ML20084L248
| ML20084L248 | |
| Person / Time | |
|---|---|
| Site: | Quad Cities  |
| Issue date: | 04/15/1974 |
| From: | Kalivianakis N COMMONWEALTH EDISON CO. |
| To: | Oleary J US ATOMIC ENERGY COMMISSION (AEC) |
| Shared Package | |
| ML20084L240 | List: |
| References | |
| NJK-74-32, NUDOCS 8305200455 | |
| Download: ML20084L248 (2) | |
Text
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py C mmhe:lth Edison
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/C' Ouad-Cities Generating Station 7 N 7
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.I Post Office Box 216
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Cordova,lihnois 61242
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April 15, 1974 Mr. John F.
O' Leary, Director Directorate of Licensing Regulation U.
S.
Atomic Energy Commission Washington, D. C.
20545
Reference:
Quad-Cities Nuclear Power Station, Unit 1 Docket No. 50-254, DPR-29, Appendix A, Sections 1.0.A.4, 3.5.B.1, and 6.6.B.l.a Dear Mr.
O' Leary:
'i'h a p"rpose of this letter ic to infor you cf the details of an abnormal occurrence which was discovered on April 6, 1974.
With Unit 1 in the cold shutdown condition during the refueling outage, the discharge piping of the "A" loop of the RHR Service Mater Syster was found to be leaking.
This occurrence was reported to the Region III Directorate of Regulatory Operations by telephone and the Region III Direc-torate of Licensing by telegram on April 6, 1974.
Since the unit was in the cold shutdown condition and no work was being performed that had the potential to drain water from the vessel, there were no Limiting Conditions for Operation violated.
However, the incident is an abnormal occurrence according to Technical Specification 1.0 A.4.
PROBLE'1 AND INVESTICATION On the morning of April 4, 1974, water was reported seeping through a crack in the turbine building wall.
It was not immediately known whether the source of the water was a pipe failure or seepage from the soil.
On the morning of April 6, 1974, after checking several other possible sources, it was determined that a leak existed in an underground section a the 16" loop "A" Residual Heat Removal System service water header.
This was determined by transfering shutdown cooling from A loop to B loop.
When this uns done the scopage into the turbine building basement was greatly reduced.
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COPY SENT REGION
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Mr. J. F. O' Leary
~ April 15, 1974 SAFETY IMPLICATIONS The low pressure coolant injection mode of the RHR system was-not affected byJthe failure.
Due to the condition of
~
i the reactor, the-containment cooling mode of the RHR system is not required.
The shutdown cooling mode 'of the -RHR. system 4
is still.-operable using loop B.
-Therefore the safety implica-
-tions of the failure'are ninor.
EVALUATIONS AND CORRECTIVE ACTIONS An. effort is now in progress to locate the exact piping fail-ure.
To date, the line has been drained,-but there is still' leakage into the isolated section of pipe of approximately 3 GPM.
The next step will be to cut a hole in the line in' the Unit 1 high pressure coolant injection room and visually, or with the aid of a television-camera, locate the leak.
At that time an evaluation will be made as to the feasibility
'of repairing'the leak and the possible cause of the failure.
As a second cour:te of action, representatives from Sargent l
and Lundy and Commonwealth Edison M & S Engineering are dis-cussing the relocation of~the pipe above ground.
Also being factored into this-second plan is a resolution of the problem reported ac an unucual event in Our 1cttcr of March G, 1574.
}
This -is the problem of the operability of the two containment cooling loops being jeopardized by a single ~ failure of certain portions of the containment cooling system.
A decision as to whether the line will be repaired or'a new exposed-line will be run will be made when the location and l
extent of the leak is known.
The results of the investigations of both cources of action will be reported to you along with the final decision on the' repair in a subsequent letter.
EVAL'UATION 'OF CUMULATIVE EXPERIENCE 4
There is no cumulative experience related ta) this incident since there have been no previous failures of this type at Quad-Cities Station.
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Very truly yours, COMMONWEALTH EDISON COMPANY QUAD-CITIES NUCLEAR POWER STATION jf!fn l ?Y!
N. J. Kalivianakis ~
Station Superintendent NJK/lk i
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cc:
Region III, Directorate of Regulatory Operations
..J.
S. Abel
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