ML20087B034

TER Pump & Valve Inservice Testing Program,Beaver Valley Power Station,Unit 2

ML20087B034
Person / Time
Site:	Beaver Valley
Issue date:	10/31/1991
From:	EG&G IDAHO, INC., IDAHO NATIONAL ENGINEERING & ENVIRONMENTAL LABORATORY
To:	NRC
Shared Package
ML20087A882	List: ML20087B034
References
CON-FIN-A-6811 EGG-NTA-9811, NUDOCS 9201100159
Download: ML20087B034 (14)

Text

- ._-

Attachment

. October 10, 1991

.- RAN 91 Page 1

. I [GG NTA-9811 TECHNICAL EVALUATION REPORT PUMP AND VALVE INSERVICE TESTING PROGRAM BEAVER VALLEY POWER STATION, UNIT 2 sh ?g Docket No. 50 834 N. B. Stockton Published October 1991 Idaho National Engineering Laboratory EG&G Idaho, Inc.

Idaho falls, Idaho 83415 Prepared for the U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Under DOE Contract No. DE AC07-761001570 '

FIN No. A6Sil TAC Nos. 62870 and 74757 K.-

9401100159 911227 PDR ADOCK 05000412' P PDR

.. . . . . -_ . . ~ - . ,

9 ABSTRACT i

This EG&G Idaho, Inc., report presents the results of our evaluation of the Beaver Valley Power Station, Unit 2, inservice Testing Program for pumps and valves whose function is safety related.

PREFACE This report is supplied as part of the " Review of Pump and Valve incervice Testing Progranis for Operating License Plants (II)* program being conducted for the U.S. Nuclear Regulatory Commission, Office of Nuclear Reactor Regulation, Mechanical Engineering Branch, by EG&G Idaho, Inc.,

Regulatory and Technical Assistance Unit.

FIN No. A6811 B&R 920 19 05 02 0 Docket No. 50 412 1AC Nos. 62870 and 74757 11

CONTENTS ABSTRACT ............................................................. 11 PREFACE .............................................................. ii

1. INTRODUCTION ..................................................... 1

2. PUMP TESTING PROGRAM ............................................. 3 2.1 Chemical Injection Pumps ................................... 3 2.1.1 Inservice Test Procedure ........................... 3

3. VALVE TESTING PROGRAM ............................................. 5 3.1 C ont a i nment Ai rl oc k s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 3.2.1 Category A VLives ................................... 5 3.2 Reactor Coolant System ...................................... 8 3.2.1 Category B Valves ................................... 8 APPENDIX A- IST PROGRAM AN0MAllES IDENTIFIED DURING THE REVIEW ......... A 1

- i i. i _ -

TECHNICAL EVALVATION L: PORT 11JMP AND VALVE INSERVICE TESTING PROGRAM BEAVER VnttEY POWER STATION. UNIT 2

1. INTRODUCTION This is a technical evaluation of relief requests in the pump and valve inseevice testing (IST) program for Beaver Valley Power Station, Unit 2, submitted by Duquesne Light Company.

With a letter dated June 14, 1990 Duquesne Light Company submitted Revisions 2A, 4, 5, and 6 of the Beaver Valley, Unit 2, pump and valve IST program. Revision 7 was submitted with a letter dated February 28, 1991.

The licensee's IST program cov?rs the first ten-year interval, which runs from November 17, 1987 to November 17, 1997. The relief requests pertain to requirements of the ASME Boiler and Pressure Vessel Code (the Code),

Section XI,1983 Edition through Summer 1983 Addenda and 10 CFR 50.55a.

Duquesne Light Company requested relief from the Code testing requirements for specific pumps and valves. These requests were reviewed using the acceptance criteria of 10 CfR 50.55a and NRC Generic Letter No.

89 04 (GL 89-04), " Guidance on Developing Acceptable Inservice Testing Programs."

