ML18117A264

Relief Requests for the Fifth 10-Year Interval Inservice Testing Program for Pumps and Valves

ML18117A264
Person / Time
Site:	Calvert Cliffs
Issue date:	05/10/2018
From:	James Danna Plant Licensing Branch 1
To:	Bryan Hanson Exelon Generation Co, Exelon Nuclear
Marshall M, NRR/DORL/LPLI, 415-2871
References
EPID L-2017-LLR-0076, EPID L-2017-LLR-0077, EPID L-2017-LLR-0078
Download: ML18117A264 (19)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 Mr. Bryan C. Hanson Senior Vice President Exelon Generation Company, LLC President and Chief Nuclear Officer Exelon Nuclear 4300 Winfield Road Warrenville, IL 60555 May 10, 2018

SUBJECT:

CALVERT CLIFFS NUCLEAR POWER PLANT, UNIT NOS. 1 AND 2 - RELIEF REQUESTS FOR THE FIFTH 10-YEAR INTERVAL INSERVICE TESTING PROGRAM FOR PUMPS AND VALVES (EPID L-2017-LLR-0076, EPID L-2017-LLR-0077, AND EPID L-2017-LLR-0078)

Dear Mr. Hanson:

By letter dated August 2, 2017 (Agencywide Documents and Access Management System (ADAMS) Accession No. ML17215A007), as supplemented by letter dated February 16, 2018 (ADAMS Accession No. ML18047A124), Exelon Generation Company, LLC (the licensee),

submitted alternatives 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 and valve inservice testing at Calvert Cliffs Nuclear Power Plant (CCNPP), Units 1 and 2.

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

Section 50.55a(z)(1 ), the licensee requested to use proposed alternatives SI-RR-01, Revision O; GV-RR-01, Revision O; and RC-RR-01, Revision 0, on the basis that the alternatives provide an acceptable level of quality and safety.

As set forth in the enclosed safety evaluation, the NRC staff has concluded that the proposed alternative requests SI-RR-01, Revision O; GV-RR-01, Revision O; and RC-RR-01, Revision 0, for CCNPP, Units 1 and 2, provide an acceptable level of quality and safety. Accordingly, the NRC staff concludes that the licensee has adequately addressed all of the regulatory requirements set forth in 10 CFR 50.55a(z)(1) for alternative requests SI-RR-01, Revision O; GV-RR-01, Revision O; RC-RR-01, Revision 0. The NRC staff authorizes the use of alternative requests GV-RR-01, Revision 0, and RC-RR-01, Revision 0, for CCNPP, Units 1 and 2, for the fifth 10-year inservice testing program interval, which begins July 1, 2018, and is scheduled to end on June 30, 2028.

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

If you have any questions, please contact the project manager, Michael Marshall, at 301-415-2871 or Michael.Marshall@nrc.gov.

Docket Nos. 50-317 and 50-318

Enclosure:

Safety Evaluation cc: Listserv Sincerely,

(:CMNJU~

Jals G. Danna, Chief Plant Licensing Branch I Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION ALTERNATIVE REQUESTS SI-RR-01. REVISION O:

GV-RR-01. REVISION O: AND RC-RR-01. REVISION 0 FIFTH 10-YEAR INTERVAL INSERVICE TESTING PROGRAM EXELON GENERATION COMPANY. LLC CALVERT CLIFFS NUCLEAR POWER PLANT. UNITS 1 AND 2 DOCKET NOS. 50-317 AND 50-318

1.0 INTRODUCTION

By letter dated August 2, 2017 (Agencywide Documents and Access Management System (ADAMS) Accession No. ML17215A007), as supplemented by letter dated February 16, 2018 (ADAMS Accession No. ML18047A124), Exelon Generation Company, LLC (the licensee),

submitted alternatives 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 and valve inservice testing (1ST) at Calvert Cliffs Nuclear Power Plant (CCNPP),

Units 1 and 2.

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

Section 50.55a(z)(1 ), the licensee requested to use proposed alternatives SI-RR-01, Revision O; GV-RR-01, Revision O; and RC-RR-01, Revision 0, on the basis that the alternatives provide an acceptable level of quality and safety.

2.0 REGULATORY EVALUATION

Section 50.55a(f) of 10 CFR states, in part, that 1ST 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 that alternatives to the requirements of paragraph (f) of 10 CFR 50.55a may be used, when authorized by the 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.

Enclosure 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.

3.0 TECHNICAL EVALUATION

3.1 Alternative Request GV-RR-01, Revision 0 3.1.1 Applicable Code Requirements The applicable ASME OM Code edition and addenda for the fifth 10-year 1ST interval at CCNPP, Units 1 and 2, is the 2012 Edition with no addenda. The fifth ten-year interval for CCNPP, Units 1 and 2, begins on July 1, 2018, and is scheduled to end on June 30, 2028.

Mandatory Appendix I, "lnservice Testing of Pressure Relief Devices in Light-Water Reactor Nuclear Power Plants," 1-8120, "Compressible Fluid Services Other Than Steam," (h), "Time Between Valve Openings," states, "A minimum of 5 min shall elapse between successive openings."

Mandatory Appendix I, 1-8130, "Liquid Service," (g), "Time Between Valve Openings," states, "A minimum of 5 min shall elapse between successive openings."

3.1.2 Code Components Affected The licensee requested an alternative to the above ASME OM Code 5-minute wait period requirements when using water or nitrogen as the test medium for the Class 1, 2 and 3 safety and relief valves listed below:

O-CC-6501-RV O-CC-6503-RV O-CC-6512-RV O-CC-6530-RV O-CC-6533-RV 1-CC-3823-RV 1-CC-3825-RV 1-CC-3827-RV 1-CC-3829-RV 1-CC-3831-RV 1-CC-3843-RV 1-CC-6450A-RV 1-CC-64 71-RV 1-CC-64 72-RV 1-CVC-125-RV 1-CVC-132-RV 1-CVC-133-RV 1-CVC-141-RV 1-CVC-149-RV 1-CVC-150-RV 1-CVC-157-RV 1-CVC-160-RV 1-CVC-171-RV 1-CVC-311-RV 1-CVC-315-RV 1-CVC-318-RV 1-CVC-321-RV 1-CVC-324-RV 1-CVC-325-RV 1-CVC-326-RV 1-RV-10243 1-RV-10246 1-RV-10273 1-RV-10276 1-Sl-211-RV 1-Sl-221-RV 1-Sl-231-RV 1-Sl-241-RV 1-S 1-409-RV 1-Sl-417-RV 1-Sl-430-RV 1-Sl-431-RV 1-Sl-439-RV 1-Sl-446-RV 1-Sl-468-RV 1-Sl-469-RV 1-Sl-6302-RV 1-SRW-1575-RV 1-SRW-1576-RV 1-SRW-1577-RV 1-SRW-1578-RV 1-SRW-1582-RV 1-SRW-1585-RV 1-SRW-1588-RV 1-SRW-1590-RV 1-SRW-1593-RV 1-SRW-1596-RV 1-SRW-4084-RV 1-SW-5205-RV 1-SW-5206-RV 1-SW-5207-RV 1-SW-5208-RV 1-SW-5209-RV 1-SW-5210-RV 1-SW-5211-RV 1-SW-5212-RV 2-CC-3823-RV 2-CC-3825-RV 2-CC-3827-RV 2-CC-3829-RV 2-CC-3831-RV 2-CC-6450A-RV 2-CC-6471-RV 2-CC-6472-RV 2-CVC-125-RV 2-CVC-132-RV 2-CVC-133-RV 2-CVC-141-RV 2-CVC-149-RV 2-CVC-150-RV 2-CVC-157-RV 2-CVC-160-RV 2-CVC-171-RV 2-CVC-311-RV 2-CVC-315-RV 2-CVC-318-RV 2-CVC-321-RV 2-CVC-324-RV 2-CVC-325-RV 2-CVC-326-RV 2-Sl-211-RV 2-Sl-221-RV 2-Sl-231-RV 2-Sl-241-RV 2-Sl-409-RV 2-Sl-417-RV 2-Sl-430-RV 2-Sl-431-RV 2-Sl-439-RV 2-Sl-446-RV 2-Sl-468-RV 2-Sl-469-RV 2-Sl-6302-RV 2-SRW-1575-RV 2-SRW-1576-RV 2-SRW-1577-RV 2-SRW-1578-RV 2-SRW-1582-RV 2-SRW-1585-RV 2-SRW-1587-RV 2-SRW-1588-RV 2-SRW-1590-RV 2-SRW-1593-RV 2-SRW-1598-RV 2-SRW-4084-RV 2-SW-5205-RV 2-SW-5206-RV 2-SW-5207-RV 2-SW-5208-RV 2-SW-5209-RV 2-SW-5210-RV 2-SW-5211-RV 2-SW-5212-RV 3.1.3

Reason for Request

In the Attachment to the letter dated August 2, 2017, the licensee states, in part:

This is a generic request for all Class 1, 2, and 3 safety and relief valves listed

[above]. For these valves, the requirement for verifying temperature stability, by waiting 5 minutes between successive openings, and adds no value. In accordance with l-8120(a), and l-8130(a), the test medium used for the relief valve testing will be the same as the normal system operating fluid. For liquid service this will be water. For compressible fluid services other than steam this will be nitrogen. In either case, the test stand and surrounding environment ambient temperature conditions are relatively fixed with negligible changes occurring over the set pressure and seat tightness test determinations. There is negligible effect on valve setpoint due to minor temperature deviations that might occur at these conditions.

Numerous Class 1, 2, and 3 safety/relief valves associated with contaminated systems are bench-tested in the "hot shop," located within the Radiologically Controlled Area in the Auxiliary Building, to prevent the spread of contamination.

These tests are performed under ambient conditions using a test medium at ambient conditions. Therefore, there is no source of thermal imbalance that might affect the test results.

Entry into the hot shop testing facility requires full Anti-Contamination clothing.

During the test, personnel are exposed to background radiation levels present in the Auxiliary Building hot shop as well as the radiation levels associated with the specific valve being tested. The proposed elimination of the hold time between successive tests for Class 1, 2, and 3 safety/relief valves listed [above] that are tested under ambient conditions using a test medium at ambient conditions reduces the duration of each test. Most importantly, reducing the hold times reduces the length of time that the test personnel must spend in close proximity to the valve. As a result, personnel radiation exposure is reduced.

For all safety and relief valves, including those located in "clean areas" that are bench-tested in the Mechanical Maintenance Shop, the proposed elimination of the hold time between successive tests will reduce the duration of each test.

