Text

Technical Evaluation Rept,Pump & Valve Inservice Testing Program,North Anna Power Station Units 1 & 2
	ML20078B155
Person / Time
Site:	North Anna
Issue date:	09/30/1994
From:	Ransom C; EG&G IDAHO, INC.
To:	; NRC
Shared Package
ML20078B157	List: ML20078B155;
References
	CON-FIN-L-2594 EGG-DNSP-11349, TAC-M88757, NUDOCS 9410210102
	Download: ML20078B155 (68)
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EGG-DNSP-11349 TECHNICAL EVALUATION REPORT PUMP AND VALVE INSERVICE TESTING PROGRAM NORTH ANNA POWER STATION, UNITS ONE AND TWO Docket Nos. 50-338 & 50-339 C. B. Rasom R. S. Hartley Published September 1994 Idaho National Engineering Laboratory EG&G Idaho, Inc.

Idaho Falls, Idaho 83415 Prepared for the U.S. Nuclear Regulatory Commission *

[ Washington, D.C. 20555

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Under DOE Contract Number DE-AC07-76IDO1570 FIN Number L2594, Task Order Number 10 TAC Numbers M88757 & M88758 i

4 ABSTRACT This report presents the results of our evaluation of the North Anna Power Station, Units One and Two, Inservice Testing Program for safety-related pumps and valves.

PREFACE This report is part of the " Technical Assistance in Support of Operating Reactors Inservice Testing Relief Requests" program conducted for the U.S. Nuclear Regulatory Commission, Office of Nuclear Reactor Regulation, Mechanical Engineering Branch, by EG&G Idaho, Inc.,

DOE /NRC Support Programs.

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FIN Number L2594 I B&R 920-19-05-02-0 Docket Numbers 50-338 & 50-339 l

TAC Numbers M88757 & M88758 ii

i CONTENTS ,

ABSTRACT................................... il PREFACE ................................... ii

1. INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I 1.1 IST Program Description . . . . . . . . . , . . . . . . . . . . . . . . I 1.2 IST Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . I 1.3 Scope and Limits of the Review . . . . . . . . . . . . . . . . . . . . . 2 ,

2. PUMP TESTING PROGRAM . . . . . . . . . . . . . . . . . . . . . . . . . 3 l 2.1 General Pump Relief Requests. . . . . . . . . . . . . . . . . . . . . . 3 2.1.1 Flow Rate and Discharge Pressure Instrument Accuracy . . . . . . 3 2.1.2 Measurement of Static Inlet Pressure on Running Pumps . . . -. . . 4 i

2.2 Residual Heat Removal Pumps ..................... 6 !

l 2.2.1 Test Frequency . . . . . . . . . . . . . . . . . . . . . . . . 6 ;

2.3 Service Water Pumps. . . . . . . . . . . . . . . . . . . . . . . . . . 7 2.3.1 Measurement of Test Quantities . . . . . . . . . . . . . . . . . 7 i 2.4 Component Cooling and Service Water Pumps. . . . . . . . . . . . . . 12 2.4.1 Curve Testing ....................... 12 2.5 Boric Acid Transfer Pumps . . . . . . . . . . . . . . . . . . . . . . 15 '

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2.5.1 Test Frequency and Duration . . . . . . . . . . . . . . . . . 15

3. VALVE TESTING PROGRAM .......................18 3.1 General Valve Relief Requests ...................18 3.1.1 Valve Ieakage Rates . . . . . . . . . . . . . . . . . . . . . 18 3.1.2 Containment Isolation Valve Corrective Actions . . . . . . . . . 19 3.1.3 Isolation Valve Izakage Rate Corrective Actions. . . . . . . . . 21 iii

3.2 Safety Injection System. . . . . . . . . . . . . . . . . . . . . . . 23 3.2.1 Category A/C Valves ....................23 3.2.2 Category C Valves. . . . . . . . . . . . . . . . . . . . . . 24 3.3 Component Cooling Water System . . . . . . . . . . . . . . . . . . 31 3.3.1 Category A/C Valves . . . . . . . . . . . . . . . . . . . . 31 i

3.4 Reactor Coolant System . . . . . . . . . . . . . . . . . . . . . . 33 3.4.1 Category A/C Valves ....................33 3.4.2 Category B Valves .....................34 3.5 Chemical and Volume Control ...................36 3.5.1 Category A/C Valves ....................36 3.5.2 Category A/C and C Valve.i .................37 3.6 Instrument Air System . . . . . . . . . . . . . . . . . . . . . . . 38 3.6.1 Category A/C Valves ....................38 3.7 Service Water System . . . . . . . . . . . . . . . . . . . . . . . 40 3.7.1 Category C Valves .....................40 3.8 Vacuum Priming System . . . . . . . . . . . . . . . . . . . . . . 41 3.8.1 Category A/C Valves ....................41 3.9 Fire Protection System . . . . . . . . . . . . . . . . . . . . . . . 42 3.9.1 Category C Valves .....................42 3.10 Post Accident Hydrogen Removal System. . . . . . . . . . . . . . . 44 3.10.1 Category A/C Valves . . . . . . . . . . . . . . . . . . . . 44 3.11 Residual Heat Removal System . . . . . . . . . . . . . . . . . . . 45 3.11.1 Category C Valves . . . . . . . . . . . . . . . . . . . . . 45

4. DEFERRED TEST EVALUATIONS . . . . . . . . . . . . . . . . . . . . . 47 4.1 Bases for Deferring Valve Exercising. . . . . . . . . . . . . . . . . . 47 iv

4.1 Bases for Deferring Valve Exercising. . . . . . . . . . . . . . . . . . 47 !

4.2 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 APPENDIX A - IST PROGRAM ANOMALIES . . . . . . . . . . . . . . . . . . A-1 TABLES 4.1 Deferred Test Evaluations North Anna Power Station, Units 1 and 2 . . . . . . . 48 r

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TECHNICAL EVALUATION REPORT PUMP AND VALVE INSERVICE TESTING PROGRAM VIRGINIA ELECTRIC AND POWER COMPANY NORTH ANNA UNITS ONE AND TWO

1. INTRODUCTION This report provides the results of the technical evaluation of certain relief requests from the pump and valve inservice testing (IST) program for North Anna Power Station, Units 1 and 2, which was submitted by the Virginia Electric and Power Company (VEPCO).

Section 2 presents VEPCO's bases for requesting relief from the requirements for pumps followed by an evaluation and conclusion. Section 3 presents similar information for valves.

Appendix A lists program inconsistencies and omissions, and identifies needed program changes.

1.1 IST Procram Descriotion VEPCO has submitted several relief requests pertaining to requirements of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (the Code),Section XI,1986 Edition, and the Code of Federal Regulations (CFR),10 CFR 50.55a. VEPCO submitted relief requests in Revision 6 of the North Anna Power Station, Units 1 and 2, pump and valve IST program with a letter dated June 14, 1990. They also transmitted a revised group of relief requests and supplemental information by letter to NRC dated October 17,1990. The relief requests in these transmittals were evaluated and an NRC Safety Evaluation (SE) was issued September 17,1993.

By a letter dated December 16,1993, VEPCO submitted Revision 7 of their North Anna Power Station, Units 1 and 2, pump and valve IST program for NRC review and approval. That program submittal contained new and revised relief requests and program l changes made in response to issues raised in the NRC's SE of September 1993. VEPCO l submitted two additional relief requests with a letter to NRC dated April 26,1994. This report provides a technical evaluation of the relief requests submitted in April 1994, and of the new relief requests and the requests in the December 1993 submittal with substantive changes from the requests submitted in 1990. The licensee's current IST program covers the second i 120 month IST interval, which began on December 14,1990, for both units. )

1.2 IST Recuirements 10 CFR 50.55a(g) states that IST of certain ASME Code Class 1,2, and 3 pumps and valves will be done per the ASME Code,Section XI, Subsections IWP and lWV, except l where reliefis granted by NRC in accordance with 10 CFR 50.55a(a)(3)(i), (a)(3)(ii), or l (f)(6)(i). VEPCO requests relief from the ASME Code testing requirements for specific 1

pumps and valves. Certain of these .equests are evaluated in this Technical Evaluation Report (TER) using the acceptance criteria of the Standard Review Plan, Section 3.9.6, NRC Generic letter No. 89-04 (GL 89-04), " Guidance on Developing Acceptable Inservice Testing Programs," and 10 CFR 50.55a. Other requests in the licensee's IST program that are not evaluated in this TER, may be granted by provisions of GL 89-04, 1.3 Scone and Limits of the Review The scope of the detailed review was limited to the relief requests and cold shutdown justifications submitted with the 'dcensee's IST program. Other portions of the program, such as general discussions, pump and valve test tables, etc., were cursorily reviewed.

Endorsement of these aspects of the program by the reviewer or NRC is not stated or implied.

Any deviation from the Code test method, freo.nency, or other requimment should be identified in the IST program and submitted according to 10 CFR 50.55a for review and approval by NRC prior to implementation.

The evaluations in this TER are applicable only to the components or groups of components identified by the submitted requests. These evaluations may not be extended to apply to similar components that are not identified by the request at this or any other comparable facility without separate review and approval by NRC. Further, the evaluations and recommendations are limited to the requirement (s) and/or function (s) explicitly discussed in the applicable TER section. For example, the results of an evaluation of a request involving testing of the containment isolation function of a valve cannot be extended to allow the test to satisfy a requirement to verify the valve's pressure isolation function, unless that extension is explicitly stated.

l VEPCO provided several cold shutdown justifications for exercising Category A, B, and C valves during cold shutdowns and refueling outages instead of quanerly. Valves identified to be tested during cold shutdowns need not be tested if testing was performed within three months of the cold shutdown. Thesejustifications were reviewed and found to be acceptable except as noted in Appendix A.

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2. PUMP TESTING PROGRAM t

The following relief requests were evaluated against the requirements of the ASME Code,Section XI,10 CFR 50.55a, and applicable NRC positions and guidelines. A summary is presented for each relief request followed by the licensee's basis for relief and the evaluation with the reviewer's recommendations. The evaluations are grouped according to topic or system. Each relief request basis and evaluation applies to both units unless specified otherwise. The pump identification numbers are prefixed with "1 " for unit one, "2 " for unit two, and "l(2) " for both units.

1 2.1 General Pump Relief Requests l

2.1.1 Flow Rate and Discharce Pressure Instrument Accuracy 2.1.1.1 Relief Request. P-13 requests relief from the flow rate and discharge pressure instrument accuracy requirements of Section XI, Paragraph IWP-4110, for the pumps identified in Section 2.1.1.1.1 below. The licensee proposes to use instruments with the ;

accuracies stated below.

2.1.1.1.1 Licensee's Basis for Recuestine Relief-The following text is quoted from relief request P-13 in Revision 7 of the North Anna Power Station, Units 1 and 2, second interval IST program submitted by letter dated December 16,1993 I

Instruments used to measure certain pump parameters receive their signal at the equipment, which is transmitted to a process rack and then to a control room indicator.

The sensor and rack accuracy can be affected by drift, temperature, and calibration ;

accuracy. The indicator has a limit of accuracy. The total loop accuracy is found by l the root sum of the squares. The only variables in this formula are the sensor calibration accuracy and the indicator accuracy. Installing new sensors and indicators to reduce the accuracy by one percent is not warranted by the increase in safety ,

obtained. The following instrument loops exceed the 2% tolerance listed in Table )

IWP 4110-1. I Instrument Component Parameter Accuracy FI-1122 1(2)-CH-P-1A,B,C Flow 2.34 %

FI-CC-100A 1(2)-CC-P-1 A Flow 2.69 %

FI-CC-100B 1(2)-CC-P-1B Flow 2.69 % i PI-SW-101 A 1(2)-SW-P-1A Discharge Pressure 3.18 %

PI-SW-101B 1(2)-SW-P-1B Discharge Pressure 3.18 %

PI-SW-Il0 1(2)-SW-P-4 Discharge Pressure 2.61 %

Alternate Testine: None 2.1.1.1.2 Evaluation-The Code requires instrument accuracies to be within the limits of Table IWP-4110-1. For flow rate and pressure the limit is i2% of full-scale. These !

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accuracy limits help to ensure that degrading pumps are identified and that degradation is not masked by excessively inaccurate measurements. The licensee proposes loop accuracies of 2.34% and 2.69% for flow rate and 2.61 % and 3.18% for pressure (discharge) as identified previously.

The installation of new sensors and indicators to reduce the accuracy error by 1.18%

for pressure readings and as high as 0.69% for flow rate would not significantly improve the licensee's ability to monitor for pump degradation. To meet the Code requirements, the licensee would have to buy and install new sensors and indicators. This would be a hardship for the licensee. Obtaining and replacing sensors and indicators to meet the Code accuracy requirements, would not significantly increase plant safety or the licensee's ability to monitor for pump degradation. However, anytime existing sensors or indicators are replaced, the new instruments should be at least as accurate as required by the Code.

The service water pumps affected by this request are the subject of other relief requests i in this submittal; P-9, P-10, and P-12. Requests P-9 and -10 are similar and address the use of discharge pressure in lieu of d/p. Request P-12 addresses the use of reference curves of d/p and flow rate. Taken separately, these requests appear to be reasonable approaches to Code t testing alternatives. However, taken together, the reviewer does not have adequate information to fully assess the impact of the combination. For instance, the reduced accuracy of the discharge pressure instrument will affect the uncertainty associated with the acceptance criteria for curve testing. Therefore, the proposed alternate should be authorized with the l provision that the licensee perform a complete assessment of the impact of the combination on l the ability to assess the operational readiness of these pumps. i l

Based on the determination that compliance with the Code requirements would result in !

a hardship or unusual difficulty without a compensating increase in the level of quality and l safety, we recommend that the proposed alternate be authorized pursuant to 10CFR50.55a(a)(3)(ii) with the following provision. The licensee should perform a complete assessment of the impact of the combination of this relief request and requests P-9, P-10, and P-12 as to their ability to assess the operational readiness of these pumps. The results of that assessment should be available for inspection at the facility.

2.1.2 Measurement of Static Inlet Pressure on Runnine Pumos !

2.1.2.1 Relief Request. P-16 requests relief from measuring static inlet pressure as required by Section XI, Table IWP-3100-1, for all pumps in the IST program. The licensee proposes that if a pump is already in operation when the plant test is conducted, only running inlet pressure will be measured.

l 2.1.2.1.1 Licensee's Basis for Recuestine Relief--The following text is quoted from relief request P-16 in Revision 7 of the North Anna Power Station, Units 1 and 2, second interval IST program submitted by letter dated December 16,1993:

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If the pump being tested is in operation as a result of normal plant or system needs, it is !

unreasonable % reconfigure system lineups just to provide for the measurement of static j inlet pressus. Inlet pressure prior to pump startup is not a significant parameter ;

needed for evaluating pump performance or condition.

Alternate Testing: When performing a test on a pump that is already in operation, inlet pressure will only be measured during pump operation. l l

2.1.2.1.2 Evaluation-The measurement of static inlet pressure for a pump can indicate whether there is sufficient net positive suction head (NPSH) to support pump operation. However, NPSH can also be determined to be adequate by observing the operation of a running pump. A pump with inadequate NPSH will experience cavitation and exhibit i degraded hydraulic performance. It is not reasonable to require the licensee to stop an operating pump, simply to measure static inlet pressure. Unnecessary starting and stopping of !

pumps subjects them to additional mechanical stresses, which can lead to unnecessary degradation. These cycles present an additional hardship when the status of the pump (running or stopped) significantly impacts plant operation. Stopping these operating pumps to measure their static inlet pressure in accordance with the Code requirements would constitute a hardship on the licensee without a compensating increase in the level of safety.

In addition, OM-6 does not require the measurement of inlet pressure. The reason for deletion of this parameter is stated in a paper in NUREG/CP-0111, " Proceedings of the l Symposium on Inservice Testing of Pumps and Valves, paper entitled " Introduction to l

ASME/ ANSI OMa-1989a Part 6 - Inservice Testing of Pumps in Light-Water Reactor Power Plants - and Technical Differences Between Part 6 and ASME Section XI, Subsection IWP,"

pages 25-58, which was written by John J. Zudans. The paper cites the following reason for deletion of the inlet pressure parameter:

Inlet pressure This parameter was deleted because of the lack of acceptance criteria.

The only reason it exists in IWP is to help the owner prepare the test and recognize that adequate suction pressure should be specified. OM-6 recognized that the owner is responsible to address testing limitations in the procedures.

The licensee should consider and address this issue as part of plant operation. In rulemaking to 10 CFR 50.55a effective September 8,1992, the 1989 Edition of ASME Section XI was incorporated in 10 CFR 50.55a(b). The 1989 Edition of Section XI provides i that rules for inservice testing of pumps are as specified in OM-6. 10 CFR 50.55a(f)(4)(iv) ,

provides that IST of pumps may meet the requirements set forth in subsequent editions and :

addenda that are incorporated by reference in 10 CFR 50.55a(b), subject to the limitations and modifications listed, and subject to NRC approval. Portions of editions or addenda may be used provided that all related requirements of the respective editions or addenda are met. As described in the preceding, OM-6 allows the deletion of measurement of inlet pressure. The staff imposed no limitations to OM-6 associated with the inlet pressure measurement requirements for pumps. Accordingly, deletion of this parameter is in compliance with the rulemaking effective September 8,1992, and relief is not required. Therefore, we recommend 5

. . s that deleting measurement of inlet pressure be approved pursuant to 10 CFR 50.55a(f)(4)(iv).

There are no related requirements that must be met as part of this approval.

2.2 Residual Heat Removal Pumos 2.2.1 Test Freauency 2.2.1.1 Eglief Request. P-5 requests relief from the test frequency requirements for the residual heat removal (RHR) pumps,1(2)-RH-P-1 A and IB, as required by Section XI, IWP-3400(c). The licensee proposes to test these pumps during refueling outages.

2.2.1.1.1 Licensee's Basis for Requestine Relief-The following text is quoted from relief request P-5 in Revision 7 of the North Anna Power Station, Units 1 and 2, second interval IST program submitted by letter dated December 16,1993:

The low pressure pumps take suction from and discharge to the reactor coolant system (RCS) which operates at 2235 psig. This pressure is well above the operating pressure of the pumps, therefore, testing during normal operation is not possible.

During cold shutdowns of short duration or if the reactor coolant pumps are left running during the cold shutdown, both trains of RHR may be required for decay heat removal and to maintain RCS temperature. Taking one train of RHR out of service for testing purposes even for a short period could allow the RCS temperature to increase to the point that the pressurizer power operated relief valve would be challenged.

