ML20195C942

Forwards Request for Addl Info Re Pump & Valve Inservice Testing Program.Response Requested within 120 Days of Ltr Date

ML20195C942
Person / Time
Site:	North Anna
Issue date:	06/09/1988
From:	Engle L Office of Nuclear Reactor Regulation
To:	Cruden D VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
References
TAC-52414, NUDOCS 8806220333
Download: ML20195C942 (8)

Text

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June 9, 1988 i

Docket flo. 50-338 DISTRIBUTION

@ Docket;fA]ep OGC-WF IIRC PDR E.-Jordan fir. D. S. Cruden Local PDR J. Partlow Vice President - Nuclear PD22 Reading ACRS(10)

Virginia Electric and Power Company S. Varga Gray File P.O. Box 26666-G. Lainas Richmond, Virginia 23261 H. Berkow -

-D.

Itiller

Dear Mr. Cruden:

L. Engle

SUBJECT:

INTERIM EVALUATION FOR PUMP AllD VALVE lilSERVICE TESTING PROGRAM, NORTil AllNA NUCLEAR POWER STATION, UNIT 1 (NA-1) (TAC NO. 52414)

By letter dated March 3, 1988, Virginia Electric and Power Company submitted a request for an exemption from 10 CFR 50.55a(g)(4)(ii) which would alica a common IST start date for both NA-1&2. That common start date would be achieved by erending the termination date of the NA-1 IST program to coincide with the termi;;ation of the NA-2 IST program. The ilA-1 IST program would be extended to terminate on December 14,(g)90,(rather than on June 6,1988.

19 The exemption for NA-1 from 10 CFR 50.55a (4) ii) was granted on April 26, 1988.

IlA-1 is currcntly in the first 120-month interval and has not yet received an

-IIRC IST SER. Since the interval, as discussed above, is only being extended by 30 months, the staff has performed a review which concentrated on the acceptability of relief requests and other problems in order to identify any major deficiencies in the NA-1 IST program. A list of questions and comments resulting from the staff's review is provided in the enclosure to this letter.

We request that your response to the staf f's comments and requests for infor-mation be provided to us within 120 days of the date of this letter.

The reporting and/or r ;ordkeeping requirements contained in this letter affect fewer than 10 respondents; therefore, OMB clearance is not required under P.L.96-511.

Sincerely, 1

Leon B. Engle, Project Manager Project Directorate 11-2 Division of Reactor Projects-1/II Office of Nuclear Reactor Regulation

Enclosure:

As stated cc w/enciesure:

See next page D:kh L 'P @ 2 Pt llBer low DI Plbr LET 6 g /88 6/C /86 6f/88 8806220333 880609 PDR ADOCK 05000338 PDR'

)

Mr. D. S. Cruden North Anna Power Station Virginia Electric & Power Company Units 1 and 2 cc:

Mr. William C. Porter, Jr.

James B. Kenley, M.D., Ccmmissioner County Administrator Department of Health Louisa County 109 Governor Street P.O. Box 160 Richmond, Virginia 23219 Louisa, Virginia 23093 Regional Administrator, Region II Michael W. Maupin, Esq.

U.S. Nuclear Regulatory Commission Hunton and Williams 101 Marietta Street N.W., Suite 2900 P. O. Box 1535 Atlanta, Georgia 30323 Richmond, Virginia 23212 Mr. W. T. Lough Virginia Corporation Commission Mr. G. E. Kane Division of Energy Regulation P. O. Box 402 P. O. Box 1197 Mineral, Virginia 23117 Richmond, Virginia 23209 Old Dominion Electric Cooperative Ellyn R. Weiss, Esq.

c/o Executive Vice President Harmon, Weiss and Jordan Innsbrook Corporate Center 2001 S Street NW 4222 Cox Road, Suite 102 Washington, DC 20009 Glen Allen, Virginia 23060 Mr. W. L. Stewart Senior Vice President - Power Virginia Electric and Power Co.

