ML20056A046

Requests Regional Waiver of Compliance for Containment Pressure Transmitter 1-PT-934 During Coming Outage

ML20056A046
Person / Time
Site:	Comanche Peak
Issue date:	07/24/1990
From:	William Cahill TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC)
To:	Martin R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML20056A045	List: ML20056A044 ML20056A046
References
TXX-90263, NUDOCS 9008030128
Download: ML20056A046 (3)

Text

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1. TXX 90263- 1 L .:: - Fi!.op e # 10010 -

?= 'E July 24,1990 -

set hesidsunt L Mr.-R. D. Martin U. S. Nuclear Regulatory Comission l

Region IV 1 61:. Ryan Plaza Dr., Suite 1000

' Arlington, Texas 76011 1

SUBJECT:

COMANCHEPEAKSTEAMELECTRICSTATION(CPSES)

DOCKET N0. 50 445 WAIVER OF COMPLIANCE FOR CONTAINMENT PRESSURE TRANSMITTER i Ref: (1) Thomas E. Murley, NRC Memorandum, Temporary Waivers of Compliance, dated February 22, 1990 1.

Gentlemen:

, In accordance with the guidance provided b '

+ requests a Regional Waiver of Compliance. This waivery Reference wi (1)ll allow repair of, T Containment Pressure Transmitter 1-PT-934 during the upcoming outage, while in Mode 3 without delaying restart. The repair will restore normal ESFAS logic and minimize the poten3ial for a spurious actuation of the CPSES ESF systems.

The specific information requested by Reference (1) is provided below.

REQUIREMENT / REQUEST:

1. 'LC0 3.3.2, Table 3.3 2, Action Statement 17. Specifically, Action 17 requires that an inoperable containment pressure channel .be ) laced in the i tripped condition within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. Currently this action is >eing cceplied with,' however TU Electric requests a Waiver of Compliance for this action  !

in order to place inoperable channel 1-PT-934 in a non-tripped condition for short periods during bellows replacement.

2. LCO 3.6.2.1, Containment Spray System. TU Electric requests a Waiver of Compliance for this ,LCO in order to make the automatic actuation of Containment Spray inoperable for both trains during short periods while 1-PT-934 is being repaired. This will be accomplished by placing the controls for heat exchanger outlet valves for each train in the " PULL OUT" position, 900S030128 900725 PDR ADOCK 05000445

-P PDC 400 North Olive Strert LB of Dallar. Tuas 75201

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TXX 90263 Page 2 of 3 q J

~l CIRCUMSTANCES:

Conta'inment pressure sensor 1-PT-934 has a bellows leak. This instrument i provides one channel of the ESFAS logic for Safety Injections (SI), Steam Line Isolation, Containment Spray actuation and Containment Isolation Phase "B". ,

With the channel for 1-PT-934 inoperable and tripped (per the required l: action), each of these logics, with' the exception of Containment Spray L

actuation will actuate with a signal from one of the remaining operable p channels. This is an undesirable situation because a single spurious signal l

or an additional instrument failure could initiate any or all of the above ESF

p. actions.

The repair procedure for this instrument will require TIG welding. The welding duration will be approximately 10 minutes at four different points'in the repair procedure. The. containment pressure instruments are sensitive to welding in the vicinity of the transmitters and electrical noise on the 7 channels are a definite possibility. Other repair methods were considered but welding is the best repair process.

The waiver described above is needed to perfom this repair during the upcoming outage while in Mode 3. Presently, TU Electric does not intend to go to Mode 4 during the outage. Going to Mode 4 would be an unnecessary thermal transient on the plant and would, in essence, extend the outage such that the-L. plant would be delayed from restarting per the present schedule.

COMPENSATORY ACTION:

A-special procedure has been written which-describes the repair activity and provides direction to the operator. The operator may quickly restore the operability of Containment Spray by moving two valves out of the " PULL 00T" position. .During the period when the Containment Spray valves are in " PULL ,

OUT' a dedicated operator wil be stationed to restore Containment Spray  !

' operability should an actual Containment Spray actuation be required. All ESF

.actuations will still occur automatically and may also be accomplished manually. The operator will have containment pressure indication available on the control board, along with other instrumentation to confirm whether a  !

Containment Spray is required.. l SAFETY SIGNIFICANCE AND POTENTIAL CONSEQUENCES fPRELIMINARY):

Since the waiver conditions will exist foi very brief times, the operators will be alerted, manual actuation will be available and the plant will be in Mode 3, any safety significance or potential consequences have been minimized and are essentially non existent. t 4

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• f ;,j. 1 TXX 90263 Page 3 of 3 DURATION:

The duration is based on the time to perfom the welding. Four steps in the repair require welding for approximately 10 minutes each time. The entire L

repair may take about four days but the waiver is only required during l

performance of the four welds.

SIGNIFICANT Maran_nt CONSIDERATION:

Since the repairs are being performed in Mode 3 with the operators alerted and -

manual. actuation quickly achievable, it is not expected that this repair with this waiver will result in any significant increase in the probability or consequences of an accident previously evaluated. The waiver would not create the possibility of a new or different kind of accident from any accident

- previously evaluated. The waiver does not involve a reduction in a margin of t

L safety. For the short duration involved and while in Mode 3, manual actuation '

can assure adequate system performance to maintain existing margins.

ENVIR0 MENTAL CONSEQUENCES:

The request only involves manipulations within the plant. These manipulations and their potential consequences are limited to the plant and will not result-in.any unplanned releases that could cause an impact on the environment.

CONCLUSION:~ ,

This waiver will allow the completion of an important repair without delaying the plant's restart and with essentially no impact on safety. This activity nas e n reviewed and approved by the Station Operations Review Committee (SORC). TU Electric requests that the NRC grant this request for a Regional Waiver of Compliance. Although the~ repair procedure only requires welding at four points, the waiver is requested "for short periods' to allow additional welding, if necessary, due to welder problems, the ami f9r weld repairs, etc.

' A response is requested prior to the close of business on July 25, 1990.

Sincerely, k ._

t William J. Cahill, Jr.

'DRW/daj c - Resident Inspectors, CPSES (3)

Document Control Desk

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