Since there are numerous safety/relief valve tests for both units and most require at least two people, the proposed elimination of the hold time between successive tests is expected to also result in a significant cumulative reduction in limited manpower resources.

Additionally, empirical data based on CCNPP plant experience supports the conclusion that the minimum hold time between successive tests has no value for safety/relief valves tested under ambient conditions using test medium at ambient conditions.

The net result of having to wait 5 minutes between successive openings is an increase in manpower and time to perform the tests, and an increase in radiation exposure when located in radiation areas, without a commensurate increase in test accuracy.

3.1.4 Proposed Alternative and Basis for Use In the Attachment to the letter letter dated August 2, 2017, the licensee states:

For the Class 1, 2, and 3 safety and relief valves [listed above],... tested under ambient conditions using test medium at ambient conditions, the 5-minute hold requirement between successive openings specified in paragraphs... 1-8120, and 1-8130, will be deleted.

Using the provisions of this request as an alternative to the specific requirements described above, will result in a reduction in personnel radiation exposure and a significant cumulative reduction in limited manpower resources and still provide acceptable relief valve test accuracy and continue to provide an acceptable level of quality and safety.

This proposed alternative is being requested pursuant to 10 CFR 50.55a(z)( 1 ).

3.1.5

NRC Staff Evaluation

The ASME OM Code, Appendix I, specifies lift setpoint test requirements for safety and relief valves. Appendix I, paragraphs l-8120(h), and 1-8130(9) require that a minimum of 5 minutes elapse between successive openings.

The NRC staff believes that the 5-minute wait time requirement is based on the assumption that the temperature of the test medium is different than the temperature of the valve. Lift setpoint testing with different valve and test medium temperatures would cause the temperature of the valve to change once the valve opens; therefore, the setpoint could be affected. The staff finds that the setpoint is unaffected when safety and relief valves are tested when the test medium and valve temperatures are the same. Thermal stabilization is achieved with no wait period between tests; consequently the setpoint is unaffected.

According to the licensee, the set pressure tests for the valves listed above are performed under ambient conditions using a water or nitrogen test medium, as appropriate, at ambient temperature conditions. As a result, there is no source of thermal imbalance that might affect the test results. Thus, the NRC staff finds that elimination of the 5 minute wait period between setpoint tests for these safety and relief valves provides an adequate method of accurately and repeatedly determining setpoints. Therefore, the NRC staff finds that the licensee's proposed alternative test methodology provides an acceptable alternative to the 5 minute wait period requirement in Appendix I, paragraphs l-8120(h) and 1-8130(9). As acknowledged by the licensee in their request, this alternative does not apply to valves that are required to be tested using saturated steam as the test media (e.g., Main Steam Safety Valves and Pressurizer Safety Valves (PSVs)). For these valves, the time and temperature requirements of 1-8110 still apply.

3.2 Alternative Request GV-RR-01, Revision 0 3.2.1 Applicable Code Requirements The applicable ASME OM Code edition and addenda for the fifth 10-year 1ST interval at CCNPP, Units 1 and 2, is the 2012 Edition with no addenda. The fifth ten-year interval for CCNPP, Units 1 and 2, begins on July 1, 2018, and is scheduled to end on June 30, 2028.

Mandatory Appendix I, "lnservice Testing of Pressure Relief Devices in Light-Water Reactor Nuclear Power Plants," 1-8110, "Steam Service," (d) "Thermal Equilibrium," states, in part, "Valves insulated in service shall be insulated in a like manner during testing."

3.2.2 Code Components Affected Mandatory Appendix I, "lnservice Testing of Pressure Relief Devices in Light-Water Reactor Nuclear Power Plants," 1-8110, "Steam Service," (d) "Thermal Equilibrium," states, in part, "Valves insulated in service shall be insulated in a like manner during testing."

Component 1-RC-200-RV 1-RC-201-RV 2-RC-200-RV 2-RC-201-RV 3.2.3

Reason for Request

Description Pressurizer Safety Valve Pressurizer Safety Valve Pressurizer Safety Valve Pressurizer Safety Valve Class 1

1 1

1 Category C

C C

C In the Attachment to the letter letter dated August 2, 2017, the licensee states, in part:

Changes in safety/relief valve body temperature can change the lift setpoint measured during inservice testing. Changes in ambient temperature or modifications to insulation also may change the lift setpoint by virtue of the resulting effect on the valve body temperature. The purpose of paragraph 1-811 O(d) is to ensure the effect of temperature variations is minimized. Requiring insulation to be installed during testing is clearly intended to also ensure the valve body's temperature, and therefore its performance, is similar to that under normal operating circumstances. CCNPP has determined the normal operating temperature profile for the pressurizer safety valves by instrumenting each valve body at several locations and recorded empirical data during normal operation.

CCNPP has previously commissioned testing using the valves' actual operating temperature profile at a national vendor's testing facility to determine the impact of having the insulation removed versus installed during testing of the pressurizer safety valves. This testing demonstrated that pressurizer safety valves, which have had their setpoints satisfactorily verified in-situ, will perform satisfactorily two years later in a laboratory setting if the valve body's actual operating temperature profile is recreated. The test was conducted using two valves adjusted to their respective setpoints (which differ by only 65 pounds per square inch (psi)).

The first series of tests was performed with each valve uninsulated. Prior to setpoint testing, each valve was thermally stabilized at the specified temperature profile to match normal operating conditions. The valves performed within their as-found setpoint tolerance.

The second series of tests was performed with each valve insulated (using the actual insulation from the plant normally installed on each valve). Prior to setpoint testing, each valve was thermally stabilized. However, due to the test configuration, the valve could not be thermally stabilized at the actual operating temperature profile. Instead, it could only be stabilized at a higher temperature.

The overall impact of the higher temperature profile is that the lift pressure for the valves is lower than when at the correct temperature profile. This is a non-conservative error because, if the valves were adjusted to lift at their operating setpoint under these conditions, they would then be set to lift by as much as approximately 2 percent high when returned to their normal plant installation.

The third series of tests was performed with each valve insulated and with the ambient temperature being varied. The variations in ambient temperature had little effect on the valve's lift pressure.

Because of differences in the test configuration and the normal plant configuration, the vendor was unable to stabilize the valves' temperature profile when insulated consistent with the one specified for normal plant operating conditions. Rather, the temperatures measured at all the points being monitored, most notably the upper and lower bonnet, were higher.

The higher temperature profile for the insulated valves in the testing configuration occurred because, when installed in the plant, these valves are attached to long runs of piping with numerous associated piping supports which serve as heat sinks for the valves, but in the testing facility these long runs of piping are no longer attached. In the plant, these heat sinks allow the valves to stabilize at a lower temperature profile even when insulated, as compared to the temperature profiles when insulated in the vendor test facility. Additionally, the presence of forced ventilation in the field increases the heat transfer out of each valve body through the insulation for the same ambient temperature when compared to the stagnant conditions present in the test configuration.

In other words, the heat input and heat output of the insulated valves in a stagnant environment cannot be balanced in the testing facility until the valves are hot enough to create the necessary heat transfer rate through the insulation needed to offset the heat input. Since the heat transfer out of the valve to the attached piping is lost, more heat output through the insulation is required. This effect is additionally aggravated by the lack of forced ventilation. As a result, the valves stabilize at a higher temperature and the lift pressure measured was lower (by as much as approximately 2 percent) with the valves insulated and at these higher temperatures.

3.2.4 Proposed Alternative and Basis for Use In the Attachment to the letter letter dated August 2, 2017, the licensee states, in part:

OM-2012 Code, Mandatory Appendix I, paragraph l-8110(e) requires the ambient temperature of the operating environment to be simulated during the set pressure test. Additionally, if the effect of ambient temperature on set pressure can be established for a particular valve type, then Appendix I allows set pressure tests to be performed using an ambient temperature different from the operating ambient temperature as long as applicable correlations between the operating and testing ambient temperatures are used.

The intent of using the normally installed insulation per paragraph 1-8110(d) and testing using the operating ambient temperature (or test ambient temperature with the appropriate correlation) is to ensure the valve performance during the test is indicative of its expected performance under service conditions. However, CCNPP has shown through comparative laboratory and in-situ tests that controlling the actual temperature profile of the valve body is a more realistic and more effective way of simulating inservice conditions and testing these valves.

Additionally, it is much less likely to produce misleading test results that could lead to inappropriate setpoint adjustments. Therefore, CCNPP considers the requirements of paragraph 1-8110(e) to be satisfied by such testing; and based on the test results obtained at the vendor"s laboratory, no correlation factor is applicable.

When testing is performed in a vendor testing facility, vice in-situ testing, the valve body's temperature profile necessary to simulate normal operating conditions for these valves will be specified. The valve shall be stabilized at the required temperature profile per the remaining portion of paragraph l-8110(d) prior to setpoint testing without requiring the valve to be insulated in a like manner to its inservice configuration.

Based on the determination that the actual temperature profile of the valve body is a more realistic and more effective way of simulating inservice conditions and testing these valves; this alternate testing will maintain acceptable relief valve test accuracy...

3.2.5

NRC Staff Evaluation

The ASME OM, Appendix I, paragraph l-8110(d), requires that valves that are insulated inservice be insulated in a like manner during lift setpoint tests. The licensee proposes to lift setpoint test the PSVs with the insulation removed when testing the valves at a test facility.

The NRC staff finds that changes in PSV body temperature can change the lift setpoint of a PSV. Changes in temperature affect critical clearances and dimensions within the PSV and any change to a critical clearance or dimension would affect the lift setpoint. The purpose of Paragraph l-8110(d) of the ASME OM Code is to ensure that the temperature profile of the PSV during normal plant operation is maintained at the test facility. Test summary results provided by the licensee demonstrate that it is appropriate to not insulate PSVs at the test facility because the configuration at the test facility with the insulation removed creates a temperature profile that is consistent with the valves' temperature during normal plant operation.

Therefore, the proposed alternative to the insulation requirement in Paragraph l-8110(d) of the ASME OM Code during lift setpoint testing of the PSVs provides an acceptable level of quality and safety.

3.3 Alternative Request GV-RR-01, Revision 0 3.3.1 Applicable Code Requirements The CCNPP Units 1 and 2 fifth 10-year 1ST program interval begins on July 1, 2018 and is scheduled to end on June 30, 2028. The applicable ASME OM Code edition for the CCNPP, Units 1 and 2, fifth 10-year 1ST program interval is the 2012 Edition.

ISTB-1400, "Owner's Responsibility," (b) states, in part, "A pump that meets both Group A and Group B pump definitions shall be categorized as a Group A pump."

