ML20064P082

Forwards Results of Flow Verification Test for Essential Raw Cooling Water Sys.Recommendations Included Supersede Commitments Made in Previous Response to IE Bulletin 81-03

ML20064P082
Person / Time
Site:	Sequoyah
Issue date:	09/07/1982
From:	Mills L TENNESSEE VALLEY AUTHORITY
To:	Adensam E Office of Nuclear Reactor Regulation
References
REF-SSINS-6820 IEB-81-03, IEB-81-3, NUDOCS 8209130097
Download: ML20064P082 (4)

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i TENNESSEE V,AL' LEY AUTHORITY

e. CH ATTANOOGA, TENNESSEE 37401 400 Chestnut Street Tower II-September 7, 1982 Director of Nuclear Reactor Regulation Attention: Ms. E. Adensam, Chief Licensing Branch No. 4 Division of Licensing U.S. Nuclear Regulatory Commission Washington, D.C. 20555

Dear Ms. Adensam:

In the Matter of ) Docket Nos. 50-327 Tennessee Valley Authority ) 50-328 As required by the Sequoyah Nuclear Plant unit 2, operating license condition 2.C.(15), TVA submitted procedures for implementation of a surveillance program on corrosion of carbon steel piping. Enclosed are the results of the flow verification test for the essential raw cooling water system that was performed in the spring of 1982.

The recommendations. included in this report supersede commitments made previously in our response to OIE Bulletin 81-03. We believe the information obtained during performance of the flow verification testing is sufficient to support the recommendations contained in this report.

The procedures for performing the flow verification testing were provided in my October 15, 1981 letter to you.

If you have any questions concerning this matter, please get in touch with J. E. Wills at FTS 858-2683 Very truly yours, TENNESSEE VALLEY AUTHORITY

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L. M. Mills, M nager Nuclear Licensing Sworn to and subscrib before me thi day of _ 1982.

uM Hota Public My Commission Expires Y

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Enclosure cc: U.S. Nuclear Regulatory Commission Region II Attn: Mr. James P. O'Reilly, Regional Administrator 101 Marietta Street, Suite 3100 Atlanta, Georgia 30303 8209130097 820907 An Equal Opportunity Employer gDRADOCK 05000327 PDR

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.. ENCLOSURE SEQUOYAH N,UCLE R PLANT '

ERCW FLOW VERIFICATION TESTING

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In accordance with our commitment Water (ERCW) Flow Verification Testto NRC, we have completed the Essentio! Raw Cooling

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The worst (SI-566). The case conditions assumed are loss of downstream dam, test was completed on Ap loss of one train of the dieselSigenerators This verifics flow and a continuous backwash of 1000 gpm of the ERCU trains unde Unit 2 - llot Standhy; for each train for the following conditions: (1) Unit 1 - LOCA, Unit 2 - flot Standby. (2) Unit 1 - Ilot Standby, Unit 2 - LOCA and (3) Unit 1 - Shutdcun Preparation for this test was quite extensive, all test connections and simulate the required conditions.rcquLringThe followingapproximately a week t alterationswpre required prior to commencing actual data temporary taking and flow balancing:

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164 connections to various flow elements. Test cynnections and vents were made with ings polyflow throughoutandtheSwagelok test. quick connections to allow for flow and prescure read-

2. Nitrogen bottlea were installed at force the associated temperature control valves (TCV's)five air conditioning un ERCU flow to the associated equipment. full open and allow full

3. An annubar flow elemeyt was required continuous-backwash flow. installed for each train to allow monitoring of th 4

The automa:ic disabled duringoperation the test. of the hackwash and flushout valves for both trains was

5. 42 FCV's were ~_

forced open to allow full ERCW flow through the associated component .

Preparation for the test begun February 27, 1982. (installation of quick connections, N 2 bottles.ccrc.) Gas It was decided to verily the positions of all' valves 1:sted on OSLA 100 (identifies the valve posi'ylons established during Pte Op Cest'ing)"

the verification several valve positions' were found to be

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. During 503-27/R2034). All other incorrect incorrect (3ee LEE SQRO-Problems flow; were encountered with the transmitters for coacainmentpositions were av removaloftrappedairinthesensinglinescorrectedtheprehlem:s,way heat exchanger The remainder of this report will discuss problems found during the various '

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Train A. Test 1 (Uaf t 1 - LOCA, Unit 2 - llot Standby) .

t March tripped.

5--When the Auxiliary control Air Compressor A was lined up, s

A solenoid valve was replaced (see LER SQRO-50-327/82035) it continually March 7--An abr.orrplly high pressure dif ferential uns discovered ~nn CS!!X quent . Subse-1A visual inspection revealed approximately 15 gallons of cl.i g c1vaging the

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• nozzle of the heat exchanger (see SQRO-50-327/82027). After investigating a

• this incident it was determined to be an isolated case of infestation l

because of inadequate distribution of chlorine prior to shutdown of the header; subsequently, allowing propagation of the clams in the nonflowing water. The remaining CSHXs were subsequently inspected and no clam problems were found.

March 10--No flow could be obtained through the Electric Board Room .

Cooler A. The TCV was discovered to be faulty. This was evaluated to be nonceportable.

The FCV for CSHX A (1-FCV-67-146) was discovered to be malfunctioning; when moved from the open position to the 50-percent position it did not move at all. When taken to the 50-percent position from the 35-percent position, there was inadequate flow for the worst case condition. However, the system was determined operable for the system conditions at that time.

The valve limit switches were adjusted to correct the problem. This was evaluated to be nonreportable.

Train A, Test 2 (Unit 1 - Hot Standby, Unit 2 - LOCA)

, No significant problems were encountered.

I Train A, Test 3 (Unit 1 - Shutdown, Unit 2 - Hot Standby)

No significant problems were encountered. .

Train B, Test 1 (Unit 1 - LOCA, Unit 2 - Hot standby)

March 26--Discovered CSHX 2B throttle valve (2-FCV-67-124) did not allow proper flow in its present position (see LER SQRO-50-328/82047); valve was adjusted for adequate flow.

I Train B, Test 2 (Unit 1 - Hot Standby, Unit 2 - LOCA)

No significant problems were encountered.

Train B, Test 3 (Unit 1 - Shutdown, Unit 2 - Hot Standby)

No significant problems were encountered.

I Summary

1. Flow blockage as a result of clams in CSHX 1 A was determined to be an isolgted case caused by an inadequate chlorination program the previous i sumser. An inspection of the remaining CSHXs provided no evidence of clams.

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2. For various components, their respective throttle valves were fotrl to not be in their proper OSLA 100 positions.

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Recommendations (continued) .

1. The chlorination program has been initiated at Sequoyah and will continue through the summer as long as the ERCU temperature requires.

This will eliminate the possibility of clam larvae surviving in the EECW system.

2. To verify that heat exchanger blockage does not occur, a heat exchanger inspection program will be instituted.

! 3 A valve inspection program that will verify the OSLA-100 throttle valve positions will be instituted. This valve verification will be performed at least quarterly.

4. To verify that the above-mentioned programs adequately take care of their associated problems and to check for flow degradation because of piping corrosion, SI-566 should be performed again starting by March 1, 1983. Following a review of the SI results, it will be determined if the SI needs to be performed again.

RRC:MJS 7/9/82 O

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