ML20084E334

Ro:On 730523,thirty Minutes After Boric Acid Transfer Pumps Started Recirculation,Control Rods Noted as Stepping Out. Caused by Malfunction of Blend Sys Valve FCV-110B.Repair Instituted & Completed on 730524

ML20084E334
Person / Time
Site:	Ginna
Issue date:	06/21/1973
From:	Amish K ROCHESTER GAS & ELECTRIC CORP.
To:	Oleary J US ATOMIC ENERGY COMMISSION (AEC)
Shared Package
ML20084E338	List: ML20084E334 ML20084E354
References
NUDOCS 8304150021
Download: ML20084E334 (2)

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tf ROCHESTLR GAS AND EL iCTRIC CORPORATION e 89 EAST AVENUC, AOCHESTER, N.Y. NS49 m =. - ..._ = %

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Mr. John F. O' Leary, Director eggj,p Directorate of Licensing y [ Q ) g ), y p \ g

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Washington, D. C. 20545

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Subject:

R. E. Ginna Nuclear Power Plant, Unit No.1 WX rf -  ; ./

Malfunction of Blend System Valve FCV-110B N,.- t; 1l*; .,

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Docket No. 50-244

Dear Mr. O' Leary:

In accordance with Ginna Station Technical Specifications, Change No. 8, Section 6.6.2, Item b-2 which requires that " discovery of any substantial i variance from performance specifications contained in the Technical Speci-

fications or in the Safety Analysis Report" shall be submitted in the form of a written report within 30 days to the Director of Licensing and to the Director of Regional Regulatory Operations office, the following is pre-sented:

, The reactor was operating normally at 1266 MW twith the Control Bank D rods at 226 steps when the incident occurred. The boric acid transfer pumps were started at approximately 1015 hours0.0117 days <br />0.282 hours <br />0.00168 weeks <br />3.862075e-4 months <br /> on May 23,1973, to re-circulate the tanks prior to sampling.

Approximately thirty minutes after the boric acid transfer pumps were started, the operator noted the control rods were stepping out (from 226 steps to 229 steps) .

' In accordance with Emergency Procedure E-11, Continuous Rod Withdrawal, the rod control selector switch was placed in manual mode.

The operator ncted that Reactor Coolant System Tavg had dropped approxi-mately 20F. The boric acid mak~eup"flbw recorder revealed a slight flow during the time the boric acid storage tanks recirculation was in progress.

The boric acid makeup integrated 10.6 gallons of boric acid. Preliminary observation' pointed to valves FCV-110B or FCV-110C leaking through. The operator then diluted the Reactor Coolant System 179 gallons. Subsequently, Tavg returned to normal (568.5 F), and the control rods were returned to automatic on the rod control modo selector switch.

Further investigation revealed that the blend system valve FCV-110B was l leaking through.

The Plant Operations Review Committee convened at 1625 hours0.0188 days <br />0.451 hours <br />0.00269 weeks <br />6.183125e-4 months <br /> to discuss 1/

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. ..e June 21,1973 70 Mr. John F. O' Leary the occurrence. A procedure EM-73, Repair of Blend System Valve FCV-110B, was presented and approved.

Repair was instituted and completed on May 24, 1973 at approximately 1230 hours0.0142 days <br />0.342 hours <br />0.00203 weeks <br />4.68015e-4 months <br />.

The operator displayed proper action by placing the rod control switch in manual mode. The maintenance repair revealed the diaphragm of FCV-110B was in need of replacement. To prevent recurrence of this incident the Plant Operations Review Committee recommended and the Plant Superintendent approved that the diaphragms of both valves FCV-110B and FCV-110C, which are on the downstream lines of the blender, be replaced and tested at each refueling shutdown.

Very truly yours, tw

,Keith W. Amish

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xc: Mr. James P. O'Reilly

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