ML20029A117

Advises of Interim Approval of Inservice Testing Program Relief Requests for Pumps & Valves W/Inconsistencies Delineated in Encl

ML20029A117
Person / Time
Site:	Fort Calhoun
Issue date:	01/30/1991
From:	Gwynn T Office of Nuclear Reactor Regulation
To:	Gates W OMAHA PUBLIC POWER DISTRICT
References
TAC-75282, NUDOCS 9102040134
Download: ML20029A117 (6)

Text

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January 30, 1991 Docket No. 50-285 DISTRIBUTION Docket file a NRC & Local PDRs PD4 1 RF PD4 1 PF Mr. W. Gary Gates BBogerMS13E4 MVirgilioMS13E4 Division Manager - Nuclear Operations PNoonan WWalker Omaha Public Power District OGCMS15B18 EJordanMNBB3701 444 South 16th Street Mall KDempseyMS7E23 ACRS(10)(P-315)

Mail Stop BE/EP 4 PHarrell, RIV TGwynn Omaha, Nebraska 68102 2247 TSu111vanMS7E23 JNorbergMS7D2

SUBJECT:

INTERIM APPROYAL OF INSERVICE TESTING PROGRAM RELIEF REQUESTS FOR PUMPS AND VALVES - FORT CALHOUN STATION, UNIT I (TAC NO. 752B2)

The NRC staff has performed en initial review of Revision 5 of the fort Calhoun Stationpumpandvalveinservicetesting(IST)programforthesecondten. year interval, which Omaha Public Power District submitted by letter dated October 8, 1990. This revision contains a number of new and revised relief requests.

At this time, we have identified several inconsistencies, which are delineated in the enclosure. With the condition that the proposed actions to resolve the inconsistencies identified are addressed by the licensee within 60 days of the receipt of this letter, we believe that an interim period of relief is appro.

priate until the staff can complete the evaluation of Revision 5 to the IST program. Since this interim approval does not represent the results of the final program review, future supplements to the Safety Evaluation Report could contain relief request denials.

Thestaffhasdeterminedthat,pursuantto10CFR50.55a(a)(3)(1), granting this interim approval for the reliefs requested in fort Calhoun IST program for the second ten-year interval will provide an acceptable level of quality and safety pending completion of the evaluation of Revision 5 to the IST program.

Sincerely, Original cicned by:

Thomas P. Gwynn, Acting Director Project Directorate IV.1 Division of Reactor Projects 111, IV, and V Office of Nuclear Reactor Regulation

Enclosure:

As stated cc w/ enclosure:

See next page

• See Previous Concurrence OFC

• PD4-1/LA

• PD4-1/PM

• 0GC

PD4-1/(A)D

TGwynnTl NAME

PNoonan

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January 30, 1991 Docket No. 50-285 Mr. W. Gary Gates Division Manager - Nuclear Operations Omaha Public Power District 444 South 16th Street Hall Mail Stop BE/EP 4 Omaha, Nebraska 68102-2247

SUBJECT:

INTERIM APPROVAL OF INSERVICE TESTING PROGRAM RELIEF REQUESTS FOR PUMPS AND VALVES - FORT CALHOUN STATION, UNIT 1 (TAC NO. 75282)

The NRC staff has performed an initial review of Revision 5 of the Fort Calhoun Stationpumpandvalveinservicetesting(IST)programforthesecondten-year interval, which Omaha Public Power District submitted by letter dated October 8, 1990.- This revision contains a number of new and revised relief requests.

At this time, we have identified several inconsistencies, which are delineated in the enclosure. With the condition that the proposed actions to resolve the inconsistencies-identified are addressed by the licensee within 60 days of the receipt of this letter, we believe that an interim period of relief is appro-priate until the staff can complete the evaluation of Revision 5 to the IST program. Since this interim approval does not represent the results of the final program review, future supplements to the Safety Evaluation Report could contain relief request denials.

