ML20084Q010
| ML20084Q010 | |
| Person / Time | |
|---|---|
| Site: | Quad Cities  |
| Issue date: | 03/19/1974 |
| From: | Kalivianakis N COMMONWEALTH EDISON CO. |
| To: | Oleary J US ATOMIC ENERGY COMMISSION (AEC) |
| Shared Package | |
| ML20084Q014 | List: |
| References | |
| NJK-74-5, NUDOCS 8306130095 | |
| Download: ML20084Q010 (2) | |
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C' Ouad-Cities Generating Station
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Post Office Box 216 D
Cordova. Illinois 61242
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Telephone 309/654-2241
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nzr6 March 19, 1974 Mr. John F.
O' Leary, Director Directorate of Licensing Regulation U.
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Atomic Energy Commission Washington, D.
C.
20545
Reference:
Quad-Cities Nuclear Power Station, Unit 1 Docket No. 254, DPR-29, Appendix A, Section 1.0.A.2 and 3.5.E.
Dear Mr. O' Leary:
The purpose of this letter is to inform you of the details of an occurrence that took place on March 10, 1974 while performing the monthly surveillance checks on the Reactor Core Isolation Cooling System (RCIC).
The motor operator would not operate turbine steam inlet valve MO l-1301-61 so the system was de-clared inoperable.
This abnormal occurrence was reported to you by telegram on March 11, 1974 and discussed with Region III, Directorate of Regulatory Operations on March 11, 1974 by tele-phone.
PROBL'EM AND INVESTIGATION When it was discovered that the turbine steam inlet valve on the RCIC system would not open, the power supply breaker was checked and found to be operating properly.
The valve was operable in the manual mode, but since the system reauires automatic operation it was declared inoperable.
The High Pres-sure Coolant Injection System (HPCI) was satisfactorily tested immediately in accordance with Technical Specification 4.5.E.2._
Electrical maintenance then determined that the motor on the valve operator was running but not causing the valve to move.
Further investigation revealed that there was suf ficient wear on the manual declutch. cam and on the trip-lever uhich causes the worm gear to engage to make it fail'to operate.
When the declutch lever was operated, the cam on the declutch le er y 8306130095 740319 A' #,
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O Mr. J. F. O' Leary March 19, 1974 shaft did not move the trip lever enough to cause the worm gear to engage.
Therefore, when the motor operated it was not engaging the worm gear and closing the valve.
EVALUATION AND CORRECTIVE ACTION A means of supplying makeup water to the reactor in the events of an isolation with a failure of th'c feedwater system was not jeopardized since the IIPCI system is the designated alternate makeup water system and was proven operable.
Additionally, the failed RCIC valve could have boon operated manually if needed.
The can and trip lever were built up with veld because spare parts were not immediately available.
The operator functions properly now; new parts have been ordered and will be installed as soon as they become available.
CAUSE The cause of this failure was excessive wear during valve op-erations causing the can and trip lever to become inoperable.
CUMULATIVE EXPERIENCE There have been no previous failures of this type on a Limit-Torque valve operator at Quad-Cities Station.
It is felt that our monthly operability surveillance is adequate to detect this type of failure.
If further failures of this type are experienced, our surveillance in this area will be increased.
Very truly yours, COT 10NWEALTII EDISON COMPANY QUAD-CITIES NUCEEAR POWER STATION
'. f b hE N. J. Kalivianakis Station Superintendent NJK/lk cc:
Region III, Directorate of Regulatory Operations e