ML20084M136

Suppl to AO 4-73-3:on 730509,pump 4A Discovered Leaking.Insp Determined Pump in Satisfactory Condition.Components of Mechanical Seal Assembly Replaced

ML20084M136
Person / Time
Site:	Turkey Point
Issue date:	11/24/1973
From:	Schmidt A FLORIDA POWER & LIGHT CO.
To:	Oleary J US ATOMIC ENERGY COMMISSION (AEC)
Shared Package
ML20084M139	List: ML20084M136 ML20084M145
References
AO-4-73-3, NUDOCS 8306020010
Download: ML20084M136 (3)

Text

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, P O BOX 3103 MIAMI. f LOR'DA 33101

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s [,;/ Q P\ FLOR;OA POAER & UGHT COMPA*.Y L

{ NOV301973*if Turkey Point Plant

• (N "A; Gs-4 ht November 24, 1973

/A Mr. John F. O' Leary, Director 'g /

Directorate of Licensing Office of Regulation U. S. Atomic Energy Commission Washington, D. C. 20545 1URKEY POLVr UNIT NO. 4 DOCKET h1MBER 50-251 SUPPLDIEST TO ABNOR\!AL OCCURRENCE NO. 4-73-3 NO. 4A RESIDUAL IIEAT REB 10 VAL PUMP IEUG\GE

Dear Mr. O' Leary:

I. INTRODUCTION On May 18, 1973, Abnormal Occurrence Report No. 4-73-3, which concerned No. 4A Residual Heat Removal Pump leakage, was submitted in accordance with Technical Specification 6.6.2a for Turkey Point Unit No. 4, Operating License No. DPR-41.

This supplemental report presents the results of inspections performed to determine the cause of No. 4A Residual Heat Removal Pump leakage.

II. INVESTIGATION No. 4A RHR pump was disassembled and inspected. The pump was found to be in satisfactory condition.

The pump mechanical seal was disassembled and inspected by both FP&L personnel and the seal manufacturer's representive.

The seal assembly stationary ring, mating ring, shaft sleeve gasket and bellows form the primary barriers to leakage along the pump shaft. All of these parts were in good condition except the bellows, which had a small slit in it.

Because of the difficulty in removing the bellows from the shaft sleeve, it is possible that the slit was made during the bellows removal.

III. CORRECTIVE ACTION '

Corrective action taken ;onsisted of replacing the* stationary ring, mating ring, shaft sleeve gasket, and bellows of the mechanical seal assembly. Such action renewed all barriers to leakage along the pdmp shaft.

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05h00hh m PDR j, COPY SENT REGION

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Mr. John F. O'LT v r ';

9NovEmb2r 24, 19 P:ga 2 In addition, the double nut arrangement (jam nut plus impeller nut) that fastens the pump impeller to the pump shaft was spot welded to prevent the nuts from cmaing loose during pump operation. Torquing of the impeller nuts applies the pressure for compression of the shaft sleeve }

gasket to attain a proper seal. Design Change No. 28-72 describes this modification.

IV.

ADDITIONAL ITEMS RELATED TO THIS OCCURENCE

1. During the inspection it was discovered that the auxiliary packing assembly whose purpose is to divert leakage past the shaft mechanical seal to a "tell tale" drain was damaged. A spring which is located between the packing ring and the bottom of the packing chamber was broken. The packing ring showed signs of being worn excessively. Failure of this assembly does not result in increased leakage from the pump.

The single packing ring was replaced by two packing rings and the spring was removed. This action was -

based on a reconmendarion by the seal manufacturer.

2. The three remaining mechanical seal gaskets other than l

the shaft sleeve gasket were replaced with Flexitallic gaskets to improve sealing capability. The replacement gaskets were approved by the pump manufacturer. This change is described in Design Change No. 20-72.

c V. ANALYSIS AND CONCLUSION 1.

The above findings are not conclusive with respect to the cause of the leakage. The bellows was the only part that was suspected. It could not be conclusively determined that the small slit existed prior to disas-sembly nor could it be determined that such a small slit would have passed fluid at the rate that was observed.

2. The overall action taken, including those listed in Section IV above, will provide the pump with an improved seal capability and will reduce the probability of having similar incidents in the future. Since making the repairs, the pump has been operated during three plant cooldowns as well as for monthly periodic tests without experiencing abnormal leakage.

Very truly yours, A. D.4#

Schmidt Director of Power Resources x

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' " Mr. John F. O'Ls "7 g November 24, 197 V

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Norman C. Mosely, Director Region II, Directorate of Regulatory Operation

'U. S. Atomic Energy Commission Suite 818, 230 Peachtree Street, N. W.

Atlanta, Georgia I

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