ML20105B883

Revised Unit Shutdowns & Power Reductions & Summary of Operating Experience Sheets for Apr 1992 Monthly Operating Rept for SONGS Unit 3

ML20105B883
Person / Time
Site:	San Onofre
Issue date:	04/30/1992
From:	Darling J SOUTHERN CALIFORNIA EDISON CO.
To:
Shared Package
ML20105B707	List: ML20105B705 ML20105B876 ML20105B883 ML20105B886 ML20105B895
References
NUDOCS 9209210264
Download: ML20105B883 (2)

Text

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! UNIT SHUTDOWNS AND POWER REDUCTIONS DOC %ET NO: 50-362

UNIT NAME

_ SONGS - 3

! REPORT MONTH: Anril 1992 DATE: 9-15-92 ,

i COMPLETED BY: J. L. Darlinq <ue TELEPHONE: (714) 368-6223 $$$-

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! CK3 CdC 8'

Method of i Shutting Cause & Corrective $$

Duration Down LER System Component Action to No 2

i No. Date Type * (Hours) Reason Reactor3 No. Code' Code' Prevent Recurrence -@

rd 1 0*

o a:

64 920410 S 0.00 B 5 NA SJ P Reduced reactor powcr to 60% to O!$acl KE COND return MFP K005 to service and i perform circulating water systes.

i heat treatment.

E5 920419 5 143.35 8 1 NA TA TRB Unit taken off line for turbine balancing.

j F 144.45 A 1 *4 AB BAF See tiote below.

Note

While commencing reactor power startup, the unit was manually tripped due to a loss of Reactor Coolant Pump (RCP) POO4 controlled bleedoff flow (CB0). P004 was stopped following the trip and a shutdown to Mode 5 was . initiated to repair -

i the ECP seal. The six bolts which attach the rotating baffle to the P004 shaft were found to have fractured. It is postulated that when the last baffle bolt fractured, the Saffle shifted and rubbed against adjacent components, resu' ting in blockage of CB0 flow to the seal. Initial observation of the baffle' bolts indicated failure due to high

! cycle fatigue. A root cause evaluation is 'in progress to determine the cause for failure of the baffle bolts. The I

P004 baffle was replaced. Other corrective actions will be determined and implemented, as necessary, based on the results of the bolt failure evaluation.

Data corrected since previous submittal.

2 2 3 F-Forced Recson: Hethod: 'IEEE Std 805-1984 5-Scheduled A-Equipment failure (Explain) 1-Manual S

B-Maintenance or Test 2-Manual Scram. IEEE Std 803A-1983 C-Refueling 3-Automatic Scram.

D-Regulatory Restriction 4-Contir.uation from E-Operator Training & License Examination Previous Month F-Administrative 5-Reduction in the Average G-Operational Error (Explaio) Daily Power Level of more

. H-Other (Explain) than 20% from the previous day 6-Other (Explain) enr.aug/17 .

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SUMMARY

OF OPERATING EXPERIENCE FOR THE MONTH  ;

i

! DOCKET NO: 50-362  ;

j- UNIT NAME: iSONGS - 3  !

DATE: 9-15-92 l COMPLETED BY: J. L. Darlina j i

TELEPHONE: (714) 368-9787 .

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! QAlg Time Event  ;

l i April '/4 (Cont.) Received Reactor Coolant Pump (RCP) P004 seal pressure 2315

{ Hi/Lo alarm. l l

2333 Manually tripped reactor and stopped RCP P004 due to a controlled bleed-off (CB0) flow less than .2 gpm and  !

decreasing. j i April 25 0320 Initiated Reactor Coolant System (RCS) cooldown to Mode  !

! 5. r i 0805 Entered Mode 4.

! i i 2307 Entered Mode 5. I

! i April 28 0925 Conmenced RCS draindown to mid-loop for RCP P004 seal l replacement.  !

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1630 RCS at mid-loop, 27" in Hot Leg.  ;

I l April 30 2400 Unit is in Mode 5, RCS drained to mid-loop for RCP P004 i i seal replacement. i i  :

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• Data corrected since previous submittal.

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