Therefore, these pumps should only be tested during reactor refuelings.

Alternate Testing: These pumps will be tested every reactor refueling.

2.2.1.1.2 Evaluation--The Code requires pumps to be tested quarterly to assess their operational readiness. The licensee proposes to test these RHR pumps during refueling ouages in lieu of quarterly or dudng cold shutdowns. These RHR pumps take a suction (the sole suction source) from and discharge to the RCS. The RHR pumps are in a standby condition during power operation and are not exposed to operational wear except when the RCS is at low pressure and the RHR system is operating. The RHR system is a low pressure system that would rupture if exposed to the normal operating RCS pressure of approximately 2235 psig. Also, the RHR motor-operated suction valves are interlocked with RCS pressure and cannot be opened when the RCS is at normal operating pressure. Therefore, compliance with the Code test frequency requirements (quarterly) is impractical. Major plant and system modifications are needed to allow qua-terly testing of the RHR pumps according to the Code l requirements. These modifications would be burdensome for the licensee.

l The licensee stated that both trains of RHR may be needed for decay heat removal (DHR) and to maintain RCS temperature during short duration cold shutdowns or if the reactor coolant pumps (RCPs) are left running during the cold shutdown. Operating the RCPs during cold shutdowns adds a significant heat load to the RCS. Also, during short duration i 6

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I cold shutdowns the decay heat load can be quite high. Taking one of the two trains of RHR out of service for testing according to the ASME Code could allow the RCS temperature to i increase and challenge the pressurizer power operated relief valve (PORV). The pump flow I measurement instrument is in the common line at the discharge of these pumps. Therefore, it 1 is impractical to test the RHR pumps individually according to the Code test method requirements when both must be operated to meet cooling demands. However, these pumps ,

are not in the standby mode; but are run continuously during most cold shutdowns and thus are i potentially subject to increased wear and other operational degradations. It may not be prudent i to arbitrarily extend the test interval to refueling outages if meaningful testing is practicable during cold shutdowns.

During RHR operations these pumps are usually both running at a relatively high flow rate in an instrumented loop. The loop is equipped to measure individual pump inlet and :

discharge pressure, and combined system flow rate. This configuration should be conducive to l the gathering of some meaningful test data during pump operation. Other licensees have proposed methods and acceptance criteria for testing operating pumps in parallel. Often pump )

vibrational characteristics are consistent over a wide range of flows. Pump bearing vibration, differential pressure, and the combined system flow rate can be measured without great difficulty. If specific reference conditions cannot be established, a curve testing approach might be considered. Therefore, the licensee should test these pumps according to the Code l test method requirements during refueling outages when the pumps can be operated I individually and during cold shutdowns when heat loads are low and it is practicable to secure l one train of RHR. The licensee should also consider developing testing methods and acceptance criteria for assessing the operational readiness of these pumps during cold shutdowns when they can only be operated in parallel.

l Based on the determination that compliance with the Code test frequency requirements is impractical and burdensome, and considering the licensee's proposal, we recommend that relief be granted pursuant to 10CFR50.55a(f)(6)(i) provided the licensee tests these pumps !

according to the Code test method requirements during cold shutdowns when heat loads are i low and individual testing is practicable, and the licensee considers testing methods and )

acceptance criteria for assessing the operational readiness of these pumps when they can only be operated in parallel.

2.3 Service Water Pumps 2.3.1 Measurement of Test Ouantities 2.3.1.1 Relief Reauest. P-9 requests relief from measuring pump inlet and differential pressure (d/p) for service water pumps,1(2)-SW-P-1 A and -1B, as required by Section XI, Paragraph IWP-3100. The licensee proposes to monitor pump discharge pressure and use it in place of d/p to monitor for pump degradation. Inlet pressure will not be measured for these pumps.

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2.3.1.1.1 Licensee's Basis for Recuesting Relief-The following text is quoted from relief request P-5 in Revision 7 of the North Anna Power Station, Units 1 and 2, second interval 1ST program submitted by letter dated December 16,1993:

These pumps take suction from the Service Water Reservoir. No inlet pressure l instrumentation is installed. The service water reservoir level indicator is located outside and several feet away from the observation point. Also, the measuring stick tends to collect residue from the surface of the reservoir, thus obscuring the markers. l Thcrefore, measuring the reservoir level can be difficult during periods of inclement l weather or low light conditions.

i However, the reservoir level fluctuates very little and can be considered to be constant. )

The Service Water Reservoir has a minimum level of 313 feet elevation as required by Technical Specifications and a maximum recorded level during past testing of 314.9 1 feet. Therefore, the expected maximum variation in reservoir level is less than 2 feet, which is less than 1 psi. The discharge pressure gauge has a full scale reading of 100 psig and typical discharge pressures range from 50 to 65 psig. Even the maximum variation, which in all probability will not occur between successive tests, is a small percentage of the total head developed by the pump. Therefore, the repeatability of the tests and the ability to detect degradation will not be significantly affected if only discharge pressure is measured.

Applying the Code acceptance criteria to discharge pressure instead of differential pressure is a conservative application of the acceptance criteria for deep draft pumps.

For these pumps, the total developed head is calculated by adding the measured discharge pressure to the height from the discharge pressure gauge to the pump impeller, and subtracting the height from the reservoir surface to the pump impeller.

1 Therefore, the measured discharge pressure will always be a smaller number than the actual total head developed by the pump. Applyirig the Section XI acceptance criteria to just the discharge pressure instead of the total developed head for a deep draft pump is a conservative application of the acceptance criteria because the operability band is smaller.

Altemate Testing: Discharge pressure will be measured in place of differential pressure.

2.3.1.1.2 Evaluation--The Code requires measurement or determination of )

pump differential pressure (d/p). D/p may be determined by subtracting the pressure i measured at a point in the inlet pipe from the pressure measured at a point in the discharge pipe. This service water pump system is not equipped to directly measure inlet or d/p. Inlet pressure can be determined by measuring the head of water above the pump suction.

However, the inlet pressure is due to the lake level, which is controlled in a tight band. The maximum difference in inlet pressure available to the pump is less than 1 psig. The pump ,

i discharge pressure is 50 psig or greater. Therefore, the maximum impact of a change in inlet 8

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pressure on discharge pressure is less than 2% of the discharge pressure value. This should not significantly decrease the licensee's ability to assess the hydraulic condition and determine operational readiness of these pumps. Also, taking the measurement en t>e a hardship on the licensee due to residue on the level marker, inadequate lighting conditions, and remoteness of the indication from the pump.

The licensee proposes to measure discharge pressure and to apply the Section XI acceptance criteria to discharge pressure in lieu of d/p. The licensee states that ". . . the measured discharge pressure will always be a smaller number than the actual total head developed by the pump." and that ". . . Applying the Section XI acceptance criteria to just the discharge pressure instead of the total developed head for a deep draft pump is a conservative application. . ." Generally, discharge pressure is a larger value than d/p. The Code has you subtract inlet pressure from discharge pressure to obtain d/p. The Code has no provision for correcting for system static head or height differences. However, for a deep draft pump with a large height difference between the suction point and the discharge point, the discharge pressure can be smaller than the d/p. Applying the acceptance criteria to the smaller quantity would be a conservative approach, since the acceptable range would be decreased. Changes in a pump's hydraulic condition would be indicated by changes in discharge pressure and flow given that the inlet suction pressure is constant (or essentially constant). Therefore, measurement and analysis of discharge pressure can allow an adequate assessment of pump operational readiness. The licensee has not thoroughly described their method, however, as described, the method is conservative with respect to the Code requirements.

The service water pumps addressed in this request are the subject of other relief requests in this submittal; P-12 and P-13. Request P-12 addresses the use of reference curves of d/p and flow rate. P-13 requests a relaxation of the accuracy requirements for discharge pressure. Taken seperately, these requests appear to be reasonable approaches to Code testing alternatives. However, taken together, the reviewer does not have adequate information to fully assess the impact of the combination. For instance, the reduced accuracy of the discharge pressure instrument will affect the uncertainty associated with the acceptance criteria for curve testing. Therefore, the proposed alternate should be authorized only with the provision that the licensee performs a complete assessment of the impact of the combination on the ability to assess the operational readiness of these pumps.

Based on the determination that requiring the licensee to measure inlet pressure and calculate d/p would be a hardship and would not provide a compensating increase in the level of quality and safety and considering the licensee's proposal to use discharge pressure in lieu of d/p we recommend that the alternative be approved pursuant with 10CFR50.55a(a)(3)(ii) with the following provision. The licensee should perform a complete assessment of the impact of the combination of this relief request and requests P-12 and P-13 as to their ability to assess the operational readiness of these pumps. The results of that assessment should be available for inspection at the facility.

2.3.1.2 Relief Request. P-10 requests relief from measuring pump inlet pressure and d/p for service water pump 1(2)-SW-P-4 as required by Section XI, Paragraph IWP-3100.

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The licensee proposes to measure pump discharge pressure and use this value in place of d/p. l Inlet pressure will not be measured for these pumps.

2.3.1.2.1 Licensee's Basis for Reestine Relief-The following text is quoted from relief request P-10 in Revision 7 of the North Anna Power Station, Uni's 1 and 2, second interval IST program submitted by letter dated Dece'mber 16,1993:

This pump takes suction from Lake Anna. No inlet pressure instrumentation is installed. The North Anna lake level indicator is located outside and several feet away !

from the observation point. Also, the measuring stick tends to collect residue from the surface of the lake, thus obscuring the markers. Therefore, measuring the lake level can be difficult during periods of inclement weather or low light conditions. l l

However, the lake level fluctuates very little from test to test and can be considered to l be constant. The lake has a minimum level of 244 feet elevation as required by Technical Specifications, and maximum and minimum recorded levels during past testing of 250.24 feet and 248.16 feet, respectively. Therefore, the expected maximum ,

variation in lake level is about 2 feet, which is less than 1 psi. The discharge pressure gauge has a full scale reading of 100 psig and the discharge pressures range from 50 to 65 psig. Even the maximum variation, which in all probability will not occur between successive tests, is a small percentage of the total head developed by the pump.

Therefore, the repeatability of the tests and the ability to detect degradation will not be significantly affected if only discharge pressure is measured.

Applying the Code acceptance criteria to discharge pressure instead of d/p is a conservative application of the acceptance criteria for the deep draft pump. For this pump, the total developed head is calculated by adding the measured discharge pressure to the height from the discharge pressure gauge to the pump impeller, and subtractir g the height from the lake surface to the pump impeller.

Therefore, the measured discharge pressure will always be a smaller number than the actual total head developed by the pump. Applying the Section XI acceptance criteria to just the discharge pressure instead of the total developed head for a deep draft pump is a conservative application of the acceptance criteria because the operability band is smaller. ,

Alternate Testing: Discharge pressure will be measured in place of differential pressure.

2.3.1.2.2 Evaluation--The Code requires measurement or determination of pump differential pressure (d/p). D/p may be determined by subtracting the pressure measured at a point in the inlet pipe from the pressure measured at a point in the discharge pipe. This service water pump system is not equipped to directly measure inlet or d/p. Inlet pressure can be determined by measuring the head of water above the pump suction.

However, the inlet pressure is due to the lake level, which is controlled in a tight band. The 10

4 maximum difference in inlet pressure available to the pump is less than 1 psig. The pump discharge pressure is 50 psig or greater. Therefore, the maximum impact of a change in inlet pressure on discharge pressure is less than 2% of the discharge pressure value. This should not significantly decrease the licensee's ability to assess the hydraulic condition and determine operational readiness of these pumps. Also, taking the measurement can be a hardship on the licensee due to residue on the level marker, inadquate lighting conditions, and remoteness of the indication from the pump.

l The licensee proposes to measure discharge pressure and to apply the Section XI acceptance criteria to discharge pressure in lieu of d/p. The licensee states that ". . . the measured discharge pressure will always be a smaller number than the actual total head developed by the pump." and that ". . . Applying the Section XI acceptance criteria to just the i discharge pressure instead of the total developed head for a deep draft pump is a conservative application. . ." Generally, discharge pressure is a larger value than d/p. The Code has you l subtract inlet pressure from discharge pressure to obtain d/p. The Code has no provision for correcting for system static head or height differences. However, for a deep draft pump with a large height difference between the sction point and the discharge point, the discharge pressure can be smaller than the d/p. Applying the acceptance criteria to the smaller quantity would be a conservative approach, since the acceptable range would be decreased. Changes in a pump's I hydraulic condition would be indicated by changes in discharge pressure and flow given that l the inlet suction pressure is constant (or essentially constant). Therefore, measurement and ,

anayisis of discharge pressure can allow an adequate assessment of pump opemtional readiness. The licensee has not thoroughly described their method, however, as described, the method is conservative with respect to the Code requirements. l

)

The service water pump addressed in this request is the subject of other relief requests in this submittal; P-12 and P-13. Request P-12 addresses the use of reference curves of d/p and flow rate. P-13 requests a relaxation of the instrument accuracy requirements for the discharge pressure instrument. Taken seperately, these requests appear to be reasonable approaches to Code testing alternatives. However, taken together, the reviewer does not have adequate information to fully assess the impact of the combination. For instance, the reduced accuracy of the discharge pressure instrument will affect the uncertainty associated with the acceptance criteria for curve testing. Therefore, the proposed alternate should be authorized with the provision that the licensee performs a complete assessment of the impact of the combination on the ability to assess the operational readiness of these pumps.

Based on the determination that requiring the licensee to measure inlet pressure and calculate d/p would be a hardship and would not provide a compensating increase in the level of quality and safety and considering the licensee's propc;;al to use discharge pressure in lieu of d/p we recommend that the alternative be approved pursuant with 10CFR50.55a(a)(3)(ii) with the following provision. The licensee should perform a complete assessment of the impact of the combination of this relief request and requests P-12 and P-13 as to their ability to assess the operational readiness of this pump. The results of that assessment should be available for inspection at the facility.

I1

2.4 Comoonent Cooline and Service Water l

2.4.1 Curve Testine 2.4.1.1 Relief Request. P-12 requests relief from the requirements of Section XI, Paragraphs IWP-3100 and -3110 to establish fixed set (s) of reference values of d/p, flow rate, j and vibration for the component cooling water pumps,1(2)-CC-P-1 A and -1B, and the service I water pumps,1(2)-SW-P-1 A, -1B, and -4. The licensee proposes to test these pumps in their i as-found condition of flow rate and d/p and to compare the results to acceptance criteria based i on a reference pump curve that is generated mathematically from the results of test data taken l at at least five points of operation.

2.4.1.1.1 Licensee's Basis for Requgsline Relief-The following text is quoted l from relief request P-12 in Revision 7 of the North Anna Power Station, Units 1 and 2, second i interval IST program submitted by letter dated December 16,1993: i Plant conditions may not be the same as when the reference values were established.

Many reference points must be established to anticipate future plant conditions. In the 1 component cooling and service water systems, reproducing one of these reference flow l points is difficult with the large butterfly valves installed and it may not be desirable to l alter cooling because of other plant operating parameters.

Past vibration data for the subject pumps has been reviewed and it has been determined that pump vibration does not vary significantly with flow rate over the range of the test

{

flow rates.

Altemate Testine: All subsequent test results will be compared to calculated reference values which are determined using the following method. A set of at least five pressure / flow points will be recorded. From these points, an equation for the line will be calculated by a computer using polynomial regression. The resulting polynomial ,

equation describes the reference curve. l l

Flow points will be taken Ntween the limits of the original data points. The resulting l pressure is then compared to the ASME XI, Table IWP-3100-2 limits. Pumps may I then be tested during normal operation without any valve throttling. An example of acceptance criteria based on a reference curve is shown in Figure 1.

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80 ::: isis sisi isis siis iisi sisi seis.:: issa siis inii s.oco s.sco 7.000 7.sco s coo s.soo s. coo s.sco so. coo so.sco it. coo t i.soo it. coo Tomi Fine mene (som) 8**"* N Figure 1. Pump Acceptance Criteria Based on a Reference Curve 2.4.1.1.2 Evaluation-The Code requires pump testing at reference values taken at points of operation that can be duplicated during subsequent testing. The pump speed is set (for variable speed pumps), the reference value of either flow rate [Q] or d/p is established, and the corresponding dependant variable of d/p or Q is measured and compared to the applicable acceptance criteria. This allows an assessment of changes in pump operational characteristics and the determination of operational readiness. These systems operate under constantly varying loads with automatic temperature control valves independently modulating flow through each heat exchanger. Due to seasonal variations in temperature of the river water and constantly changing heat loads, the pump configuration and system flow rate vary.

13

It is also difficult to achieve predefined reference points using the large butterfly valves installed in these systems. Reconfiguring the system loads to achieve fixed reference points risks damage to components due to interruption or loss of the cooling supply. Therefore, it is impractical to control this type of system to allow repeatability of reference values during power operation or outages when the heat loads constantly change and remain relatively high.

Where it is impractical to test at a reference value of flow rate or differential pressure, testing in the "as found" condition and comparing values to an established reference curve may be an acceptable alternative. Pump curves represent an infinite set of reference points of flow rate and d/p. Establishing a reference curve for a pump when it is known to be operating acceptably, and basing the acceptance criteria on this curve, can permit evaluation of pump condition and detection of degradation. There is, however, a higher degree of uncertainty associated with using a curve to assess operational readiness. Therefore, the development of the reference curve should be as accurate as possible. Additionally, when using reference curves, it may be more difficult to identify instrument drift or to trend changes in component -

condition.

Establishing a reference test point for the pumps in these systems is impractical during power operation and most cold shutdowns due to the impact on the system and the cooled equipment. Therefore, as-found testing using a reference curve may be the only practical-alternative to the Code requirements. This testing can be acceptable if the following elements are incorporated into the IST program and procedures for developing and implementing the curve (s):

a. Curves are developed, or manufacturer's pump curves are validated, when the pumps are known to be operating acceptably.

b. The reference points used to develop or validate the curves are measured using instruments at least as accurate as required by the Code.

c. Curves are based on an adequate number of data points, with a minimum of five,

d. Points are beyond the " flat" portion (low flow rates) of the curve in a range which includes or is as close as practicable to design basis flow rates.

c. Accey.ance criteria based on the curves does not conflict with Technical Specification (TS) or Facility Safety Analysis Report operability criteria, for flow rate and d/p, for the affected pumps.

f. If vibration levels vary significantly over the range of pump conditions, a method for assigning appropriate vibration acceptance criteria should be developed for regions of the pump curve.

g. When the reference curve may have been affected by repair, replacement, or routine service, a new reference curve shall be determined or the previous curve revalidated by an inservice test.