These TER relief request evaluations are applicable only to the components or groups of components identified by the submitted relief requests. These evaluations may not be extended to apply to similar components that are not identified by the request at this or another comparable facility without separate review and approval by the 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 reouest invulving 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.

1

Section 2 of this report presents the evaluations and conclusions for the Beaver Valley, Unit 2, pump testing program relief requests that were

$1bmitted, or substantially revised, since the issuance of Geiieric letter No. 89 04. similar information is presented in Section 3 for the valve testing program. The licensee's IST program relief requests that were current on April 3, 1989 were approved by this Generic Letter. These pre approved relief requests were also reviewed but are not evaluated in this report. l 1

Anomalies noted in the licensee's program during the course of this  !

review, including pre approved relief requests, are listed in Appendix A.

]

The licensee should resolve these items in accordance with the evaluations, conclusions, and guidelines presented in this report.

Th 'ew of the Duquesne Light Company justifications for exercising Categor,y n, B, and C valves during cold shutdowns and refueling outages instead of quarterly during power operation found these justifications to be acceptable except as noted'in Appendix B.

2 m

1

2. PUMP TESTING PROGRAM l l

The following relief requests were evaluated against the reouirements of the Code,Section XI,10 CFR 50,55a, and applicable NRC positions and guidelinas. A summary and the licensee's basis for each relief request is l

rresented. The evaluation and recommendation follow. They are grouped I according to topic or system.

2.1 Chemical Iniection Pumpji 2.1.1 Inservice Test procedure 2.1.1.1 Relief Reauest. The licensee has requested relief from the pump test procedure requirements of Section XI, Paragraph IWP-3100, for the chemical injection pumps, 2QSS-P24A and P24B. The licensee has proposed utilizing pump discharge pressure and flow rate for evaluating pump performance.

2.1.1.1.1 Licensee's Basis for Reanstina Relief The function of these pumps is to provide a Na0ll water solution to the suction of the quench spray pumps during an accident. Since these pumps are rotary positive displacement pumps, flow rate and differential- pressure are independent variables. Unlike centrifugal <tyle pumps, it is not necessary to measure both parameters to assess the hydraulic performance of these pumps.

Alternate Test: Pump discharge pressure and flow rate will be utilized for evaluating pump performance in OST 2.13.10A and OST 2.13.10B.

2.1.1.1.2 Evaluation--The outlet pressure of positive displacement pumps is dependant on the pressure of the system into which they are pumping and is not affected significantly by ei'.er inlet pressure (providing adequate net positive suction head ey' ts) or flow rate. For these pumps, differential pressure and flow rate 4re not dependant variables, as they are for centrifugal type pumps. Diff' ential pressure is not a meaningful parameter in determining if hyd .ulic degradation is occurring. The licensee's proposed alternati* , to use pump discharge pressure as a test 3

quantity in lieu of differential pressure, is sufficient to determine the hydraulic condition of these positive displacement pumps and would, therefore, provide an acceptable level of quality and safety. However, since pump degradation may result in the loss of capacity at higher pressures, flow rate measurement (at a reference speed) should be performed at a reference discharge pressure which is equal to or greater than the pressure at wh'ich the pumps would be required to perform their safety function. Further, the measured values of flow should be compared to reference values and have acceptance criteria applied, as outlined by Paragraph IWP-3100.

Based on the determination that tes, g these pumps without differential pressure measurement would provide an acceptable level or quality and safety, relief may be granted provided the licensee performs pump testing as outlined at?ve.

4

. 3. VALVE TESTING PROGRAM The following relief requests were evaluated agt. inst the requirements of the Code,Section XI,10 CFR 50.55a, p.nd applicable NRC positions and guidelines. A summary and the licensee's basis for each relief request is l presented. The evaluation and recommendation follow. They are grouped l according to topic or system.