Post Office Box 26666 Richmond, Virginia 23261 Mr. Patrick A. O' Hare Office of the Attorney General Supreme Court Building 101 North 8th Street i

Richmond, Virginia 23219 Resident Inspector / North Anna c/o U.S. NRC Senior Resident Inspector Route 2, Box 78 Mineral, Virginia 23117 k

I, b

ENCLOSURE REQUEST FOR INFORf1ATION PUMP AND VALVE INSERVICE TESTING PROGRAM NORTH ANNA POWER STATION, UNIT N0. 1 DOCKET N0. 50-338 By letter dcted March 3,1988, Virginia Electric and Power Company submitted a request for an exemption from 10 CFR 50.55a(g)(4)(ii) which would allow a common start date for North Anna Units 1 and 2 Inservice Testing (IST) programs.

The Unit 1 IST program would be extended to terminate on December 14, 1990, rather than the current date of June 6,1988.

In order to focilitate extending the termination date for the Unit 1 IST program, a preliminary review of the October 5.1983 program was perforrred utilizing the acceptance criteria and guidance contained in the following documents: ASME Code Section XI, Code interpretations when applicable, the Code of Federal Regu-lotions 10 CFR Part 50, the Standard Review Plan, Section 3.9.6, and the Draf t Regulatory Guide and Value/ Impact Statement titled, "Identification of Valves for Inclusion in Inservice Testing Programs."

This partial review focused on the relief requests submitted.

Each relief re-quest was evaluated to determine 1) if testing the affected ccmponents in accordance with the Code requirements would be impractical, ?) whether the licensee's proposed testing would provide a reasonable alternative to the Code requirements, and 3) whether it would place an unreasonable burden on the licensee if the Code requirements were inposed.

l The following are program deficiencies found in the review which must be changed to ensure program conformance with the above standards and the NRC staff positions.

1.

VALVE PROGRAM General 1.

The Code permits valves to be exercised during cold shutdowns where it is not practical to exercise them during plant operation.

10 CFR Part 50 allows valves that cannot be exercised quarterly or at cold shutdown to be exercised during refueling intervals if specific relief is granted.

These valves are specifically identified by the licensee and are full-stroke exercised during cold shutdowns or, when relief is granted, at refueling cutages.

The NRC staff requires that the licensee provide a technical justification for each valve that cannot be exercised quarterly t

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during power operations that clearly explains the technical difficulties or hazards encountered during that testing.

Relief requests and cold shutdown justification bases should indicate the negative consequences that make testing at the Code-reouired frequency impractical, such as endangering personnel, equipment damage, or resulting in a plant shutdown.

T. sting at an increased frequency because.of logistics problems or for the sake of convenience to the licensee is not considered an adequate justification.

Based on the technical trerit of the justification, the NRC 5taff will then evaluate the impracticability of exercising those valves quarterly and either allow testing during cold shutdowns cr grant relief to perform the testing at refueling outages.

The relief justifi-cations in the North Anna IST program need to include more detailed tech-nical justification.

2.

Valves which are full-stroked at a cold shutdown or refuelir,g frequency can often be partial-stroke exercised quarterly during power operation.

The licensee has identified the valves which are full-stroke exercised on a cold shutdown or refueling frequency but has rot identified any partial-stroke exercising done on a quarterly basis.

3.

When a measured flowrate through a check valve is used as the positive means to verify a full-stroke exercise of the valve disk, the NRC staff's position is that the measured flowrate through the valve must be at least equal to the maximum flow rate identified in any of the plant's safety analyses.

This criteria is required for the test to be considered an adequate demonstration of the full-stroke requirement. Any flow rate less than this will be considered partial-stroke exercising unless it can be shown (by some means such 6s measurement of the differential pressure ecross the valve), that the check valve's disk position at the lower flow rate would permit maximum required flow through the valve.

In many cases, especially in the safety injection systems, the licensee does not meet this requirement for full-stroke exercising of check valves.

Some specific cases will be addressed in this evaluation, but the licensee should evaluate the testing of all the check valves in the IST program to ensure that each check valve is truly meeting the requirements of a full-stroke.

4.

Where check valves cannot be full-stroked exercised with flow or an exter-nal exerciser at any frequency, a relief request must be submitted re-questing to disassemble the valve to ensure freedom of disk movement.

The sample disassembly and inspection program involves grouping similar valves and testing one valve in each group during each refueling outage. The sampling technique requires that each valve in the group be the same design (manufacturer, size, model number, and materials of construction) and have the same service conditions.

Additionally, at each disassembly the licensee must verify that the disassembled valve is capable of full-stroking and that the internals of the valve are structurally sound (no loose or cor-roded parts). Also, if the disassembly is to verify the full-stroke capa-bility of the valve, the disk should be manually exercised.