, The service water pumps addressed in this request are also the subject of other relief requests in this submittal; P-9, P-10, and P-13. Requests P-9 and -10 are similar and address the use of discharge pressure in lieu of d/p. P-13 requests a relaxation of the instrument accuracy requirements for the discharge pressure instrument. Taken separately, these requests 14

y l

1 appear to be reasonable approaches to Code testing alternatives. However, taken together, the I reviewer does not have adequate information to fully assess the impact of the combination.

For instance, the reduced accuracy of the discharge pressure instrument will affect the uncertainty associated with the acceptance criteria for curve testing. Therefore, the proposed i alternate should be authorized with the provision that the licensee performs a complete assessment of the impact of the combination on the ability to assess the operational readiness of l these pumps.

Based on the determination that establishing the reference flow rate or d/p is

! impractical and burdensome during quarterly testing, and considering that measuring as-found conditions and using reference curves to evaluate these parameters can permit an adequate l assessment of pump operational readiness, relief should be granted from this Code requirement l pursuant to 10CFR50.55a(f)(6)(i) with the following provisions. The licensee should follow the seven guidelines identified above for using reference curves, if practicable. Where it is not practicable to follow these guidelines, the licensee should identify the specifics of their alternative and justify the deviations and show the adequacy of their proposed testing. Also, l for the service water pumps,1(2)-SW-P-1 A, -1B, and -4, the licensee should perform a l

complete assessment of the impact of the combination of this relief request and requests P-9, P-10, and P-13 as to their ability to assess the operational readiness of these pumps. The results of that assessment should be available for inspection at the facility.

2.5 Boric Acid Transfer Pumps 2.5.1 Test Frecuency and Duration 2.5.1.1 Relief Recuest. P-15 requests relief from the test frequency and test duration requirements for boric acid transfer pumps,1-CH-P-2A, -2B, -2C, and -2D as required by Section XI, Paragraphs IWP-3400 and -3500. The licensee proposes to test these pumps quarterly on the recirculation loop. During refueling outages, the licensee proposes to place the pumps on the recirculation loop for three minutes and then direct full flow to the RCS for two minutes. Test data will be recorded when flow is directed to the RCS.

2.5.1.1.1 Licensee's Basis for Recuestine Relief-The following text is quoted from relief request P-15 in Revision 7 of the North Anna Power Station, Units 1 and 2, second interval IST program submitted by letter dated December 16,1993:

Permanent flow instrumentation is not installed on the recirculation piping, which is the ;

only test loop available for quarterly testing. To measure flow, flow must be l l

established to the emergency and alternate boration paths and then to the charging )

pump suctions. This flow would increase the RCS boron inventory and cause a {

reactivity transient during normal operation. 4 During cold shutdown, the emergency and alternate boration path valves are tested with

! flow. However, this test is short in duration to minimize the amount of boric acid injected into the RCS. The pump test requires an extended period of boric acid i 15 l

1

injection, which would upset the RCS boron balance and possibly impact the ability of l l

the plant to restart. Therefore, this test should only be performed during cold shutdowns on the way to reactor refueling while the RCS is being borated or during reactor refuelings.

During RCS boration or during reactor refuelings, extended periods of pump operation on high speed can either interfere with the boration process or adversely affect the boron balance in the RCS. Therefore, to limit the amount of boric acid injected into the RCS during the pump tests, the pumps will be run for two minutes with flow to the RCS before the test quantities are measured. l l

Alternate Testine: These pumps will be tested every quarter on the recirculation loop.

Inlet pressure, differential pressure and vibration will be measured. Every reactor refueling, inlet pressure, differential pressure, flow and vibration will be measured I after the pumps have been run for two minutes with flow to the RCS.

2.5.1.1.2 Evaluation-The Code requires quarterly pump testing and specifies I the minimum test duration. These pumps take their suction from the boric acid tanks. The recirculation line, which is the line available for the quarterly test at power is not instmmented for flow rate. Inlet and d/p can be monitored quarterly along with pump vibration but, due to l the lack of instrumentation, it is impractical to measure flow rate. It is possible to use the j instrumented line using the emergency and alternate boration paths to the charging pump l suctions but this is impractical since it would inject highly concentrated boric acid into the l RCS. During power operation this could cause a reactivity transient and possible a plant shutdown, which would be burdensome to the licensee.

During cold shutdown the alternate and emergency boration paths are tested with flow, but for a short time period only. Longer periods of pump operation would significantly increase the amount of boron in the RCS. The higher concentrations of boron in the RCS would require large amounts of water to dilute to critical boron concentration. In order to provide space for this dilution, water must be letdown from the RCS which must be treated* as radioactive waste. The time and effort required to perform the dilution and treat the radioactive waste water could delay plant start-up. This also, would be burdensome to the licensee.

The licensee's proposal to perform full flow testing during refueling outages while the RCS is being borated for reactor refueting or during refuelings when boron concentration needs to be increased, should allow an adequate assessment of operational readiness. The licensee has further requested at refueling to run these pumps for 3 minutes on the recirculation line and then for 2 minutes at full flow into the RCS to prevent over boration of the RCS and maintain proper chemistry control. The licensee's proposal would ensure that the pump was run for a minimum of 5 minutes prior to collecting data as required by the Code.

OM-6 requires that a pump be run at least two minutes after pump conditions are as stable as the system permits. The licensee's proposal conforms with the test duration specified in OM-6.

16

In rulemaking to 10CFR50.55a effective September 8,1992, the 1989 Edition of ASME Section XI was incorporated in 10CFR50.55a(b). The 1989 Edition of Section XI provides that the rules for IST of pumps are as specified in OM-6. 10CFR50.55a(f)(4)(iv) provides that IST of pumps may meet the requirements set forth in subsequent editions and addenda that are incorporated by reference in 10CFR50.55a(b), subject to the limitauons and modifications listed, and subject to NRC approval. Portions of editions or addenda may i>e used provided that all related requirements of the respective editions or addenda are met.

OM-6, Paragraph 5.6, permi'3 running the pump only two minutes after the sytem is as stable as conditions permit. The MRC staff imposed no limitations to OM-6 associated with test duration. Accordingly, the licensee's proposed alternate testing is in compliance with the rulemaking effective September 8,1992, and relief is not required. Therefore, we recommend that the alternative test duration be approved pursuant to 10CFR50.55a(f)(4)(iv), provided the licensee implements all related requirements. There are no related requirements associated with the test duration.

Based on the determination that compliance with the Code requirements is impractical and burdensome, and considering the licensee's proposal, relief should be granted as requested pursuant to 10CFR50.55a(f)(6)(i).

l l

17

1

.. l 1

3. VALVE TESTING PROGRAM l l

The following valve relief requests were evaluated against the requirements of the 1986 l Edition of the ASME Code,Section XI,10 CFR 50.55a, and applicable NRC positions and i guidelines. A summary is presented for each relief request followed by the licensee's basis for I relief and the evaluation with the reviewer's recommendations. The evaluations are grouped according to topic or system. Each relief request evaluation is applicable to both units unless specified otherwise. Unit 1 relief request identifiers are shown without parenthesis, while Unit 2 request numbers are shown inside parenthesis, e.g., V-39 (V-40). The valve identification numbers are also shown in this manner with the Unit I numbers shown without parenthesis and the Unit 2 request numbers shown inside parenthesis, e.g.,1-SI-47 (2-SI-18).

3.1 General Valve Relief Reauests 3.1.1 Valve Leakare Rates 3.1.1.1 Relief Reauest. V-59 (V-59) requests relief from assigning individual leakage rates to the listed containment isolation valves (CIVs) as required by Section XI, Paragraph IWV-3426. The licensee proposes to group these valves and assign a permissible leak rate to the entire group.

3.1.1.1.1 Licensee's Basis for Recuesting Relief-The following text is quoted from relief request V-59 (V-59) in Revision 7 of the North Anna Power Station, Unit 1 (Unit 2), second interval IST program submitted by letter dated December 16,1993:

The piping configurations for some containment penetrations do not allow for the individual leakage testing of the containment isolation valves.

Altemate testing: In cases where containment isolation valves cannot be individually leakage tested, the containment isolation valves are grouped based on the configuration restraints and the groups are assigned permissible leakages. The groups are subject to the acceptance criteria described in IWV-3427(a).

3.1.1.1.2 Evaluation-Section XI requires that Category A valves be leak rate tested to verify their seat tightness. GL 89-04, Position 10, states: "The staff has determined that the leak test procedures and requirements for containment isolation valves specified in 10 CFR 50, Appendix J are equivalent to the requirements ofIWV-3421 through 3425.

However, the licensee must comply with the Analysis of Leakage Rates and Corrective Action requirements of Paragraph IWV-3426 and 3427(a)." The licensee proposes to leak rate test the ,

listed CIVs in groups assigning permissible leakage limits for the group and following the acceptance criteria and corrective actions of IWV-3427(a).

)

l Section XI is a component test Code to monitor individual component condition and degradation to assess their operational readiness, therefore, these valves should be individually leak rate tested where practicable. When individual leak rate testing is impractical, because of 18 ,

1 l

l

the lack of necessary test taps and/or isolation valves, testing in groups can be acceptable. The group leakage limits need to be conservatively set such that excessive leakage through any individual valve in the group can be detected and the appropriate corrective actions taken.

According to the P&ID's supplied by the licensee, it is impractical to test these valves individually because of the lack of necessary test taps and isolation valves. The systems would require design changes and modifications in order to perform individual valve leak tests.

These changes and modifications could delay plant start-up and be burdensome to the licensee.

The licensee's proposal to test these valves in groups and then assign a permissible leakage rate to the group should provide reasonable assurance of the leak tight integrity of the valve groups.

Based on the determination that compliance with the Code requirements is impractical and burdensome, and considering the licensee's proposal, we recommend that relief be granted pursuant to 10CFR50.55a(f)(6)(i) with the following provision. The maximum group leakage rate limits should be conservatively based on the smallest valve in the group so that corrective actions will be taken whenever the leak tight integrity of any of the group valves is in question.

3.1.2 Containment Isolation Valve Corrective Actions 3.1.2.1 Relief Reauest. V-69 (V-70) requests relief from the leak rate test corrective action requirements of Section XI, Paragraph IWV-3427(a), for all of the CIVs in the IST program. The licensee proposes to allow an evaluation of CIV leakage rates that are above the allowable leakage limits for individual valves as long as the overall containment leakage is less than 0.6L,. If the evaluation indicates that the containment leakage rate will remain below 0.6L, until the next Type C tests, the licensee proposes that the valve with the high leakage rate need not be repaired or replaced.

3.1.2.1.1 Licensee's Basis For Reauestine Relief-The following text is quoted from relief request V-69 (V-70) in Revision 7 of the North Anna Power Station, Unit 1 (Unit 2), second interval IST program submitted by letter dated December 16,1993:

Permissible valve leakage rates are based on each valve's possible contribution to the total leakage rate for the containment system. The total containment leakage rate must be less than 0.6L, as defined in Technical Specification 4.4.C. Exceeding an individual valve's permissible leakage rate may have no affect on the containment's ability to maintain an overall leakage rate less than 0.6L,. Also, there may be plant conditions, or schedule constraints, that preclude repair or replacement of a valve when the individual leakage limit is exceeded, but the overall leakage limits for the Type C-tested valves is met. In these cases, imposing the Code requirements of repair or replacement would create an undue burden with no compensating benefit to quality and safety when the bases for leakage limits is met for the overall limit necessary to ensure containment integrity.

19

Alternate Testing: In addition to repair or replacement as corrective actions, an evaluation can be performed which demonstrates that even if a valve has exceeded its permissible leakage rate, the overall containment leakage rate will be maintained below 0.6L, until the next Type C tests. No repair or replacement is necessary if the i evaluation is performed. However, when the plant conditions are not such that a repair I or replacement would adversely impact plant startup and/or continued operations, an evaluation is not appropriate.

3.1.2.1.2 Evaluation-Section XI requires that Category A valves be leak rate tested once every two years to verify their seat tightness. GL 89-04, Position 10, permits the l use of 10 CFR 50, Appendix J in lieu of the requirements of IWV-3421 through 3425 for CIVs but requires compliance with the requirements of Paragraphs IWV-3426 and 3427(a). If a valve's leakage rate exceeds the permissible value, IWV-3427(a) requires that the valve be

)

l replaced or repaired. The licensee proposes that when an individual valve exceeds its leakage !

limit, in lieu of repairing or replacing the valve, the option be available to perform an ,

evaluation that demonstrates that the overall containment leakage rate will be maintained below l 0.6L, until the next Type C tests.

1 1

Section XI is intended to verify th : operational readiness of individual components.

Failure of a valve to meet an acceptance criteria indicates that the valve is degraded and may not be capable of performing its safety function. However, the Category A leakage limit assigned to individual CIVs is an artificially derived value because the only leakage sensitive limit for valves whose only Category A function is containment isolation is the 0.6L, total l leakage from containment limit. If a CIV exceeds its leakage rate limit, it indicates that the l valve has not seated tightly and may be degraded. However, exceeding an individual CIV leakage rate limit does not indicate that the group of all CIVs cannot meet their leak tight safety function unless the 0.6L, total leakage limit is exceeded. Applying the analysis of ;

leakage rates and corrective action requirements of Paragraphs IWV-3426 and 3427(a) in this i I

situation may not be appropriate because the group of all CIVs can meet their leak tight safety function. Requiring the licensee to delay plant startup or to shutdown the plant to repair or replace a CIV that exceeds its individual limit would be a hardship and would not provide a l compensating increase in the level of quality and safety as long as the overall leakage rate is I less than 0.6L,.

If the leakage rate for a valve is significant for its size, beyond the leakage associated with seat damage or slight misalignment, it could indicate other significant valve degradation problems that could result in the valve failing to go to its safety position. In this case, continued plant operation prior to valve repair or replacement may not be appropriate. This is especially true for smaller valves that may have significant leakage for their size without )

causing the overall leakage rate to approach the 0.6L, limit. In cases where a valve's leakage rate is so high that its closure capability is questionable, it is not only a concern of exceeding the leak rate testing requirements of Paragraph IWV-3420, it is also a concern with not meeting the valve exercising requirements of Paragraph IWV-3412 or -3522.

I The licensee did not provide details about the evaluation that would be performed to 20 l 1

I

demonstrate that "even if a valve has exceeded its permissible leakage rate, the overall containment leakage rate will be maintained below 0.6L, until the next Type C tests." To make this determination it may be necessary to ascertain the root cause of the increased leakage rate and establish the rate at which this degradation could progress. This evaluation is an important aspect of this request and should be performed in a manner that provides a high level of assurance that delaying the repair or replacement of individual valves with high leakage rates will not result in exceeding the 0.6L, limit before the next leakage rate tests.

Based on the determination that requiring the licensee to delay plant startup or to shutdown the plant to repair or replace a CIV that exceeds its individual limit would be a hardship and would not provide a compensating increase in the level of quality and safety as long as the leakage rate does not indicate the probability of severe valve degradation and the overall leakage rate is less than 0.6L,, we recommend that the alternative be approved pursuant with 10CFR50.55a(a)(3)(ii) with the following provision. The licensee's evaluation should be documented and be performed in a manner that provides a high level of assurance that delaying the repair or replacement of valves with high leakage rates will not result in exceeding the 0.6L, limit before the next leakage rate tests.

This alternative should not be used for valves that perform a limited leakage function in addition to or other than containment isolation (e.g., pressure isolation), because the basis for the leakage limits for these valves is different than the total containment leakage limit discussed above.

3.1.3 Isolation Valve Leakace Rate Corrective Actions 3.1.3.1 Relief Request. V-75 (V-76) requests relief from the leak rate test corrective action requirements of Section XI, Paragraph IWV-3427(a), for the refueling water storage tank (RWST) isolation valves listed below. The licensee proposes to allow an evaluation of leakage rates that are above the allowable leakage limits for individual valves as long as the overall allowable leakage rate to the RWST remains below the overall limit for the RWST. If the evaluation indicates that the overall leakage rate is below the RWST limit, the licensee proposes that the valve (s) with the high leakage rate need not be repaired or replaced.

Unit i Valves Unit 2 Valves 1-CH-MOV-1115B 2-CH-MOV-2115B 1-CH-MOV-1115D 2-CH-MOV-2115D 1-SI-47 2-SI-18 1-SI-MOV-1885A 2-SI-MOV-2885A 1-SI-MOV-1885B 2-SI-MOV-2885B 1-SI-MOV-1885C 2-SI-MOV-2885C 1-SI-MOV-1885D 2-SI-MOV-2885D 3.1.3.1.1 Licensee's Basis For Reauestine Relief--The following text is quoted from relief request V-75 (V-76) in the licensee's submittal for North Anna Power Station, Units 1 and 2, dated April 26,1994:

21

Valves 1-CH-MOV-1115B and D (2-CH-MOV-2115B and D), and 1-SI-47 (2-SI-18) are in the supply lines to the charging pumps from the RWST. Valves 1-SI-MOV-1885A, B, C, and D (2-SI-MOV-2885A, B, C, and D) are on test lines that run from the discharge of the low head SI pumps to the RWST. During recirculation mode transfer, the RWST is isolated and the low head SI pumps recirculate highly contaminated water from the containment sump to the reactor vessel. The RWST isolation valves work as a system of valves to protect the RWST from the contaminated sump water. Permissible valve Inhge rates are based on each valve's possible ,

contribution to the total allowable leakage rate to the RWST. When the leakages from l each valve have been measured and summed, an individual valve's permissible leakage rate may have been exceeded but the overall allowable leakage to the RWST may not have been exceeded. In these cases, a repair or replacement may not be necessary l because the system ofisolation valves has been verified to be performing adequately. !

Alternate Testinz: In addition to repair or replacement as corrective actions, an evaluation can be performed which demonstrates that even if a valve has exceeded its permissible leakage rate, the overall leakage rate to the RWST will be maintained below the overall allowable RWST leakage rate. No repair or replacement is necessary if the evaluation is performed. I 3.1.3.1.2 Evaluation-Section XI requires that Category A valves be leak rate tested once every two years to verify their seat tightness. The Section XI Code is intended to l verify the operational readiness ofindividual components. Failure of a valve to meet an

)

acceptance criteria indicates that the valve is degraded and may not be capable of performing its safety function. However, the leakage rate limits assigned to individual RWST isolation valves are artificially derived values because the only leakage sensitive limit for these valves is the overall leakage limit to the RWST. If one of these valves exceeds its leakage rate limit, it indicates that the valve has not seated tightly and may be degraded. However, exceeding an individual leakage rate limit does not indicate that the group of all RWST isolation valves cannot meet their leak tight safety function unless the leakage limit to the RWST is exceeded.

