ML20084C719

AO 250-74-7:on 740508,while Attempting to Start Three Auxiliary Feedwater Pumps,Pumps a & B Failed to Start & C Started But Tripped When Attempt Made to Feed Steam Generators.Caused by Packing Too Tight.Packing Loosened

ML20084C719
Person / Time
Site:	Turkey Point
Issue date:	05/17/1974
From:	Schmidt A FLORIDA POWER & LIGHT CO.
To:	Oleary J US ATOMIC ENERGY COMMISSION (AEC)
References
AO-250-74-7, NUDOCS 8304080183
Download: ML20084C719 (3)

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hir. John F. O' Leary, Director 3. M Directorate of Licensing Office of Regulation 30-250 U. S. Atomic Energy Commission Washington, D. C. 20545

Dear h!r. O' Leary:

ABNORh!AL OCCURRENCE NO. 250-74-7 h!AY 17, 1974 OCCURRENCE DATE: FMY 8, 1974 TURKEY POINT UNIT NO. 3 h!ALFUNCTION OF AUXILIARY FEEDWATER PUh1PS A. CONDITIONS PRIOR TO OCCURRENCE The reactor was in routine power operation at 98% power.

B. DESCRIPTION OF OCCURRENCE At appraximctcly 10 : ~J A.?4. , ?4ay 8, 1974, an attempt. was made to test start the three auxiliary feedwater pumps (AFP) from the Unit 3 control console. The console indicated that all three motor operated valves were open, thus allowing steam to drive the auxiliary feedwater pump turbines; however, the "A" and "B" AFP's failed to start and the "C" AFP started but tripped when the operator attempted to feed the steam generators.

Several additional attempts were made to start the auxiliary feedwater pumps, however, each attempt produced similar results.

The ensuing investigation revealed that the "A" and "B" AFP's-were mechanically bound and that the "C" AFP turbine regulating valve pneumatic controller and governor assembly were mal-functioning.

C. CAUSE OF OCCURRENCE All th ;c AFP's had been tes ted satisfactorily on blay 7, 1974, accord.ng to Operation Procedure OP7304.1 which is the monthly test. After the test, the pump packing was adjusted on the "A" and "B" pumps. Apparently, the packing was tightened with the pumps secured, and packing was tight enough to prevent the pumps from starting. The pumps were not tested for operability after the packing was tightened.

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i May 17, 1974

! The exact cause of'the "C" AFP malfunction could not be

determined immediately. The initial investigation on May 8, 1974, identified dirty governor linkage as the most I

likely cause of the malfunction. The linkages were c1 caned, oiled and appeared to be operating normally because the "C" 1

AFP was then tested and performed satisfactorily.

1 D. ANALYSIS OF OCCURRENCE 1

Both Unit 3 main feedwater pumps were operational during the time when the auxiliary feedwater pumps were inoperabic. There-

!' fore, neither reactor safety nor the health and safety of the public were jeopardized by this occurrence.

E. CORRECTIVE ACTION The immediate corrective action consisted of the following:

! a. The "A" auxiliary feedwater pump packing was tempor-

arily loosened and the pump was tested with satis-factory results.

b. The "B" AFP was repacked and tested with satisfactory

, results.

c. The "C" AFP governor linkages were c1 caned, oiled and

.i exercised and the pump was tested and performed sat-isfactorily In that all three AFP's performed satisfactorily when tested on May 8, 1974, it appeared that the causes of auxiliary feed-water pump failures had been corrected.

, The packing was replaced on the "A" AFP on May 9, 1974. How-ever, when the pump was tested following the packing replace-

! ment a sticking governor linkage was. discovered. The linkage 4

was c1 caned and oiled and the pump was then tested and per-formed satisfactorily.

When the "C" AFP again malfunctioned during a. test start on May 15, 1974, and again on May 16, 1974, the ensuing inves-tigation revealed a pneumatic controller / governor response problem. The governor was rigorously exercised via rapid adjustments of the compensating needle to dislodge any foreign matter that might cause the sluggish operation of the governor assembly. The pneumatic controller output air signal to the governor was also boosted to compensate for the governor sluggishness. The "C" AFP was then tested three consecutive i

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Page 3 May 17, 1974 times on May 16, 1974, and performed satisfactorily. At the same time, the "A" and "B" AFP's were also tested with sat-isfactory results.

In view of the fact that the failures of the "A" and "B" AFP's have been attributed to improperly performed maintenance, the Plant Manager will issue a directive defining precau-tionary requirements which shall be met prior to releasing work documentation on safety related systems.

In the future, all preventive maintenance schedules for safety related equipment will be more conspicuously designated as safety related, and the necessity to adhere to the forthcoming precautions will be emphasized to all maintenance personnel.

F. FAILURE DATA This is the first malfunction of this type at Turkey Point since operational testing.

Very truly yours, r$2dh7 / //

D{h74M J M /

(, A . D. Schmidt Director of Power Resources DNR/kaw cc: Mr. Norman C. Moseley Mr. Jack R. Newman