ML19308D243

RO-77-56:on 770602,steam-driven Emergency Feed Pump Failed to Autostart on Main Steam Supply Lineup.Caused by Steam Line Condensation Restraining Throttle Valve.Drain Capacity from Run of Piping Upstream of Valve Increased

ML19308D243
Person / Time
Site:	Crystal River
Issue date:	06/27/1977
From:	FLORIDA POWER CORP.
To:
Shared Package
ML19308D231	List: ML19308D230 ML19308D243
References
NUDOCS 8002270698
Download: ML19308D243 (2)

Text

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gl Performing SurvefIlance Procedure SP-349 in' power operation (Mode 1), Steam Driven 7 89 Emergency Feod Pump-(EFP-2) experienced ov.erspeed trip upon initial start on Main _

gl g Steam Lincup. Redundant Pump (Motor Driven bFP-1) available and operable. This uns.

7 89 gl a repeti'tive occurrence. Pump was started on Main Steam supply in recire mode and ,

7 09 (LER 77-5/n

@l 7 89 declarrd'coerable.

pr ut systru cause covmntNT ccommtNt SUPfMR kWAJF ACIVEt A VOLATON cCDE COMPONrNT COct W

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7 89 10 11 12 17 43 44 47 48 CAUSE DESCR'PTION 9 Q lCondensatic ' in steam supplv line prevented throttle valve from closine fast enouch to

't 89 0 l prevent overspeed trip on initial cold start. Modiflad drain system en mwne re - vinede 7 19 Post modification tests demoristrated success of corrective action.

(' lofcondensation.

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% POW 184 oTHtH STATUS Discovany DISCOVERY OtsCat"TCPr STATUS h .lE l l1l0 l 0 l .l NA l lCl 'lPerformanceofSP-349-78 9 10 12 13 44 45 46 FORV Of ,

ACIMTV C063f TNT LOCATCN Of r.CttASE RCtta$t0 AMOUNT Of ACTMTY 7 8 ll 9

Q Q Of F:tLE ASE l 10 11 NA ,

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45 NA PERSONNEL EXPOSURES .

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LzJ l 7 89 11 12 13 PERSONNEL INJunlES

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NUM8tA OCSCRJTON . .

ll l0l0l0l11 12l 7 89 NA OFTSITE CONSEQUEN::ES .

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t l 7' 89 l LOCS On DAMAGE TO FACILITY l iver Otsen PeCN -

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9 A00iTIONAL FACTOG3 8004 270 gg See Attached Supplementary information I

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Supplsmentary Inform; tic Report No.: .50-302/77 .

2. Facility: Crystal River Unit #3

3. Report Date: 27 June 1977 t-

4. Occurrence Date: 2 June 1977 1

5.

Identification of occurrence:

Failure of Steam Driven Emergency Feed Pump (EFP-2) to autostart on Main Steam supply lineup contrary to Technical Specification 3.7.1.2.b which requires two Emergency Feed Pumps available and operable from two in dependent power sources.

6. Conditions Prior to Occurrence:

Mode 1 operation at approximately 100% power.

7. Description of Occurrence:

, During th's conduct of Emergency Feedwater System's operability demonstration, l' Surveillance Procedure (S?-349), EFP-2 tripped on over speed upon initial start. ..

Pump was then manually started in recire mode and left running continuously in j order to declare operability. l

8. Designation of Apparent Cause: .

Cause was initially actributed to a faulty governor. After installation of a ,

new governor and adjustment of tile linkage, the problem persisted. Further evalua- l tion of the problem by Plant Staff, Production Engineering, and Manufacturers' Representatives indicates that the problem can probably be attributed to condensation in the steam line, restraihing the throttle valve (ASV-3) from closing rapidly enough I

to prevent overspeed and resultant trip.

i

9. Analysis of occurrence:

)

There is no hazard to plant or public associated with this occurrence, inasmuch as ,

the redundant motor driven Emergency Feed Pump-has been available and operable and EFP-2 has been in operable status either running in recirc mode or manually.

10. Corrective Action to Prevent Recurrence:

To prevent accumulation of condensation in the steam supply line upstream of the  !

throttle valve, the drain system has been modified to increase drain capacity from the run of piping upstream of the valve. Subsequent multiple test starts from cold condition have demonstrated resolution of the problem.  ;

11. Failitre Data:

Similar' occurrence on.3-7-77 was reported on LER 77-24, and again on 4-16-77 as reported on LER 77-37. During attempts to correct the problem, post maintenance

testing has resulted in overspeed trip on numerous occasions.

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