Applying the analysis of leakage rates and corrective action requirements of Paragraphs IWV-3426 and -3427(a) in this situation may not be appropriate because the group of valves can meet their leak tight safety function. Requiring the licensee to delay plant startup or to shutdown the plant to repair or replace one of these valves that exceeds its individual limit would be a hardship and would not provide a compensating increase in the level of quality and safety as long as the overall leakage rate is less than the specified limit to the RWST.

If the leakage rate for a valve is significant for its size, beyond the leakage associated with seat damage or slight misalignment, it could indicate other significant valve degradation problems that could result in the valve failing to go to its safety position. In this case, continued plant operation prior to valve repair or replacement may not be appropriate. This is especially true for smaller valves that may have significant leakage for their size without causing the overall leakage rate to approach the overall limit. In cases where a valve's leakage rate is so high that its closure capability is questionable, it is not only a concern of exceeding 22

the leak rate testing requirements of Paragraph IWV-3420, it is also a concern with not meeting the valve exercising requirements of Paragraph IWV-3412 or -3522.

The licensee did not provide details about the evaluation that would be performed to demonstrate that "even if a valve has exceeded its permissible leakage rate, the overall leakage rate to the RWST will be maintained below the overall allowable RWST leakage rate." To make this determination it may be necessary to ascertain the root cause of the increased leakage rate and establish the rate at which this degradation could progress. This evaluation is an important aspect of this request and should be performed in a manner that provides a high level of assurance that delaying the repair or replacement ofindividual valves with high leakage rates will not result in exceeding the overall limit before the next leakage rate tests.

Based on the determination that requiring the licensee to delay plant startup or to shutdown the plant to repair or replace a RWST isolation valve that exceeds its individual limit would be a hardship and would not provide a compensating increase in the level of quality and safety as long as the leakage rate does not indicate the probability of severe valve degradation and the overall leakage rate is less than limit, we recommend that the alternative be approved I pursuant with 10CFR50.55a(a)(3)(ii) with the following provision. The licensee's evaluation I should be documented and be performed in a manner that provides a high level of assurance that delaying the repair or replacement of valves with high leakage rates will not result m ;

exceeding the overall limit before the next leakage rate tests.

This alternative should not be used for valves that perform a limited leakage function in addition to or other than limiting leakage to the RWST (e.g., pressure isolation), because the ,

basis for the leakage limits for these valves is different than the overall leakage to the RWST '

limit discussed above. I 3.2 Safety Injection System 3.2.1 Cateeory A/C Valves 3.2.1.1 Relief Recuest. V-40 (V-41) requests relief from the test frequency I requirements of Section XI, Paragraph IWV-3521 for safety injection accumulator make-up and nitrogen supply check valves 1-SI-106 and -110 (2-SI-132 and -136). The licensee proposes to verify valve reverse flow closure every refueling outage, not to exceed once every 24 months.

3.2.1.1.1 Licensee's Basis for Requestine Relief-The following text is quoted .

from relief request V-40 (V-41) in Revision 7 of the North Anna Power Station, Unit 1 l (Unit 2), second interval IST program submitted by letter dated December 16,1993:

These check valves must seat upon reversal of flow in order to fulfill their safety functions. The only method to verify closure is to perform a leak rate /back pressure test. Since the valves are located inside containment, they cannot be tested every three months. These valves will be exercised only during refueling outages because the small 23

increase in safety gained by testing during cold shutdown des not justify the burden of performing a leak rate test.

Alternate Testine: Exercise for operability every refueling (not to exceed 24 months).

3.2.1.1.2 Evaluation-The Code requires a full-stroke exercise of safety-related check valves quarterly, if practical, or during cold shutdowns if quarterly full-stroke exercising is impractical. The licensee proposes to exercise these valves closed as pairs instead of individually at the frequency described in TS Table 4.1-2A. If a pair fails the test, both valves will be subject to inspection, repair, or replacement. These are simple check valves w hich are located inside containment. It appears that the only practical conventional method to verify reverse flow closure is by performing a leak rate /back flow test. It is impractical to leak test these valves during power operations because this would require a containment entry.

Containment entry is restricted during power operations due to high radiation levels and other personnel safety hazards. A leak rate test is a non-routine test requiring planning, special plant modes, and an elaborate test configuration. Performance of this leak test at cold shutdown could delay plant start-up. This would be burdensome to the licensee. The licensee's proposal to verify reverse flow closure every refueling outage, not to exceed 24 months, should provide a reasonable assurance of operational readiness.

Rulemaking to 10CFR50.55a effective September 8,1992, allows the use of portions of OM-10, provided that all related requirements are met. The staff imposed no limitations to OM-10 associated with the test frequency requirements for check valves and determined that the related requirements to OM-10, Paragraph 4.3.2.1, are found in Paragraph 6.2. The licensee's proposal is consistent with the provisions of OM-10 for test frequency.

Accordingly, the relief requested by the licensee is covered by the rulemaking effective September 8,1992, as described above, and reliefis not required. It is recommended that the alternative proposed by the licensee be approved pursuant to 10CFR50.55a(f)(4)(iv), provided the related requirements of OM-10, Paragraph 6.2 are met. Implementation of related !

requirements is subject to NRC inspection.

3.2.2 Cateeory C Valves 3.2.2.1 Relief Request. V-53 (V-54) requests relief from the test frequency requirements of Section XI, Paragraph IWV-3521 for the low head safety injection pump seal water supply check valves 1-SI-4 and -21 (2-SI-6 and -29). The licensee proposes to verify closure of these valves by leak rate testing them each refueling outage.

3.2.2.1.1 Licensee's Basis for Requestine Relief-The following text is quoted l from relief request V-53 (V-54) in Revision 7 of the North Anna Power Station, Unit 1 (Unit 2), second interval 1ST program submitted by letter dated December 16,1993:

Due to the plant configuration, these valves cannot be verified closed using system flow. The only method to verify closure other than disassembly and inspection is to perform a back pressure test using a primary grade water supply as the pressure source.

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To perform the back pressure test on these 3/4" check valves, each LHSI pump must be removed from service for approximately two hours. With one ECCS train out of service, the plant must enter the Technical Specification Action Statement per Paragraph 3.5.2.a and proceed to hot shutdown within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. Including the preparation for the test which consists of connecting primary grade water to the test volume using supply hoses, the entire test for each valve takes several hours to perform. Also, the seal water line, which may contain contaminated water, must be drained and vented. Considering that one train of ECCS must be removed from service for an extended period of time which degrades the safety of the plant, and the difficulty in performing the back pressure test, testing these 3/4" check valves to the closed position every three months is not practical.

These valves are also subject to leak testing, which is performed every reactor refueling. A leak test provides more information concerning the condition of the valve seats than just a back pressure test. When compared to the Code reg': ements for a backseat test performed every cold shutdown, the performance of a leak test every refueling outage is an alternative that provides an acceptable level of quality and safety.

Altemate Testing: Exercise to the closed position every reactor refueling.

3.2.2.1.2 Evaluation-The Code requires a full-stroke exercise of safety-related check valves quarterly, if practical, and provides a hierarchy for part and full-stroke exercising quarterly or during cold shutdowns if quarterly full-stroke exercising is impractical. The licensee proposes to exercise these valves closed during refueling outages.

These valves are in the seal water supply lines to the LHSI pumps. The only feasible conventional method for verifying these valves in the closed position is back pressure or leak rate testing. It is impractical to back pressure test these valves quarterly during power operation because it requires removing a LHSI pump from service, connecting a primary grade water supply to the test volume using hoses, perforning the test, draining and venting the header, and returning the system to service. This testing involves substantial setup and takes several hours to conduct for each LHSI train, which removes the LHSI train from service, thereby reducing its availability. Performing this testing during cold shutdowns could delay plant start-up. This would be burdensome to the licensee. The licensee's proposal to verify the closure of these valves by leak rate testing them each refueling outage is a better quality test than simply exercising the valves closed and should provide additional information about valve condition. Performing the better test less frequently should provide a reasonable assurance of valve operational readiness.

Rulemaking to 10CFR50.55a effective September 8,1992, allows the use of portions of OM-10, provided that all related requirements are met. The staffimposed no limitations to OM-10 associated with the test frequency requirements for check valves and determined that the related requirements to OM-10, Paragraph 4.3.2.1, are found in Paragraph 6.2. The licensee's proposal is consistent with the provisions of OM-10 for test frequency.

Accordingly, the relief requested by the licensee is covered by the rulemaking effective 25

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l September 8,1992, as described above, and relief is not required. It is recommended that the )

alternative proposed by the licensee be approved pursuant to 10CFR50.55a(f)(4)(iv), provided I the related requirements of OM-10, Paragraph 6.2 are met. Implementation of related requirements is subject to NRC inspection.

3.2.2.2 Relief Request. V-39 (V-40) requests relief from the test frequency requirements of Section XI, Paragraph IWV-3521, for the refueling water storage tank (RWST) supply to charging pump suction header check valve 1-SI-47 (2-SI-18). The licensee I

proposes to part-stroke exercise this valve open at cold shutdowns and to full-stroke exercise it open and verify reverse flow closure at refueling outages.

i 3.2.2.2.1 Licensee's Basis for Requesting Relief-The following text is quoted )

from relief request V-39 (V-40) in Revision 7 of the North Anna Power Station, Unit 1 )

(Unit 2), second interval IST program submitted by letter dated December 16,1993: l 1

l Full or part-stroke exercising this valve during power operation would require charging pump suctions be aligned with the Refueling Water Storage Tank. This alignment would cause a sudden increase in Reactor Coolant System boron inventory. Full flow for the charging system cm only be established during reactor refueling when the RCS is depressurized. To verity valve closure, the refueling water storage tank must be l isolated which is a violation of Technical Specification 3.1.2.1.b during normal operation. The only method to verify closure other than disassembly and inspection is ,

to perform a leak rate /back pressure test. This valve is also subject to leak testing, I which is performed every reactor refueling. Verification of closure will be performed during the leak test every reactor refueling instead of every cold shutdown because the I small increase in safety gained by testing during cold shutdown does not justify the ,

burden of draining the lines and performing a leak rate test. !

l Alternate Testing: Exercise to the partially open position during cold shutdown, j exercise to the full open and closed positions every reactor refueling. j 3.2.2.2.2 Evaluation-The Code requires a full-stroke exercise of safety-related check valves quarterly, if practical, and provides a hierarchy for part and full-stroke exercising quarterly or during cold shutdowns if quarterly full-stroke exercising is impractical. The licensee proposes to part-stroke exercise this valve at cold shutdowns and full-stroke exercise it open and verify its closure by leak rate testing during refueling outages.

It is impractical to full or partial-stroke exercise this valve open or verify its reverse flow closure during power opera.ons. In order to exercise it to the open position, the charging pump suction must be aligned to the RWST. Aligning the charging pump suction to the RWST during power operations would inject highly concentrated boric acid into the RCS causing a power transient and a possible reactor shutdown and/or trip. Verifying reverse flow closure of this valve, during power operations, would require isolating the RWST from the charging pumps which is a violation of plant Technical Specification (TS) 3.1.2.1.b.

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. I Full-stroke exercising this valve during cold shutdowns would create a concern for low-temperature overpressurization (LTOP) of the reactor coolant system and could cause possible pressurized thermal shock (PTS). The system would require design changes and modifications to perform the testing at the Code required frequency. Requiring the licensee to make these changes and modifications would be burdensome. The licensee proposes to part-stroke exercise this valve open during cold shutdown and to full-stroke exercise it open and verify its reverse flow closure every refueling outage. The licensee's proposal to verify the closure of this valve by leak rate testing each refueling outage is a better quality test than simply exercising the valve closed and should provide additional information about valve condition. The proposed testing should provide a reasonable assurance of valve operational readiness.

Rulemaking to 10CFR50.55a effective September 8,1992, allows the use of portions of OM-10, provided that all related requirements are met. The staff imposed no limitations to OM-10 associated with the test frequency requirements for check valves and determined that the related requirements to OM-10, Paragraph 4.3.2.1, are found in Paragraph 6.2. The licensee's proposal is consistent with the provisions of OM-10 for test frequency.

Accordingly, the relief requested by the licensee is covered by the rulemaking effective September 8,1992, as described above, and relief is not required. It is recommended that the alternative proposed by the licensee be approved pursuant to 10CFR50.55a(f)(4)(iv), provided the related requirements of OM-10, Paragraph 6.2 are met. Implementation of related requirements is subject to NRC inspection.

3.2.2.3 Relief Request. V-42 (V-43) requests relief from the test frequency requirements of Section XI, Paragraph IWV-3521 for accumulator discharge and cold leg injection check valves,1-SI-125, -127, -142, -144, -159, and -161 (2-SI-151, -153, -168,

-170, -185, and -187). The licensee proposes to exercise these valves at refueling outages using flow from a reduced pressure eccumulator discharge and to verify a full-stroke using nonintrusive techniques. During the first outage where a nonintrusive technique is used, all valves will be verified to full-stroke open using nonintrusives. During subsequent outages, one valve from each of the two groups will be verified to full-stroke open using 3onintrusives.

If the nonintrusive techniques cannot be used to verify a full-stroke exercise of these valves, one valve from each group will be disassembled, inspected, and manually exercised on a sampling basis every other refueling outage.

3.2.2.3.1 Licensee's Basis for Requestine Relief-The following text is quoted from relief request V-42 (V-43) in Revision 7 of the North Anna Power Station, Unit 1 (Unit 2), second interval IST program submitted by letter dated December 16,1993:

These valves cannot be partial or full flow tested during normal operation because the accumulator pressure (600 to 650 psig) is below Reactor Coolant System pressure and the injection of borated water would upset the reactor coolant chemistry. During cold shutdown, the RCS pressure may still prevent full flow testing. Also, discharging the accumulators would challenge the Low Temperature Overpressure Protection System.

A partial flow test is not practical during cold shutdowns. The flow from the 27

I accumulator is dependent on the pressure differential between the accumulator and the RCS. The pressure differential cannot be controlled to the fine degree necessary to preclude dumping too much water into the pressurizer, thus making it difficult to control pressurizer level while pressure is being reduced during cooldown. Also, the RCS temperature is high during short cold shutdowns. Dumping cold accumulator water into the RCS could thermally shock the system.

The accumulators must be isolated to verify closure using back flow for valves 1-SI-127, -144 and -161 (2-SI-153, -170, and -187). The small increase in safety gained by performing the back seat check valve tests every cold shutdown versus every reactor refueling does not justify the added burden of the increased test frequency. The use of non-intrusive monitoring techniques are being evaluated for confirming full disk movement. If non-intrusive techniques can provide a " positive means" for verifying ;

obturator movement, a sampling program will be used as described below due to the burden of applying these techniques in the field.

Alternate Testing: During the first refueling outage where non-intrusive techniques are used, all valves in the group will be tested to verify that the techniques verify valve obturator movement. During subsequent refueling outages, flow testing will be performed on all valves in the group, but the non-intrusive techniques need be applied only to one valve in each group, on a rotating basis, unless indications of problems are ;

identified. In this case, all valves in the group will be subjected to the non-intrusive ;

techniques. Valves 1-SI-125, -127, -142 and -159 (2-SI-151, -153, -168, and -185) ;

will be in one group, and valves 1-SI-144 and -161 (2-SI-170 and -187) will be in the l other group. Because valves 1-SI-144 and -161 (2-SI-170 and -187) are downstream from where RHR connects to the SI line, they experience different service conditions than the other valves. The test frequency is in accordance with Generic Letter 89-04, ;

Position 2.

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The flow test will consist of discharging the accumulator from an initial pressure that is l less than 600 psig. Discharging the accumulator at a lower initial pressure reduces the severity of the transient and the risk of adverse effects on the reactor coolant system.

The low pressure test should provide enough flow to force the disk to the full open position. If full disk movement cannot be confirmed using nonintrusive monitoring, these valves will be placed into two groups and one valve from each group will be j disassembled and inspected every other reactor refueling. Thejustification for the extended disassembly and inspection schedule is available at the station. Valves 1-SI-127, -144 and -161 (2-SI-153, -170, and -187) will be confirmed closed every )

reactor refueling. j 3.2.2.3.2 Evaluation--The Code requires check valves to be exercised to the position (s) required to fulfill their safety function (s). To verify the disk position of check valves that do not have external disk position indication, the Code allows the use of indirect evidence (such as changes in system pressure, flow, temperature, or level) or other positive means. Nonintrusive techniques can be used as "other positive means" to verify the full-stroke 28

of check valves, although in most cases the flow rate must be sufficient to stroke the valves to their backstops. The licensee proposes to use nonintrusive techniques to verify the capability of the subject valves to open. They propose to perform the nonintrusive testing on a sampling basis during refueling outages. During the first refueling outage that this test method is employed, all valves will be tested using nonintrusive methods. During subsequent refueling outages, all valves will be exercised at the partial flow rate used during the initial testing and one valve from each group will be verified open using nonintrusives.

Nonintrusive techniques have been shown to be effective in verifying a full-stroke exercise of check valves by industry group testing programs and by on-site testing at commercial nuclear facilities. Various nonintrusive techniques or combinations of different l

techniques, have also been shown to be capable of detecting degradation of check valves i

during testing programs and on-site testing. If performed in accordance with quality assurance !

program requirements, these techniques are considered "other positive means" in accordance l with Section XI, Paragraph IWV-3522(b), and reliefis not required for their use except as I would be necessary for the testing frequency.

1 These valves are the accumuhtor discharge and cold leg injection header check valves. !

The only flow path through these valves is into the RCS. It is impractical to exercise these valves open during power operations because neither the accumulators nor the RHR pumps are capable of overcoming normal operating RCS pressure Valves 1-SI-144 and -161 (2-SI-170 and -187) are part-stroke exercised by RHR flow during cold shutdowns since they are in the RHR flow paths to the RCS cold legs. However, it is impractical to exercise the remaining valves because the accumulator discharge isolation valves are closed during shutdown and required to remain closed to prevent accumulator discharge which could lead to a LTOP of the RCS. Therefore, it is impractical to verify a full-stroke exercise of these valves with flow quarterly during power operations or during cold shutdowns. Even during refueling outages, a l full differential pressure accumulator 6scharge could damage reactor core components. l Therefore, the only practical nonintrusive method of full-stroke exercising these valves is to pass a partial flow through them and verify a full-stroke using nonintrusive diagnostics.

