ML20090D840

AO-50-219/74-60:on 741122,during Surveillance Test,Sensor 1B11A2 on Isolation Condensor a Actuated at Value Exeeding Tech Spec Limit.Caused by Sensor Repeatability.Setpoint Accuracy & Tolerance Under Investigation

ML20090D840
Person / Time
Site:	Oyster Creek
Issue date:	12/02/1974
From:	Ross D JERSEY CENTRAL POWER & LIGHT CO.
To:	Giambusso A US ATOMIC ENERGY COMMISSION (AEC)
References
AO-50-219-74-60, NUDOCS 8303030225
Download: ML20090D840 (3)

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Jersey Central Power & Light Company n[*

O MADISON AVENUE AT PUNCH BOWL ROAD

• MORRISTOWN, N.J.07960

• 201-539-6111

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General g.}. { Public Utilities Corporation SYSTEN December 2, 1974 A. '\.!l.C, _ _.. ~

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Mr. A. Giambusso S.%g.

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Deputy Director for Reactor Projects h,J g

Directorate of Licensing JA . ..,

United States Atomic Energy Commission 'W - .

Washington, D. C. 20545 -

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Dear Mr. Giambusso:

Subj ect: Oyster Creek Station Docket No. 50-219 Abnormal Occurrence Report No. 50-219/74-60 The purpose of this letter is to forward to you the attached Abnormal Occurrence Report in compliance with paragraph 6.6.2.a of the Technical Specifications.

Enclosed are forty copies of this submittal.

V ry truly yours, M'

Donald A. Ross Manager, Generating Stations-Nuc1 car es Enclosures cc: Mr. J. P. O'Reilly, Director Directorate of Regulatory Operations, Region 1 12303 fb'Yf i.

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Jersey Central Power & Light Company b,/

MADISON AVENUE AT PUNCH BOWL ROAD

• MORRISTOWN, N.J.07960

• 201-539-6111 manue w rus General [j,{ Public Utilities Corporation srsran OYSTER CREEK NUCLEAR GENERATING STATION FORKED RIVER, NEW JERSEY 08731 Abnormal Occurrence Report No. 50-219/74-60 Report Date December 2, 1974 9

Occurrence Date November 22, 1974 Identification of Occurrence Violation of the Technical Specifications, Table 3 . 1 . 1 . 11. 2 , isolation condenser condensate high flow line break sensor IB11A2 was found to actuate at a value in excess of the Technical Specification limit of 27 inches water. This event is considered to be an abnormal occurrence as defined in the Technical Specifi-cations, paragraph 1.15B.

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Conditions Prior to Occurrence The plant was at steady state power with major parameters as follows:

Power: Reactor, 1908 MWt Electric, 665 MWe Flow: Recirculation, 15.3 x 104 gpm Feedwater, 7.13 x 10 6 lb/hr Reactor Pressure: 1020 psig Stack Cas: 22,100 pCi/sec Description of Occurrence l

l On Friday, November 22, 1974, at approximately 1045, while performing routine surveillance testing on the isolation condenser condensate high flow line break sensors, it was observed that sensor IB11A2 (located on the A isolation condenser) actuated at a value in excess of the Technical Specification limit of 27 inches water. The complete condensate line break sensor surveillance results were as follows:

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Abnormal Occurrence Report No. 50-219/74-60 Page 2 Isolation Condenser A As Found As Left Sensor (inches water) (inches water)

IB11A1 27 27 IB11A2 29 27 Isolation Condenser B As Found As Left Sensor (inches water) (inches water) 1B11B1 26.5 26.5 1B11B2 27 27 The 1B11A2 sensor was recalibrated and retested. The surveillance retest yielded a trip point of 27 inches water.

Apparent Cause of Occurrence The cause of this occurrence is sensor repeatability, which is a recognized problem.

Analysis of Occurrence This event is considered to have no safety significance. IIad a condensate line high flow condition occurred requiring isolation of the A isolation condenser, the redundant sensor, IB11A1, wot;d have actuated at the Technical Specification limit of 27 inches water.

Corrective Action Setpoint accuracy and tolerance in not only these instruments but others as well is under investigation by Jersey Central Power S Light Company and GPU Service Corporation personnel in conjunction with the General Electric Company.

A Plant Operations Review Committee Action Item has been assigned to investigate the conservatism in the 27 inches of water setpoint of the isolation condenser condensate high flow line break sensor. This investigation may show that a margin between the Technical Specification setpoint and the minimum operational setpoint may be established to allow for the lack of sensor repeatability.

Failure Data A previous abnormal occurrence involving these switches was reported in Abnormal Occurrence Report No. 50-219/74-23.

Pertinent manufacturer data:

Type: Barton Differential Pressure Switch Range: 0-60 inches water Pressure Rating: 1500 psig Serial No.: 1811A2 - 27E-965