ML20039D328

LER 81-030/03L-0:on 811130,emergency Diesel Generator B Failed to Reach Rated Output Voltage Following Automatic Start Initiated by Safety Injection Signal.Caused by Faulty auto-voltage Adjust Reostat.Failure Due to Normal Wear

ML20039D328
Person / Time
Site:	Robinson
Issue date:	12/23/1981
From:	Cox H CAROLINA POWER & LIGHT CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML20039D324	List: ML20039D323 ML20039D328
References
LER-81-030-03L, LER-81-30-3L, NUDOCS 8112310527
Download: ML20039D328 (3)

Text

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NRC FORM 366 U. S. NUCLEAR REGULATORY COMMISSION (7-77)

• LICENSEE EVENT REPORT CONTROL BLOCK: l 1

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(PLEASE PRINT OR TYPE ALL RECUIRED INFORMATION) l7 o l 18 9 l l S lLICENSEE C l HCODE l B l R14l 2 l@l 15 0 l 0 l - l LICENSE 0 l 0 lNUMBER 0 l 0 l 0 l- l 0 l 250 l@l 26 4 l1 l1' l1 l 1 l@l57 CAT LICENSE TYPE JO l lg 58 CON'T loltl S$nCE l L @l 0 l 5 DOCKETl 0 l 010 l 2'l 6 l1 l@l 1 11 l 3 l0 l 8 l174 l@l1 l 2REPORT l 2 lDATE 3 l 8 l180 l@

7 8 60 61 NUMBER 68 69 EVENT DATE 75 EVENT DESCRIPTION AND PROBABLE CONSEQUENCES h o 2 lOn November 30, 1981, at 1449 hours0.0168 days <br />0.403 hours <br />0.0024 weeks <br />5.513445e-4 months <br /> with the unit at hot shutdown conditions, "B" l-10 la l l Emergency Diesel Generator (EDG) failed to reach rated output voltage following an -l g o l4 ; l automatic start initiated by a Safety Injection Signal and was declared inoperable. l g g lThe cause of failure was a faulty auto-voltage adjust reostat. This event resulted l 0 6 l in a degraded mode permitted by a Limiting Condition For Operation specified by l g o l 7 l l Technical Specification 3.7.2.d and is reportable pursuant to 6.9.2.b.2. "A" EDG' l l O l8 l lwas operable so there was no threat to the public health and safety. l 7 8 9 80

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CAUSE DESCRIPTION AND CORRECTIVE ACTIONS h l i l O l lThe auto-voltage adjust reostat was replaced,' and "B" EDG was tested and declared l 1 1 'loperable at 0600 hours0.00694 days <br />0.167 hours <br />9.920635e-4 weeks <br />2.283e-4 months <br /> on December 1, 1981. This event is the result of component I g3 g7g l failure due to normal wear. No further action is considered necessary. I i 3 l  !

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STA S  % POWER oTHER STATUS I O RY DISCOVERY DESCRIPTION 1 5 W h l0l0l0lhl N/A l M @l ~

Operator Observation l ACTIVITY CO TENT RELEASED OF RELEASE AMOUNT OF ACTIVITY LOCATION OF RELE ASE 7.

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PERSONNEL EXPOSURES NUMBER TYPE DESCRIPTION W lOl0l0l@lZl@l N/A l PERSONNEL INJU IES NUVSER DESCRIP'10N 7

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NAME OF PREPARER owad T. Cox PHONE: OD E N

Item 10 On November 30, 1981, at 1449 hours0.0168 days <br />0.403 hours <br />0.0024 weeks <br />5.513445e-4 months <br /> with the unit at hot shutdown conditions, "B" Emergency Diesel Generator (EDG) failed to reach rated output voltage following an automatic start initiated by a Safety Injection Signal and was declared inoperable.

The cause of failure was a faulty auto-voltage adjust reostat. This event resulted in a degraded mode permitted by a Limiting Condition For Operation specified by Technical Specification 3.7.2.d and is reportable pursuant to 6.9.2.b.2. "A" EDG was operable so there was no threat to the public health and safety.

s Item 27 The auto-voltage adjust reostat was eplaced, and "B" EDG was tested and declared operable at 0600 hours0.00694 days <br />0.167 hours <br />9.920635e-4 weeks <br />2.283e-4 months <br /> on December 1, 1981. This event is the result of component failure due to normal wear. No further action is considered necessary.

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SUPPLEMENTAL INFORMATION FOR LICENSEE EVENT REPORT 81-30

1. Cause Description and Analysis On November 30, 1981, at 1449 hours0.0168 days <br />0.403 hours <br />0.0024 weeks <br />5.513445e-4 months <br /> with the unit at hot shutdown conditions, "B" Emergency Diesel Generator (EDG) failed to reach rated output voltage following an automatic start from a Safety Injection Signal. An attempt was made to increase the voltage manually with negative results. The cause of failure was deter-mined to be a faulty auto-voltage adjust reostat.

"B" EDG was declared inoperable at 1449 hours0.0168 days <br />0.403 hours <br />0.0024 weeks <br />5.513445e-4 months <br /> which resulted in a degraded mode permitted by the Limiting Condition For Operation specified by Technical Specification 3.7.2.d and is reportable pursuant to 6.9.2.b.2. "A" EDG also started at 1449 hours0.0168 days <br />0.403 hours <br />0.0024 weeks <br />5.513445e-4 months <br /> on November 30, 1981, and was operated at fully load conditions dur-ing the event so there was no threat to the public health.and safety.

2. Corrective Action The auto-voltage adjust reostat was replaced, and "B" EDG was tested and declared operable at 0600 hours0.00694 days <br />0.167 hours <br />9.920635e-4 weeks <br />2.283e-4 months <br /> on December 1, 1981.

3. Correcti.e Action To Prevent Recurrence This event was the result of component failure due to normal wear.

No further action is considered necessary.

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