3.1 Containment Airlocks 3.1.1 Otteaory A Valves  !

3.1.1.1 Relief Reauest. The licensee has requested relief from the individual valve leakage rate method, analysis, and corrective action requirements of Section XI, Paragraph IWV 3420, for the personnel airlock equalization valves listed below. The licensee has proposed performing a Type B leak test for these valves semiannually in accordance with 10CFR50, Appendix J and lechnical Specification 4.6.1.3.b.l. The licensee has also proposed assigning a maximum permissible leakage rate for the entire airlock and using this value as the. acceptance criteria for initiating corrective action in accordance with IWV 3427(a).

2PHS-100 2PHS-101 2PHS-Il0 2PHS-Ill 2PHS-il2 2PHS-ll3 3.1.1.1.1 Licensee's Basis for Reauestina Relief--These containment isolation valves are leak tested in accordance with 10CFR50, Appendix J, Type B. Since the acceptance criteria for Appendix J. Type B testing is more limiting than ASME Section XI, additional leak testing in accordance with'ASME Section XI would-be redundant, in addition, as shown on the attached figure for the personnel air lock, the configuration of this containment penetration (i.e., a single test connection located in the airlock between six airlock equalization valves) is such that individual leakage rates for each specific valve cannot be determined using the test method of 10CFR50, Appendix J. In this case, assigning maximum permissible leakage rates for each valve would not be practical.

5

Alternate Test: Leak test semiannually in accordance with Technical Specification 4.6.1.3.b.1, 10CfR50, Appendix J and IWV-3426 per 2BVT 1.47.B. In addition, assign a maximum permissible leakage rate for the entire airlock to then be used as the criteria for initiating corrective action in accordance with IWV 3427(a).

3.1.1.1.2 [y_aluation -These equalizing valves for the ccrsonnel airlock also serve as containment isolation valves and receive a Type B leak rate test in accordance with 10CFR50, Appendix J. However, since there is only one test connection located between the six valves, it is impractical to individually leak test each valve.

These valves could only be individually leak rate tested after significant redesign of the system. These modiftt.ations would be burdensome for the licensee due to the cost involved.

The ';censce's proposed alternative, perform an Appendix J. Type B, leak test semiannually in accordance with Technical Specifications and assign a maximum permissible leakage rate for the entire airlock to be used as the acceptance criteria for initiating corrective action per IWV-3427(a), would provide reasonable assurance of operational readiness.

Based on the determinstion that compliance with the Code requirements '

is impractical, that the licensee's proposed alternative would provide reasonable assurance of operational readiness, and considering the burden on the licensee if the Code requirements were imposed, relief may be granted as requested.

3.1.1.2 Relief Reauest. The licensee has requested relief from the individual valve leakage rate method, analysis, and corrective action -

requirements of Section XI, Paragraph IWV 3420, for the emergency airlock equalization valves, 2PHS-201 and -202. The licensee has proposed performing c Type B let.x test for these valves semiannually in accordance with 10CFR50, Appendix J and Technical Specification 4.6.1.3.b.l. The licensee has also proposed assigning a maximum permissible leakage rate for the entire airlock and using this value as the acceptance criteria for initiating corrective action in accordance with IWV-3427(a).

6

_, 3.1.1.2.1 Licensee's Basis for Reauestina Relief--These l containment isolation valves are leak tested in accordance with 10CFR50, Appendix J, Type B. Since the acceptance criteria for Appendix J Type B testing is more limiting than ASME Section XI, additional leak testing in accordance with ASME Section XI would be redundant. In addition, as shown on the attached figure for the emergency air lock, the configuration of this containment penetration (i.e., a single test connection located in the emergency airlock between two airlock equalization valves) is such that individual leakage rates for each specific valve cannot be determined using the test method of 10CFR50, Appendix J. In this case, assigning maximum permissible leakage rates for each valve would not be practical.

Alternate Test: Leak test semiannually in accordance with Technical Specification 4,6.1.3.b.1, 10CFR50, Appendix J and IWV-3426 per 2BVT 1.47.10. In addition, assign a maximum permissible leakage rate for the entire airlock to then be used as the criteria for initiating corrective action in accordance with IWV-3427(a).

