ML20210U388

Rev 1 to RO 80-46:on 801104 & 21,overspeed Trip Lever on Turbine for Auxiliary Feedwater Pump P-318 Found in Tripped Position.Cause Still Undetermined.Start of Turbine Will Be Attempted Prior to Resetting Device If Condition Reoccurs

ML20210U388
Person / Time
Site:	Rancho Seco
Issue date:	02/09/1987
From:	Julie Ward SACRAMENTO MUNICIPAL UTILITY DISTRICT
To:	Martin J NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM), NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
References
80-46, JEW-87-104, NUDOCS 8702180468
Download: ML20210U388 (2)

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3.uu.SACRAMENTO MUNICIPAL UTILITY DISTRICT O P, o. Box 15830, Sacramento CA 95852-1830,(916) 452-3211 AN ELECTRIC SYSTEM SERVING THE HEART OF CALIFORNIA JEW 87-104 FEBF 9 1937 3

J. B. Martin, Regional Administrator Region V Office of Investigation and Enforcement Attn Document Control Desk U. S. Nuclear Regulatory Commission Washington, D. C. 20555 Docket No. 50-312 Rancho Seco Nuclear Generating Station Unit #1 License No. DPR-54 LICENSEE EVENT REPORT 80-46, REVISION 1, OVERSPEED TRIP LEVER ON THE TURBINE FOR THE AUXILIARY FEEDWATER PUMP WAS FOUND TRIPPED .

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Dear Mr. Martin:

The Sacramento Municipal Utility District is hereby submitting a l revised report on Reportable Occurrence 80-46 sent to your office l on December 3, 1980.

l On November 4, 1980, the overspeed trip lever on the turbine for the Auxiliary Feedwater pump, P-318, was found tripped. The pump, P-318, is a dual-drive pump with both an electrical motor drive and a turbine drive. On that date surveillance procedure SP 210.01A, " Quarterly Turbine / Motor Driven Auxiliary Feedwater Pump P-318 Surveillance and In-Service Test" was being performed.

The section of the test which utilizes the motor as the prime mover had been completed. Prior to running the section of the test which utilizes the turbine as the prime mover, it was discovered that the overspeed trip lever was in the tripped position. The trip lever was reset and the remainder of the surveillance test was performed.

At that time it was thought that the lever may have tripped due to vibration as a result of running the pump via the motor drive just prior to the discovery. However, as an added precaution a daily visual check of the overspeed trip device was initiated.

On November 21, 1980, the overspeed trip lever was again found in an apparent tripped position. The trip device was reset and the pump was successfully started and run via the turbine drive.

8702180468 870209 PDR /,g7h ADOCK 05000312 S PDR f e

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RANCHO SECO NUCLEAR GENERATING STATION O 14440 Twin Cities Road, Herald, CA 95638-9799;(209) 333-2935

• J. B. Martin 2 February 9,1987 l

The pump had not been run via the motor drive since the November 4 occurrence and, therefore, the tripped condition could not be attributed to vibration. The cause of the tripped condition could not be determined.

The review of this occurrence by the Plant Review Committee revealed that whether the overspeed trip device is actually tripped or not is not readily apparent. To determine whether the j device is tripped requires close examination as the position of the lever itself can be misleading. On both occasions, the apparent trip was reset prior to attempting a turbine start. In the future, if the trip lever is found in an apparent tripped condition, a start of the turbine will be attempted prior to resetting the device. This action will provide positive indication whether or not an actual tripped condition existed, k

A readily evident indication device has been installed on the l

( trip mechanism as committed to in the original submittal on this l event. Additionally, IDADS computer point Zl622 will now alarm in [

the Control Room if the overspeed device trips. There~ fore, even l )'

though the daily visual check of this device ~ instituted as a i result of the November 4 occurrence is now part of the normal I shift equipment rounds, the District no longer considers this to be a mandatory requirement, per the previous version of this LER. ll It should be noted that the redundant Auxiliary Feedwater Pump, P-319, was operable at all times. Additionally, P-318 itself was fully operable via the motor drive. Only the " automatic start feature" of the pump would be affected if a tripped condition existed.

The turbine drive of the Auxiliary Feedwater pump P-318 is manufactured by Terry Steam Turbine Company.

There were no plant transients nor power reductions associated with this event.

If there are any questions concerning this report, please contact i Mr. Ron W. Colombo at the Rancho Seco Nuclear Generating Station. l Sincerely, Jo E. Ward eputy General Manager, Nuclear Attachment cc: Region V (2)

INPO

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