Because of the difficulty and time required to set up the test equipment and to perform nonintrusive testing of these valves, testing each of these valves every refueling outage would be burdensome to the licensee. Exercising all of these valves with flow every refueling outage and verifying a valve from each group using nonintrusives on a sampling basis should provide a reasonable assurance of valve operational readiness.

By performing nonintrusive testing initially on all valves in the group, the licensee demonstrates that the partial flow fully opens all of the valves and that the nonintrusive method is capable of verifying a full-stroke. By repeating the flow test for all valves each refueling outage under the same conditions, the licensee passes the same flow rate through the valves that has been shown to full-stroke them when they are in good condition. The nonintrusive l verification of one of the group valves, verifies that the sampled valve is capable of a full- i stroke, which provides assurance that it is not significantly degraded. Since the sampled valve is representative of all group valves, this testing provides assurance of the operational readiness of all group valves. If the licensee finds a problem with the sampled valve, the l l

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i remaining group valves would be checked with the nonintrusive technique during that outage. ;

When the system has not been modified and the flow and pressure conditions are repeated, no '

phenomena should invalidate the testing as verified initially that would not be indicated by a problem in one of the group valves. If the licensee modifies the system or performs the testing with different test conditions, the initial verifications should be repeated.

The following guidelines should be observed when using nmintrusive testing techniques in a sampling plan during refueling outages: i

a. Part-stroke exercise the valves quarterly or during cold shatdowns if practical.

b. The valves in the group should meet the grouping criter:a of GL 89-04, Position 2.

c. The test pressures and flow conditions should cause the valves to fully stroke.

d. During the initial test, verify a full-stroke of all group valves using nonintrusives.

e. During subsequent tests, exercise each valve with flow at the prescribed test conditions.

f. At each test, perform nonintrusive verification on one group valve on a rotating schedule.

g. If problems are found with the sampled valve that are determined to affect the operational readiness of the valve, test the other group valves using nonintrusive techniques during the same outage.

The licensee's proposed alternate testing appears to comply with most of the above conditions, however, it is unclear from the submittal if all of these conditions are met. The licensee should verify that the testing of the subject valves complies with all of these guidelines. The proposed grouping in this request does not appear to comply with the GL 89-04 requirement that group valves have the same service conditions. Valve 1-SI-127 (2-SI-153) is the second check valve (closer to the RCS) in the injection line from the accumulator to the RCS while the other three group valves are the first check valves (closer to the accumulators).

Valve 1-SI-127 (2-SI-153) is normally subjected to RCS pressure, water chemistry, and possibly elevated temperatures while the other group valves do not normally experience these conditions. These and other possible differences may affect the corrosion, erosion, wear, etc.

for this valve such that it is not representative of the other valves in the proposed group. The :

licensee also indicated that these valves will be disassembled and inspected in accordance with GL 89-04, Position 2, if they cannot be verified to full-stroke exercise using nonintrusive j techniques. If disassembly and inspection is used, the licensee should ensure that the valves are grouped for disassembly in accordance with Position 2 as discussed above and that all of the Position 2 criteria for extending the disassembly interval are met and documented.

Based on the impracticality and burden of meeting the Code requirements for the ;

subject valves and considering that the proposed testing should provide a reasonable assurance J of valve operation readiness if all of the guidelines identified above for this test method are satisfactorily met, we recommend that relief be granted from the Code requirements pursuant with 10CFR50.55a(f)(6)(i) with the following provision. To use this method, all of the guidelines listed in this evaluation should be satisfied.

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1

3.3 Comoonent Cooline Water System 3.3.1 Category A/C Valves 3.3.1.1 Edief Request. V-3 (V-3) requests relief from the test frequency requirements !

of Section XI, IWV-3521 for the component cooling water supply to RCP auxiliaries containment isolation check valves 1-CC-84, -119, and -154 (2-CC-78, -115, and -152). The l

licensee proposes to verify reverse flow closure capability each refueling outage. )

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3.3.1.1.1 Licensee's Basis for Requestine Relief-The following text is quoted from relief request V-3 (V-3) in Revision 7 of the North Anna Power Station, Unit 1 (Unit 2), I second interval IST program submitted by letter dated December 16,1993:

These check valves must seat upon reversal of flow in order to fulfill their safety functions. The only exercise method to verify this actuation is to perform a leak rate test /back pressure test. Since the valves are located inside containment and their systems are required during power operation, they cannot be tested every three months. 1 The valves will be exercised only during refueling outages because the small increase in I safety gained by testing during cold shutdown does net justify the burden of draining i lines and performing leak rate tests.

Alternate Testing: Exercise for operability each refueling (not to exceed 24 months).

3.3.1.1.2 Evaluation-The Code requires a full-stroke exercise of safety-related check valves quarterly, if practical, and provides a hierarchy for part and full-stroke exercising quarterly or during cold shutdowns if quarterly full-stroke exercising is impractical. The licensee proposes to exercise these valves closed during refueling outages.

These are simple check valves which must seat upon reversal of flow to perform their safety function. These valves are located inside containment. It is impractical to verify reverse flow closure of these valves during power operation because containment entry is required. Containment entry is restricted during power operation because of high radiation levels and other personnel safety hazards. In addition, a leak test can be an involved test requiring special plant modes, draining piping, test equipment hookup, and an elaborate test configuration. Performance of this test at cold shutdown could delay plant start-up, which would be burdensome to the licensee. The licensee's proposal to verify the reverse flow closure of these valves in conjunction with leak rate testing performed each refueling outage should provide reasonable assurance of the operational readiness of these valves.

Rulemaking to 10CFR50.55a effective September 8,1992, allows the use of portions of OM-10, provided that all related requirements are met. The staff imposed no limitations to OM-10 associated with the test frequency requirements for check valves and determined that the related requirements to OM-10, Paragraph 4.3.2.1, are found in Paragraph 6.2. The licensee's proposal is consistent with the provisions of OM-10 for test frequency.

Accordingly, the relief requested by the licensee is covered by the rulemaking effective 31

September 8,1992, as described above, and relief is not required. It is recommended that the alternative proposed by the licensee be approved pursuant to 10CFR50.55a(f)(4)(iv), provided the related requirements of OM-10, Paragraph 6.2 are met. Implementation of related requirements is subject to NRC inspection.

3.3.1.2 Relief Recuest. V-70 (V-71) requests relief from the test frequency requirements of Section XI, Paragraph IWV-3521, for the component cooling water supply to the RHR heat exchangers check valves 1-CC-193 and -198 (2-CC-194 and -199). The licensee proposes to part-stroke exercise these valves open quarterly and full-stroke exercise them open and verify their reverse flow closure each refueling outage, not to exceed 24 months.

3.3.1.2.1 Licensee's Basis for Recuestine Relief-The following text is quoted from relief request V-70 (V-71) in Revision 7 of the North Anna Power Station, Unit 1 (Unit 2), second interval IST program submitted by letter dated December 16,1993.

]

Valves 1-CC-193 and -198 (2-CC-194 and -199) are check valves in the component cooling lines to the RHR heat exchangers and must close for isolation and open to allow RHR flow. The only exercise method to verify closure is to perform a leak rate test /back pressure test. These lines cannot be drained for back seat testing because the RHR system is needed during cold shutdown to control the RCS temperature. To establish full flow through Valves 1-CC-193 and 198 (2-CC-194 and -199) for testing ;

to the full open position, increased component cooling flow must be directed through !

the RHR heat exchangers. During cold shutdown and reactor refueling when fuel is in the vessel, increased flow to the RHR heat exchangers reduces the volume of the RCS inventory by reducing the RCS temperature. This reduction in volume can be large enough as to cause excessive makeup demands to the RCS. Therefore, the full flow test should be performed during reactor refueling when the vesse! b defueled. The vessel is defueled every refueling outage.

Alternate Testing: Exercise for closure each refueling (not to exceed 24 months) and full open every reactor refueling when the vessel is defueled. Partial-stroke open every quarter.

3.3.1.2.2 Evaluation-The Code requires a full-stroke exercise of safety-related check valves quarterly, if practical, and provides a hierarchy for part and full-stroke exercising quarterly or during cold shutdowns if quarterly full stroke exercising is impractical. The licensee proposes to part-stroke exercise these valves quarterly and to full-stroke exercise them and verify their reverse flow closure during refueling outages.

These check valves perform a safety function in the open and closed position. The only practical method to verify reverse flow closure of these valves is to perform a leak rate /back flow test. A leak rate /back flow test can be an involved test requiring special plant modes, draining piping, test equipment hookup, and an elaborate test configuration. Performing this

, testing would result in the affected RHR train being out of service for an extended time and would increase the unavailability of the RHR train to support a reactor shutdown and cooldown 32

should the need occur. Therefore, it is impractical to perform a reverse flow closure test during power operations. A leak rate /back flow test is time consuming, therefore, performing this testing at cold shutdown could delay plant start-up, which would be burdensome to the licensee. The licensee's proposal to verify reverse flow closure each refueling outage, not to exceed 24 months, should provide a reasonable assurance of the reverse flow closure capability of these valves.

It is impractical to full-stroke exercise these valves open quarterly because establishing full flow through an idle RHR heat exchanger could cause thermal stresses that could damage the heat exchanger and result in its premature failure. During cold shutdowns and refueling outages when there is fuel in the vessel, it is impractical to establish full flow through these valves because the RHR system is used for cooling and full cooling flow to the heat exchangers could result in an excessive RCS cooldown rate and reduction in RCS coolant volume. The licensee's proposal to part-stroke exercise these valves open quarterly and full-stroke exercise them open every refueling outage when the reactor vessel is defueled appears to be the only practicable testing for these valve and should provide a reasonable assurance of valve operational readiness.

Rulemaking to 10CFR50.55a effective September 8,1992, allows the use of portions of OM-10, provided that all related requirements are met. The staff imposed no limitations to OM-10 associated with the test frequency requirements for check valves and determined that the related requirements to OM-10, Paragraph 4.3.2.1, are found in Paragraph 6.2. The licensee's proposal is consistent with the provisions of OM-10 for test frequency.

Accordingly, the relief requested by the licensee is covered by the rulemaking effective September 8,1992, as described above, and reliefis not required. It is recommended that the alternative proposed by the licensee be approved pursuant to 10CFR50.55a(f)(4)(iv), provided the related requirements of OM-10, Paragraph 6.2 are met. Implementation of related requirements is subject to NRC inspection.

3.4 Reactor Coolant System 3.4.1 Category A/C Valves 3.4.1.1 Relief Request. V-28 (V-28) requests relief from the tcii trequency requirements of Section XI, Paragraph IWV-3521, for the primary grade water supply to RCP seal standpipe containment isolation check valve,1-RC-149 (2-RC-162). The licensee proposes to exercise this valve for operability each refueling outage, not to exceed 24 months.

3.4.1.1.1 Licensee's Basis for Requestine Relief-The following text is quoted from relief request V-28 (V-28) in Revision 7 of the North Anna Power Station, Unit 1 (Unit 2), second interval IST program submitted by letter dated December 16,1993:

This check valve must seat upon reversal of flow in order to fulfill its safety function.

The only method to verify this actuation is to perform a leak rate test. Since the valve is located inside containment, it cannot be tested every three months. 1-RC-149 33

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1 (2-RC-162) is in the primary grade water to pressurizer relief tank and the #2 seal stand I pipe: This line cannot be drained during short cold shutdowns because the PRT is ]

required during normal cold shutdowns. Standpipe level must be maintained when the j RCS is pressurized to control leakage. The valve will be exercised only during )

refueling outages because the small increase in safety gained by testing during cold shutdown does notjustify draining lines and performing a leak rate test.

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Altemate Testing: Exercise for operability each refueling (not to exceed 24 months). l 3.4.1.1.2 Evaluation-The Code requires a full-stroke exercise of safety-related check valves quarterly, if practical, and provides a hierarchy for part and full-stroke exercising quarterly or during cold shutdowns if quarterly full-stroke exercising is impractical. The licensee proposes to exercise this valve every refueling outage. l l

This is a simple check valve located inside containment and must seat upon reversal of )

flow to perform its safety function. According to the P&ID's, the only practical method to verify reverse flow closure is to perform a leak rate test. It is impractical to verify reverse flow closure of these valves during power operation because containment entry is required.

Containment entry is restricted during power operation because of high r.Jation levels and other personnel safety hazards. In addition, a leak test can be an involved test requiring special plant modes, draining piping, test equipment hookup, and an elaborate test '

configuration. Performance of this test at cold shutdown could delay plant start-up, which would be burdensome to the licensee. The licensee's proposal to verify the reverse flow closure of these valves in conjunction with leak rate testing performed each refueling outage should provide reasonable assurance of the operational readiness of these valves.

Rulemaking to 10CFR50.55a effective September 8,1992, allows the use of portions of OM-10, provided that all related requirements are met. The staffimposed no limitations to OM-10 associated with the test frequency requirements for check valves and determined that the related requirements to OM-10, Paragraph 4.3.2.1, are found in Paragraph 6.2. The licensee's proposal is consistent with the provisions of OM-10 for test frequency.

Accordingly, the relief requested by the licensee is covered by the rulemaking effective i September 8,1992, as described above, and reliefis not required. It is recommended that the alternative proposed by the licensee be approved pursuant to 10CFR50.55a(f)(4)(iv), provided the related requirements of OM-10, Paragraph 6.2 are met. Implementation of related requirements is subject to NRC inspection.

I 3.4.2 Category B Valves )

1 l

3.4.2.1 Relief Request. V-57 (V-58) requests relief from the test frequency 4 requirements of Section XI, Paragraph IWV-3411, for the reactor vessel head vent valves listed in the following table. The licensee proposes to exercise these valves during cold !

shutdowns when the RCS is depressurized but not more frequently than once every three months.

34

Unit One Unit Two 1-RC-SOV-101A-1 2-RC-SOV-201A-1 1-RC-SOV-101 A-2 2-RC-SOV-201A-2 1-RC-SOV-101B-1 2-RC-SOV-201B-1 1-RC-SOV-101B-2 2-RC-SOV-201B-2 3.4.2.1.1 Licensee's Basis for Requestine Relief-The following text is quoted from relief request V-57 (V-58) in Revision 7 of the North Anna Power Station, Unit 1 (Unit 2), second interval IST program submitted by letter dated December 16,1993:

These valves are the Reactor Vessel Head Vent Valves. Full or part-stroke exercising these valves at power could release reactor coolant into the reactor vessel refueling cavity. Stroking of these valves has been performed while the Reactor Coolant System was pressurized. This test revealed that when the upstream valve was stroked, the downstream valve tended to lift due to the motive force of the steam. As long as these valves remain closed under RCS pressure, they are an effective isolation boundary.

However, these valves should not be stroked while the Reactor Coolant System is pressurized. These valves will be exercised during each cold shutdown when the Reactor Coolant System is depressurized.

Alternate Testing: Exercise for operability during cold shutdown when the RCS is depressunzed (but not more frequently than once per three months).

3.4.2.1.2 Evaluation--The Code requires an exercise of safety-related valves quarterly, if practical, or during cold shutdowns if quarterly exercising is impractical. The licensee proposes to exercise these valves during those cold shutdowns when the RCS is depressurized.

These valves are solenoid operated vent valves which relieve RCS pressure to the reactor vessel refueling cavity / containment atmosphere. There are two parallel vent paths, each containing two series isolation valves. These series valves are susceptible to line pressure surges (burping). It is impractical to exercise these valves quarterly during power operations because of the possibility of burping the other series isolation valve open. This unintentional lifting of the other isolation valve would release reactor coolant to the containment atmosphere increasing the contamination levels. Exercising these valves during cold shutdowns would require depressurizing the RCS cach cold shutdown. Depressurizing the RCS each cold shutdown could delay plant start-up and be burdensome to the licensee. The licensee proposes to exercise these valves during cold shutdown when the RCS is depressurized, but not more ,

frequently than once every three months. The licensee's proposal should provide a reasonable I assurance of valve operational readiness.

Rulemaking to 10CFR50.5.',a effective September 8,1992, allows the use of portions of OM-10, provided that all related requirements are met. The staff imposed no limitations to OM-10 associated with the test frequency requirements for check valves and determined that the related requirements to OM-10, Paragraph 4.3.2.1, are found in Paragraph 6.2. The 35 i

l j

licensee's proposal is consistent with the provisions of OM-10 for test frequency.

Accordingly, the relief requested by the licensee is covered by the rulemaking effective September 8,1992, as described above, and relief is not required. It is recommended that the alternative proposed by the licensee be approved pursuant to 10CFR50.55a(f)(4)(iv), provided the related requirements of OM-10, Paragraph 6.2 are met. Implementation of related i requirements is subject to NRC inspection.

3.5 Chemical and Volume Control i

3.5.1 Category A/C valves 3.5.1.1 Relief Request. V-72 (V-73) requests relief from the test frequency requirements of Section XI, Paragraph IWV-3521, for the charging pump suction from the volume control tank (VCT) isolation check valve,1-CH-215 (2-CH-153). The licensee proposes to exercise this valve closed every refueling outage.

3.5.1.1.1 Licensee's Basis for Requesting Relief-The following text is quoted from relief request V-72 (V-73) in Revision 7 of the North Anna Power Station, Unit 1 (Unit 2), second interval IST program submitted by letter dated December 16,1993:

Due to the plant configuration, this valve cannot be verified closed using flow. The only method to verify closure other than disassembly and inspection is to perform a leak rate /back pressure test. During normal operation, this valve cannot be isolated to perform a back pressure test because normal letdown and charging flow would be interrupted. Also, if the valve was isolated during normal operation, the charging pumps would have to be secured. This valve is also subject to leak testing, which is performed every reactor refueling. Verification of closure will be performed during the leak test every reactor refueling instead of every cold shutdown because the small increase in safety gained by testing during cold shutdown does not justify the burden of performing a leak rate test.

Alternate Testing: Exercise to the closed position every reactor refueling.

3.5.1.1.2 Evaluation-The Code requires a full-stroke exercise of safety-related check valves quarterly or during cold shutdowns if quarterly testing is impractical. This testing is to demonstrate that the valves are capable of moving to their safety function position (s) to assess their operational readiness. The licensee proposes to exercise this valve closed during leak rate testing every refueling outage.