A dif#erent valve of each group is required to be disassembled, inspected, and '.anually full-struke exercise at each refueling outage, until the entire group has been tested.

If the disassembled valve's full-stroke

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3 capability is in question, the remaining valves in that group must also be disassembled, inspected, and manually full-stroke exercised during the same outage.

5.

The NRC staff position is that the some of the emergency diesel generator auxiliary systems perforrn a safety-related function even though thay are rot ASME Code Class 1, 2 or 3.

In start system, from the check valve (particular, the diesel generator air s) between the compressor (s) and the receiver (s) to the engine, including the air start solenoids, has a safety-related function.

From the review of the North Anna IST program, it appears that the volves in the diesel generator air start system have not been included in the IST program.

The appropriate valves in the emergency diesel generator oir start system rnust be included in the IST program and tested in accordance with the Code requirements.

6.

In many relief requests, the proposed alternate testing reference a i

testing frequency not te exceed once per 9 months. ASME identified this testing frequency as a typographical error in the 1974 edition through summer 1975 addenda under testing of check valves.

Check valve testing is required by Section XI to be done at a 3-month interval. All inappro-priate references to the 9-month interval must be removed from the IST program.

7.

For valves that require maintenance which can affect valve ope

• ability, the licensee must perform post-maintenance testing to ensure valve opera-bility prior to return to service.

Based on actual plant data which has j

shown valve performance failure after maintenance, the staff will not grant relief from the exercising requirements of IWV-3200 as requested in North Anna letter dated October 28, 1987, Serial No.87-634 Recirculation Spray 1.

In relief request RS-Note-02, the licensee has not demonstrated the imprac-ticality of performing the valve testing at cold shutdowns.

Inconvenience to the licensee is not suitable justification.

Safety Injection 1.

Industry experience has shown that low Temperature ov % ressure (LT0P) protection systems may be challenged or sufficient expansion volume in the RCS may not be available when performing a full-stroke exercise test of safety injection system check valves using ficw.

These problems arise from the high flow rates necessary to accomplish a full-stroke exercise and be-cause the flow is injected into the RCS.

Relief requests SI-Hote-06

-07, and -12 indicate a full-stroke exercise of safety injection check valves at a cold shutdown frequency. These relief requests should be reevaluated by the licensee to determine if 1) a full stroke for these check valves is being achieved when tested at cold shutdown (see General Corment #3), 2) the LT0P and expansion volume considerations stated above apply to the testing of these check valves, and 3) the exercising of these check valves should be performed at refueling intervals vice cold shutdowns, t

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2.

Industry experience has shown that a full-stroke exercise of the check l

valves in the discharge lines of the accumulators usually does not occur i

even at refueling when flow from the accumulators is used bec;use of the I

very high flow rate needed and the lack of suf ficient expansion vitume i

in the RCS.

The licensee should reevaluate the testing of the valves in relief request SI-flote-10 and indicate how conformance with the tode is l

being met.

3.

Industry experience has shown that LTOP protection systems may be chal-lenged and/or suf ficient expansion volume in the RCS may not be. available when performing a full-stroke exercise test of safety injection system check valves using flow. These problems arise from the high flow rates necessary to accomplish a full-stroke exercise and because the flow is injected into the RCS, Relief request SI-ilote-11 indicated a full-stroke exercise of safety injection check va'ves at a cold shutdown frequency.

This relief request should be reevalu~ 'd by the licensee for check valves 1-SI-79,-90, -185, -201, -206, and -20/ to determine if 1) a full stroke fur these check valves is being achieved when tested at cold shutdown (see General Comment #3), 2) the LTOP and expansion volume considerations stated above apply to the testing of these check valves, and 3) the exer-cising of these check valves should be performed at refueling intervals vice cold shutdowns.

P& ids indicate that the individual flow measurement is not possible f or check valves 1-SI-95, -99, -103, -209, -211, and -213.

Unless the safety flow rate ti rough these valves can be measured for each valve individually, full-stroke exercising cannot be verified using flow.

The licensee should reevaluate the testing of these chcck valves and re-write the relief request as necessary (See General Coments #3 and #4).

4.

P&lDs indicate there is no instrumentation installed which measures ficw through each individual check valve in relief request SI-Note-09. Unless the safety flow rate through these valves can be measured for each valve individually, full-stroke exercising cannot be verified using using flow.