3.3.2 Code Components Affected The licensee has requested to use the proposed alternative described below for the pumps listed in Table 1.

Pump ID Pump Description ASME Code Class ASME OM Pump Group 11 LPSI Low Pressure Safety 2

A/B Injection (LPSI) Pump 12 LPSI LPS1Pump12 2

A/B 21 LPSI LPSI Pump 21 2

A/B 22 LPSI LPSI Pump 22 2

A/B 3.3.3

Reason for Request

In the Attachment to the letter letter dated August 2, 2017, the licensee states, in part:

LPSI Pump Group Classification ASME OM-2012 Code, Subsection ISTB, lnservice Testing of Pumps in Light--Water Reactor Nuclear Power Plants - Pre-2000 Plants, paragraph ISTB-2000, Supplemental Definitions, defines Group A pumps as "pumps that are operated continuously or routinely during normal operation, cold shutdown, or refueling operations," and Group B pumps as, "pumps in standby systems that are not operated routinely except for testing." The LPSI pumps clearly meet the definition of Group B pumps during normal operation in Modes 1-4. However, in Modes 5-6, the LPSI pumps are used for shutdown cooling and meet the definition of Group A pumps.

Subsection ISTB, paragraph ISTB-1400(b) states, in part, that "A pump that meets both Group A and Group B pump definitions shall be categorized as a Group A pump." This means that the LPSI pumps would be classified as Group A and would be subjected to the same quarterly test requirements as continuously operated pumps.

The LPSI pumps are tested quarterly using the minimum recirculation flow path from each pump through the minimum recirculation flow common header and back to the refueling water tank. The common header is instrumented with an ultrasonic flow meter. However, flow is not throttled during the quarterly test to eliminate the potential for pump overheating and damage should flow inadvertently be throttled below that required to ensure adequate pump cooling.

The LPSI pumps are also tested at a substantial flow rate (approximately 3000 gallons per minute (gpm)) during every refueling outage, as well as during planned and unplanned cold shutdown periods when plant conditions and circumstances permit. These tests are the [ASME] OM Code Comprehensive Pump Tests (CPTs) (formerly known at CCNPP as "Large Flow Rate" tests). The CPT flow rate meets the OM-2012 Code, Mandatory Appendix V, Pump Periodic Verification Test (PPVT) Program, requirements.

NUREG/CP-0137, Volume 1, Proceedings of the Third NRC/ASME Symposium on Valve and Pump Testing, includes a paper entitled, "Description of Comprehensive Pump Test Change to ASME OM Code, Subsection ISTB." This paper describes the philosophy of classifying pumps in one group or the other (Group A vs. Group B). According to this paper, the intent of having different test requirements for the different pump groups is to relate the amount and degree of quarterly performance monitoring required to the amount of degradation expected due to pump operation.

Requiring the LPSI pumps to be tested quarterly as Group A pumps during normal operation in Modes 1-4 is contrary to the philosophy of the referenced paper. Quarterly testing subjects the LPSI pumps to increased test requirements, performance monitoring, and potentially more degradation due to low-flow operation at the time when they are standby pumps and would not otherwise be subject to operation-induced degradation. In fact, out of all of the Emergency Core Cooling System (ECCS) and Auxiliary Feedwater pumps, the LPSI pumps are the ones, due to their design and test conditions, for which the detrimental effects of cumulative low-flow operation are the most drastic.

CCNPP considers the requirement to test the LPSI pumps as Group A pumps during normal operation in Modes 1-4 to be potentially detrimental on a long-term basis. Therefore, CCNPP proposes that the LPSI pumps be treated as Group B pumps during normal operation in Modes 1-4 and tested accordingly.

Additionally, in Generic Letter (GL) 89-04, Position 9, the NRC determined that, in cases where the pump flow can only be established through a non-instrumented, minimum-flow path during quarterly pump testing, and a path exists at cold shutdown or refueling outages to perform a test of the pump under full or substantial flow conditions, the increased interval is an acceptable alternative to the [ASME OM] Code requirements. Therefore, the proposed alternative testing of LPSI pumps as Group B pumps during Modes 1-4 and as Group A pumps during Modes 5-6 is consistent with GL 89-04, Position 9.

The impact of obtaining certain test parameters required b OM-2012 Code, Table ISTB-3000-1, "lnservice Test Parameters," ensuring the pumps are running for a minimum of 2 minutes at stable conditions (ISTB-5100(a)(1)) during quarterly Group A testing, and other considerations are discussed below.

Differential Pressure Measurements CCNPP's current quarterly Group A pump test program requires differential pressure to be measured. Group A quarterly ECCS pump tests must be performed using very accurate (+/- Y2 percent ) test pressure gauges. These pressure gauges would be installed prior to, and removed after, each test (an annual total of 32 gauge installation/removal evolutions). The OM-2012 Code does not require these very accurate gauges; however, they are necessary because the hydraulic margin available, based on design calculations, is less than the amount of degradation allowed by Subsection ISTB. Using less accurate permanently installed pressure gauges could result in a pump being unnecessarily declared inoperable solely due to pressure gauge uncertainty.

Installation and removal of these test pressure gauges for each LPSI pump every quarter would require significant dedication of manpower, results in significant cumulative annual radiation dose, increased radioactive waste, increased wear on fittings, and additional challenges for possible personnel contamination.

CCNPP estimates that eliminating the test pressure gauge installation and removal evolutions will save at least 1/8 man-rem per year and almost 100 man-hours per year.

Quarterly LPSI pump tests are performed using the minimum recirculation flow path under low-flow conditions. In this region, the pumps are operating at or near shut-off head, the pump curves are flat or nearly flat, and pump differential pressure is not very sensitive to pump degradation. Flow rate alone is an adequate indication of possible pump degradation or flow blockage since the minimum recirculation flow path is a fixed-resistance flow path. The conclusion that measurement of pump differential pressure is of minimal value is supported by historical test data.

For testing the LPSI pumps as Group B pumps, the operational readiness is reasonably assured without requiring quarterly differential pressure measurements. This will allow CCNPP to cease these gauge installation and removal evolutions every quarter, while maintaining an acceptable level of quality and safety.

Vibration Measurements CCNPP's current quarterly Group A pump test program requires pump vibration measurements. The overall vibration readings recorded during quarterly low-flow testing have always been relatively "high." These vibration readings have been subject to spectral analysis under the Rotating Machinery Condition Monitoring Program, which is separate from the 1ST Program. The spectral analyses have consistently confirmed the major contributor to the "high" overall vibration readings occurs at the blade pass frequency for each LPSI pump and is not indicative of bearing degradation. However, the [ASME] OM Code does not require spectral analysis. Therefore, the effects of low-flow operation on a centrifugal pump make the required broadband vibration readings during the current quarterly test of minimal value. This conclusion is supported by the CCNPP historical test data. Under the OM-2012 Code, the operational readiness of Group B pumps is reasonably assured without requiring quarterly vibration measurements.

Based on this, CCNPP believes that an acceptable level of quality and safety is still maintained while many of the burdens and costs associated with vibration testing, including cumulative annual radiation dose and man-power, will be eliminated.

LPSI Pump Bearing Acceptance Criteria During Low-Flow Testing For the fourth 1ST interval, the surveillance procedures used to perform the CPTs required vibration measurements to be recorded in terms of velocity. CCNPP long ago recognized the benefit of velocity over displacement for analyzing pump vibrations and has included such measurements in the CCNPP Predictive Maintenance (PdM) group's Rotating Machinery Vibration Monitoring Program which conducts periodic vibration monitoring and analysis of numerous pumps and motors (including the LPSI pumps) beyond that required for the 1ST Program. The Rotating Machinery Vibration Monitoring Program includes spectral analysis of the vibration measurements.

The PdM group's long-term vibration data trend (1995 through present), during quarterly testing of the LPSI pumps using the minimum recirculation flow path shows consistent results and stable performance with no unexplainable significant changes. The quarterly tests are performed at approximately 55-65 gpm, which is between approximately 1.3 percent to 1.6 percent of the LPSI pumps' "Best Efficiency Flow Rate." The Best Efficiency Flow Rate is based on the original vendor pump curve. It is used instead of the system's design flow rate because the onset of pump internal recirculation and cavitation is a function of the pump's performance characteristics, not the system's design requirements.

Operating the LPSI pumps at low flow rates results in a variety of effects (e.g.,

internal recirculation, cavitation, and force imbalance on the impeller), which contribute to increased vibration. Spectral analysis of the LPSI pump vibration measurements reveals (1) a general increase in the broadband noise levels which is indicative of internal recirculation and cavitation, and (2) discrete spikes at frequencies corresponding to the blade pass frequency which is indicative of force imbalances acting on the impeller. The analysis confirms the presence and effect of these phenomena.

Many of the normal vibration levels experienced when operating the LPSI pumps under low-flow conditions during quarterly testing routinely exceed or challenge the absolute Alert Acceptance Criterion of 0.325 inches per second specified in Table ISTB-5121-1, Centrifugal Pump Test Acceptance Criteria. If the LPSI pumps are classified as Group A pumps, applying the [ASME] OM Code criteria will necessitate either [doubling the test frequency and] testing at six-week intervals, or [generating] a new evaluation each quarter.

The following factors lead to the conclusion that the current vibration levels recorded during LPSI minimum recirculation flow testing are acceptable and are not indicative of any pump mechanical problems or degradation, and, therefore, that the LPSI pumps are operating acceptably.

(1)

The long-term stability of the vibration trend based on data from the surveillance tests and CCNPP Rotating Machinery Vibration Monitoring Program obtained during quarterly minimum recirculation flow testing.

(2)

Spectral analysis confirmed the major contributor to the overall vibration levels recorded during quarterly minimum recirculation flow testing is consistent with phenomena which are well known to be associated with operation of a centrifugal pump at low flow rates and also well known to cause higher vibrations at these low flow rates.

(3)

The overall vibration levels recorded during large flow testing of the LPSI pumps are significantly reduced compared to the levels recorded during the quarterly minimum recirculation flow tests and are consistent with vibration levels experienced while testing centrifugal pumps at substantial flow rates in other systems and applications.

( 4)

Spectral analysis confirmed that the major contributors to the overall vibration levels observed during quarterly minimum recirculation flow testing which are associated with operation of a centrifugal pump at low flow rates are significantly reduced during large flow testing of the LPSI pumps.

(5)

Similar vibration patterns have been observed for the other standby ECCS pumps, although the effects are not as pronounced as they are for the LPSI pumps because the LPSI pumps are the pumps which are tested at the lowest flow condition relative to their Best Efficiency Flow Rate.

