ML20085G819

AO BFAO-50-259/7456W:on 741115,RCIC Tripped on Overspeed During Auto Initiation.Caused by Servo Out of Alignment W/Governor Level.Servo Adjusted

ML20085G819
Person / Time
Site:	Browns Ferry
Issue date:	11/25/1974
From:	Eric Thomas TENNESSEE VALLEY AUTHORITY
To:	Case E US ATOMIC ENERGY COMMISSION (AEC)
Shared Package
ML20085G822	List: ML20085G819 ML20085G828
References
NUDOCS 8308290382
Download: ML20085G819 (2)

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\' ABNORW.L OCCURRE::CE REPORM Reptrt I!o. : EFAO-50-259/7456W Report Date: I cvember 25, 1974 Occurr.ence Date: Icyctber 15, 197h Facility: Browns Ferry Iuclear Plant Unit 1 Identificatien of Cccurrence Unit 1 ECIC tripped on overspeed during auto-initiaticn.

Conditicns Pricr tc Occurrence Prior to the occurrence, the unit was operating at apprcximately 70 percent reactor pcwer during turbine-generator acceptance testing.

Descripticn of Cecurrence At 2215 en 17ove=ber 15, the unit 1 RCIC tripped on overspeed during routine auto-initiatica surveillance testing. The ECIC was declared inoperable, and the required curveillance cn other CSSC syatens was ccnducted to ensure that they were cperable.

Desirnation of Arrarent Cance cf Cccurrence A visual inspectica of the gcVernor valve assembly revealed that the rercte servo (which centrols the governor valve) was out cf alignment with the gcVerncr lever. This binding of the governor valvc linimge clcwed the response time of the reacte servo and allcoed the turbine to overspeed.

Analvaic cf Cecurrence During the pericd cf tire that the ECIC turbine was inoperable, all renaining cafety cycten vere available, the unit remainen in cperaticu, and there .: era no advarse effect ca the health and cafety of the public due to thic cccurrence.

Ccrrective Acticn Th'e renct: servo wac ad.jucted until it was in align ~.ent with the governer 2 ever.

All pivct point cf the zovert.cr lever were checked fer binding and lutricated.

The gcVernor lever was tanually operated and the spring between the neunting plate and the governcr lever ad. justed until the lever operated freely, returninc the governor valve to the fall open positicn. The ECIC turbine was then ; tarted successfully en auto-initiation on two successive attempts and declared operable.

Faik re Data The ccvernor valve assecbly ic a special EG-R governer with ficher travel limitor. The governor asse:rbly is manufactured by Wcedward Governor.

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Er. Edsen G. Case ,- .ccm/s/- '

Actin ~ Director of Licensing

.~ _._../g/ \,V T Office of Regulation . J' U.S. Atonic Energy Cor:niscion Washington, DC 20545 ,

Lear 2/.r. Case:

TO!ESSEE VI.LLEY AUTH02ITi - 3R7.0:3 FERRY !!UCLEAR FI/JE U.'r..T 1 -

DOC:G'T : 0 50-259 - FACILITY OPERATII G LICli3E DPR IdiI:0R'E OCCUP2E';CE RE2CRT .33'AO-50-259/7456'.7 The enclosed report in to provide details concernin:; RCIC which tripped on overspeed durity; auto-initiation c.nd is cutnitted in accordance with Appendir A to ',egulatory Guide 1.16, Revision 1, October 1973. rnic event occurred on 3rowns Ferri I;uclear Plant unit 1 on liovenber 15, 1974 Very truly yours, i T !:~ESSEE VALLEY AUTHORITI

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, t . -o E. F. Thonac Director of Pouer Production Enclosure CC (Enclocure):

15. Horan C. Ibseley, Director Region II Regulatory Doeratienc Office, USAEC l 230 Peachtree Street,17.7., Suite 618

! Ittlanta, Georgin. 30303 t

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n..s COPY SENT REGION- 2