ML20084J212
| ML20084J212 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 08/17/1973 |
| From: | Carroll J, Reeves D, Ross D JERSEY CENTRAL POWER & LIGHT CO. |
| To: | Anthony Giambusso, James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I), US ATOMIC ENERGY COMMISSION (AEC) |
| References | |
| AO-73-17, NUDOCS 8305120247 | |
| Download: ML20084J212 (5) | |
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" f Jersey Central Power & Light Company M ADisoH AVENUE AT PUNCH BOWL Ro AD e MoRRISTOWN, N.J. 07960 0 539-6111 August 17, 1973
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Mr. A. Giarabusso Deputy Director for Reactor Projects b
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United States Atomic Energy Commission e
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Dear Mr. Giambusso:
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Subject:
Oyster Creek Station Docket No. 50-219 Diesel Generator The purpose of this letter is to report a failure of a component which could have caused the failure of No. 1 diesel generator to start. This event is considered te be an abnormal occurrence as defined in the Technical Specifications, Paragraph 1.1SD.
Notification of this event, as required by the Technical Specifications, Paragrcph 6.6.2a, was made to the AEC Region 1 Directorate of Regulatory Operations on Wednesday, August 8, 1973.
While conducting a routine six-month surveillance inspection of the No. I diesel generator, it was discovered that one of the two starting motors failed to engage. This engagement failure would have prevented the unit from starting under normal conditions. The engagement shaft bushing at the pinion end of the starting motor was discovered to be rotating with the shaft.
Due to wear, the bushing hcd slipped out of position thus preventing the pinion gear from engaging the engine ring gear.
Details of the diesel generator starter are as follows:
Manufacturer:
Delco Remy Model No.:
110975811 Serial No.:
222 Voltage:
64VDC Prior starter failures, although all associated with failed or weak starter solenoids, arc tabulated belcw:
Date Diesel Generator Problem 10/19/69 2
Doth. starter pinion solenoids were burnt, causing "hard" de system ground.
2/21/70 1
No reasen i nd.
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August 17, 1973 Date Diesel Generator Probicm 10/03/70 1
Starter motor pinions not en-gaging the ring gear properly.
12/04/72 2
One of the two starter motor pinions failed to engage.
Ileavier duty solenoid installed.
Based on our review of past starter failures, this appears to be the first one associated with mechanical failure of the starting motor. To correct this situation, a new starter motor was installed and tested satisfactorily.
Control lead connections were tightened and a satisfactory operability test was then conducted.
The significance of this event is minimal due to the fact that the difficulty was identified and corrected in conjunction with a routine six-month surveillance inspection, llad this condition gone undetected, a failure of one diesel to start has been considered in Appendix I. to the FDSAR which contains a probability analysis regarding the availability of standby cooling systems and includes an analysis of off-site power availability concurrent with a loss of coolant accident. The results indicated that the reliability of available power from off-site sources or from a scif-contained unit -- only one diesel generator was considered in the analysis -- was quite high. Since the station is provided with two separate diesel generator units, having one unit out of service has no effect at all upon the results of the analysis.
In addition, the effects of single bus operation during a loss of coolant accident was analyzed in Amendment 32 to the PDSAR and the uait loading under this condition was found to be within
.the normal KVA rating of the dicsol generator. Thus, there is' no additional safety significance associated with this event beyond that aircady analyzed.
To prevent this type of failure from reoccurring, the diesel manufacturer (General Motors) will be contacted and requested to supply the following:
(a)
Recommendations for. a positive locking mechanism to secure the shaft bushing at the pinion end of the starting motor.
(b)
Recommendations for preventative maintenance on the diesel generator starters.
In addition, the station's semi-annual diesel generator inspection procedure will be reviewed and revised, as required, based on the experience gained from this evcnt and possible future recommendations from the manufacturer.
h'e are enclosing fort) copics of this report.
Very truly yours, k/.
Donald A. Ross Manager, Nuc1 car Generating Stations pk cc:
Mr. J. P. O'Reilly, Director
.-Directorate of Regulatory Operations, Region 1
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To:
James P. O'Roi11y Directorato of Rcquiatory Operations Region I 631 Park Avenuo King of Prussia, Pennsylvania 19406 From:
Jerscy Contral Power & Light Compan')
Oyster Crcok 1;uclear Generating Staticn Docket #50-219 Forked RL ver, i;cw Jer.sey 08731
Subject:
Abnormal Occurrcnco Rcport 73-17 The followirg is a preliminary rcpart being submittcd in complianco with the Technical Specifications paragraph 6.6.2.
- 1 Preliminary Approval:
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Mr. A. Gianhusso !
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Datas 8/7/73 Times 2:30 p.m.
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Abnormal Occurrence Report No. 73-17
SUBJECT:
Failure of #1 Diesel Generator to start.
This event is considered to be an abnormal occurrence as defined in the Technical Spe:Lfications, paragraph 1.15D.
Notification of this event as required by the Technical Specifications, para-graph G.6.2.a, was made to AEC Region I, Directorate of Regulatory Operations, by telephone on Wednesday, August 8,1973, at 11:20 a.m.,
and by telecopier on Wednesday, August 8,1973, at 2:40 p.m.
SITUATION:
While conducting a routine six-month inspection of #1 Diesel l
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l Generator, it was discovered that one of the two starting motors l
l occasionally failed to engage, consequently preventing the unit l
from starting.
CAUSE:
The engagecent shaft bushing at the pinion end of the starting motor was discovered to have been rotating with the shaft. Due to wear, tha bushing had slipped out of position and prevented l
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the pinion gear from engaging the engine ring gear.
REMEDIAL, ACTION:
A new starter motor was installed and tested satisfactorily.
1 However, when an operability test was later attempted, the same starter failed to engage, requiring realignment of the motor.
A satisfactory operability test was then conducted and the unit was' returned to service.
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SAFETY SIGNIFICANCE:
Appendix "L" to the FDSAR contains a probability analysis re-garding the availability of standby cooling systems and includes an analysis of off-site power availability concurrent with a loss of coolant accident.
The results indicated that the reliability of available power from.off-site sources or from a self contained unit only one (1) diesel generator was considered in the analysis -
was quite high. Since the station is provided with two (2) sep-arate diesel generator units, having one (1) unit out of service has no offect at all upon the results of the analysis. In addi-
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tion, the effects of single bus operation during a loss of coolant accident was analyzed in Amendment 32 to the FDSAR and the unit loading under this condition was found to be within the normal KVA rating of the diesel generator.
Thus, there is no addi'tional safety significance associated with this event beyond that already
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analyzed.
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Prepared by:
I cce, Date:
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