(6)

The LPSI pumps have no history of mechanical failures nor have they required significant maintenance on a regular basis.

The "Large Flow Rate" tests for the LPSI pumps have been in use at CCNPP since approximately 1991. At a minimum, each pump has been tested during each refueling outage since these tests were implemented. Vibration data (in both displacement and velocity) was collected during these tests via the surveillance tests themselves and the CCNPP Rotating Machinery Vibration Monitoring Program. The vibration data recorded during these large flow rate tests show the overall vibration levels drop significantly, as expected.

Furthermore, spectral analysis of these results show the general broadband noise and spikes at discrete frequencies caused by the blade passing are significantly reduced.

The overall vibration levels observed during quarterly LPSI pump minimum recirculation flow testing, augmented by spectral analysis, are not sufficiently high as to prevent detection of increases in the LPSI pump vibration levels, which would be indicative of mechanical degradation. Furthermore, the vibration monitoring during less frequent LPSI CPT, also augmented by spectral analysis, provides even greater opportunities to detect increases in the LPSI pump vibration levels, which would be indicative of mechanical degradation.

CCNPP's experience has shown that spectral analysis of the vibration measurements obtained during quarterly minimum recirculation flow testing is sufficiently sensitive to changes in the pumps' mechanical condition and provides reasonable assurance that mechanical degradation can be detected early.

Performing pump testing at double the normal quarterly frequency when vibration levels exceed the acceptance criteria specified in Table ISTB-5121-1 is physically possible (i.e., it is practicable). Such increased frequency testing will potentially reduce LPSI pump reliability and increase the probability of LPSI pump degradation, damage, or failure. Therefore, such testing is considered impractical because, though it is possible to perform such increased frequency testing, the potential reduction in LPSI pump reliability and potential increase in the probability of LPSI pump degradation, damage, or failure is a result, which is contrary to the intent of the 1ST Program.

The run time of these pumps during an operating cycle is very limited since operation at low flow rates is detrimental to the pumps. Performing increased frequency testing on a regular basis during the operating cycle would increase the run time of these pumps by as much as approximately 30 percent. 10 CFR 50.55a(z)(1) and (z)(2) address alternatives when the [ASME] OM Code requirement would result in a hardship/burden with no commensurate increase in the level of quality or safety [(z)(2)] or an alternative provides an equivalent level of quality and safety [(z)(1 )]. Not only would increased frequency testing of the LPSI pumps be an inefficient use of resources, but such unnecessary testing may actually result in a real potential to reduce the level of quality and safety and; therefore, should be avoided if possible.

Minimum Pump Run-Time If the LPSI pumps are classified as Group B pumps, the two-minute minimum pump run-time for quarterly tests is also eliminated. Eliminating the minimum pump run-time requirement and the requirement to record differential pressure and vibration levels is expected to slightly reduce the length of each pump test.

This will help to reduce the cumulative run-time of each LPSI pump under lowflow conditions to support testing, with a commensurate reduction in potential pump wear.

Other Considerations These proposed changes simplify the quarterly 1ST pump test to allow combining the quarterly 1ST pump test into the related quarterly engineering safety features actuation logic test for each pump. As a result, the total number of starting demands on each pump motor to support testing may be reduced and the cumulative run-time of each LPSI pump under low-flow conditions to support testing may be further reduced. CCNPP estimates that this course of action could eliminate approximately two hours of operation under low-flow conditions for each LPSI pump per year.

Relationship to CCNPP Technical Specification (TS) Surveillance Requirement (SR)

The CCNPP TS SR for each pump (SR 3.5.2.3) requires periodic testing of each LPSI pump to verify that the "developed head at the test flow point is greater than or equal to the required developed head." The specified frequency for the SR is, "in accordance with the lnservice Test Program." CCNPP's TS SR does not contain any additional (explicit or implied) testing requirements for these pumps beyond those required by the 1ST Program. This means that, as long as the testing complies with the requirements of the approved 1ST Program, there is no conflict with CCNPP's TS SR. Therefore, none of the changes to the 1ST Program requested in this proposed alternative would conflict with any CCNPP's TS SRs.

As previously stated, the LPSI pumps are typically run continuously during cold shutdown and refueling operations, depending on the decay heat rate. As a result, they may be subject to operation-induced degradation in Modes 5-6.

Therefore, the LPSI pumps will be treated as Group A pumps during any quarterly test that comes due during cold shutdown or refueling operations.

However, typically during Modes 5-6, a CPT is preferable to a Group A test tor the LPSI pumps. This avoids the need to realign the LPSI pumps out of the normal shutdown cooling line-up and also avoids the detrimental effects of testing the LPSI pumps at low-flow conditions. Therefore, CCNPP expects that a CPT will typically be substituted for any Group A test that may be required during Modes 5-6.

In response to a request for additional information, the licensee stated that the pump manufacturer's recommended minimum flow rate is 40 gpm, and that the quarterly test flow rate of 55-65 gpm is maintained by a flow orifice that is permanently installed in the minimum recirculation line. The licensee also stated that a stainless steel impeller design, vibration monitoring during testing, vibration trending, and augmented pump internal inspections are factors used to minimize the potential for pump degradation during quarterly testing.

3.3.4 Proposed Alternative and Basis for Use The licensee requested an alternative to the pump categorization requirement of the ASME OM Code. The licensee proposes that the LPSI pumps be tested as standby pumps (Group B) during Modes 1-4, power operation, and as continuously operating pumps (Group A) during Modes 5-6, refueling operations. During refueling operations, the CPT will be substituted for a quarterly Group A test that comes due.

3.3.5

NRC Staff Evaluation

The licensee has proposed that the LPSI pumps be tested as standby pumps (Group B) during Modes 1-4 and as continuously operating pumps (Group A) during Modes 5-6. In Modes 5-6, the CPT may be substituted for a quarterly Group A test that comes due during a mid-cycle cold shutdown period as provided by Subsection ISTB of the ASME OM Code. ISTB-5000 states that when a Group A test is required, a CPT may be substituted. The licensee states that a CPT will be performed instead of a Group A test during Modes 5-6.

ISTB-2000 defines Group A pumps as "pumps that are operated continuously or routinely during normal operation, cold shutdown, or refueling operations;" and Group B pumps as "pumps in standby systems that are not operated routinely except for testing." Based on these definitions, the LPSI pumps meet the definition of Group B pumps during normal operation in Modes 1-4. In Modes 5-6, the LPSI pumps are used for shutdown cooling and meet the definition of Group A pumps. 1STB-1400(b) states that "A pump that meets both Group A and Group B pump definitions shall be categorized as a Group A pump." This would normally cause the LPSI pumps to be classified as Group A. However, because of the inability to achieve a substantial flow rate in Modes 1-4, it is not possible to conduct a Group A test that would provide very much meaningful data to detect degradation due to the relatively flat profile of the pump hydraulic curve and the higher vibration levels present at these near shut-off head flow conditions.

Additionally, the LPSI pumps are standby pumps during Modes 1-4 and little degradation is expected with respect to hydraulic performance during the operational period when the pumps are idle.

In GL 89-04, Position 9, the NRC determined that, in cases where flow can only be established through a non-instrumented, minimum-flow path during quarterly pump testing, and a path exists at cold shutdown or refueling outages to perform a test of the pump under full or substantial flow conditions, the increased interval is an acceptable alternative to the ASME OM Code requirements. Therefore, the proposed alternative testing of the LPSI pumps as Group B during Modes 1-4 and as Group A during Modes 5-6 is consistent with GL 89-04, Position 9, and provides reasonable assurance of operational readiness of the LPSI pumps.

The licensee referenced a paper titled "Description of Comprehensive Pump Test Change to ASME OM Code, Subsection ISTB," that is included in NUREG/CP-0137, Volume 1. This NUREG is a compilation of papers presented at an NRC/ASME Symposium on Valve and Pump Testing. The NRC staff notes that statements and opinions advanced in the papers presented at the symposium are individual expressions of the authors and not those of either ASME or the NRC.

The licensee states that the overall vibration readings recorded during quarterly low-flow testing have always been relatively high when compared to the ASME OM Code acceptance criteria.

These vibration readings have been subject to spectral analysis under CCNPP's Rotating Machinery Condition Monitoring Program, which is separate from the 1ST Program. The spectral analyses have consistently confirmed the major contributor to the high overall vibration readings occurs at the blade pass frequency for each LPSI pump and is not indicative of bearing degradation. The long-term vibration trend (1995 through present) during quarterly testing of the LPSI pumps using the minimum recirculation flow path shows consistent results and stable performance with no unexplainable significant changes. The licensee will continue to perform spectral analysis under CCNPP's Rotating Machinery Condition Monitoring Program. The spectral analysis is above and beyond the ASME OM Code requirements. Therefore, the operational readiness of the LPSI pumps with the proposed Group B pump test (Modes 1-4) is reasonably assured without requiring quarterly vibration measurements, which are not required by the ASME OM Code for Group B pumps.

The CCNPP, TS SR 3.5.2.3, requires verification that the LPSI pump's developed head at the test flow point is greater than or equal to the required developed head in accordance with the frequency established by the 1ST program. As stated above, the LPSI pumps will be tested as Group B pumps during Modes 1-4, and Group A pumps during Modes 5-6 (every refueling outage, as well as during planned and unplanned cold shutdowns). A CPT may be substituted for a Group A test per the ASME OM Code. The quarterly Group B test will be performed using the minimum recirculation flow path under low-flow conditions and only flow will be measured.

The TS requirement to measure pump head will be performed at the frequency for Group A or CPT tests as required by the modified 1ST program.

The NRC staff notes that this same alternative request was authorized for use for CCNPP, Units 1 and 2, for the current (fourth) 10-year 1ST program interval.

4.0 CONCLUSION

As set forth above, the NRC staff determined that for alternative requests SI-RR-01, Revision-0; GV-RR-01, Revision O; and RC-RR-01, Revision 0, for CCNPP, Units 1 and 2, provide an acceptable level of quality and safety. Accordingly, the NRC staff concludes that the licensee has adequately addressed all of the regulatory requirements set forth in 10 CFR 50.55a(z)(1 },

for these alternative requests. Therefore, the NRC staff authorizes the use of alternative requests SI-RR-01, GV-RR-01 and RC-RR-01 for CCNPP, Units 1 and 2, for the fifth 10-year 1ST program interval, which begins July 1, 2018, and is scheduled to end on June 30, 2028.