This valve is in the line from the VCT to the charging pump suction. It is a simple check valve not equipped with an external operator or position indication. To verify this valve closes to restrict reverse flow requires a reverse differential pressure across the valve or the use of a non-intrusive technique when system flow is stopped. It is impractical to perform this testing quarterly during power operation because it would require stopping letdown flow, normal charging flow, and seal water flow to the RCP seals. This would cause perturbations 36

in RCS pressure, loss of pressurizer level control, and possible damage to the RCP seals.

These conditions could result in a plant trip or shutdown. Stopping charging flow and RCP l seal flow during cold shutdowns when one or more RCP remains in operation could cause l

pressure and level transients and damage the pump seals. During cold shutdowns when the RCPs are stopped, setting up and performing this testing could delay the return to power i

operation, which would be burdensome to the licensee. The licensee's proposal to verify the l

reverse flow closure of this valve during leak rate testing at refueling outages gives reasonable assurance of operational readiness.

Rulemaking to 10CFR50.55a effective September 8,1992, allows the use of portions of OM-10, provided that all related requirements are met. The staff imposed no 1 imitations to OM-10 associated with the test frequency requirements for check valves and determined that

the related requirements to OM-10, Paragraph 4.3.2.1, are found in Paragraph 6.2. The licensee's proposal is consistent with the provisions of OM-10 for test frequency.

Accordingly, the relief requested by the licensee is covered by the rulemaking effective September 8,1992, as described above, and relief is not required. It is recommended that the alternative proposed by the licensee be approved pursuant to 10CFR50.55a(f)(4)(iv), provided the related requirements of OM-10, Paragraph 6.2 are met. Implementation of related requirements is subject to NRC inspection.

3.5.2 Category A/C and C valves 3.5.2.1 Relief Recuest. V-10 (V-10) requests relief from the test frequency requirements of Section XI, Paragraph IWV-3521 for charging water containment isolation check valves,1-CH-322, -330, -336, -358, -380, and -402 (2-CH-260, -284, -308, -331,

-332, and -335). These valves are located in the following flow paths, normal charging line, RCP seal water supply lines, and RCP seal water return line. The licensee proposes to exercise these valves every refueling outage, not to exceed 24 months.

3.5.2.1.1 Licensee's Basis for Requestine Relief--The following text is quoted from relief request V-10 (V-10) in Revision 7 of the North Anna Power Station, Unit 1 (Unit 2), second interval IST program submitted by letter dated December 16,1993:

These check valves must seat upon reversal of flow in order to fulfill their safety functions. The only method to verify this actuation is to perform a leak rate /back pressure test. Since the valves are located inside containment and their systems are required during power operation, they cannot be tested every three months.1-CH-322 (2-CH-335) is in the normal charging line to the RCS. These lines cannot be drained during short cold shutdowns because charging flow is often maintained. 1-CH-336, 358, and 380 (2-CH-260, 284, and -308) are in the RCP seal water supply lines, and 1-CH-402 (2-CH-331) is in the RCP seal water return line. Seal flow is used during cold shutdown to reduce RCS leakage and to float the RCP seals. 1-CH-330 (2-CH-332) is the charging supply to loop fill header, inside containment isolation valve. A local backseat / leak test inside containment is required to verify closure for valve 1-CH-330 (2-CH-332). The valves will be exercised only during refueling 37

. _ _ - _ _ - - _ _ _ _ _ _ _ _ _ _ _ . b

outages because the small increase in safety gained by testing during cold shutdown does notjustify the burden of draining lines and performing leak rate tests.

Alternate Testing: Exercise for operability every refueling (not to exceed 24 months) 3.5.2.1.2 Evaluation-The Code requires a full-stroke exercise of safety-related check valves quarterly or during cold shutdowns if quarterly testing is impractical. This testing is to demonstrate that the valves are capable of moving to their safety function position (s) to assess their operational readiness. The licensee proposes to exercise these valves closed during leak rate testing every refueling outage.

These are simple check valves located inside containment or in systems required to be in operation during power operations. Containment entry is restricted during power operation due to high radiation levels and other personnel safety hazards. Isolating systems, such as, charging or RCP seal water injection / return, could adversely affect plant operations by requiring plant shutdown due to loss of RCS inventory or RCPs being secured. Therefore, it is impractical to exercise these valves during power operation. These valves must seat upon loss or reversal of flow in order to perform their safety functions. The only practical method to verify reverse flow closure capability of these valves is to perform a leak /back flow test. A leak test can be an involved test requiring special plant modes, draining piping, test equipment hookup, and an elaborate test configuration. Performance of this test at cold shutdown could delay plant start-up, which would be burdensome to the licensee. The licensee's proposal to verify the reverse flow closure of these valves in conjunction with leak rate testing performed each refueling outage should provide reasonable assurance of the operational readiness of these valves.

Rulemaking to 10CFR50.55a effective September 8,1992, allows the use of portions of OM-10, provided that all related requirements are met. The staffimposed no limitations to OM-10 associated with the test frequency requirements for check valves and determined that the related requirements to OM-10, Paragraph 4.3.2.1, are found in Paragraph 6.2. The licensee's proposal is consistent with the provisions of OM-10 for test frequency.

Accordingly, the relief requested by the licensee is covered by the rulemaking effective September 8,1992, as described above, and reliefis not required. It is recommended that the alternative proposed by the licensee be approved pursuant to 10CFR50.55a(f)(4)(iv), provided the related requirements of OM-10, Paragraph 6.2 are met. Implementation of related requirements is subject to NRC inspection.

3.6 Instrument Air System 3.6.1 Cateeory A/C Valves 3.6.1.1 Relief Request. V-21 (V-21) requests relief from the test frequency requirements of Section XI, Paragraph IWV-3521, for instrument air inside containment isolation check valves, I-IA-55 and -149 (2-IA-250 and -428). The licensee proposes to exercise these valves every refueling outage, not to exceed 24 months.

38

1 3.6.1.1.1 Licensee's Basis for Reauestine Relief-The following text is quoted from relief request V-21 (V-21) in Revision 7 of the North Anna Power Station, Unit 1 (Unit 2), second interval IST program submitted by letter dated December 16,1993:

These check valves must seat upon reversal of flow in order to fulfill their safety functions. The only method to verify this actuation is to perform a leak rate test. I Since the valves are located inside containment, they cannot be tested every three l months. 1-IA-55 (2-IA-250) is in the instrument air supply line to containment. 1 Testing this valve renders the instruments and components supplied by instrument air '

inside containment inoperable. They will be exercised only during refueling outages ;

because the small increase in safety gained by testing during cold shutdown does not I justify performing leak rate tests.

Alternate Testine: Exercise for operability each refueling (not to exceed 24 months) l l

3.6.1.1.2 Evaluation-The Code requires a full-stroke exercise of safety-related ;

check valves quarterly or during cold shutdowns if quarterly testing is impractical. This testing is to demonstrate that the valves are capable of moving to their safety function position (s) to assess their operational readiness. The licensee proposes to exercise these valves closed during leak rate testing every refueling outage.

These are simple check valves, located inside containment, that must seat upon cessation or reversal of flow in order to perform their safety function. The ortly practical method to verify reverse flow closure is to perform a leak /back flow test. It is impractical to !

exercise these valves closed quarterly during power operations, because this would require ;

containment entry. Containment entry is restricted during power operations due to high i radiation levels and other personnel safety hazards. In addition, a leak test can be an involved test requiring special plzd mob, draining piping, test equipment hookup, and an elaborate '

test configuration. Performance of this test at cold shutdown could delay plant start-up, which !

would be burdensome to the licensee. The licensee's proposal to verify the reverse flow l closure of these valves in conjunction with leak rate testing performed each refueling outage should provide reasonable assurance of valve operational readiness.

Rulemaking to 10CFR50.55a effecdve September 8,1992, allows the use of portions of OM-10, provided that all related requirements are met. The staff imposed no limitations to OM-10 associated with the test frequency requirements for check valves and determined that the related requirements to OM-10, Paragraph 4.3.2.1, are found in Paragraph 6.2. The licensee's proposal is consistent with the provisions of OM-10 for test frequency.

Accordingly, the relief requested by the licensee is covered by the rulemaking effective September 8,1992, as described above, and reliefis not required. It is recommended that the alternative proposed by the licensee be approved pursuant to 10CFR50.55a(f)(4)(iv), provided the related requirements of OM-10, Paragraph 6.2 are met. Implementation of related requirements is subject to NRC inspection.

39

3.7 Service Water System 3.7.1 Cateeory C Valves 3.7.1.1 Relief Request. V-63 (V-64) requests relief from the test frequency requirements of Section XI, Paragraph IWV-3521, for service water pump discharge check valves,1-SW-3 and -10 (2-SW-3 and -10). The licensee proposes to part-stroke exercise these i valves open quarterly and to full-stroke exercise them open and verify their reverse flow l closure capability every refueling outage.

3.7.1.1.1 Licensee's Basis for Requestine Relief-The following text is quoted from relief request V-63 (V-64) in Revision 7 of the North Anna Power Station, Unit 1 l (Unit 2), second interval IST program submitted by letter dated December 16,1993:

These check valves cannot be full flow tested during normal operation or cold l shutdown because the Recirculation Spray Heat Exchangers must be included in the ;

flow path in order for full flow conditions to be established. As described in Relief Request V-45 (V-46), introduction of senice water to the Recirculation Spray Heat Exchangers is prohibited without subsequently draining the heat exchangers. This requirement makes testing during normal operation or cold shutdowns impractical.

Monitoring the discharge pressure gauge of the non-running pump would reveal gross failure of the check valve. However, this test may not detect leakage past the valve due to a partially stuck open disk. The service water pumps are deep draft pumps with enough tolerance between the impellers and the pump casing to pass significant flow without pressurizing the discharge piping to a detectable degree. The verification of full disk closure using back flow can only be performed when design flow it achieved during the service water pump tests. Verification of design flow for the running pump demonstrates adequate back seating for the discharge check valves of the nonrunning pumps. However, the observation of the non-running pump discharge gauge to detect gross failure can and should be performed every three months.

Alternate Testine: These valves will be partial flow tested every three months, and full flow and closure tested every reactor refueling. The non-running pump discharge gauge-will be observed once every three months to detect gross failure of the disk to seat.

3.7.1.1.2 Evaluation--The Code requires a full-stroke exercise of safety-related check valves quarterly, if practical, and provides a hierarchy for part and full-stroke exercising quarterly or during cold shutdowns if quarterly full-stroke exercising is impractical. The licensee proposes to part-stroke exercise these valves quarterly and to full-stroke exercise them and verify their reverse flow closure during refueling outages.

These check valves are located at the discharge of the service water and auxiliary service watter pumps. In order to full-stroke exercise these valves with design flow the 40

recirculation spray heat exchangers, located inside containment, must be included in the flow path. The licensee committed to the NRC to drain these heat exchangers whenever service water has been introduced into them. Containment entry during power operations is restricted because of high radiation levels and other personnel hazards. Therefore, it is impractical to full-stroke exercise these valves with design flow during power operations. Exercising these valves with design flow during cold shutdown would require draining the recirculation spray heat exchangers. Draining these heat exchangers is a non-routine evolution that would involve a significant number of plant personnel and time to accomplish. This could delay plant start up and be burdensome to the licensee.

The only practical method of verifying reverse flow closure of these valves involves verifying design flow from an operating pump, which provides assurance that there is not significant back flow through the check valves on the discharge of the idle pumps. As discussed above, it is impractical to establish design flow through the service water pumps quarterly during power operation or cold shutdowns. There is a pressure transmitter upstream of the check valves being tested. When one or more of the service water pumps are idle, the idle pump's pressure transmitter can be compared to service water header pressure to verify reverse flow closure of the idle pump's discharge check valve. The licensee is making this check quarterly but has found it to be only capable of detecting gross failure of a valve to close because of the relatively large pump tolerances.

Rulemaking to 10CFR50.55a effective September 8,1992, allows the use of portions of OM-10, provided that all related requirements are met. The staffimposed no limitations to OM-10 associated with the test frequency requirements for check valves and determined that the related requirements to OM-10, Paragraph 4.3.2.1, are found in Paragraph 6.2. The licensee's proposal is consistent with the provisions of OM-10 for test frequency.

Accordingly, the relief requested by the licensee is covered by the rulemaking effective September 8,1992, as described above, and relief is not required. It is recommended that the alternative proposed by the licensee be approved pursuant to 10CFR50.55a(f)(4)(iv), provided the related requirements of OM-10, Paragraph 6.2 are met. Implementation of related requirements is subject to NRC inspection.

3.8 Vacuum Primine System 3.8.1 Category A/C Valves 3.8.1.1 Relief Request. V-46 (V-47) requests relief from the test frequency requirements of Section XI, Paragraph IWV-3521, for the condenser air removal inside containment isolation check valve,1-VP-12 (2-VP-24). The licensee proposes to exercise this valve closed each refueling outage.

3.8.1.1.1 Licensee's Basis for Reauesting Relief-The following text is quoted from relief request V-46 (V-47) in Revision 7 of the North Anna Power Station, Unit 1 (Unit 2), second interval IST program submitted by letter dated December 16, 1993:

41

This check valve must seat upon reversal of flow in order to fulfill its safety function.

'Ihe only method to verify this actuation is to perform a leak rate test. Since the valve is located inside containment, it cannot be tested every three months. The valve will be exercised during refueling outages because the small increase in safety gained by testing during cold shutdown does notjustify performing a leak rate test.

Alternate Testinn: Exercising for operability each refueling (not to exceed 24 months) 3.8.1.1.2 Evaluation-The Code requires a full-stroke exercise of safety-related check valves quarterly or during cold shutdowns if quarterly testing is impractical. This testing is to demonstrate that the valves are capable of moving to their safety function position (s) to assess their operational readiness. The licensee proposes to exercise this valve closed during leak rate testing every refueling outage.

This is a simple check valve, located inside containment, that must seat upon cessation or reversal of flow in order to perform its safety function. The only practical method to verify reverse flow closure is to perform a leak /back flow test. It is impractical to exercise this valve closed quarterly during power operations, because this would require containment entry.

Containment entry is restricted during power operations due to high radiation levels and other personnel safety hazards. In addition, a leak test can be an involved test requiring special plant modes, draining piping, test equipment hookup, and an elaborate test configuration.

Performance of this test at cold shutdown could delay plant start-up, which would be burdensome to the licensee. The licensee's proposal to verify the reverse flow closure of this valve in conjunction with leak rate testing performed each refueling outage should provide reasonable assurance of valve operational readiness.

Rulemaking to 10CFR50.55a effective September 8,1992, allows the use of portions of OM-10, provided that all related requirements are met. The staff imposed no limitations to OM-10 assocuted with the test frequency requirements for check valves and determined that the related requbements to OM-10, Paragraph 4.3.2.1, are found in Paragrapa 6.2. The licensee's proposal is consistent with the provisions of OM-10 for test frequency.

Accordingly, the relief requested by the licensee is covered by the rulemaking effective September 8,1992, as described above, and reliefis not required. It is recommended that the alternative proposed by the licensee be approved pursuant to 10CFR50.55a(f)(4)(iv), provided the related requirements of OM-10, Paragnph 6.2 are met. Implementation of related requirements is subject to NRC inspection.

3.9 Fire Protection System 3.9.1 Category C Valves 3.9.1.1 Relief Reauest. V-16 (V-16) requests relief from the test frequency requirements of Section XI, Paragraph IWV-3521, for inside containment fire protection supply check valve,1-FP-272 (2-FP-79). The licensee proposes to exercise this valve every refueling outage, not to exceed 24 months.

42

i

. i 3.9.1.1.1 Licensee's Basis for Reauestine Relief-The following text is quoted from relief request V-16 (V-16) in Revision 7 of the North Anna Power Station, Unit 1 (Unit 2), second interval IST program submitted by letter dated December 16,1993:

This check valve must seat upon reversal of flow in order to fulfill its safety function. l The only method to verify this actuation is to perform a leak rate /back pressure test.

Since the valve is located inside containment, it cannot be tested every three months.

1-FP-272 (2-FP-79) is in the containment fire protection system. Testing this valve l will render the fire protection system inoperable. It will be exercised only during refueling outages because the small increase in safety gained by testing during cold shutdown does act justify the burden of draining the lines and performing a leak rate )

test.

1 Alternate Testine: Exercise for operability every refueling (not to exceed 24 months) l l

3.9.1.1.2 Evaluation-The Code requires a full-stroke exercise of safety-related I check valves quarterly or during cold shutdowns if quarterly testing is impractical. This !

testing is to demonstrate that the valves are capable of moving to their safety function position (s) to assess their operational readiness. The licensee proposes to exercise this valve l closed during leak rate testing every refueling outage.

This is a simple check valve, located inside containment, that must seat upon cessation l or reversal of flow in order to perform its safety function. The only practical method to verify I reverse flow closure is to perform a leak /back flow test. It is impractical to exercise this valve closed quarterly during power operations, because this would require containment entry.

Containment entry is restricted during power operations due to high radiation levels and other ;

personnel safety hazards. In addition, a leak test can be an involved test requiring special !

plant modes, draining piping, test equipment hookup, and an elaborate test configuration. )

Performance of this test at cold shutdown could delay plant start-up, which would be l burdensome to the licensee. The licensee's proposal to verify the reverse flow closure of this valve in conjunction with leak rate testing performed each refueling outage should provide reasonable assurance of valve operational readiness. .

/

Rulemaking to 10CFR50.55a effective September 8,1992, allows the use of portions of OM-10, provided that all related requirements are met. The staff imposed no limitations to j OM-10 associated with the test frequency requirements for check valves and determined that the related requirements to OM-10, Paragraph 4.3.2.1, are found in Paragraph 6.2. The licensee's proposal is consistent with the provisions of OM-10 for test frequency.

Accordingly, the relief requested by the licensee is covered by the rulemaking effective September 8,1992, as described above, and relief is not required. It is recommended that the alternative proposed by the licensee be approved pursuant to 10CFR50.55a(f)(4)(iv), provided the related requirements of OM-10, Paragraph 6.2 are met. Implementation of related requirements is subject to NRC inspection.

l 43 ,

i 1

3.10 Post Accident Hydrocen Removal System 3.10.1 Category A/C Valves 3.10.1.1 Relief Request. V-20 (V-20) requests relief from the test frequency requirements of Section XI, Paragraph IWV-3521, for the inside containment isolation hydrogen analyzers and recombiner check valves,1-HC-14 and -18 (2-HC-15 and -20). The licensee proposes to exercise these valves every refueling outage not to exceed 24 months.

