ML20085H154

AO BFAO-50-259/7445W:on 740820,RCIC Failed to Start During Autoinitiation.Caused by Turbine Trip on Overspeed Due to generator-signal Converter & EG-M Control Being Out of Calibr.Equipment Recalibr

ML20085H154
Person / Time
Site:	Browns Ferry
Issue date:	08/30/1974
From:	Eric Thomas TENNESSEE VALLEY AUTHORITY
To:	Case E US ATOMIC ENERGY COMMISSION (AEC)
Shared Package
ML20085H157	List: ML20085H154 ML20085H158
References
NUDOCS 8308300272
Download: ML20085H154 (2)

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i . ' TENNESSEE VALLEY AUTHOAITY CHAs s ANOCGA, TENNESSEE MTij d 4 4:Ah 37401 L L/ LM

-Y' O ANNIVE A 3APY August 30, 1974

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Mr. John F. O' Leary, Director <\^ / .4 2A - ,.@ ,

50-259 Directorate of Licensing N,,dtJ. / -

Office of Regulation U.S. Atomic Energy Co::: mission Washington, DC 20545

Dear Mr. O' Leary:

TENUESSEE VALLEY AUTHORITY - BROWNS FERRY NUCLEAR PLANT UNIT 1 -

DOCKET NO. 50-259 - FACILITY OPERATING LICENSE DPR ABNORMAL OCCURREUCEREPORTBFAO-50-259/7445W "he enclosed report is to provide details concerning the failure of aCIC to start during auto-initiation and is submitted in accordance with Appendix A to Regulator / Guide 1.16, Revision 1, October 1973.

This event occurred on Browns Ferry Nuclear Plant unit 1 on August 20, 1974 Very truly yours, TENNESSEE VALLEY AUTHORITY

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/~ E. F. Tho=as 8 Director of Power Production Enclosure CC (Enclosure):

Mr. Norman C. Moseley, Director Region II Regulatory Operations Office, USAEC 230 Peachtree Street, Hu., Suite 818 Atlanta, Georgia 30303 [S S ywj p f 8308300272 740830 PDR ADOCK 05000259 S PDR 9131 T

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ABNORMAL OCCURRENCE REPORT  %

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Report No.: BFAO-50-259/7445W q Report Date: August 30, 197h i Occurrence Date: August 20, 1974 .1 Facility: Browns Ferry Uuclear Plent - Unit 1 i Identification of Occurrence '!

RCIC failure to start during auto-initiation.

Conditions Prior to Occurrence The unit 1 reactor had just scrc=ned. The reactor was at approximately  :

3257 Ist and 1080 ige before the scram. ,

Description of Occurrence Followin6 the scran of the unit 1 reactor, the RCIC turbine tripped during l automatic initiation. Several unsuccessful attecpts to manually start RCIC vere made before satisfactory operation was achieved.

Designation of Arparent Cause The turbine apparently tripped on overspeed since there was no isolation or other indication of a specific turbine trip. The combination of Remp Generator-Signal Converter and EG-M control box was out of calibration and could have caused overspeeding.

An@fcis of Occurrence Safe recovery from the scram was accomplished throu;;h the use of other engineered safeguard systems. HFCI was used to restore vessel inventory.

Corrective Action The Ramp Generator-Signal Converter and the EG-M were recalibrated and surveillance testing initiated to prove pump operability. The turbine >

performed satisfactorily during this testing. The electronic overspeed i was functionally tested and found to be working properly at the correct settings. A modification change request has been forwarded to TVA Design i f

to cove the E -M end Ramp Generator-Signal Converter from their present location to lessen the effect of heat and vibration on the solid-state components in these devices. 5 4

Failure Data m-M: Woodward Part No. 8270-849 Ramp Generator-Eignal Converter: Woodward Part Ul. 3270-957 3

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