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

Principal Contributors: R. Wolfgang, NRR J. Billerbeck, NRR Date: May 10, 2018

ML18117A264 iOFFICE DORL/LPL 1 /PM DORL/LPL 1 /LA NAME MMarshall I Betts DATE 05/02/18 05/01/18 IOFFICE DE/EMIB/BC*

DORL/LPL 1 /BC NAME SBailey JDanna DATE 03/08/17 05/10/18

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 Mr. Bryan C. Hanson Senior Vice President Exelon Generation Company, LLC President and Chief Nuclear Officer Exelon Nuclear 4300 Winfield Road Warrenville, IL 60555 May 10, 2018

SUBJECT:

CALVERT CLIFFS NUCLEAR POWER PLANT, UNIT NOS. 1 AND 2 - RELIEF REQUESTS FOR THE FIFTH 10-YEAR INTERVAL INSERVICE TESTING PROGRAM FOR PUMPS AND VALVES (EPID L-2017-LLR-0076, EPID L-2017-LLR-0077, AND EPID L-2017-LLR-0078)

Dear Mr. Hanson:

By letter dated August 2, 2017 (Agencywide Documents and Access Management System (ADAMS) Accession No. ML17215A007), as supplemented by letter dated February 16, 2018 (ADAMS Accession No. ML18047A124), Exelon Generation Company, LLC (the licensee),

submitted alternatives 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 and valve inservice testing at Calvert Cliffs Nuclear Power Plant (CCNPP), Units 1 and 2.

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

Section 50.55a(z)(1 ), the licensee requested to use proposed alternatives SI-RR-01, Revision O; GV-RR-01, Revision O; and RC-RR-01, Revision 0, on the basis that the alternatives provide an acceptable level of quality and safety.

As set forth in the enclosed safety evaluation, the NRC staff has concluded that the proposed alternative requests SI-RR-01, Revision O; GV-RR-01, Revision O; and RC-RR-01, Revision 0, for CCNPP, Units 1 and 2, provide an acceptable level of quality and safety. Accordingly, the NRC staff concludes that the licensee has adequately addressed all of the regulatory requirements set forth in 10 CFR 50.55a(z)(1) for alternative requests SI-RR-01, Revision O; GV-RR-01, Revision O; RC-RR-01, Revision 0. The NRC staff authorizes the use of alternative requests GV-RR-01, Revision 0, and RC-RR-01, Revision 0, for CCNPP, Units 1 and 2, for the fifth 10-year inservice testing program interval, which begins July 1, 2018, and is scheduled to end on June 30, 2028.

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

If you have any questions, please contact the project manager, Michael Marshall, at 301-415-2871 or Michael.Marshall@nrc.gov.

Docket Nos. 50-317 and 50-318

Enclosure:

Safety Evaluation cc: Listserv Sincerely,

(:CMNJU~

Jals G. Danna, Chief Plant Licensing Branch I Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION ALTERNATIVE REQUESTS SI-RR-01. REVISION O:

GV-RR-01. REVISION O: AND RC-RR-01. REVISION 0 FIFTH 10-YEAR INTERVAL INSERVICE TESTING PROGRAM EXELON GENERATION COMPANY. LLC CALVERT CLIFFS NUCLEAR POWER PLANT. UNITS 1 AND 2 DOCKET NOS. 50-317 AND 50-318

1.0 INTRODUCTION

By letter dated August 2, 2017 (Agencywide Documents and Access Management System (ADAMS) Accession No. ML17215A007), as supplemented by letter dated February 16, 2018 (ADAMS Accession No. ML18047A124), Exelon Generation Company, LLC (the licensee),

submitted alternatives 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 and valve inservice testing (1ST) at Calvert Cliffs Nuclear Power Plant (CCNPP),

Units 1 and 2.

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

Section 50.55a(z)(1 ), the licensee requested to use proposed alternatives SI-RR-01, Revision O; GV-RR-01, Revision O; and RC-RR-01, Revision 0, on the basis that the alternatives provide an acceptable level of quality and safety.

2.0 REGULATORY EVALUATION

Section 50.55a(f) of 10 CFR states, in part, that 1ST 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 that alternatives to the requirements of paragraph (f) of 10 CFR 50.55a may be used, when authorized by the 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.

Enclosure 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.

3.0 TECHNICAL EVALUATION

3.1 Alternative Request GV-RR-01, Revision 0 3.1.1 Applicable Code Requirements The applicable ASME OM Code edition and addenda for the fifth 10-year 1ST interval at CCNPP, Units 1 and 2, is the 2012 Edition with no addenda. The fifth ten-year interval for CCNPP, Units 1 and 2, begins on July 1, 2018, and is scheduled to end on June 30, 2028.

Mandatory Appendix I, "lnservice Testing of Pressure Relief Devices in Light-Water Reactor Nuclear Power Plants," 1-8120, "Compressible Fluid Services Other Than Steam," (h), "Time Between Valve Openings," states, "A minimum of 5 min shall elapse between successive openings."

Mandatory Appendix I, 1-8130, "Liquid Service," (g), "Time Between Valve Openings," states, "A minimum of 5 min shall elapse between successive openings."

3.1.2 Code Components Affected The licensee requested an alternative to the above ASME OM Code 5-minute wait period requirements when using water or nitrogen as the test medium for the Class 1, 2 and 3 safety and relief valves listed below:

O-CC-6501-RV O-CC-6503-RV O-CC-6512-RV O-CC-6530-RV O-CC-6533-RV 1-CC-3823-RV 1-CC-3825-RV 1-CC-3827-RV 1-CC-3829-RV 1-CC-3831-RV 1-CC-3843-RV 1-CC-6450A-RV 1-CC-64 71-RV 1-CC-64 72-RV 1-CVC-125-RV 1-CVC-132-RV 1-CVC-133-RV 1-CVC-141-RV 1-CVC-149-RV 1-CVC-150-RV 1-CVC-157-RV 1-CVC-160-RV 1-CVC-171-RV 1-CVC-311-RV 1-CVC-315-RV 1-CVC-318-RV 1-CVC-321-RV 1-CVC-324-RV 1-CVC-325-RV 1-CVC-326-RV 1-RV-10243 1-RV-10246 1-RV-10273 1-RV-10276 1-Sl-211-RV 1-Sl-221-RV 1-Sl-231-RV 1-Sl-241-RV 1-S 1-409-RV 1-Sl-417-RV 1-Sl-430-RV 1-Sl-431-RV 1-Sl-439-RV 1-Sl-446-RV 1-Sl-468-RV 1-Sl-469-RV 1-Sl-6302-RV 1-SRW-1575-RV 1-SRW-1576-RV 1-SRW-1577-RV 1-SRW-1578-RV 1-SRW-1582-RV 1-SRW-1585-RV 1-SRW-1588-RV 1-SRW-1590-RV 1-SRW-1593-RV 1-SRW-1596-RV 1-SRW-4084-RV 1-SW-5205-RV 1-SW-5206-RV 1-SW-5207-RV 1-SW-5208-RV 1-SW-5209-RV 1-SW-5210-RV 1-SW-5211-RV 1-SW-5212-RV 2-CC-3823-RV 2-CC-3825-RV 2-CC-3827-RV 2-CC-3829-RV 2-CC-3831-RV 2-CC-6450A-RV 2-CC-6471-RV 2-CC-6472-RV 2-CVC-125-RV 2-CVC-132-RV 2-CVC-133-RV 2-CVC-141-RV 2-CVC-149-RV 2-CVC-150-RV 2-CVC-157-RV 2-CVC-160-RV 2-CVC-171-RV 2-CVC-311-RV 2-CVC-315-RV 2-CVC-318-RV 2-CVC-321-RV 2-CVC-324-RV 2-CVC-325-RV 2-CVC-326-RV 2-Sl-211-RV 2-Sl-221-RV 2-Sl-231-RV 2-Sl-241-RV 2-Sl-409-RV 2-Sl-417-RV 2-Sl-430-RV 2-Sl-431-RV 2-Sl-439-RV 2-Sl-446-RV 2-Sl-468-RV 2-Sl-469-RV 2-Sl-6302-RV 2-SRW-1575-RV 2-SRW-1576-RV 2-SRW-1577-RV 2-SRW-1578-RV 2-SRW-1582-RV 2-SRW-1585-RV 2-SRW-1587-RV 2-SRW-1588-RV 2-SRW-1590-RV 2-SRW-1593-RV 2-SRW-1598-RV 2-SRW-4084-RV 2-SW-5205-RV 2-SW-5206-RV 2-SW-5207-RV 2-SW-5208-RV 2-SW-5209-RV 2-SW-5210-RV 2-SW-5211-RV 2-SW-5212-RV 3.1.3

Reason for Request

In the Attachment to the letter dated August 2, 2017, the licensee states, in part:

This is a generic request for all Class 1, 2, and 3 safety and relief valves listed

[above]. For these valves, the requirement for verifying temperature stability, by waiting 5 minutes between successive openings, and adds no value. In accordance with l-8120(a), and l-8130(a), the test medium used for the relief valve testing will be the same as the normal system operating fluid. For liquid service this will be water. For compressible fluid services other than steam this will be nitrogen. In either case, the test stand and surrounding environment ambient temperature conditions are relatively fixed with negligible changes occurring over the set pressure and seat tightness test determinations. There is negligible effect on valve setpoint due to minor temperature deviations that might occur at these conditions.

Numerous Class 1, 2, and 3 safety/relief valves associated with contaminated systems are bench-tested in the "hot shop," located within the Radiologically Controlled Area in the Auxiliary Building, to prevent the spread of contamination.

These tests are performed under ambient conditions using a test medium at ambient conditions. Therefore, there is no source of thermal imbalance that might affect the test results.

Entry into the hot shop testing facility requires full Anti-Contamination clothing.

During the test, personnel are exposed to background radiation levels present in the Auxiliary Building hot shop as well as the radiation levels associated with the specific valve being tested. The proposed elimination of the hold time between successive tests for Class 1, 2, and 3 safety/relief valves listed [above] that are tested under ambient conditions using a test medium at ambient conditions reduces the duration of each test. Most importantly, reducing the hold times reduces the length of time that the test personnel must spend in close proximity to the valve. As a result, personnel radiation exposure is reduced.

For all safety and relief valves, including those located in "clean areas" that are bench-tested in the Mechanical Maintenance Shop, the proposed elimination of the hold time between successive tests will reduce the duration of each test.

Since there are numerous safety/relief valve tests for both units and most require at least two people, the proposed elimination of the hold time between successive tests is expected to also result in a significant cumulative reduction in limited manpower resources.

Additionally, empirical data based on CCNPP plant experience supports the conclusion that the minimum hold time between successive tests has no value for safety/relief valves tested under ambient conditions using test medium at ambient conditions.