3.10.1.1.1 Licensee's Basis for Recuesting Relief-The following text is quoted from relief request V-20 (V-20) in Revision 7 of the North Anna Power Station, Unit 1 (Unit 2), second interval IST program submitted by letter dated December 16,1993:

These check valves must seat to provide containment isolation and open to sample hydrogen to fulfill their safety functions. The only method to verify closure is to perform a local leak rate test. Since the valves are located inside containment, they cannot be tested every three months. They will be verified closed only during refueling outages because the small increase in safety gained by testing during cold shutdown does not justify the burden of performing leak rate tests.

To test these valves either partially or full open requires either a locally installed rotameter (inside containment) or significant manipulation of the hydrogen recombiner system. In addidon, should a containment pressurization event occur while operating the hydrogen recombiners, there is a possibility of exceeding the design pressure of the recombiner system, which is a low pressure system intended for use after the containment depressuizes. They will be verified open at least once every 18 months during the testing of the hydrogen recombiner system because the small increase in safety gained by testing during normal operation or cold shutdown does not justify potential risk of overpressurizing the hydrogen recombiner system, or the added burden of disrupting normal plant operation to manipulate the recombiner system or of installing the rotameter and performing the test on the more frequent basis.

Alternate Testine: Exercise to the closed position every refueling (not to exceed 24 months). Exercise to the full open position at least once every 18 months.

3.10.1.1.2 Evaluation-The Code requires a full-stroke exercise of safety-related check valves quarterly or during cold shutdowns if quarterly testing is impractical.

This testing is to demonstrate that the valves are capable of moving to their safety function position (s) to assess their operational readiness. The licensee proposes to exercise these valves closed during leak rate testing every refueling outage and to full-stroke exercise them open at least once every 18 months.

These are simple check valves, located inside containment, that must seat upon cessation or reversal of flow and open to pass flow in order to perform their safety functions.

The only practical method to verify reverse flow closure is to perform a leak /back flow test. It 44

is impractical to exercise this valve closed quarterly during power operations, because this would require containment entry. Containment entry is restricted during power operations due to high radiation levels and other personnel safety hazards. In addition, a leak test can be an involved test requiring special plant modes, draining piping, test equipment hookup, and an elaborate test configuration. Performance of this test at cold shutdown could delay plant start-up, which would be burdensome to the licensee.

It is impractical to full-stroke exercise these valves open quarterly during power operations because this would require either entering containment to install a rotameter or operating the hydrogen recombiner. A containment pressurization event during hydrogen recombiner operation could result in damage to the recombiner. The recombiner is tested once every 18 months. Additional recombiner testing to full-stroke exercise these valves would increase the chance of recombiner damage. Full-stroke exercising these valves open once every 18 months and verifying their closure at refueling outages should give reasonable assurance of their operational readiness.

Rulemaking to 10CFR50.55a effective September 8,1992, allows the use of portions of OM-10, provided that all related requirements are met. The staffimposed no limitations to OM-10 associated with the test frequency requirements for check valves and determined that the related requirements to OM-10, Paragraph 4.3.2.1, are found in Paragraph 6.2. The licensee's proposal is consistent with the provisions of OM-10 for test frequency.

Accordingly, the relief requested by the licensee is covered by the rulemaking effective September 8,1992, as described above, and relief is not required. It is recommended that the al;ernative proposed by the licensee be approved pursuant to 10CFR50.55a(f)(4)(iv), provided the related requirements of OM-10, Paragraph 6.2 are met. Implementation of related requirements is subject to NRC inspection.

3.11 Residual Heat Removal System 3.11.1 Cateeory C Valves 3.11.1.1 Relief Request. V-74 (V-75) requests relief from the test frequency requirements of Section XI, Paragraph IWV-3521, for the RHR pump discharge check valves, 1-RH-7 and -15 (2-RH-7 and -15). The licensee proposes to exercise these valves every refueling outage.

3.11.1.1.1 Licensee's Basis for Requestine Relief-The fotowing text is quoted from relief request V-74 (V-75) in Revision 7 of the North Anna Powu Station, Unit 1 (Unit 2), second interval IST program submitted by letter dated Dec.:mber 16,1993:

These RHR pump discharge check valves can only be partial or full stroke exercised to the open position and verified closed during the testing of RHR pumps 1-RH-P-1A and 1-RH-P-1B (2-RH-P-1A and -1B).- The low pressure pumps take suction from and discharge to the reactor coolant system which operates at 2235 psig. This pressure is well above the operating pressure of the pumps, therefore, testing during normal 45

i

' operation is not possible. During cold shutdowns of short duration or if the reactor coolant pumps are left running during the cold shutdown, both trains of RHR may be required for decay heat removal and to maintain RCS temperature. Taking one train of l RHR out of service for testing purposes even for a short period could allow the RCS temperature to increase to the point that the pressurizer power operated relief valve would be challenged. Therefore, thescipumps and the discharge check valves should only be tested during reactor refuelings.

Alternate Testine: Exercise to the open and closed positions every reactor refueling.

3.11.1.1.2 Evaluation-The Code requires a full-stroke exercise of safety-related check valves quarterly or during cold shutdowns if quarterly testing is impractical.

This testing is to demonstrate that the valves are capable of moving to their safety function position (s) to assess their operational readiness. The licensee proposes to exercise these valves open and closed every refueling outage.

These are simple check valves on the discharge of the RHR pumps, which perform a safety function in both the open and closed positio" The only practical method to exercise these valves open is to establish flow through them. 'e only flow path through these valves is into the RCS. It is impractical to exercise these vaius open with flow during power operations because the RCS is at a pressure of around 2235 psig and the RHR pumps are not capable of developing sufficient head to overcome RCS pressure. These pump discharge check valves can be verified closed when their pump is idle and design flow is established through the other pump. This testing is impractical quarterly during power operations because flow cannot be established into the RCS as discussed above. It is impractical to perform this testing during every cold shutdown because operation of both trains of RHR may be required to maintain RCS temperature. Taking a train of RHR out of service to test these valves could challenge a reactor safety system and lengthen the outage, which would be burdensome to the licensee. The licensee's proposal to full-stroke exercise open and verify the reverse flow closure of these valves every refueling outage should provide reasonable assurance of valve operational readiness. Also, although the licensee does not take credit in the relief request, these valves receive a part-stroke exercise every cold shutdown, however, a full-stroke cannot be verifled unless one of the pumps is secured, which is not always practical as discussed above.

Rulemaking to 10CFR50.55a effective September 8,1992, allows the use of portions of OM-10, provided that all related requirements are met. The staffimposed no limitations to OM-10 associated with the test frequency requirements for check valves and determined that the related requirements to OM-10, Paragraph 4.3.2.1, are found in Paragraph 6.2. The licensee's proposal is consistent with the provisions of OM-10 for test frequency.

Accordingly, the relief requested by the licensee is covered by the rulemaking effective September 8,1992, as described above, and relief is not required. It is recommended that the alternative proposed by the licensee be approved pursuant to 10CFR50.55a(f)(4)(iv), provided the related requirements of OM-10, Paragraph 6.2 are met. Implementation of related requirements is subject to NRC inspection.

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4. DEFERRED TEST EVALUATIONS The following Cold Shutdown Justifications involve the frequency of testing safety-related valves. These justifications are listed in Table 4.1 and are evaluated in accordance with the exercising frequency requirements of Section X1, Paragraph IWV-3411or IWV-3521, !

as applicable.

1 4.1 Bases for Deferrine Valve Exercising l Section X1, Paragraphs IWV-3411and IWV-3521, permit deferral of full-stroke exercising until cold shutdowns when this exercising is not practicable during plant operation. ,

The justification for deferral of stroke testing should be documented in the Test Plan.

1 1

4.2 Conclusion For all of these deferred test justifications where the licensee has demonstrated the impracticality of full-stroke exercising the listed valves quarterly, deferral of this testing until cold shutdowns is covered by Section XI. Accordingly, the licensee's propcsed alternate testing is in compliance with the Code.

Where full-stroke exercising is impractical quarterly,Section XI requires part-stroke exercising quarterly if practical. Where full-stroke exercising is deferred until cold shutdowns, the licensee should part-stroke exercise the applicable valves as specified by Section XI, IWV-3411 or IWV-3521, as appropriate.

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TABLE 4.1 DEFERRED TEST EVALUATIONS NORTH ANNA POWER STATION, UNITS 1 AND 2 Item Valve Identification Justification for Deferring Valve Proposed Alternate Evaluation of the Number Exercising Testing Justification CSV-1 Component Cooling Failure of these valves in the closed These valves will be It is impractical to System Valve (s): position wouki result in a loss of full-stroke exercised exercise these valves As listed in IST % mat cooling flow to the reactor during cold shutdowns quarterly. brefore, program coolant pumps thermal barriers, lube oil, (but not more the alternative is in stator and/or shroud coolers, b frequently than every accordance with Section increased level of safety gained from three months). XI, IWV-3411.

exercising these valves durmg power operation does not justify the operational consequences should they fail in the closed position, h valve controllers do not allow for a part-stroke exercise test.

CSV-3 CH Valve (s): To achieve full flow through these check These valves will be It is impractical to 1-CH-84 valves, a flow path must be established full-stroke exercised exercise these valves 1-CH 102 to the RCS. This test would allow the during cold shutdowns quarterly. brefore, 2-CH-I l8 injection of boric acid into the RCS (but not more the alternative is in 2-CH-133 which wouki upset the boron frequently than every accordance with Section concentration in the pnman plant water. three months). These XI, IWV-3411.

valves will be partial stroke exercised every quarter.

CSV-4 Chemical & Volume Full or part-stroke exercising these bse valves will be It is impractical to i Control System valves during power operation wouki full-stroke exercised exercise these valves Valve (s): j cause a sudden increase in RCS boron during cold shutdowns quarterly. Wrefore, As listed in IST )

inventory by providing flow from the (but not more the altemative is in l program emergency and ahernate boration paths frequently than every l accordance with Section to charging pump suctions. Also, the three months). XI, IWV 3411.

valve controller for 14H-MOV-1350 (2-CH-MOV-2350) does not allow for a part-stroke exercise test. h increased level of safety gained from full or part stroke exercising these valves during power operation does not justify the operational consequences associated with reactivity transients. Manual valve 1-CH-241 (2-CH-156) will be stroked open when the siternate boration path is established every coki shutdown. N '

increased level of safety gained by exercising this valve every quarter does not justify the added burden of performing a separate test just for the manual valve.

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Item Valve Idendfication Justification for Deferring Valve Proposed Alternate Evaluation of the Number Exercising Testing Justification CSV-5 Cheaucal & Volume Exercising these valves during power These valves will be It is impractical to Control System Valves: operation interrupts letdown flow from full-stroke exercised exercise these valves As listed in IST the RCS to the volume control tank. If during cold shutdowns quarterly. 'Iberefore, program the valves shoukt fail <losed, reactor (but not more the ahernative is in coolant inventory control woukt be frequently than every accordance with Section lost. The pressurizer level control three months). XI,IWV 3411.

program controls RCS inventory by regulatmg the operation of the charging flow control valve so that the charging input flow to the RCS and reactor coolant pump seat injection flow into the RCS matches letdown flow. Also, exercising these valves during normal operation will interrupt letdown flow through the regenerative heat exchanger.

This flow interruption woukt allow a slug of relatively cool charging water to thermal shock the nozrje connecting the 3" charging line to the 27' loop 2 cold leg injection line. The valve controllers do not allow for a part stroke exercise test.

CSV-6 Chemical Volume Full or part-stroke exercising these Nee valves will be It is impractical to Control System Valves: valves during power operation woukt full-stroke exercised exercise these valves As listed in IST require that charging pump suction be during coki shutdowns quarterly. brefore, program aligned with the Refueling Water (but not more the alternative is in Storage Tank. That alignment woukt frequently than every accordance with Section cause a sudden increase in RCS boron three months). XI, IWV-3411.

inventory. The increased level of safety gained from full or part-stroke exercising these valves during power operation does not justify the operational consequences of reactivity transients.

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Item Valve Identificadlon Justafication for Deferring Valve Proposed Akernate Evaluation of the Number Exercising T*=*la! Justification CSV-7 Chemacal & Volume Varying letdown flow through the These valves will be It is impractical to Control System Regenerative Heat Exchanger will cause full-stroke exercised exercise these valves Valve (s): variations in charging flow durmg cold shutdowns quarterly. Therefore, 1 CH-MOV-1289A te.nperatures This is not desirable (but not more the ahernative is in 1-CH-MOV-1289B since decreased charging tsenperatures frequently than every accordance with Section 2-CH-MOV-2289A result in reactivity increases and thermal three months). XI, IWV-3411. .

2.CH-MOV-2289B stress on the piping and heat exchanger.

Full or part-stroke exercising these valves durms power operation would isolate the normal charging flow path from the charging pumps to the RCS.

Also, the valve controllers do not allow for a part-stroke exercise test. b i smallincrease in safety gained by exercising these valves every three months does not justify the operational consequences of pmviding an alternate charging flow path durmg power operation.

CSV-12 Feedwater Valve (s): These check valves must seat upon These valves will be h is impractacal to I-FW-47 reversal of flow to fulfill their safety full-stroke exercised exercise these valves 1-FW-79 functions. b only method to verify during cold shutdowns quarterly. brefore, 1-FW 111 this actuation is to perform a back (but not more the ahernative is in 2-FW 62 pressure test. Since the valves must frequently than every accordance with Section 2-FW-92 be open to sustain power operation, three months). XI, IWV-3521.

2 FW 126 they cannot be taatart every three months.

CSV-13 Main Steam (MS) Refer to IST program for extensive The VOTES test l' is impractical to non-retum valves discussion. Full or part-stroke desenbed (in the IST exercise these valves (NRVS): exercising of these valves during power program) will be quarterly. brefore, 1-MS-NRV-101 A operation would result in a turbine and performed on each MS the alternative is in 1-MS-NRV-101B reactor trip. NRV during the accordance with Section 1-MS-NRV 101C cooldown process XI, IWV-3411.

2-MS-NRV-201A going into each planned 2-MS-NRV-201B cold shutdown. This 2-MS-NRV-201C test will not be performed more often then once every three months.

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Item Valve Identification Justification for Deferring Valve Proposed Alternate Evaluation of the Exercising Testing Justification

. Number CSV 14 MS Valves: Full or part-stroke exercising these These valves will be It is impractical to 1-MS TV 109 valves durmg power operation woukt full-stroke exercised exercise these valves 2-MS-TV-209 cause undesirable prwsure transients in during cok! sk:Anwns quarterly. "Iberefore, the high pressure secondary drains (but not more the alternative is in system. Also, the valve controller frequently than every accordance with Sectaon does not allow for a part-stroke exercise three months). XI, IWV 3411.

test. b increased level of safety gained fmm exercising these valves durmg power operation does not justify i the operational consa7- of these pressure vanatans.

CSV-16 MS Valves: bee valveis are in positions required to These valves will be It is impractical to j 1-MS-TV-101 A sustain power operation Full or part- full-stroke exercised exercise these valves 1-MS-TV-101B stroke exercising these valves during during cok! shutdowns quarterly. brefore, 1 MS-TV-101C normal operation wouki resuh in a (but not more the ahernative is in 2-MS-TV-201 A reactor trip and SI. Also, the valve frequently than every accordance with Section ,

2 MS-TV-201B controllers do not allow for part-stroke three months). XI, IWV-3411.

2-MS-TV-201C exercise tests, bee valves are tested during coki shutdown (heatup or cooldown).

CSV-18 Residual Heat Removal These valves isolate the RHR System, bee valves will be it is impractical to (RHR) Valve (s): which is a 600 lb class system, from the full-stroke exercised exercise these valves 1-RH-MOV 1700 RCS during power operation. These during cold shutdowns quarterly. Wrefore, 1-RH-MOV-1701 valves are normally closed and cannot (but not more the alternative is in 1 RH-MOV 1720A be opened when RCS pressure is above frequently than every accordance with Section 1-RH-MOV-1720B 418 psig due to system interlocks, three months). XI, IWV-3411.

2 RH-MOV 2700 brefore, the valves cannot be full or 2-RH-MOV-2701 part-stroke exercised during power 2-RH-MOV-2720A operation. Also, the valve controllers 2-RH MOV-2720B do not allow for a part-stroke exercise test.

CSV-20 RHR Valve (s): b position of these valves is "Ihese valves will be It is impractical to 1-RH-FCV-1605 determined by deman:1 controllers and full-stroke exercised exercise these valves 1-RH-HCV-1758 must be observed locally to verify during cok! shutdowns quarterly. brefore, 2-RH-FCV-2605 proper valve operation. bse valves (but not more the alternative is in 2-RH-HCV-2758 are located inside contennwt frequently than every accordance with Section therefore, they cannot be full or three months). XI, IWV-3411.

part-stroke exercised every three months, l

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Item Valve Identification Justifkation for Deferring Valve Proposed Alternate Evaluation of the Number Exercising Testing Justification CSV-23 Safety Injection (SI) he valves provide isolation for he valves will be It is impractical to .

Unit ! Valve (s): altemate SI paths to the RCS. As full-stroke exercised exercise these valves l only 1-SI-MOV-1836 reqtured by Technical Specificatsons dunng cold shutdowns quarterly. Therefore, ;

l-SI-MOV-1869A, B (TS) 3/4.5.2.a. they are closed with (but not more the alternative is in l l-SI-MOV 1890A, B power removed from the valve actuators frequently than every accordance with Section I durmg Modes 1,2, and 3. Full or three months). XI, IWV-3411.

part-stroke exercising these valves !

during power operation wouki be in l violation of TS. Also, the valve codrollers do not allow for a part-stroke exercise test. ,

I CSV-24 SI Valve (s): The Acc="ler Discharge Isolation These valves will be It is impractical to l l-SI MOV-1865A Valves are in ' heir safety positions with full-stroke exercised exercise these valves {

1-SI-MOV 1865B power removed from the valve actuators during cok! shutdowns quarterly. brefore, 1 1-SI-MOV-1865C during Modes 1, 2, and 3, and when the (but not more the alternative is in j 2-SI MOV-2865A pressurizer pressure is greater than 1000 frequently than every acconiance with Section 2-SI-MOV-2865B peig as specified in TS 3/4.5.1. bee three months). XI,IWV 3411.

2-SI-MOV-2865C valves couki be called upon to open in Mode 3 when the pressurizer is less than 1000 psig. Full or part-stroke exercising during power operation would be in ;

violation of TS and decrease plant safety. Also, the valve controllera do not allow for a part-stroke exercise test.

