ML20084E225

Ro:On 740509,during Surveillence Procedure PT 16,little Flow Reduction Occurred Following Opening of Motor Driven Auxiliary Feedwater Pump a & B Discharge Valve.Cause Unapparent.Frequency of Surveillance Test Increased

ML20084E225
Person / Time
Site:	Ginna
Issue date:	06/07/1974
From:	Amish K ROCHESTER GAS & ELECTRIC CORP.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
NUDOCS 8304140449
Download: ML20084E225 (2)

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ROCHESTER CAS AND ELECTRIC CORPORATION e E9 EAST AVENUE, ROCHESTER, N.Y.14649 L

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June 7,1974 k

Mr. James P. O'Reilly, Director E Directorate of Regulatory Operations Region I U. S. Atomic Energy Commission 631 Park Avenue King of Frussia, Pennsylvania 19406 k

Subject:

Unusual Event - Malfunction of the A and the B Motor Driven Auxiliary Feedwater Pump's . Discharge Valves F R. E. Ginna Nuclear Power Plant, Unit No.1 F Docket No. 50-244 '

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Dear Mr. O'Reilly:

1, In accordance with Ginna Station Technical Specifications, Section 6.6.2, Item b-2 which requires that " discovery of any substantial variance from performance specifications contained in the Technical Specifications or r

" in the Safety Analysis Report" shall be submitted in the form of a written report within 30-days to the Director of the Regional Regulatory Operations y office, the following is presented-i \

E During the~ performance of monthly surveillance procedure -PT 16, " Auxiliary -

1 Feedwater System Flow Check" on May 9,1974 it was noted that, after the 3-in-auxiliary feedwater pumps had started and that the valves had opened y normally, very little flow reduction subsequently occurred to indicate that 72 k the normal throttling sequence had been initiated. The flow for the 1A pump '

- remained at approximately 275 gpm and for the 1B pump at approximately 264 gpm; normal flow is automatically adjusted to under 230 gpm for each f pump, after the closing circuit has been established. In accordance with E the procedure, the discharge flows were manually adjusted locally to about 200 gpm to acquire test data.

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b Instrument repair personnel inspected the instrumentation and bistables -

associated with the motor operated discharge valve for each pump.

E Adjustments were made to the setpoints of the flow bistables in the T closing circuit for each valve to determine response of the valves. As 7

the setpoints were reduced proper valve response was verified. The -

F settings have been reduced such that the resulting final flow rate for cach pump is 210 gpm to insure proper flow reduction below 230 gpm is e achieved. -

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[_ The discharge valves are equipped with selector switches at the main control R board and manual control of the valves may be assumed by the operators if fA[}g ,

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ROCHUTER G A5 AND ELECTRIC ?P. .v SHEET NO. 2, N 7 Junc 7,1974 To Mr. James P. O'Reilly .

the valve does not throttle closed when required. The operators are accustomed to controlling auxiliary feedwater pump discharge valves manually during unit startups, shutdowns, maintaining hot shutdown, and cooldowns. In doing so, they are familiar with restricting continuous l flow to less than 230 gpm for each pump. In addition, in the case of an

{ automatic start of these pumps they are charged with verifying and l achieving the proper discharge flow rates. Further, a review of plant l

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procedures is being made to insure that appropriate guidance is included.

The failure of the valves to throttle closed is an isolated occurrence as this was the first such occurrence. No explanation for the malfunction is readily apparent since the bistable settings on May 9,1974 should not have changed from the previous performance of PT 16 on April 9,1974.

In order to insure that this is an isolated occunence, and to acquire more l extensive data for evaluating the performance of this system, the frequency j of surveillance testing of the valves has been increased to weekly, and

. flow bistable current values and dial settings.are to be recorded. As of June 6,1974, each pump has been started six Jmes. Satisfactory valve action was observed each time. Weekly surveillance will continue until ,

confidence is acquired that the incident was not a result of an inadequacy in system design.

l Very uly yours,

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/17h a Keith W. Amish 1

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