The net result of having to wait 5 minutes between successive openings is an increase in manpower and time to perform the tests, and an increase in radiation exposure when located in radiation areas, without a commensurate increase in test accuracy.

3.1.4 Proposed Alternative and Basis for Use In the Attachment to the letter letter dated August 2, 2017, the licensee states:

For the Class 1, 2, and 3 safety and relief valves [listed above],... tested under ambient conditions using test medium at ambient conditions, the 5-minute hold requirement between successive openings specified in paragraphs... 1-8120, and 1-8130, will be deleted.

Using the provisions of this request as an alternative to the specific requirements described above, will result in a reduction in personnel radiation exposure and a significant cumulative reduction in limited manpower resources and still provide acceptable relief valve test accuracy and continue to provide an acceptable level of quality and safety.

This proposed alternative is being requested pursuant to 10 CFR 50.55a(z)( 1 ).

3.1.5

NRC Staff Evaluation

The ASME OM Code, Appendix I, specifies lift setpoint test requirements for safety and relief valves. Appendix I, paragraphs l-8120(h), and 1-8130(9) require that a minimum of 5 minutes elapse between successive openings.

The NRC staff believes that the 5-minute wait time requirement is based on the assumption that the temperature of the test medium is different than the temperature of the valve. Lift setpoint testing with different valve and test medium temperatures would cause the temperature of the valve to change once the valve opens; therefore, the setpoint could be affected. The staff finds that the setpoint is unaffected when safety and relief valves are tested when the test medium and valve temperatures are the same. Thermal stabilization is achieved with no wait period between tests; consequently the setpoint is unaffected.

According to the licensee, the set pressure tests for the valves listed above are performed under ambient conditions using a water or nitrogen test medium, as appropriate, at ambient temperature conditions. As a result, there is no source of thermal imbalance that might affect the test results. Thus, the NRC staff finds that elimination of the 5 minute wait period between setpoint tests for these safety and relief valves provides an adequate method of accurately and repeatedly determining setpoints. Therefore, the NRC staff finds that the licensee's proposed alternative test methodology provides an acceptable alternative to the 5 minute wait period requirement in Appendix I, paragraphs l-8120(h) and 1-8130(9). As acknowledged by the licensee in their request, this alternative does not apply to valves that are required to be tested using saturated steam as the test media (e.g., Main Steam Safety Valves and Pressurizer Safety Valves (PSVs)). For these valves, the time and temperature requirements of 1-8110 still apply.

3.2 Alternative Request GV-RR-01, Revision 0 3.2.1 Applicable Code Requirements The applicable ASME OM Code edition and addenda for the fifth 10-year 1ST interval at CCNPP, Units 1 and 2, is the 2012 Edition with no addenda. The fifth ten-year interval for CCNPP, Units 1 and 2, begins on July 1, 2018, and is scheduled to end on June 30, 2028.

Mandatory Appendix I, "lnservice Testing of Pressure Relief Devices in Light-Water Reactor Nuclear Power Plants," 1-8110, "Steam Service," (d) "Thermal Equilibrium," states, in part, "Valves insulated in service shall be insulated in a like manner during testing."

3.2.2 Code Components Affected Mandatory Appendix I, "lnservice Testing of Pressure Relief Devices in Light-Water Reactor Nuclear Power Plants," 1-8110, "Steam Service," (d) "Thermal Equilibrium," states, in part, "Valves insulated in service shall be insulated in a like manner during testing."

Component 1-RC-200-RV 1-RC-201-RV 2-RC-200-RV 2-RC-201-RV 3.2.3

Reason for Request

Description Pressurizer Safety Valve Pressurizer Safety Valve Pressurizer Safety Valve Pressurizer Safety Valve Class 1

1 1

1 Category C

C C

C In the Attachment to the letter letter dated August 2, 2017, the licensee states, in part:

Changes in safety/relief valve body temperature can change the lift setpoint measured during inservice testing. Changes in ambient temperature or modifications to insulation also may change the lift setpoint by virtue of the resulting effect on the valve body temperature. The purpose of paragraph 1-811 O(d) is to ensure the effect of temperature variations is minimized. Requiring insulation to be installed during testing is clearly intended to also ensure the valve body's temperature, and therefore its performance, is similar to that under normal operating circumstances. CCNPP has determined the normal operating temperature profile for the pressurizer safety valves by instrumenting each valve body at several locations and recorded empirical data during normal operation.

CCNPP has previously commissioned testing using the valves' actual operating temperature profile at a national vendor's testing facility to determine the impact of having the insulation removed versus installed during testing of the pressurizer safety valves. This testing demonstrated that pressurizer safety valves, which have had their setpoints satisfactorily verified in-situ, will perform satisfactorily two years later in a laboratory setting if the valve body's actual operating temperature profile is recreated. The test was conducted using two valves adjusted to their respective setpoints (which differ by only 65 pounds per square inch (psi)).

The first series of tests was performed with each valve uninsulated. Prior to setpoint testing, each valve was thermally stabilized at the specified temperature profile to match normal operating conditions. The valves performed within their as-found setpoint tolerance.

The second series of tests was performed with each valve insulated (using the actual insulation from the plant normally installed on each valve). Prior to setpoint testing, each valve was thermally stabilized. However, due to the test configuration, the valve could not be thermally stabilized at the actual operating temperature profile. Instead, it could only be stabilized at a higher temperature.

The overall impact of the higher temperature profile is that the lift pressure for the valves is lower than when at the correct temperature profile. This is a non-conservative error because, if the valves were adjusted to lift at their operating setpoint under these conditions, they would then be set to lift by as much as approximately 2 percent high when returned to their normal plant installation.

The third series of tests was performed with each valve insulated and with the ambient temperature being varied. The variations in ambient temperature had little effect on the valve's lift pressure.

Because of differences in the test configuration and the normal plant configuration, the vendor was unable to stabilize the valves' temperature profile when insulated consistent with the one specified for normal plant operating conditions. Rather, the temperatures measured at all the points being monitored, most notably the upper and lower bonnet, were higher.

The higher temperature profile for the insulated valves in the testing configuration occurred because, when installed in the plant, these valves are attached to long runs of piping with numerous associated piping supports which serve as heat sinks for the valves, but in the testing facility these long runs of piping are no longer attached. In the plant, these heat sinks allow the valves to stabilize at a lower temperature profile even when insulated, as compared to the temperature profiles when insulated in the vendor test facility. Additionally, the presence of forced ventilation in the field increases the heat transfer out of each valve body through the insulation for the same ambient temperature when compared to the stagnant conditions present in the test configuration.

In other words, the heat input and heat output of the insulated valves in a stagnant environment cannot be balanced in the testing facility until the valves are hot enough to create the necessary heat transfer rate through the insulation needed to offset the heat input. Since the heat transfer out of the valve to the attached piping is lost, more heat output through the insulation is required. This effect is additionally aggravated by the lack of forced ventilation. As a result, the valves stabilize at a higher temperature and the lift pressure measured was lower (by as much as approximately 2 percent) with the valves insulated and at these higher temperatures.

3.2.4 Proposed Alternative and Basis for Use In the Attachment to the letter letter dated August 2, 2017, the licensee states, in part:

OM-2012 Code, Mandatory Appendix I, paragraph l-8110(e) requires the ambient temperature of the operating environment to be simulated during the set pressure test. Additionally, if the effect of ambient temperature on set pressure can be established for a particular valve type, then Appendix I allows set pressure tests to be performed using an ambient temperature different from the operating ambient temperature as long as applicable correlations between the operating and testing ambient temperatures are used.

The intent of using the normally installed insulation per paragraph 1-8110(d) and testing using the operating ambient temperature (or test ambient temperature with the appropriate correlation) is to ensure the valve performance during the test is indicative of its expected performance under service conditions. However, CCNPP has shown through comparative laboratory and in-situ tests that controlling the actual temperature profile of the valve body is a more realistic and more effective way of simulating inservice conditions and testing these valves.

Additionally, it is much less likely to produce misleading test results that could lead to inappropriate setpoint adjustments. Therefore, CCNPP considers the requirements of paragraph 1-8110(e) to be satisfied by such testing; and based on the test results obtained at the vendor"s laboratory, no correlation factor is applicable.

When testing is performed in a vendor testing facility, vice in-situ testing, the valve body's temperature profile necessary to simulate normal operating conditions for these valves will be specified. The valve shall be stabilized at the required temperature profile per the remaining portion of paragraph l-8110(d) prior to setpoint testing without requiring the valve to be insulated in a like manner to its inservice configuration.

Based on the determination that the actual temperature profile of the valve body is a more realistic and more effective way of simulating inservice conditions and testing these valves; this alternate testing will maintain acceptable relief valve test accuracy...

3.2.5

NRC Staff Evaluation

The ASME OM, Appendix I, paragraph l-8110(d), requires that valves that are insulated inservice be insulated in a like manner during lift setpoint tests. The licensee proposes to lift setpoint test the PSVs with the insulation removed when testing the valves at a test facility.

The NRC staff finds that changes in PSV body temperature can change the lift setpoint of a PSV. Changes in temperature affect critical clearances and dimensions within the PSV and any change to a critical clearance or dimension would affect the lift setpoint. The purpose of Paragraph l-8110(d) of the ASME OM Code is to ensure that the temperature profile of the PSV during normal plant operation is maintained at the test facility. Test summary results provided by the licensee demonstrate that it is appropriate to not insulate PSVs at the test facility because the configuration at the test facility with the insulation removed creates a temperature profile that is consistent with the valves' temperature during normal plant operation.

Therefore, the proposed alternative to the insulation requirement in Paragraph l-8110(d) of the ASME OM Code during lift setpoint testing of the PSVs provides an acceptable level of quality and safety.

3.3 Alternative Request GV-RR-01, Revision 0 3.3.1 Applicable Code Requirements The CCNPP Units 1 and 2 fifth 10-year 1ST program interval begins on July 1, 2018 and is scheduled to end on June 30, 2028. The applicable ASME OM Code edition for the CCNPP, Units 1 and 2, fifth 10-year 1ST program interval is the 2012 Edition.

ISTB-1400, "Owner's Responsibility," (b) states, in part, "A pump that meets both Group A and Group B pump definitions shall be categorized as a Group A pump."

3.3.2 Code Components Affected The licensee has requested to use the proposed alternative described below for the pumps listed in Table 1.