CSV-29 Auxihary Feedwater he valves cannot be part or full flow hse valves will be It is impractical to Unit I (AF) Valve (s): tested during normal operation because full-stroke exercised exercise these valves only 1-FW-61 the dedicated AF flow paths wouki have during cok! shutdowns quarterly. brefore, 1 FW-95 to be isolated. Wae dedicated flow (but not more the alternative is in 1-FW 63 paths are required by the TS for normal frequently than every accordance with Section I-FW-125 operation. three months). XI, IWV-3411.

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Item Valve Identification Justification for Deferring Valve Proposed Alternate Evaluation of the Number Exercising Testing Justification CSV-30 Instrument Air (IA) Check valves 1 IA-944,948,952, These valves will be It is impractical to Unit i Valve (s): 2-1A-504,510, and 516 blate the full-stroke exercised exercise these valves CSV-31 As isted in IST 8

normalIA supply from the backup during coki slastdowns quarterly. brefore, Unit 2 program bottled air supply for the MS pressure (but not more the alternative is in control valves 1-MS-PCV-101 A, B, C, frequently than every accordance with Sectwo 2-MS-PCV-201 A, B, and C. Valves three months). XI, IWV-3521, 1 IA-959, %3, 971, 2-IA-525, 531, and 537 isolate the normal IA supply to the AF valves 1 FW-HCV-100A, B, C, 2-FW-HCV-200A, B, and C. Valves I-IA-%7, 975,2-IA-543 and 549 isolate the normal IA supply to the AF valves 1-FW-PCV-159A, B,2-FW-PCV 259A and D. To back seat test check valves 1-IA-504,510,516,2-IA-944,948 and 952, the IA system must be isolated to all three MS pressure control valves and the lines vented. To back seat test check valves 1-IA-959,963, %7,971,975, 2-IA-525,531,537,543 and 549, the IA system must be isolated to all five AF valves and the lines vented. Isolating this many valves that are important to safety during normal operation wouki degrade the safety of the plant arxl be disrugive to plant operation.

CSV 31 AF Valve (s): Stroke time is dependent on how quickly These valves will be It is impractical to Unit 1 1-FW HCV 100A the operator can turn the knob to the full-stroke exercised exercise these valves CSV 32 1-FW-HCV-100B potentiometer which controls valve during coki shutdowns quarterly. Therefore, Unit 2 1-FW-HCV-100C position. Several turns of the knob are (but not more the alternative is in 2 FW-HCV-200A necessary to full stroke the valve. frequently than every accordance with Section 2-FW HCV-200B Isolating IA and electrical power to the three months). XI, IWV-3411.

2-FW-HCV-200C valve during the performance of the fail i safe test is the only valk! method for full stroke exercising and stroke timing these valves. b fail safe test cannot be performed during normal operation because these valves must be available in the event of a reactor trip.

CSV-32 AF Valve (s): During normal operation, these valves These valves will be It is impractical to Unit 1 1-FW-PCV-159A control AF header pressure and cannot fulletroke exercised exercise these valves ;

CSV-33 1-FW PCV-159B be full stroked. Isolating IA and during cok! shutdowns quarterly, brefore, j Unit 2 2 FW PCV-259A electrical power to the valve during the (but not more the alternative is in )

2-FW PCV-259B performance of the fail safe test is the frequently than every accordance with Section only valid method for full stroke three months). XI, IWV-3411. l exercising and stroke timing these I valves. b fail safe test cannot be performed during normal operation l because these valves must be in service.

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Item Valve Identification Justification for Deferring Valve Proposed Alternate Evaluation of the Number Exercising ,

Testing Justification CSV-33U Main Steam Valve (s): Dunng normal operation, steam These valves will be It is impractical to nit I l MS-TV-Il3A co~ta== in the bypass lines because full-stroke exercised exercise these valves CSV-34 1 MS-TV-113B these valves are normally closed. dunng coki shutdowns quarterly. brefcee, Unit 2 1-MS TV-113C Exercising these valves durmg normal (but not more the ahernative is in 2-MS-TV-213A operation wouki introduce a water slug frequently than every accordance with Section 2-MS-TV-213B to the turbine. three months). XI, IWV-3411.

2-MS 'IV-213C CSV-34 Service Water (SW) Durmg normal operstion, the lines hoe valves will be It is impractical to Unit i Valve (s): between the SW supply and return full-stroke exercised exercise these valves CSV-35 As listed in IST header isolation valves given above during coki shutdowns quarterly. brefore, Unit 2 program. ard the recirculation heat exchanger (but not more the alternative is in isolation valves are ==:nt=M dry to frequently than every accordance with Sectbn ensure that no SW enters the beat three months). XI, IWV-3411.

exchangers. Stroking the header isolation valves desenbod above would introduce SW into the lines. bse lines wouki have to be drained aAer each test.

CSV-35 SW Valve (s): These check valves must open to allow bse valves will be It is impractical to Unit 1 As listed in IST service water to the charging pump full-stroke exercised exercise these valves CSV-36 program tube oil coolers, seal coolers and gear during coki shutdowns quarterly. Therefore, Unit 2 box coolers. Flow through these valves (but not more the alternative is in can be detected by differential pressure frequently than every accordance with Section instrumentation across the coolers. three months). These XI, IWV-3521.

However, full flow conditions wouki valves will be partial have to be measured by using temporary stroke exercised every uhrasonic flow instrumentation. b quarter, uhrasonic flow transducers and their mounting carriages must be installed and the transducers referenced to a no flow cordition before each test. AAer each test, the equipment must be removed from the fieki and decontammated if necessary. This process must be performed six times for the 12 valves listed above. Therefore, use of the uhrasonic flow instrumentation is very labor intensive ard not practical for quarterly testing.

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Item Valve identificatic, Justification for Deferring Valve Proposed Ahernate Evaluation of the !

Number Exerrising Tewtian Justification CSV-38 Chenucal and Vohune These check valves omst open to allow 1 These valves will be It is impractical to !

Unit 1 Control Valve (s): charging pump recirculation. There is full-stroke exercised exercise these valves CSV-39 l-CH-252 no permanently mounted matrumentation dunng coki shutdowns l quarterly. Therefore, '

Unit 2 1-CH-264 to measure full flow on the recirculaten (but not more the alternative is in 1 1-CH-277 line. brefore, full flow conditions will frequendy than every accordance with Section i 2-CH-176 have to be measured try using temporary XI, IWV.3521.

three months). I 2.CH-191 ultrasome flow instrumentation. The 2-CH-206 ultrasome flow traaaAr- s and their mounting carnagw must be installed and the truaaAvers referveced to a no flow condition before each test. After each test, the equipment must be removed from the fieki and Mnnt.~;n.e A iinecenaq. This procou naast be performed three times for the three valves listed above.

Therefore, use of the ultrasor.;c flow instrumentation is very labor intensive and not practical for quarterly testing.

Test experience has shown that the discharge pressure drop is undetectable when flow through the recirculation line is established in conjunction with norma

charging.

Therefore, quarterly partial flow testing is not verifiable.

i CSV.39 SW Vaive(s): These check valves must open to allow To ensure an It is impractical to Unit I l-SW-252 SW to the charging pump coolers. unmterrupted redundant exercise these valves ocly 1-SW-255 Downstream instrumentation can be used SW supply to the quarterly. Therefore, '

to verify the presence of flow in the charging pump seal the alternative is in j valves. However, individually full water coolers, these accordance with Section flow testing each check valve requires check valves will XI, IWV-3521.

secunng the paralle! SW supply header be full flow tested to the charging pump seal coolers. during coki shutdown l but not more frequeuly then once every three months. The valves will be partial flow tested every three months.

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Item Valve Identincation Justincation for Deferring Valve - Proposed Alternate Evahastion of the Number Exercising Testing Justification CSV-41 AF Valve (s): 1-FW-145 These normally locked closed ====1 Exercising these valves k is impractical to 1-FW-180 valves are opaned as required by the on a cold shutdown test exercise thsee valves 1.FW-162 abnormal operating procedures to frequency (but not quarterly. Therefore, 1-FW-227 provide SW to the AF pumps in the more fr=y==aly then the akernative is in 2-FW-147 ovest of en accident where all normal once every three accordance with Section 2 FW 164 AF pump supplies have been e=han=t l. months), is -t-r=*= to XI, IWV-3411.

2-FW 182 openmg thsee valves every three months demonstrase that the to fulfill quarterly testang ry 2-FW-202 valves can be opened would accelerate the buildup of sludge in in the case where SW the supply lines frani the SW system. is require as a supply The supply Imes are flushed once every for the AF pumps.

18 n-sha to reduce the buddup of sludge and to idanedy if there is any ama=lan== of Asiatic clams or shell debris in the lines. han=e these ma-al valves remman in the closed position durmg normal operation and are not subject to wear.

CSV-42 Reactor Coolant Full or part-etroke exercising these lhese valves will be It is impractacal to Valve (s): valves durmg power operations would full-stroke exercised exercise these valves 1-RC-PCV 1455C cause high differential pressure euross durmg cold ahi*tawns quarterly. Therefore, 1-RC-PCV-1456 the PCV Block Valves. Akhough these (but not more the akernative is in 2-RC-PCV-2455C valves are designed to se-- - =t-sa this frequently than every accordance with Section 2-RC-PCV-2456 differential pressure, cycling wouki three months). XI, IWV-3411.

eventually degrade the block valves seating capability, thus decreasing plant safety. Also, the valve controllers do not allow for a pag-stroke exercise test.

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e 9

s APPENDIX A IST PROGRAM ANOMALIES A-1

4 APPENDIX A IST PROGRAM ANOMALIES Inconsistencies and omissions in the licensee's program noted during the course of this review are summarized below. The licensee should resolve these items in accordance with the evaluations, conclusions, and guidelines presented in this report.

1. In TER section 2.1.1.1 Pump Relief Request P-13, the licensee requests relief from the flow rate and discharge pressure instrument accuracy requirements of Section XI, Paragraph IWP-4110, for pumps 1(2)-CH-P-1A, -1B, and -lC, 1(2)-CC-P-1 A and -1B, and 1(2)-SW-P-1A, -1B, and -4. The service water pumps are the subject of other relief requests in this sul,mittal; P-9, P-10, and P-12. Taken together, the reviewer does not have adequate information to fully assess the impact of the combination. We recommend that the proposed alternate E authorized pursuant to 10CFR50.55a(a)(3)(ii) with the following provisin The licensee should perform a complete assessment of the impact of the combination of this relief request and requests P-9, P-10, and P-12 as to their ability to assess the operational readiness of these pumps. The results of that assessment should be available for inspection at the facility.

2. In TER section 2.2.1.1, Pump Relief Request P-5, the licensee requests relief from the test frequency requirements of Section XI, Paragraphs IWP-3400(a) and -3500(a) for the RHR pumps. The licensee proposes to test them during refueling outages. However, the flow loop is equipped to measure individual pump inlet and discharge pressure, and combined system flow rate. This configuration should be conducive to the gathering of some meaningful test data during pump operation. It may not be prudent to arbitrarily extend the test interval to refueling outages if meaningful testing is practicable during cold shutdowns. We recommer.d that relief be granted pursuant to 10CFR50.55a(f)(6)(i) provided the licensee tests these pumps according to the Code test method requirements during cold shutdowns when heat loads are low and individual testing is practicable, and the licensee considers testing methods and acceptance criteria for assessing the operational readiness of these pumps during cold shutdowns when they can only be operated in parallel.

3. In TER sections 2.3.1.1 and 2.3.1.2, Pump ' Relief Requests P-9 and P-10, the licensee requests relief from measuring pump inlet and d/p for service water pumps 1(2)-SW-P-1 A -1B, and -4 as required by Section XI, Paragraph IWP-3100. The licensee proposes to monitor pump discharge pressure and use it in place of d/p to monitor for pump degradation. Inlet pressure will not be measured for these pumps. These pumps are the subject of other relief requests in this submittal; P-12 and P-13. The reviewer does not have adequate information to fully assess the impact of the combination of these requests. We recommend that the alternative be approved pursuant with A-2

e A

10CFR50.55a(a)(3)(ii) with the following provision. The licensee should

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( perform a complete assessment of the impact of the combination of this relief i

request and requests P-12 and P-13 as to their ability to assess the operational readiness of these pumps. The results of that assessment should be available for inspection at the facility.

l 4. In TER section 2.4.1.1, Pump Relief Request P-12, the licensee requests relief l

from establishing fixed set (s) of reference values for component cooling water and service water pumps as required by Section XI, Paragraphs IWP-3100 and

-3110. The licensee proposes to te:;t these pumps in their as-found condition of flow rate and d/p and to compare the results to acceptance criteria based on a reference pump curve that is generated mathematically from the results of test data taken at at least five points of operation. The service water pumps,1(2)-

SW-P-1 A, -1B, and -4 are also the subject of other relief requests in this submittal; P-9, P-10, and P-13. The reviewer does not have adequate information to fully assess the impact of the combination. Relief should be granted from this Code requirement pursuant to 10CFR50.55a(f)(6)(i) with the following provisions. The licensee should follow the seven guidelines identified in section 2.4.1.1 for using reference curves, if practicable. Where it is not practicable to follow these guidelines, the licensee should identify the specifics of their alternative and justify the deviations and show the adequacy of their proposed testing. Also, for the service water pumps, the licensee should i perform a complete assessment of the impact of the combination of this relief request and requests P-9, P-10, and P-13 as to their ability to assess the operational readiness of these pumps. The results of that assessment should be available for inspection at the facility.

5. In Relief Request V-59 (see TER section 3.1.1.1), the licensee requests relief from assigning individual leakage rates to various valves as required by Section XI, Paragraph IWV-3426, and proposes to leak rate test these valves in groups. Leak rate !

testing in groups can be acceptable provided this testing does not permit excessive leak through an individual valve in the group without taking appropriate corrective action.

Therefore, the ledage limit for the group should be conservative considering the i number and size of the valves in the group so that excessive leakage through any panicular valve in the group results in appropriate corrective action.

6. In Relief Request V-42 (V-43), the licensee requests relief from the test frequency requirements of Section XI and proposes to exercise the accumulator discharge and cold leg injection check valves by performing a low pressure dimge of the accumulator each refueling outage and to verify a full-stroke using nonintrusive techniques on one valve from each group on a sampling basis. Use of nonintrusive techniques canbe a positive means of verifying a full-stroke exercise as allowed by the Code, however, to use this technique on a sampling basis, the guidelines listed in the TER evaluation should be followed l

A-3

(see TER Section 3.2.2.3.3). The licensee's proposed alternate testing appears to comply with most of these guidelines, however, it is unclear from the submittal if all of these conditions are met. The licensee should verify that the testing of the subject valves complies with all of these guidelines.

The proposed grouping in this request does not appear to comply with the GL 89-04 requirement that group valves have the same service conditions. Valve 1-SI-127 (2-SI-153) is the second check valve (closer to the RCS) in the injection line from the accumulator to the RCS while the other three group valves are the first check valves (closer to the accumulators). Differences in service conditions may affect the corrosion, erosion, wear, etc. for this valve such that it is not representative of the other valves in the proposed group. The licensee should justify the proposed grouping or bring it into compliance with the grouping criteria of GL 89-04.

7. Several of the licensee's relief requests are approved by GL 89-04 and are not evaluated in this TER. The licensee indicates compliance with GL 89-04, but does not specifically address all aspects of the Generic Letter provisions in the requests. In these cases, it is assumed that the licensee is complying with all of the requirements of the applicable GL 89-04 positions. Reliefis not granted for the above relief requests for testing that deviates from that prescribed in GL 89-04. Whether the licensee complies with the provisions of GL 89-04 is subject to NRC inspection. If the licensee intends to deviate from a GL 89-04 position, a revised relief request specifically stating the deviation from GL 89-04 guidance must be submitted for review and approval prior to implementing the testing.

8. Valve relief requests V-33, -42 (-43), and -73 (-74) are for check valves that may not be practically verified closed using system pressure or flow or full-stroke exercised open with flow per GL 89-04, Position 1. The licensee proposes to full-stroke exercise these valves by sample disassembly, inspection, and a manual exercise. The NRC considers valve disassembly and inspection to be a maintenance procedure and not a test equivalent to the exercising produced by fluid flow. This procedure has some risk, which make its routine use as a substitute for testing undesirable when some method of testing is possible.

Disassembly and inspection, to verify the full-stroke open or closure capability of check valves is not a recommended option when exercising can be practically performed by system pressure, flow, or other positive means. Check valve disassembly is a valuable maintenance tool that can provide much information about a valve's internal condition and as such should be performed under the maintenance program at a frequency commensurate with the valve type and service. ;

Some test method may be feasible to full-stroke exercise these valves. The licensee should consider methods such as using nonintrusive techniques (e.g., acoustics, !

ultrasonics, magnetics, radiography, and thermography) to verify a full-stoke exercise !

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of the subject check valves. This testing may only be practical at cold shutdowns or refueling outages. The licensee should perform their investigation and if a test method is found to be practicable, the IST requirements of the applicable valves'should be satisfied by testing instead of disassembly and inspection. If testing is not practicable and disassembly and inspection is used, it must be performed in accordance with GL 89 04, Position 2. The licensee should raspond to this concern.

9. V-69 (V-70) requests relief from the leak rate corrective action requirements of Section XI for all CIVs in the IST program and proposes to allow an evaluation of leakage rates

' above the allowable limits instead of repair or replacement as long as the overall containment leakage is less than 0.6L,. The licensee did not provide details about the evaluation that would be performed. The evaluations should be performed in a manner that provides a high level of assurance that delaying the repair or replacement of valves with high leakage rates will not result in exceeding the 0.6L, limit before the next leakage rate tests. The licensee should document in the program plan how these evaluations will be performed and what will be included (see Section 3.1.2.1).

10. V-75 (V-76) requests relief from the leak rate corrective action requirements of Section XI for the RWST isolation valves and proposes to allow an evaluation of leakage rates above the allowable limits instead of repair or replacement as long as the overall -

containment leakage is less than the overall RWST leakage limit. The licensee did not provide details about the evaluation that would be performed. The evaluations should be performed in a manner that provides a high level of assurance that delaying the repair or replacement of valves with high leakage rates will not result in exceeding the overall RWST limit before the next leakage rate tests. The licensee should document in the program plan how these evaluations will be performed and what will be included (see Section 3.1.3.1).

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v t e Letter Sequence Other
TAC:M88757, (Open)
Initiation Acceptance... Administration Questions Answers Results Approval... Other: ML20078B155
MONTHYEAR1994-09-30 [Table View]

ML20078B155

Text

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