Thestaffhasdeterminedthat,pursuantto10CFR50.55a(a)(3)(1), granting this interim approval for the reliefs requested in Fort Calhoun IST program for i

the second ten-year interval will provide an acceptable level of quality and.

safety pending completion of the evaluation of Revision 5 to the IST program.

Sincerely, A

l'

/

1 Thomas P. Gwyn,

eting Director Project Directo ate IV-1 Division of Reactor Projects III.-IV, and V Office of Nuclear Reactor Regulation

Enclosure:

As stated l

l cc w/ enclosure:

l See next page l

Mr. W. Gary Gates Omaha Public Power District Fort Calhoun Station, Unit No. 1 cc:

Harry H. Voigt, Esg.

LeBoeuf, Lamb, Leiby & MacRae 1333 New Hampshire Avenue, NW Weshington, D.C.

20036 Mr. Jack Jensen, Chairman Washington County Board of Supervisors Blair, Nebraska 68008 Mr. Raymond P. Mullikin, Resident inspector U.S. Nuclear Regulatory Commission Post Office Box 309 Fort Calhoun, Nebraska 68023 Mr. Charles B. Brinkman, Manager Washington Nuclear Operations Combustion Engineering, Inc.

12300 Twinbrook Parkway, Suite 330 Rockville, MD 20852 Regional Administretor, Region IV U.S. Nuclear Regulatory Commission Office of Executive Director for Operations 611 Ryan Plaza Drive, Suite 1000 Arlington, Texas 76011 Harold Borchert, Director Division of Radiological Health Nebraska Department of Health 301 Centenniel Mall, South Post Office Box 95007 Lincoln, Nebraska 68509 Mr. T. L. Patterson, Manager Fort Calhoun Station Post Office Box 399 Fort Calhoun, Nebraska 68023

i C.

l Enclosure Qh FT. CALHOUN IST PROGRAM REVISION 5 IllCONSISTENCIE5 IDENT]f JED DURINE FRELIMINARY R! VIEW 1.

Code Exception Number G2 for Valves: The relief from IWV-3427(b) of the ASME Code granted through Generic Letter 89-04, Attachment 1, Position 10, applies only to CIVs under containment leak rate testing. Therefore, the licensee should change the applicability of this relief request from all Category A type valves to only CIVs.

2.

Code Exception Numbers ES, E7, and E10 for Valves: The licensee has proposed using disassettly and inspection to verify the full-stroke open capability cf check valves.

While disassembly and inspection is an accept-able method for verifying the fell-stroke open capability of check valves, the NRC staff considers valve disassed ly and inspection to be e mainten-ance procedure with inherent risks which make its use as a substitute for testing undesirable when other testing methods are possible.

The hRC staff positions regarding check valve disassembly and inspection to verify the full-stroke open capability are explained in detail in Generic Letter No. 89 04, Attachment 1, Item 2.

The minutes on the public meetings on Generic Letter flo. 89-04 regarding this staff positiun further stipulate that a partial stroke exercise test usir.g flow is expected to be performed af ter disassembly and inspection is completed but before the valve is returned to service.

A preferred alternative is to verify that these vahes move to their fully open position by use of non-intrusive diagnostic testing techniques during a reduced flow test at least once each refueling outage.

The licensee should investigate cathods to perform a partial flow test of the disassembled valves before they_are returned to service.

The licensee shoulo also investigate the use of non-intrusive diagnostic techniques to demonstrate that these valves swing fully open during partial flow testing.

If another method is developed to verify the full-stroke capability of these valves, these relief requests should be revised or withdrawn.

3.

Code Exemption Nuder E18 for Valves:

The licensee should provide justification for not testing during cold shutdown when RCS is depressurized and the RCPs are secured.

4.

Code Exemption Number E30 and E38 for Valves: The licensee should provide justification for not testing during cold shutdowns when RCS is depressurized and RCS temperature is less than 130'F with RCPs off.