3.1.1.2.2 Evaluatiou -These equalizing valves for the emergency airlock also serve as containment isolation valves and receive a Type B leak rate test in accordance with 10CfR50, Appendix J. Honever, sir,te there is only one test connection located between the two valves, it is impractical to individually leak test each valve.

These valves could only be individually leak rate tested after significant redesign of the system. These modifications would be burdensome for the licensee due to the cost involved.

The licensee's proposed alternative, to perform a Type B leak test semiannually in accordance with Appendix J and Technical Specifications, and assign a maximum permissible leakage rate for the entire airlock to be used as the acceptance criteria for initiating corrective action per IWV-3427(a), would provide reasonable assurance of operational readiness.

Based on the determination that compliance with the Code requirements is impractical, that the licensee's proposed alternative would provide reasonable assurance of operational readiness, and considering the burden 7

on the licensee if the Code requirements were imposed, relief may be granted as requested.

3.2 Reactor Coolant System 3.2.1- Cateaory B Valves 3.2.1.1 Relief Reauest. The licensee has requested relief from Oae valve exercising and stroke timing frequency requirements of Section XI, Paragraphs IWV-3411 and 3413, for the reactor vessel head vent valves listed below. .The licensee has proposed full-stroke exercising and stroke -

timing these valves during refueling outages.

2RCS 50V200A 2RCS-SOV200B 2RCS 50V201A 2RCS 50V201B 2RCS HCV250A 2RCS HCV250B 3.2.1.1.1- Licensee's Basis for Reauestina Relief These valves are normally closed and are only required to be opened during accident conditions. Westinghouse does not recommend these valves be tested at temperatures above 2000 F or pressures exceeding 300 psia. (Reference PSE SSA 4743 -dated February 8, 1985, " Reactor Head Vent / Cold Shutdown SystemTesting"). Degradation of the system can result from repeated strokes at greater than thess temperatures / pressures. Full-stroking may not be performed during cold shutdown because the reduced pressure which is required to-perform this test may not be obtainable, in addition, strob testing if attempted at cold shutdown could extend the length of a plant.

. shutdown due to extensive preparatory work in establishing the proper

. reactor coolant system conditions.

Alternate Test: Full-stroke and time at refueling per OST 2.6.9.-

3.2.1.1.2 Evaluation -Exercising these valves at temperatures or 0

pressures above 200 F or 300 psia could result in degradation of these safety-related valves. Reactor coolant system pressure is not reduced below 300 psia each cold shutdown, therefore, it'is not practical to exercise' these valver avery coid shutdown.

A

These valves could only be exercised quarterly during power operation at elevated temperatures and pressures after significant redesign of the system. Depressurizing the reactor coolant system every cold shutdown to exercise these valves with the current system desigm would cause delays in the return to power. These modifications and dela/s would be burdensome for the licensee due to the costs involved.

The licersee's proposed alternative, to full-stroke exercise and stroke tinie these valves during refueling outages would provide reasonable assurance of operational readiness.

4 Based on the determination that compliance with the Code requirements is impractical, that the licensee's proposed alternative would provide reasonable assurance of operational readiners, and considering the burden

- on the licensee if the Code requirements were imposed, relief may be a granted as requested.

=

1 9

p.

i.,

APPENDIX A IST PROGRAM AWOMALIES IDENTIFIED DURING THE REVIEW A-I

l.

APPENDlX A IST PROGRAM AN0MAllES FOUND DURING THE REVIEW Incensistencies 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. Tht. licensee's IST program states that pump curves will be used as reference values for pump testing when plant conditions preclude returning a pump to the same reference condition for its normally scheduled surveillance. The Code provides for multiple sets of reference values by allowing "...one or more fixed sets of reference values...at points of operation readily duplicated during subsequent inservice testing." Using a reference pump curve to rempare differential pressure and flow rate for pump inservice testing may provide an acceptable alternative to the Code requirements. However, a pump curve represents an infinite set of data points for pump flow rate and head, not all of which are verified by measurement. Since this testing method may not be equivalent to the Code requirements, relief should be individually requested for each pump. In each relief request, the licensee should demonstrate either the impracticalitv of the Code required testing or that the proposed alternative would provide an equivalent level of quality and safety. It is important that the insitu reference curve is developed, or the manufacturer's curve validated, when the pump is known to be operating acceptably and is based on, or validated by, an adequate number of measurement points. Since the levels of vibration may vary significantly over the range of pump conditions encountered during testing, the licensee should develop a method of assigning vibration reference values and acceptance criteria that would be equivalent to the Code requirements.

