10 CFR 50.55a(f)(5)(iii), Surry Power Station requests relief from the specific ISTB Code requirements identified in this relief request.

In its letter dated March 26, 2024, the licensee stated, in part, that:

The oil sampling for the Units 1 a nd 2 Containment Spray pumps 1/2-CS -P-1A and 1/2-CS-P-1 B is performed on a quarterly basis as part of the quarterly pump test. The oil analysis is performed as soon as practical following retrieval of the sample.

The NRC staff finds that the use of lube oil sampling and analysis can aid in the condition assessment of rotating equipment.

NRC Staff Evaluation

The CS pumps 1-CS-P-1A, 1-CS-P-1B, 2-CS-P-1A, and 2-CS-P-1B fall within the scope of the ASME OM Code and are defined as Class 2, Group B pumps. In addition to quarterly Group B testing and biennial CPT testing for those CS pumps, the ASME OM Code, Subsection ISTB, requires in paragraph ISTB-3400 that a PPV test shall be performed biennially in accordance with Subsection ISTB. In relief request P-2, the licensee states that it is not possible to achieve the design-basis accident flow rate required for th e PPV test with the current test loop at SPS, Units 1 and 2. Therefore, pursuant to 10 CFR 50.55a(f)(5)(iii), the licensee requests relief from the specific ASME OM Code, Subsection ISTB, PPV test requirements for the CS pumps 1-CS-P-1A, 1-CS-P-1B, 2-CS-P-1A, and 2-CS-P-1B on the basis of impracticality. As an alternative, the licensee proposes that the CPT testing will follow the guidance of ASME OM Code, Subsection ISTB, paragraph ISTB-5123, on a quarterly basis. The licensee states that the CS pumps will be subject to additional testing, trending, and diagnostic analysis per the Surry Predictive Maintenance Program.

In in the Surry Predictive Maintenance Program section its letter dated October 12, 2023, the licensee states, in part, that, For the CS pumps, this program employs predictive monitoring techniques, such as vibration monitoring and analysis beyond that required by ISTB, and oil sampling and analysis. In its letter dated March 26, 2024, the licensee stated in part that:

The additional vibration testing is performed on the clutch and the motor of the Units 1 and 2 Containment Spray pumps (Mark Nos. 1/2 -CS-P-1A and 1/2 -CS -P -1 B). The acceptable range, alert range, and required action range are chosen based on the same criteria that are used for the 1ST points on the component (i.e., in accordance with the Group A test requirements in OM Code Section ISTB, Table ISTB -5121 -1). The data are reviewed and trended and, if an unusual condition is noted, a Condition Report is generated in the station Corrective Action System to track the necessary corrective actions.

The NRC staff finds that the vibration monitoring de scribed by the licensee is sufficient to detect minor imbalances and aids in condition assessment and pump degradation.

The NRC staff has determined that the combination of testing of the CS pumps on portions of the pump curve that have a well-defined slope and the enhanced use of predictive maintenance techniques support the licensees proposal in re lief request P-2. The NRC staff finds that performing the PPV tests for CS pumps 1-CS-P-1A, 1-CS-P-1B, 2-CS-P-1A, and 2-CS-P-1B in conformance with certain ASME OM Code requirements at the design-basis accident flow rate is impractical as provided in 10 CFR 50.55a(f)(5)(iii). Further, the NRC staff finds that the licensee's proposed alternative for CPT testing the CS pumps at 60% of the design-basis accident flow rate along with additional testing, trending, and diagnostic analysis per the Surry Predictive Maintenance Program provides reasonable assurance that the affected pumps are performing adequately. Based on the above, the NRC concludes that conformance with certain ASME OM Code requirements is impractical, and the proposed alternative is acceptable.

4.0 CONCLUSION

As set forth above, the NRC staff has determined that granting relief pursuant to 10 CFR 50.55a(f)(6)(i) is authorized by law and will not endanger life or property or the common defense and security and is otherwise in the public interest giving due consideration to the burden upon the licensee that could result if the requirements were imposed on the facility. Further, the proposed alternatives described in Relief Requests P-1 and P-2 provide reasonable assurance that applicable pumps at SPS, Units 1 and 2, are performing adequately, in consideration that conformance to certain ASME OM Code requirements is impractical.

Accordingly, the NRC staff concludes that t he licensee has adequately addressed all of the regulatory requirements set forth in 10 CFR 50.55a(f)(5)(iii) to justify that the specific ASME OM Code requirements for the applicable RHR pumps in relief request P-1, and the CS pumps in relief request P-2, are impractical at SPS, Units 1 and 2. Therefore, the NRC staff grants Relief Requests P-1 and P-2 for the Sixth Interval IST Program at SPS, Units 1 and 2, which will begin on May 10, 2025, and end May 9, 2034.

All other ASME OM Code requirements for which relief or an alternative was not specifically requested and granted or authorized (as applicable) in the subject requests remain applicable.

Principal Contributors: Nicholas Hansing, NRR Thomas Scarbrough, NRR

Dated: July 17, 2024

ML24165A123 OFFICE NRR/DORL/LPL2-1/PM NRR/DORL/LPL2-1/LA NRR/DEX/EMIB/BC NAME JKlos KGoldstein (KEntz for) SBailey DATE 6/11/2024 6/18/2024 6/11/2024 OFFICE NRR/DORL/LPL2-1/BC NRR/DORL/LPL2-1/PM NAME MMarkley JKlos DATE 7/17/2024 7/17/2024