5.

Code Exemption Number E35 for Yalves:

The niinutes from the public meetings on Generic Letter 89-04 state that the use of disassembly to verify valve closure capability may be acceptable depending on whether verification by flow or pressure measurement is practical. However, the NRC staff considers valve disassembly and inspection to bs a maintenance procedure that is not equivalent to the Code required exercise testing.

l l

2 QW This procedure has risks which may make its routine use as a substitute for testing undesirable when some other method of testin; is possible.

Check valve disasser21y is a valuable maintenance tool tiet can provide a great deal of information about valve's internal condition and, as such, should be performed under the maintenance progran at a frequency commen-urate with the value type and service. While the licensee's proposed alternative should provide reasonable assurance that these valves are capable of performing their safety function in the closed position, the licensee should investigate other methocs of exercising them to the closed position. Specifically, the licensee should investigate the use of leak testing (reverse flow closure verification) or non-intrusive diagnostic techniques such as acoustics or radiography to demonstrate that these valves close when subjected to reverse flow condhions.

l The minutes from the public meetings on Generic Letter 89-04 also state that partical-stroke exercise testing with flow is expected to be performed af ter valve disassembly and inspection is completed, but before returning the valve to service. This post-inspection testing provides a degree of confidence that the disassem)1ed valve has becn reassembled properly and that the disk moves freely.

The licensee should investigate methods to perform a partial flow test of the disassenbled valves before they are returned to service. The licensee should also investigate methods, other than disassembly and inspection, of verifying the reverse flow closure capability of these valves. This l

relief request should be revised or deleted if another method is developed to verify the reverse flow closure capability.

6.

Code Exception Number E44 for Valves: The licensee has provided a cold shutdown justification for full-stroke exercising valves SI-135, SI-143 and SI-149, Containment Spray Pump Discharge Check Valves, during cold l

shutdowns when the CS pumps are able to be aligned to the shutdown cooling heat exchanges (i.e., when the primary coolant temperature is less than 120'F). A relief request should have been provided because these valves l

will r.ot he exercised each cold shutdown. The licensee should correct l

this error.

l 7.

Code Exception Number 45 for Pumps: The licensee has proposed a full scale range of flow measuring instrument that is approximately six times the reference value in lieu of the Code required limit of three times the l

reference valve or less. This proposal, when combined with the instrument occuracy requirements of 22% of full scale, effectively limits the total measurement accuracy for flow rate -instrumentation to 212% of the reference value. The flow measurement that is off by 12% would be a questionable indicator of pump degradation.

The licensee should, therefore, investigate the procurernent and installation of instrumentation - preferably, ocn-intrusive types - that meet the Code range and occuracy requirements.

o

-3 T( }i 8.

Code Exception humber E6 for Pumps: The licensee should develop a nethod to evaluate vibration measurements taken while using the pump curves. A set of vibration reference values ray have to be established for each pump curve used, since the vibretion characteristics can vary, depending on where the pump is operating relative to the pump curve.

9.

Code Exce> tion humber E8 for Pumss: The Code section (i.e., IWP-3230(a))

from whici relief is requested s1ould be specified in this relief request.

Also, the licensee did not provide adequate basis for deleting the corrective action requirement of IWP-3230(a) relative to Alert Range of IWP-3100 2 for Chargir9 Pumps CH-1A, B, C.

The argunent that "a) plying the tolerance frem Table IWD-3100-2 yields 6n acceptance range whic1 is very difficult to read on a flow indicator with a range of 0-240 gpm" is invalid.

The reason is that 0-240 gpm is approximately twice the range allowed by the Code. As indicated in the staff's evaluation of Code Exception Nu d er ES, above, the instrumentation should have a range of three times reference value or less, approximately 0-120 gpm. The need for this relief recuest should be rebssessed since the acceptance range should not be very c;ifficult to read if the test is performed using acceptable instrumentation.

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