The acceptance criteria of Table IWP-3100-2 should be applied. These points should be addressed in the relief requests.

A-3 l

0'

2. In pump relief request No. 3 (Revision 4), the licensee proposes .

calculating the suction pressure of the recirculation spray and service water pumps. This relief request was preapproved by Generic Letter No. 89-04. The licensee has demonstrated that measuring suction pressure, as required by the Code, is impractical. However, this relief request does not address the issue of accuracy. The licensee's proposed alternative is acceptable provided the calculations are within the accuracy that would result from using instruments meeting the Code accuracy requirements. The licensee should respond to this staff concern within 90 days.

3. In pump relief request No. 4 (Revision 4), the licensee proposes calculating the flow rate of the diesel fuel oil transfer pumps. This relief request was preapproved by Generic Letter No. 89-04. The licensee has demonstrated that measuring pump flow rate, as required by the Code, is impractical. However, this relief request does not address the issue of_ accuracy. The licensee's proposed alternative is acceptable provided the calculations are within the accuracy that would result from using instruments meeting the Code accuracy requirements.

The licensee should respond to this staff ccncern within 90 days.

4. In pump relief request No. 8 (Revision 2A), the licensee proposes using discharge pressure and flow rate to evaluate the performance of the ,

chemical injection pumps. Relief may be granted provided the licensee performs pump testing at a reference speed and reference discharge pressure equal to or greater than the pressure at which the pumps would be required to perform their safety function. Further, the measured values of flow should be compared to reference values and have acceptance criteria applied as outlined in IWP-3100. (Reference section 2.1.1.1 of this report.)

5. In valve relief request Nos. 23, 24, 25, 26, 27, and 28 the licensee has proposed leak rate testing containment isolation valves and dampers _ '

in groups and assigning a maximum permissible leakage rate to each group. These relief requests were preapproved by Generic Letter No. 89-04. The licensee has demonstrated that individual leak rate A-4

'V .

7, . testing,- as required by the Code, isj impractical for the valves listed in these relief requests ~ For situations where there are ~ multiple -

containment isolation valves branching from a common header, ascribing-all _ leakage:through the penetration = to one valve could cause the 6 performance of baseless' maintenance on.optrable valvesc The licensee-

=

has stated that maximum leakage rates will be assigned-to each valve ,

group and will. be used as the acceptance criteria for determining

-whether corrective action will be taken as required by Paragraph IWV-3427(a). However, the licensee.has neither provided.the maximum permissible leakage rates for:each valve group nor the method used to

-determine them. The licensee's proposed alternative would provide r

reasonable.~ assurance of operational readiness provided the assigned limiting leakage rate for each valve group is conservatively established regarding-the number and sizes of valves in the group. The --

assigned maximum' group leakage rates should be based-on the smallest

valve in the; group so that corrective: actions are taken whenever the

-leak-tightJintegrity of any valve of that group is.in question. .The:

-licensee should respond-to this staff concern within 90 days.- -

6. In general the proposed alternate testing in the relief requests submitted by the licensee regarding oump. testing, valve' exercising, or valve stroke timing frequency stateLthat testing-will be. performed.per -

-Beaver Valley. Unit 2, test procedures. Since the licensee did not submit-copies-of their testing procedures,- it.is presumed tl.at these

= procedures are in accordance with the Code requirements or Generic Letter No. 89-04: positions.

l p:

L p A-5 L

L . _ .