Pump ID Pump Description ASME Code Class ASME OM Pump Group 11 LPSI Low Pressure Safety 2

A/B Injection (LPSI) Pump 12 LPSI LPS1Pump12 2

A/B 21 LPSI LPSI Pump 21 2

A/B 22 LPSI LPSI Pump 22 2

A/B 3.3.3

Reason for Request

In the Attachment to the letter letter dated August 2, 2017, the licensee states, in part:

LPSI Pump Group Classification ASME OM-2012 Code, Subsection ISTB, lnservice Testing of Pumps in Light--Water Reactor Nuclear Power Plants - Pre-2000 Plants, paragraph ISTB-2000, Supplemental Definitions, defines Group A pumps as "pumps that are operated continuously or routinely during normal operation, cold shutdown, or refueling operations," and Group B pumps as, "pumps in standby systems that are not operated routinely except for testing." The LPSI pumps clearly meet the definition of Group B pumps during normal operation in Modes 1-4. However, in Modes 5-6, the LPSI pumps are used for shutdown cooling and meet the definition of Group A pumps.

Subsection ISTB, paragraph ISTB-1400(b) states, in part, that "A pump that meets both Group A and Group B pump definitions shall be categorized as a Group A pump." This means that the LPSI pumps would be classified as Group A and would be subjected to the same quarterly test requirements as continuously operated pumps.

The LPSI pumps are tested quarterly using the minimum recirculation flow path from each pump through the minimum recirculation flow common header and back to the refueling water tank. The common header is instrumented with an ultrasonic flow meter. However, flow is not throttled during the quarterly test to eliminate the potential for pump overheating and damage should flow inadvertently be throttled below that required to ensure adequate pump cooling.

The LPSI pumps are also tested at a substantial flow rate (approximately 3000 gallons per minute (gpm)) during every refueling outage, as well as during planned and unplanned cold shutdown periods when plant conditions and circumstances permit. These tests are the [ASME] OM Code Comprehensive Pump Tests (CPTs) (formerly known at CCNPP as "Large Flow Rate" tests). The CPT flow rate meets the OM-2012 Code, Mandatory Appendix V, Pump Periodic Verification Test (PPVT) Program, requirements.

NUREG/CP-0137, Volume 1, Proceedings of the Third NRC/ASME Symposium on Valve and Pump Testing, includes a paper entitled, "Description of Comprehensive Pump Test Change to ASME OM Code, Subsection ISTB." This paper describes the philosophy of classifying pumps in one group or the other (Group A vs. Group B). According to this paper, the intent of having different test requirements for the different pump groups is to relate the amount and degree of quarterly performance monitoring required to the amount of degradation expected due to pump operation.

Requiring the LPSI pumps to be tested quarterly as Group A pumps during normal operation in Modes 1-4 is contrary to the philosophy of the referenced paper. Quarterly testing subjects the LPSI pumps to increased test requirements, performance monitoring, and potentially more degradation due to low-flow operation at the time when they are standby pumps and would not otherwise be subject to operation-induced degradation. In fact, out of all of the Emergency Core Cooling System (ECCS) and Auxiliary Feedwater pumps, the LPSI pumps are the ones, due to their design and test conditions, for which the detrimental effects of cumulative low-flow operation are the most drastic.

CCNPP considers the requirement to test the LPSI pumps as Group A pumps during normal operation in Modes 1-4 to be potentially detrimental on a long-term basis. Therefore, CCNPP proposes that the LPSI pumps be treated as Group B pumps during normal operation in Modes 1-4 and tested accordingly.

Additionally, in Generic Letter (GL) 89-04, Position 9, the NRC determined that, in cases where the pump flow can only be established through a non-instrumented, minimum-flow path during quarterly pump testing, and a path exists at cold shutdown or refueling outages to perform a test of the pump under full or substantial flow conditions, the increased interval is an acceptable alternative to the [ASME OM] Code requirements. Therefore, the proposed alternative testing of LPSI pumps as Group B pumps during Modes 1-4 and as Group A pumps during Modes 5-6 is consistent with GL 89-04, Position 9.

The impact of obtaining certain test parameters required b OM-2012 Code, Table ISTB-3000-1, "lnservice Test Parameters," ensuring the pumps are running for a minimum of 2 minutes at stable conditions (ISTB-5100(a)(1)) during quarterly Group A testing, and other considerations are discussed below.

Differential Pressure Measurements CCNPP's current quarterly Group A pump test program requires differential pressure to be measured. Group A quarterly ECCS pump tests must be performed using very accurate (+/- Y2 percent ) test pressure gauges. These pressure gauges would be installed prior to, and removed after, each test (an annual total of 32 gauge installation/removal evolutions). The OM-2012 Code does not require these very accurate gauges; however, they are necessary because the hydraulic margin available, based on design calculations, is less than the amount of degradation allowed by Subsection ISTB. Using less accurate permanently installed pressure gauges could result in a pump being unnecessarily declared inoperable solely due to pressure gauge uncertainty.

Installation and removal of these test pressure gauges for each LPSI pump every quarter would require significant dedication of manpower, results in significant cumulative annual radiation dose, increased radioactive waste, increased wear on fittings, and additional challenges for possible personnel contamination.

CCNPP estimates that eliminating the test pressure gauge installation and removal evolutions will save at least 1/8 man-rem per year and almost 100 man-hours per year.

Quarterly LPSI pump tests are performed using the minimum recirculation flow path under low-flow conditions. In this region, the pumps are operating at or near shut-off head, the pump curves are flat or nearly flat, and pump differential pressure is not very sensitive to pump degradation. Flow rate alone is an adequate indication of possible pump degradation or flow blockage since the minimum recirculation flow path is a fixed-resistance flow path. The conclusion that measurement of pump differential pressure is of minimal value is supported by historical test data.

For testing the LPSI pumps as Group B pumps, the operational readiness is reasonably assured without requiring quarterly differential pressure measurements. This will allow CCNPP to cease these gauge installation and removal evolutions every quarter, while maintaining an acceptable level of quality and safety.

Vibration Measurements CCNPP's current quarterly Group A pump test program requires pump vibration measurements. The overall vibration readings recorded during quarterly low-flow testing have always been relatively "high." These vibration readings have been subject to spectral analysis under the Rotating Machinery Condition Monitoring Program, which is separate from the 1ST Program. The spectral analyses have consistently confirmed the major contributor to the "high" overall vibration readings occurs at the blade pass frequency for each LPSI pump and is not indicative of bearing degradation. However, the [ASME] OM Code does not require spectral analysis. Therefore, the effects of low-flow operation on a centrifugal pump make the required broadband vibration readings during the current quarterly test of minimal value. This conclusion is supported by the CCNPP historical test data. Under the OM-2012 Code, the operational readiness of Group B pumps is reasonably assured without requiring quarterly vibration measurements.

Based on this, CCNPP believes that an acceptable level of quality and safety is still maintained while many of the burdens and costs associated with vibration testing, including cumulative annual radiation dose and man-power, will be eliminated.

LPSI Pump Bearing Acceptance Criteria During Low-Flow Testing For the fourth 1ST interval, the surveillance procedures used to perform the CPTs required vibration measurements to be recorded in terms of velocity. CCNPP long ago recognized the benefit of velocity over displacement for analyzing pump vibrations and has included such measurements in the CCNPP Predictive Maintenance (PdM) group's Rotating Machinery Vibration Monitoring Program which conducts periodic vibration monitoring and analysis of numerous pumps and motors (including the LPSI pumps) beyond that required for the 1ST Program. The Rotating Machinery Vibration Monitoring Program includes spectral analysis of the vibration measurements.

The PdM group's long-term vibration data trend (1995 through present), during quarterly testing of the LPSI pumps using the minimum recirculation flow path shows consistent results and stable performance with no unexplainable significant changes. The quarterly tests are performed at approximately 55-65 gpm, which is between approximately 1.3 percent to 1.6 percent of the LPSI pumps' "Best Efficiency Flow Rate." The Best Efficiency Flow Rate is based on the original vendor pump curve. It is used instead of the system's design flow rate because the onset of pump internal recirculation and cavitation is a function of the pump's performance characteristics, not the system's design requirements.

Operating the LPSI pumps at low flow rates results in a variety of effects (e.g.,

internal recirculation, cavitation, and force imbalance on the impeller), which contribute to increased vibration. Spectral analysis of the LPSI pump vibration measurements reveals (1) a general increase in the broadband noise levels which is indicative of internal recirculation and cavitation, and (2) discrete spikes at frequencies corresponding to the blade pass frequency which is indicative of force imbalances acting on the impeller. The analysis confirms the presence and effect of these phenomena.

Many of the normal vibration levels experienced when operating the LPSI pumps under low-flow conditions during quarterly testing routinely exceed or challenge the absolute Alert Acceptance Criterion of 0.325 inches per second specified in Table ISTB-5121-1, Centrifugal Pump Test Acceptance Criteria. If the LPSI pumps are classified as Group A pumps, applying the [ASME] OM Code criteria will necessitate either [doubling the test frequency and] testing at six-week intervals, or [generating] a new evaluation each quarter.

The following factors lead to the conclusion that the current vibration levels recorded during LPSI minimum recirculation flow testing are acceptable and are not indicative of any pump mechanical problems or degradation, and, therefore, that the LPSI pumps are operating acceptably.

(1)

The long-term stability of the vibration trend based on data from the surveillance tests and CCNPP Rotating Machinery Vibration Monitoring Program obtained during quarterly minimum recirculation flow testing.

(2)

Spectral analysis confirmed the major contributor to the overall vibration levels recorded during quarterly minimum recirculation flow testing is consistent with phenomena which are well known to be associated with operation of a centrifugal pump at low flow rates and also well known to cause higher vibrations at these low flow rates.

(3)

The overall vibration levels recorded during large flow testing of the LPSI pumps are significantly reduced compared to the levels recorded during the quarterly minimum recirculation flow tests and are consistent with vibration levels experienced while testing centrifugal pumps at substantial flow rates in other systems and applications.

( 4)

Spectral analysis confirmed that the major contributors to the overall vibration levels observed during quarterly minimum recirculation flow testing which are associated with operation of a centrifugal pump at low flow rates are significantly reduced during large flow testing of the LPSI pumps.

(5)

Similar vibration patterns have been observed for the other standby ECCS pumps, although the effects are not as pronounced as they are for the LPSI pumps because the LPSI pumps are the pumps which are tested at the lowest flow condition relative to their Best Efficiency Flow Rate.

(6)

The LPSI pumps have no history of mechanical failures nor have they required significant maintenance on a regular basis.

