05000219/LER-1981-070, Forwards LER 81-070/03L-0.Detailed Event Analysis Encl

Forwards LER 81-070/03L-0.Detailed Event Analysis Encl

ML20040F479
Person / Time
Site:	Oyster Creek
Issue date:	01/28/1982
From:	Carroll J GENERAL PUBLIC UTILITIES CORP.
To:	Haynes R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20040F480	List: 05000219/LER-1981-070, Forwards LER 81-070/03L-0.Detailed Event Analysis Encl 05000219/LER-1981-070-03, /03L-0:on 811231,isolation Condenser Isolation Pipe Break Sensor IB11A1 Tripped Above Tech Spec Limit. Caused by Instrument Repeatability.Setpoint Lowered.Switches Will Be Replaced During Future Refueling Outage
References
NUDOCS 8202090250
Download: ML20040F479 (3)

LER-1981-070, Forwards LER 81-070/03L-0.Detailed Event Analysis Encl

Event date:
Report date:
2191981070R00 - NRC Website

text

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P.O. Box 388 N

Forked River, New Jersey 08731 639-693-6000 Writer's Direct Dial Number:

January 28, 1982 Mr. Ronald C. Haynes, Administrator

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U.S. Nuclear Regulatory Commission 631 Park Avenue

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8 King of Prussia, PA 19406 l.

Dear Mr. Haynes:

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Subject: Oyater Creek Nuclear Generating Station Docket No. 50-219 Q: rj r Licensee Event Report O

Reportable Occurrence No. 50-219/81-70/3L This letter forwards three copies of a Licensee Event Report to report Reportable Occurrence No. 50-219/81-70/3L in compliance with paragraph 6.9.2.b.1 of the Technical Specifications.

Very truly yours,

'J.

T. Carroll, Jr.

/

Acting Director - Oyster Creek JTC:lse Enclosures cc:

Director (40 copies)

Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, D.C.

20555 Director (3)

Office of Management Information and Program Control U.S. Nuclear Regulatory Commission Washington, D.C.

20555 NRC Resident Inspector (1)

Oyster Creek Ihclear Generating Station Forked River, NJ 08731 8202090250 820128 PDR ADOCK 05000219 S

PDR GPU Nuclear is a part of the Genera! Public Utilities System

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OYSTER CREEK NUCLEAR GENERATING STATION Forked River, New Jersey 08731 Licensee Event Report Reportable Occurrence No. 50-219/81-70/3L Report Date January 28, 1982 Occurrence Date December 31, 1981 Identification of Occurrence During surveillance testing, the Isolation Condenser pipe break sensor IBllAl tripped at a value greater than that specified in the Technical Specifications, Table 3 1.1, Item H.2.

This event is considered to be a reportable occurrence as defined in the Technical Specifications, paragraph 6 9 2.b.l.

Conditions Prior to Occurrence The reactor was shutdown with the reactor coolant. temperature less than 2120F.

Description of Occurrence The setpoint of Isolation Condenser pipe break sensor IBilAl was retested prior to the scheduled periodic surveillance test as recommended by the Plant Operations Review Committee upon review of Reportable Occurrence No. 81-56.

The sensor was found to trip at 28 5" H O which is greater than the Technical 2

Specification limit of less than or equal to 27 0" H O Delta P.

2 Apparent. Cause of Occurrence The cause is attributed to instrument repeatability.

Analysis of Occurrence The Isolation Condenser pipe break sensors are designed to provide protection in the event of a steam or condensate line pipe break outside the containment,

and are located on pipe bends inside the containment.

During normal plant operations, the Isolation Condensers are in a standby condition and the condensate return lines are isolated by normally closed isolation valves.

+

Reportable Occurrence Page 2 Report No. 50-219/81-70/3L Analysis of Occurrence (Continued)

There are four sensors for each Isolation Condenser which will automatically isolate the condenser in the event of a persistent high flow condition (high flow being an indication of a pipe break). Two sensors are located on the steam line inlets (IB05Al and IB05A2 for "A" Condenser and IB05B1 and IB05B2 for "B" Condenser) and two sensors are located on the condensate return lines (IB11A1 and IBilA2 for "A" Condenser and IB11B1 and IBilB2 for "B" Condenser).

For each condenser, a signal from any one of the four sensors will, after a 35 second-time delay, initiate closure of all four isolation valves for that condenser.

Since the steam line pipe break sensors for "A" Condenser would have actuated within the required limits to isolate the condenser, the effect of sensor IBilAl tripping at a slightly higher value is minimized.

Corrective Action

On December 31, 1981, IBllAl setpoint was adjusted to 26.2" H O Delta P.

2 Later, a procedure change was made to lower the setpoint of the IBil's from 27 0 +0, -1 down to 24 0 +1.5 This change should help the IBil switches to trip below the Technical Specification limit of less than or equal to 27 0" H 0.

The switches were retested on January 16, 1982, and yielded the 2

following data:

"As Found" Desired "As Left" Value ("H O Delta P) _ Setpoint ("H O Delta P)

Value ("H O Delta P) 2 2

2 IBilAl 26.0 24.0 +1 5 24.8 IBllA2 25 0 24.o 71 5 25 0 IB11B1 26.6 24.0[15 24.3 IBilB2 25 4 24 0 +1 5 25 4 These switches will be replaced during a future refueling outage with an improved design.

Failure Data Manufacturer: ITT Barton Model:

1. 228A Indicating Pressure Switch Range:

0-60 "H20