ML17262A929
ML17262A929 | |
Person / Time | |
---|---|
Site: | Ginna ![]() |
Issue date: | 07/16/1992 |
From: | Mecredy R ROCHESTER GAS & ELECTRIC CORP. |
To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
References | |
IEB-80-24, NUDOCS 9207230070 | |
Download: ML17262A929 (5) | |
Text
ACCELERATED D STBXBUTION DEMONS TION SYSTEM REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)
ACCESSION NBR:9207230070 DOC.DATE: 92/07/16 NOTARIZED: NO DOCKET FACTL:50-244 Robert Emmet Ginna Nuclear Plant, Unit 1, Rochester G
05000244 AUTH.NAME AUTHOR AFFILIATION MECREDY,R.C.
Rochester Gas S Electric Corp.
RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)
SUBJECT:
Special rept:on 920702,containment (CNMT)
Sump A actuation received due to svc water leak inside containment.
Alternatives to redesign 6 replacement of CNMT ricirc fan cooling coils will be considered during 1994 outage.
DISTRIBUTION CODE:
IE22D COPIES RECEIVED:LTR ENCL SIZE:
TITLE: 50.73/50.9 Licensee Event Report (LER), Incident Rpt, etc.
NOTES:License Exp date in accordance with 10CFR2,2.109(9/19/72).
05000244 RECIPIENT ID CODE/NAME PD1-3 LA JOHNSONiA INTERNAL: ACNW AEOD/DSP/TPAB NRR/DET/EMEB 7E NRR/DLPQ/LPEB10 NRR/DREP/PRPB11 NRR/DST/SICBSH3 NRR/DST/SRXB SE RES/DSIR/EIB COPIES LTTR ENCL 1
1 1
1 2
2 1
1
'1 1
1 1
2 2
1 1
1 1
1 1
RECIPIENT ID CODE/NAME PD1-3 PD AEOD/DOA AEOD/ROAB/DSP NRR/DLPQ/LHFB10 NRR/DOEA/OEAB NRR/DST/SELB SD R
LBSD1 02 RGN1 FILE 01 COPIES LTTR ENCL 1
1 1
1 2
2 1
1 1
1 1
1 1
1 1
1 1
1 EXTERNAL: EG&G BRYCE,J.H NRC PDR NSIC POORE,W.
3 3
L ST LOBBY WARD 1
1 NSIC MURPHY,G.A 1
1 NUDOCS FULL TXT 1
1 1
1 1
1 Ye aye'f7 e( ~s NOTE TO ALL"RIDS" RECIPIENTS PLEASE HELP US TO REDUCE WASTE! CONTACT THE DOCUMENT CONTROL DESK, ROOM Pl-37 (EXT. 20079) TO ELIMINATEYOUR NAMEFROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!
TOTAL NUMBER OF COPIES REQUIRED:
LTTR 30 ENCL 30
lain ROCHESTER GAS AND ELECTRIC CORPORATION t
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e9 EAST AVENUE, ROCHESTER N.K 14649-0001 ROBERT C. MECREDY Vice Preridenl Cinna Nuclear Production TELEPrlOhE AcrucooEPle 646 2700 July 16, 1992 U.S. Nuclear Regulator 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 Regulator Commission Region I 475 Allendale Road King of Prussia, PA 19406 Ginna USNRC Senior Resident Inspector 9207230070 9207ih PDR ADOCK 05000244 8
PDR p(30
~IS Pyre I p~g g
SERVXCE WATER LEAK INSIDE CONTAXNMENT PRE-&Pl?NT CONDITIONS The Plant was at approximately 974 steady state reactor power.
The Results and Test (RST)
Group had completed Periodic Test procedure, PT-2.7 (Service Water System) at approximately 1100 EDST, July 2, 1992.
IX.
DESCRIPTION OF &TENT On July 2,
1992 at approximately 1340
- EDST, with the reactor at approximately 97% full power, a
Containment (CNMT)
Sump "A" Pump Actuation was received.
The Control Room operators, after calculating the actuation interval between the last two (2) pump actuations to have decreased by 54.7 percent, suspected some type of increased leakage inside of CNMT.
An investigation to determine the cause of leakage 'inside CNMT was immediately initiated.
Indications of a 'possible Reactor Coolant System leak were not presents 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 Reactor Coolant System leakage.
- However, the frequency of dumps of the CNMT Recirc Fan Cooler Condensate Collectors for the "C"
CNMT Recirc Fan had increased.
Based upon these indications, a service water leak in the "C"
CNMT Recirc Fan cooling coils was suspected.
Preparations for a CNMT entry for investigation of the leak were immediately commenced.
At approximately 1950 EDST on July 2,
- 1992, personnel entered CNMT and at approximately 2007 EDST, the "C"
CNMT Recirc Fan Cooler was identified as having a service water leak from its cooling coils.
The "C"
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 (i.e.,
WR/TR f9201484) to repair the service water leak associated with the "C"
CNMT Recirc Fan Cooler.
All other Recirc Fan Coolers were inspected with no leakage identified.
The Control Room operators notified higher supervision, the Nuclear Regulatory Commission (NRC) and the NRC Resident Inspector of the event.
CORRECTIVE ACTION A.
ACTION TAKEN TO REHJRN AFFECTED SYSTEMS TO PRE-EVENT NORMAL STATUS.
Work order package 9201484 was developed to perform a tube repair in accordance with procedure EM-745.
(Repair Of Containment Fan Cooling Coils) and the disposition of NCR 92-314 using General Brazing Specification 400 and Qualified Brazing Procedure Specifications 400-1-A1.
This repair attempt failed, as the tube defect propagated along the tube through the tube 'heet and became inaccessible for braze repair.
The disposition of NCR 92-314 was subsequently revised to permit cutting the tube and soldering caps on the tube at the discharge header and at the second to third pass return 'U'end using Qualified Brazing Procedure, BPS 400-2.
Upon completion of the repair, a
leakage test was conducted to prove the adequacy of the soldering cap joints.
Prior to reaching operating pressure during the leak test, an additional leak was located in the g8 tube in the supply header.
This new leak apparently resulted from the current repair activities.
The unit was again isolated to:-perm'it repair of the newly identified leak.
This tube was inaccessible to repair from the same access location.
NCR 92-317 was initiated and dispositioned to permit disassembly of a portion of the cooler plenum to provide access to the tube from a more direct access point.
This defect was repaired using BPS 400-6-Al to braze a lap joint tube material overlay.
The braze joints were visually examined and leak tested at operating pressure to verify acceptability of the tube repairs (no indication of leakage was apparent).
The "C"
CNMT Recirc Fan Cooler was subsequently returned to service.
~
~
B..
ACTION TAKEN OR PLANNED TO PREKBlT RECURR19lCE-The underlying cause of the event was determined to be tube wall thinning in an area that has experienced turbulent flow for a number of years, aggravated by service water system test configurations during the performance of PT-2.7.
The following actions to prevent recurrence are planned:
o
=
Alternatives to the redesign and replacement of the CNMT Recirc Fan cooling coils (EWR 5275 currently planned to commence during the 1994 outage) will be considered.
The need for expedited replacement of some cooling coils will also be considered under this EWR.
0 Mechanical Engineering and the R&T groups have initiated an assessment of PT-2.7.
With assistance from the Nuclear Safety and Licensing
- group, current test configurations and test methods will be compared against ASME Section XI requirements and expected post-accident configuration and operation.
'he results of this assessment will be evaluated for changes to the frequency and methodology of performing PT-2.7.