The "Large Flow Rate" tests for the LPSI pumps have been in use at CCNPP since approximately 1991. At a minimum, each pump has been tested during each refueling outage since these tests were implemented. Vibration data (in both displacement and velocity) was collected during these tests via the surveillance tests themselves and the CCNPP Rotating Machinery Vibration Monitoring Program. The vibration data recorded during these large flow rate tests show the overall vibration levels drop significantly, as expected.

Furthermore, spectral analysis of these results show the general broadband noise and spikes at discrete frequencies caused by the blade passing are significantly reduced.

The overall vibration levels observed during quarterly LPSI pump minimum recirculation flow testing, augmented by spectral analysis, are not sufficiently high as to prevent detection of increases in the LPSI pump vibration levels, which would be indicative of mechanical degradation. Furthermore, the vibration monitoring during less frequent LPSI CPT, also augmented by spectral analysis, provides even greater opportunities to detect increases in the LPSI pump vibration levels, which would be indicative of mechanical degradation.

CCNPP's experience has shown that spectral analysis of the vibration measurements obtained during quarterly minimum recirculation flow testing is sufficiently sensitive to changes in the pumps' mechanical condition and provides reasonable assurance that mechanical degradation can be detected early.

Performing pump testing at double the normal quarterly frequency when vibration levels exceed the acceptance criteria specified in Table ISTB-5121-1 is physically possible (i.e., it is practicable). Such increased frequency testing will potentially reduce LPSI pump reliability and increase the probability of LPSI pump degradation, damage, or failure. Therefore, such testing is considered impractical because, though it is possible to perform such increased frequency testing, the potential reduction in LPSI pump reliability and potential increase in the probability of LPSI pump degradation, damage, or failure is a result, which is contrary to the intent of the 1ST Program.

The run time of these pumps during an operating cycle is very limited since operation at low flow rates is detrimental to the pumps. Performing increased frequency testing on a regular basis during the operating cycle would increase the run time of these pumps by as much as approximately 30 percent. 10 CFR 50.55a(z)(1) and (z)(2) address alternatives when the [ASME] OM Code requirement would result in a hardship/burden with no commensurate increase in the level of quality or safety [(z)(2)] or an alternative provides an equivalent level of quality and safety [(z)(1 )]. Not only would increased frequency testing of the LPSI pumps be an inefficient use of resources, but such unnecessary testing may actually result in a real potential to reduce the level of quality and safety and; therefore, should be avoided if possible.

Minimum Pump Run-Time If the LPSI pumps are classified as Group B pumps, the two-minute minimum pump run-time for quarterly tests is also eliminated. Eliminating the minimum pump run-time requirement and the requirement to record differential pressure and vibration levels is expected to slightly reduce the length of each pump test.

This will help to reduce the cumulative run-time of each LPSI pump under lowflow conditions to support testing, with a commensurate reduction in potential pump wear.

Other Considerations These proposed changes simplify the quarterly 1ST pump test to allow combining the quarterly 1ST pump test into the related quarterly engineering safety features actuation logic test for each pump. As a result, the total number of starting demands on each pump motor to support testing may be reduced and the cumulative run-time of each LPSI pump under low-flow conditions to support testing may be further reduced. CCNPP estimates that this course of action could eliminate approximately two hours of operation under low-flow conditions for each LPSI pump per year.

Relationship to CCNPP Technical Specification (TS) Surveillance Requirement (SR)

The CCNPP TS SR for each pump (SR 3.5.2.3) requires periodic testing of each LPSI pump to verify that the "developed head at the test flow point is greater than or equal to the required developed head." The specified frequency for the SR is, "in accordance with the lnservice Test Program." CCNPP's TS SR does not contain any additional (explicit or implied) testing requirements for these pumps beyond those required by the 1ST Program. This means that, as long as the testing complies with the requirements of the approved 1ST Program, there is no conflict with CCNPP's TS SR. Therefore, none of the changes to the 1ST Program requested in this proposed alternative would conflict with any CCNPP's TS SRs.

As previously stated, the LPSI pumps are typically run continuously during cold shutdown and refueling operations, depending on the decay heat rate. As a result, they may be subject to operation-induced degradation in Modes 5-6.

Therefore, the LPSI pumps will be treated as Group A pumps during any quarterly test that comes due during cold shutdown or refueling operations.

However, typically during Modes 5-6, a CPT is preferable to a Group A test tor the LPSI pumps. This avoids the need to realign the LPSI pumps out of the normal shutdown cooling line-up and also avoids the detrimental effects of testing the LPSI pumps at low-flow conditions. Therefore, CCNPP expects that a CPT will typically be substituted for any Group A test that may be required during Modes 5-6.

In response to a request for additional information, the licensee stated that the pump manufacturer's recommended minimum flow rate is 40 gpm, and that the quarterly test flow rate of 55-65 gpm is maintained by a flow orifice that is permanently installed in the minimum recirculation line. The licensee also stated that a stainless steel impeller design, vibration monitoring during testing, vibration trending, and augmented pump internal inspections are factors used to minimize the potential for pump degradation during quarterly testing.

3.3.4 Proposed Alternative and Basis for Use The licensee requested an alternative to the pump categorization requirement of the ASME OM Code. The licensee proposes that the LPSI pumps be tested as standby pumps (Group B) during Modes 1-4, power operation, and as continuously operating pumps (Group A) during Modes 5-6, refueling operations. During refueling operations, the CPT will be substituted for a quarterly Group A test that comes due.

3.3.5

NRC Staff Evaluation

The licensee has proposed that the LPSI pumps be tested as standby pumps (Group B) during Modes 1-4 and as continuously operating pumps (Group A) during Modes 5-6. In Modes 5-6, the CPT may be substituted for a quarterly Group A test that comes due during a mid-cycle cold shutdown period as provided by Subsection ISTB of the ASME OM Code. ISTB-5000 states that when a Group A test is required, a CPT may be substituted. The licensee states that a CPT will be performed instead of a Group A test during Modes 5-6.

ISTB-2000 defines Group A pumps as "pumps that are operated continuously or routinely during normal operation, cold shutdown, or refueling operations;" and Group B pumps as "pumps in standby systems that are not operated routinely except for testing." Based on these definitions, the LPSI pumps meet the definition of Group B pumps during normal operation in Modes 1-4. In Modes 5-6, the LPSI pumps are used for shutdown cooling and meet the definition of Group A pumps. 1STB-1400(b) states that "A pump that meets both Group A and Group B pump definitions shall be categorized as a Group A pump." This would normally cause the LPSI pumps to be classified as Group A. However, because of the inability to achieve a substantial flow rate in Modes 1-4, it is not possible to conduct a Group A test that would provide very much meaningful data to detect degradation due to the relatively flat profile of the pump hydraulic curve and the higher vibration levels present at these near shut-off head flow conditions.

Additionally, the LPSI pumps are standby pumps during Modes 1-4 and little degradation is expected with respect to hydraulic performance during the operational period when the pumps are idle.

In GL 89-04, Position 9, the NRC determined that, in cases where flow can only be established through a non-instrumented, minimum-flow path during quarterly pump testing, and a path exists at cold shutdown or refueling outages to perform a test of the pump under full or substantial flow conditions, the increased interval is an acceptable alternative to the ASME OM Code requirements. Therefore, the proposed alternative testing of the LPSI pumps as Group B during Modes 1-4 and as Group A during Modes 5-6 is consistent with GL 89-04, Position 9, and provides reasonable assurance of operational readiness of the LPSI pumps.

The licensee referenced a paper titled "Description of Comprehensive Pump Test Change to ASME OM Code, Subsection ISTB," that is included in NUREG/CP-0137, Volume 1. This NUREG is a compilation of papers presented at an NRC/ASME Symposium on Valve and Pump Testing. The NRC staff notes that statements and opinions advanced in the papers presented at the symposium are individual expressions of the authors and not those of either ASME or the NRC.

The licensee states that the overall vibration readings recorded during quarterly low-flow testing have always been relatively high when compared to the ASME OM Code acceptance criteria.

These vibration readings have been subject to spectral analysis under CCNPP's Rotating Machinery Condition Monitoring Program, which is separate from the 1ST Program. The spectral analyses have consistently confirmed the major contributor to the high overall vibration readings occurs at the blade pass frequency for each LPSI pump and is not indicative of bearing degradation. The long-term vibration trend (1995 through present) during quarterly testing of the LPSI pumps using the minimum recirculation flow path shows consistent results and stable performance with no unexplainable significant changes. The licensee will continue to perform spectral analysis under CCNPP's Rotating Machinery Condition Monitoring Program. The spectral analysis is above and beyond the ASME OM Code requirements. Therefore, the operational readiness of the LPSI pumps with the proposed Group B pump test (Modes 1-4) is reasonably assured without requiring quarterly vibration measurements, which are not required by the ASME OM Code for Group B pumps.

The CCNPP, TS SR 3.5.2.3, requires verification that the LPSI pump's developed head at the test flow point is greater than or equal to the required developed head in accordance with the frequency established by the 1ST program. As stated above, the LPSI pumps will be tested as Group B pumps during Modes 1-4, and Group A pumps during Modes 5-6 (every refueling outage, as well as during planned and unplanned cold shutdowns). A CPT may be substituted for a Group A test per the ASME OM Code. The quarterly Group B test will be performed using the minimum recirculation flow path under low-flow conditions and only flow will be measured.

The TS requirement to measure pump head will be performed at the frequency for Group A or CPT tests as required by the modified 1ST program.

The NRC staff notes that this same alternative request was authorized for use for CCNPP, Units 1 and 2, for the current (fourth) 10-year 1ST program interval.

4.0 CONCLUSION

As set forth above, the NRC staff determined that for alternative requests SI-RR-01, Revision-0; GV-RR-01, Revision O; and RC-RR-01, Revision 0, for CCNPP, Units 1 and 2, provide an acceptable level of quality and safety. Accordingly, the NRC staff concludes that the licensee has adequately addressed all of the regulatory requirements set forth in 10 CFR 50.55a(z)(1 },

for these alternative requests. Therefore, the NRC staff authorizes the use of alternative requests SI-RR-01, GV-RR-01 and RC-RR-01 for CCNPP, Units 1 and 2, for the fifth 10-year 1ST program interval, which begins July 1, 2018, and is scheduled to end on June 30, 2028.

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

Principal Contributors: R. Wolfgang, NRR J. Billerbeck, NRR Date: May 10, 2018

ML18117A264 iOFFICE DORL/LPL 1 /PM DORL/LPL 1 /LA NAME MMarshall I Betts DATE 05/02/18 05/01/18 IOFFICE DE/EMIB/BC*

DORL/LPL 1 /BC NAME SBailey JDanna DATE 03/08/17 05/10/18