The licensee should reevaluate the testing of these check valves and re-write the relief as necessary (See General Coments #3 and (4).

Quench Spray 1

1.

IW-3522 requires a pusitive means be used to verify that a check valve disk moves to its full open position.

In the case where a mechanical exerciser is used, the torque, cr force, required to move the valve oisk must be measured and be within the specifications of the Code.

Relief re-quest QS-Note-01 states that the check valves in the relief request will be exercised manually but does not mention torque measurement.

If the torque cannot be measured then the requirements of the Code are not being met and the valves in this relief request will either have to be exercised by flow or by sample disassembly. The licensee should reevaluate this relief request and rewrite it to indicate how conformance with the Code is being met.

2.

PLMP PROGRAtt 1.

The staff recognizes the advantages of measuring pump vibration in units of velucity rather than displacement. liowever, IRD Mechanalysis is unacceptable as a standard of reference for the purrp vibration limits.

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e 5

A reasonable alternative to Section 1.1, when velocity vibration monitor-ing is desired, is OM-6.

Relief to measure vibution velocity can be granted if the licensee adopts all vibration monitoring requirements in-ciuding the methods of measuring the vibration +.nat are at least as encompassing and as conservative as those found in OM-6.

2.

Lack of installed instrumentation is not considered sufficient technical justification for granting relief from the requirements of Section XI.

The licensee has several options that the staff will consider.

The staff will consider individual relief requests that are seeking tem-porary relief until permanent instrumentation is installed as long as they clearly state when the instrumentation will be in service.

Another option to the licensee is to request relief, en an individual basis, to perform as complete a quarterly test as possible measuring all of the available instrumented parameters and obligate to perform higher flow tests in which all parameters required by the Code are measured at the earliest possiblF Trequency (cold shutdown or refueling). An example of this is in relief request #2, where no installed flow instrumentation exists. On a quarterly frequency, a test can be performed measuring everything but the flow. Then at refueling outages, the pumps can be run actually injecting into the RCS and all test parameters required by the Code, including flow using a downstream flow instrument in the injection line, can be measured.

A third option available is to use other positive means to measure a parameter not instrumented. An example would be to calculate pump inlet pressure from a tank level or to determine a pump flow rate by measuring a change in a tank level providing that these substituted rethods meet the accuracy requirements of Section XI.

Relief requests #2, #3, and #4 must be rewritten to conform with one of these requirements.

3.

In relief request #3, part 3, the difficulty involved in removing insula-tion from around a pump is not considered acequate technical justification to allow granting relief from vibration measurement.

4.

Relief request #4, part 2 is covered in number 2 above.

In this part, the licensee must assure the staff that measuring a change in tank level meets the accuracy requirements of the Code, in relief request #4, part 3, the licensee must provide more detailed technical justification for not measuring vibration, lube oil level and pressure and bearing temperature of these pumps quarterly. The staff does not consider elimination of a test as a reascnable alternative to the Code requirements.

5.

The staff considers the RHR system to have a safety function. Relief re-quest #5 must be rewritten to include a technical justificatica for testing RHR at cold shutdown.

6.

Section XI requires pump differential pressure to ',e measured and the staff considers differential pressure an important parameter in detecting hydraulic degradation of a pump.

In cases where water level is used to determine the inlet pressure to a pu:q, the inlet pressure must be calcu-lated and a differential pressure established for the pump. Relief re-quests #9 and #10 nost be rewritten to conform to this requirement.

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7.

The staff recognizes that cccasionally a system exists that does not 6110w the licensee to establish repeatable reference conditions. An example of this would be a chill water system that runs constantly under various loou conditions.

In these cases, relief can be granted allowing o

a curve of reference values to be used.

However, it is recognized that this' alternative testing method is not equivalent to the Code requirements.

Trending the data using this testing method does not provide results that are as reliable or conclusive.

In the llorth Anna letter dated October 28, 1987, Serial No.87-634, the licensee has requested relief to develop curves for all pumps in the IST program regardless of system character-istics. The staff Will not grant blanket relief requests of this nature.

The licensee must request relief to develop a pump curve on a system-specific basis providing an individual technical justification for each.

The staff will tr.an review each relief on its own merit and consider granting relief on a system-by-system basis.

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