ML20084D213

AO-50-219/74/30:on 740514,generator Load Rejection Scram Failed to Operate at Turbine Steaming Rates Greater than 40% of Rated While in Run Mode.Cause Under Investigation. Switch Recalibr

ML20084D213
Person / Time
Site:	Oyster Creek
Issue date:	05/15/1974
From:	Carroll J, Rone A JERSEY CENTRAL POWER & LIGHT CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
AO-50-219-74-30, NUDOCS 8304110002
Download: ML20084D213 (4)

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if?pt; To: James P. O'Reilly " 47 a/y D ctorate of Regulatory Operations -

631 Park Avenue King of Prussia, Pennsylvania 19406 From: Jersey Central Power G Light Company Oyster Creek Nuclear Generating Station Docket #50-219 Forked River, New Jersey 08731

Subject:

Abnormal Occurrence Report No. 50-219/74/30 ,

The following is a preliminary report being submitted in compliance with the Technical Specifications, paragraph 6.6.2.

Preliminary Approval: >

b /.L e f f _ 5/15/74

.h T. Carroll, Jr. Date cc: Mr. A. Giambusso - -

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8304110002 740515 j

$DRADOCK05000 COPY SENT REGION. /

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c Initial Telephonc- p Date of p Report Date: 5', j;/ 74 Occurrence. / 5/14/74 Initial Nritten . , Time of ,

Report pate: 5/15/74 er Occurren ce: 1540 OYSTER CREEK NUCLEAR GENERATING STATION FORKED RIVER, NEW JERSEY 03731 Abnormal Occurrence Report No. 50-219/74/ 30 IDLlirIFIC ATION Violation of the Technical Specifications, Tabic 3.1.1.A.12, OF OCCURRENCE: which requires the generator load rejection scram to be operabic at turbine steaming rates greater than 40". of rated while in the RUN mode.

This event is considered to be an abnormal occurrence as de-fined in the Technical Specifications, paragraph 1.15B .

CONDITIONS PRIOR TO OCCURRENCE: Steady State Power Routine Shutdown llot Standby Operation Cold Shutdown Load Changes During X Refueling Shutdown Routine Power Operation Routine Startup __ __ _ Other (Speci fy)

Operation DESCRIPTION While performing routine surveillance testing on the generator OF OCCURRE.;CE:

load rejection anticipatery scram, it was observed that pressure switch PSil-C failed to trip at the nominal trip pressure of i

180 psig. The switch senses third stage extraction pressure from l

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the 11. P. turbine and forms a bypass around the PSL-C pressure 1 l  !

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switch contacts, which senses acceleration relay oil pressure,  ;

and the turbine stop valve position switch contacts. These act t l 1

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O O Abnormal Occurrence Report No. 50-219/74/30 . , Page 2

.r to initiate a reactor scram through the condenser low vacuum contacts in the scram circuitry (1K11,1F12, 2K11, and 2F12).

As part of the surveillance test, PSil-C was pressurized to 100 psig without the corresponding trip. The pressure was increased to ascertain the trip point and it was found te operate at 197 psig. A third stage extraction pressure of 180 psig correspor.ds to turbine steam flow of 40% and 197 psig corresponds to a flow of approximately 45%. Therefore, the bypass around the PSL-C and S. V. position switch contacts would have been in effect at 45*6 turbine flow during power operation instead of 40*6 It should be noted that its associated redundant switch PSil-A performed satis factorily.

APPARENT CAUSE Design Procedure OF OCCURRENCE: Manufacture Unusual Service Condition Installation / Inc. Environmental Const ruction Component Failurc Operator Other (Specify)

The cause of the occurrence is presently under investigation.

ANALYSIS OF The safety significance of this occurrence is minimal since the OCCURRENCE :

redundant switch (PSil-A) performed satisfactorily. In addition the purpose of the switch is to bypass the reactor scram due to turbine trip at a point when the bypass valves are abic to accept the reactor steam production. The anticipatory scram acts to minimi e fuel thermal transients in the event of a turbine trip with failure to bypass at power levcis in excess of 1600 Wt.

s 4

Abnormal Occurrence Report No. 50-219/74/30 , , Page 3

.r Since the plant is designed to withstand this transient at 1600 Mit, the switch operation at44*6 of rated steam flow would, in f the event the redundant switch failed to operate, be of no Concern.

CORRECTIVE The switch was recalibrated and tested satisfactorily.

ACTION:

Fall.URE DATA: Manuf acture r: Barksdalc #B2T-A12SS Range: Adjustable from 50-1200 psig Proof Pressure: 1800 psig l'

O 1-Prepared by: d. I s 't ; -

N Date: 5/15/74

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