ML20084E096

AO 50-244/74-20:on 741209,deficiency Found in Monthly Surveillance Test Procedure PT-16 Re Auxiliary Feedwater Flow.Caused by Incorrect Ref Pressure Value.Test Procedure PT-16 Revised Based on New Data from Flow Balance

ML20084E096
Person / Time
Site:	Ginna
Issue date:	12/18/1974
From:	White L ROCHESTER GAS & ELECTRIC CORP.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20084E098	List: ML20084E096 ML20084E099
References
AO-50-244-74-20, NUDOCS 8304140080
Download: ML20084E096 (3)

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ROCHESTER GAS AND ELECTRIC CORPOPATION e 89 EAST AVENUE, ROCilESTER, N.Y.1:649 LF )N D WHITE. JR. r t t i ..o y vectPktbesNr 4 i r a r. c t s .u '5 4 +' 2 701)

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December 18, 1974 j ' jgx 4,/ .;s.

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Mr. James P. O'Reilly, Director k _C1 e,% jo h Uh' O ~t:

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Directorate of Regulatory Operations .'A ' $T,f:T' f, ' ',

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King of Prussia, Pennsylvania 19406 '

Subject:

Abnormal Occurrence 74-20, Deficiency in Monthly' ,

Surveillance Test Procedure, PT-16, Auxiliary Feedwater Flow R. E. Ginna Nuclear Power Plant, Unit No.1 Docket No. 50-244

Dear Mr. O'Reilly:

In accordance with Technical Specifications, Article 6.6.2a, the attached report of Abnormal Occurrence 74-20 is hereby_ submitted. -

Very truly yours ,

fadd, .

L. D. White, Jr.

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, 1. . Report Number: 50-244/74-20 2a. Report Date: December 18, 1974 2b. Occurrence Date: December 9,1974

3. Facility: R. E. Ginna Nuclear Power Plant, Unit No.1

4. Identification of Occurrence:

This abnormal occurrence is defined by Technical Specification Article 1.99: Observed inadequacies in the implementation of administrative or procedural controls such that the inadequacy causes or threatens to cause

• the existence or development of an unsafe condition in connection with the operation of the plant.

5. Conditions Prior to Occurrence:

The unit was at full licensed power.

6. Description of the Occurrence:

During a review of the original motor driven auxiliary feedwater pump system flow balance data, a deficiency was discovered in the monthly surveillance test procedure PT-16, Auxiliary Feedwater Flow. The procedure did not permit recognition of the fact that the administrotive elecfrical limit on the open position of the discharge motor operated valve (MCV) of each of the two motor driven auxiliary feedwater pumps prevented these pumps from delivering required flow at postulated maximum pressure.

7. Designation of Apparent Cause of Cccurrence:

The reference pressure value given as an acceptance limit in test procedure PT-16 was incorrect. The MOV outlet pressure measured during the initial f?ow balance test was given instead of the higher MOV inlet pressure value. Therefore no adjustments were made to the MCV electrical open limit in recognition of the need to compensate for the gradual loss of pump efficiency.

8. Analysis of Cccurrence:

The auxiliary feedwater pumps are required to furnish an alternate supply of feedwater to the steam generators after loss of normal feedwater and subsequent reactor trip from low steam generator level. This alternate feedwater supply furnishes a heat sink to remove residual core heat and prevents the loss of primary system fluid through pressurizer relief

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ACR 50-244/74-20 cont'd,

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. . - - valves. The Plant's Final Description and Safety Analysis Report, Item 14.1.9 and Fig.14.1.9-1 states that the delivery of 200 gpm to either steam generator will provide sufficient cooling capability for primary system protection.

Whenever the reactor is being maintained critical two of the three auxiliary feedwater pumps must be operable; normally all three pumps are available for service. The steam driven pump is capable of deliver-ing a total flow rate of 400 gpm or 200 gpm to each steam generator.

With only the two motor driven pumps available for service, and with the electrical position limits in effect, their lowest estimated total flow delivery, 358 gpm, provided an adequate flow margin above the minimum .

required for the accident mode. At all times each pump's MOV was capable of being placed in the manual mode and opened to the 100%

position to establish flow in excess of design flow. It is considered that no hazard was presented to the general public.

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9. Corrective Action:

The electrical limit on the position of each of the two MOV's was removed, and the test procedure PT-16.1, Auxiliary Feedwater System Flow Balance was performed. The monthly surveillance test procedure, PT-16, Auxiliary Feedwater Flow was then revised based on the new data from the flow balance. The flow check procedure was used to verify that each of the two motor driven auxiliary feedwater pumps will catisfy the accident condition.

10. Failure Data:

Not applicable.

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