ML20055D035

Forwards Addl Info Re Svc Water Sys Noncode Temporary Repair,Per 900621 Application.Util Will Perform Ultrasonic Testing of Pipe Wall Adjacent to Fillet Weld Repair & on Patch.Insps Will Be Performed at 90-day Intervals

ML20055D035
Person / Time
Site:	Hope Creek
Issue date:	06/26/1990
From:	Labruna S Public Service Enterprise Group
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
GL-90-05, GL-90-5, NLR-N90131, NUDOCS 9007030125
Download: ML20055D035 (5)

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. 1 Pubhc Service Electri: ano cas Company

. 1 Stanley LaBruna PutAc Service Electric and Gas, Company P.O Box 236. Hancocks Bndge, NJ 08038 609-339-4800 va e, woc o - Nscw owe,<,%

JUN 2 61990 NLR-N90131 United States Nuclear Regulatory Commission Document Control Desk ,

Washington, DC 20555 Gentlemen:

REQUEST FOR ADDITIONAL INFORMATION SERVICE WATER SYSTEM NONCODE TEMPORARY REPAIR HOPE CREEK GENERATING STATION DOCKET NO. 50-354 In response to your request for additional information regarding our application on June 21, 1990 to perform a noncode temporary repair of the Hope Creek Generating Station (HCGS) Service Water System (SWS), Public Service Electric and Gas (PSE&G) provides the attached. To assure integrity of the temporary repair, PSE&G will perform ultrasonic testing of the pipe wall adjacent to the fillet weld repair and on the patch itself. These inspections will be performed at 90 day intervals v.ntil the code repair is made. Based on the responses provided and the low safety l implications of the temporary repair, PSE&G requests expeditious approval of our application.

Sincerely, r

DMM 1

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p{00703cl25 900626 p,DR ADOCK 05ooo334 PDC f

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,. .s Document Control Desk 2 JUN 2 61990 NLR-N90131 C Mr. C. Y. Shiraki Licensing Project Manager Mr. T. P. Johnson Senior Resident Ir4spector Mr'. T. Martin, Administrator Region I Mr. Kent Tosch, Chief New Jersey Department of Environmental Protection Division of Environmental Quality Bureau of Nuclear Engineering CN 415 Trenton, NJ 08625 i

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Stress Group Response to NRC Verbal Question Regarding HCGS Request Pursuant to Generic Letter 90-05 I

The PSE&G Stress Analysis broup has reviewed the following areas with respect to structural stability concerns raised by the NRR office of the USNRC:  ;

1 The area of reenforcement for an equivalent 7" opening in the 30" diameter l service water piping has been evaluated. The results indicate that suificient  ;

excess wall thickness beyond minimum required wall thickness exists such that no  ;

additional reinforcement is required for the opening. The 7" opening is the approximate length of the diagonal of the proposed 5"x 5"x 3/8" temporary )

repair plate. '

Existing pipe stresses have been modified to account for the opening in the {

30" diameter header. Conservatively, a Stress Intensification Factor of 10.44 i has been applied and all modifled stresses remain within code allowables, i

• Concerns with respect to crack propagation are minimal based upon the facts that the identified flaw 1) initially developed as a result of MIC intrusion i through a defect in the pipe protective coating, 2) the MIC colony caused the l

protective pipe coating to blister, 3) the colony and blister were subsequently washed away, and 4) exposed the carbon steel to the erosive offects of the river water. This flaw, as well as past piping degradation in the HCGS Service Water, System, is smooth surfaced in nature and not a crack type flaw. The bei.dary stresses at the interface of the degraded area with the base wall thickness will be reduced by the patch plate. Also, stress concentrations will be minimized as localized forces and moments will be transferred to the area surrounding the patch plate where nominal vall thickness exists.

A review of the pipe stress was performed in accordance with the HCGS TSAR, l Section 3.6.2.1.2 (Moderate Energy Pipe Breaks). The intensitled stresses at-l the patch location satisfy the requirements specified such th'at no break point needs to be postulated.

There are presently no other pipe patches located within Hope Creek Generating Station.

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HOPE CREEK SERVICE WATER SYSTEM LEAK

1. Is the service water line with the leak (patch) isolable from the main service water line?

The line is isolable from the main service water line by isolating RACS from service water.

2. Assuming a large line break at the patch, how will control room operators know of the event? i The SACS Heat Exchanger room in which the patch would be located is equipped with a flood alarm. Should a large line break occur at the patch, the blarm would indicate in the main control room .

Will there be periodic visits to the area of the patch?

How frequently?

Operations personnel make routine tours through the area three times per day. Tours are once during each eight hour period from 0700-1500, 1500-2300 and 2300-0700. These tours are documented per procedure OP-DL.ZZ-004(Q).

3. What are the potential consequences of a large break at the patch?

Loss of cooling water supply to the non safety-related RACS heat exchangers and possible flooding of the B SACS Heat Exchanger room,

a. Any loss of access to the ultimate heat sink for decay heat removal?

Isolation of the RACS Htx cooling water would not cause any loss of access to the ultimate heat sink for decay heat removal. The service water system would l supply cooling via the SACS syctem to components required l for decay heat removal. RACS does not have a safety-related function and provides a heat sink for non-essential plant components only. Failure of the RACS does not compromise any safety-related system or component, nor does it prevent a safe shutdown of the

, plant.

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b. Any loss of essential equipment due to flooding?

Should flooding of the SACS Heat Exchanger room occur, the flooding would be confined to that room by l watertight doors. SACS is designed with two loops,

! either of which is capable of supplying sufficient cooling to bring the plant to a safe shutdown condition.

Flooding of the room containing the leak will not affect the second leop.

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4. Are there any special operating procedures that deal with a postulated large pipe break at the patch?

Response to the flooding alarm in the 3ACS Heat Exchanger room is covered by procedure OP-AR.ZZ-001(Q),

Attachment B5. Should flooding cause the annunciator to alarm in the control room, the procedure requires an operator be dispatched to investigate. Should the alarm prove to be valid, operations would follow emergency '

operating procedure OP-EO ZZ-103(Q) to mitigate the consequences of the flooding and isolate the source, if applicable.

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