ML17262A972

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Special Rept:On 920813,D Containment Recirc Fan Cooler Declared Inoperable Due to Svc Water Leak in D Containment Recirc Fan Cooling Coils.Work Order Package 9201647 Developed to Perform Repair,Per Procedure EM-745
ML17262A972
Person / Time
Site: Ginna Constellation icon.png
Issue date: 08/24/1992
From: Mecredy R
ROCHESTER GAS & ELECTRIC CORP.
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
IEB-80-24, NUDOCS 9209010271
Download: ML17262A972 (6)


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ACCESSION NBR: 9209010271 DQC. DATE: 92/08/24 NOTARIZED:

NO DOCKET ¹ FACIL: 50-244 Robert Emmet Ginna Nuclear Planti Unit 1.

Rochester G

05000244 AUTH. NAME AUTHOR AFFILIATION MECREDYi R. C.

Rochester Gas 8c Electric Corp.

REC IP. NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk>

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SUBJECT:

Special rept: on 920813'iscovered that svc eater" leak on cooling coils. Work Order package 9201647 developed to perform tube repair.

DISTRIBUTION CODE:

IE22D COPIES RECEIVED: LTR ENCL SIZE:

TITLE: 50. 73/50. V.Licensee Event Report (LER) i Incident Rpti etc.

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NOTES: License Exp date in accordance with 10CFR2i 2. 109(9/19/72).

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1 NOTE TO ALL"RIDS RECIPIENTS:

PLEASE HELP US TO REDUCE WASTE! CONTACT THE DOCUMENT CONTROL DESK.

ROOM Pl 37 (EXT. 504 2065) TO ELIMINATEYOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!

TOTAL NUMBER OF COPIES REQUIRED:

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89 EAST AVENUE, ROCHESTER N.Y. 14649-0001 ROBERT G MECREDY Vice Psestdent Ginne Nuclees Psoduction TELEPHOkE AREACOOK 718 646 2700 August 24, 1992 U.S..Nuclear Regulatory Commission Document Control Desk Washington, DC 20555

Subject:

Service Water Leak Inside Containment R.E.

Ginna Nuclear Power Plant Docket No.

50-244 In accordance with the requirements of IE Bulletin No. 80-24, (Prevention of Damage Due to Water Leakage Inside Containment),

the attached 14 day report is hereby submitted.

Very truly yours, xc:

Robert C.

Mecredy U. S. Nuclear Regulatory Commission Region I 475 Allendale Road King of Prussia; PA 19406 Ginna USNRC Senior Resident Inspector OIOO92 pg3 tI-Q sQtI 920901027i 920824 PDR ADOCK 05000244 S

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14 Da Re ort of Service Water Leak Inside Containment PRE-EVENT PLANT CONDITIONS The plant was at approximately 974 steady. state reactor power.

Investigations were underway to determine the source of increased leakage to Containment (CNMT)

Sump A.

Indications of a

possible Reactor 'Coolant System (RCS) leak were not present; i.e.

no significant unexplainable increases or changes were observed on radiation monitors R-11 and R-12, (CNMT Air Particulate Monitor and CNMT Radioactive Gas Monitor, respectively),

the CNMT dewpoint, or RCS leakage.

However, the frequency of dumps of the CNMT Recirc Fan Cooler Condensate Collectors for the D

CNMT Recirc Fan had increased.

Based upon these indica-

tions, a Service Water (SW) leak in the D CNMT Recirc Fan Cooling Coils was suspected.

DESCRIPTION OF EVENT On August 13, 1992 at approximately 1430 EDST, an inspection of the D

CNMT Recirc Fan Cooling Coils. was performed.

This inspection revealed a

Service Water leak on the cooling coils for the D

CNMT Recirc Fan.

The D

CNMT Recirc Fan Cooler was declared inoperable and Service Water to the fan cooler was isolated.

A Ginna Station Work Request or Trouble Report (WR/TR) was initiated (WR/TR/

f9201647) to repair the Service Water leak associated with the D CNMT Recirc Fan Cooler.

The Control Room operators notified higher supervision, the Nuclear Regulatory Commission (NRC),

and the NRC Resident Inspector of the event.

III.

CORRECTIVE ACTION A.

ACTION TAKEN TO RETURN AFFECTED SYSTEMS TO PRE-EVENT NORMAL STATUS:

Work Order package 9201647 was developed to perform a tube repair in accordance with procedure EM-745 (Repair Of Containment Fan Cooling Coils) and the disposition of NCR 92-350 using general brazing specification 400 and qualified brazing specification BPS 400-6.

As the location of the service water leak (i.e.

on the "U" Bend end of the coil at the tube sheet intersection) was inaccessible due to inter-ference with the tube sheet and limited work area, qualified brazing specification BPS 400-6 could not be performed.

fi 1

The disposition of NCR,92-350 also permitted cutting the tube and soldering

'caps or installing plugs on the tube at the discharge header and at the second to third pass return "U" bend using qualified brazing procedure BPS-400-2.

This option was used.

Upon successful completion'f the repair, a leakage test was conducted to prove the, adequacy of the soldered cap installed at the second to third pass return "U" bend and the plug installed at the discharge header.

The brazed joints were visually examined for leakage at operating pressure to verify acceptability of the tube repairs.

No indication of leakage was apparent.'he D

CNMT Recirc Fan was subsequently returned to service.

B.

ACTION TAKEN'R PLANNED TO PREVENT RECURRENCE:

.The underlying cause of the event was determined to be tube wall thinning in the area that has experienced turbulent flow during the operating history of the cooling coils.

The following actions to prevent recurrence are planned:

Alternative to the redesign and replacement of CNMT Recirc Fan Cooling Coils (EWR-5275,currently planned to commence during the 1994 outage) will be considered.

Expedited replacement of spare cooling coils has been initiated under EWR-5275.