05000219/LER-1981-056, Forwards LER 81-056/03L-0.Detailed Event Analysis Encl

Forwards LER 81-056/03L-0.Detailed Event Analysis Encl

ML20039C099
Person / Time
Site:	Oyster Creek
Issue date:	12/14/1981
From:	Carroll J JERSEY CENTRAL POWER & LIGHT CO.
To:	Haynes R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20039C100	List: 05000219/LER-1981-056, Forwards LER 81-056/03L-0.Detailed Event Analysis Encl 05000219/LER-1981-056-03, /03L-0:on 811113,isolation Condenser Isolation Pipe Break Sensors IB11A1 & IB11A2 Tripped at Value Greater than Tech Spec Limits.Caused by Instrument Repeatability & Drift.Switches Reset & Will Be Replaced in Future Outage
References
NUDOCS 8112280403
Download: ML20039C099 (3)

LER-1981-056, Forwards LER 81-056/03L-0.Detailed Event Analysis Encl

Event date:
Report date:
2191981056R00 - NRC Website

text

.

t OYSTER CREEK NUCLEAR GENERATING STATION ammse G R.'".12 %,*iG c,~, c.n c w s.

(609)693-6000 P.O BOX 388

• FORKED RIVER

• NEW JERSEY

• 08731 Decarber 14,1 I ID g s ;Il s.

Mr. Bonald Haynes, Director u...MD 7

Office of Inspection and Enforement

/

Region I OECgg7 United States Nuclear Regulatory Ommission L -.

IL Q

~

King of Prussia, Pennsylvania 19406 N' E [,' j?"%

631 Park Avenue yso

Dear Mr. Haynes:

I~ k >' '

SUBJECT: Oyster Creek Nuclear Generating Station Docket No. 50--219 Licensee Ennt Report Reportable Occurrence No. 50-219/81-56/3L This letter forwards three copies of a Licensee Event Report to report Reportable Occurrence No. 50-219/81-56/3L in cmpliance with paragraph 6.9.2.b.1 of the Technical Specifications.

Very truly yours,

/

&M

. T. Carroll, J.

Acting Director yster Creek Enclosures cc: Director (40 copies)

Office of Inspection and Enforc ment United States Nuclear Regulaury Camission Washington, D.C.

20555 Director (3)

Office of Managment Information and Program Control United States Nuclear Regulatory Camission Washington, D. C. 20555 NBC Resident Inspector (1)

Oyster Creek Nuclear Generating Station Forked River, N. J.

7 A

hb?0$0 Offfgfg i

PDR

-.----________-.-----._-___o

OYSIER CREEK NUCLEAR GENERATING STATICN Forked River, New Jersey 08731 Licensee Event Report-Reportable Occurrence No. 50-219/81-56/3L Report Date Decerber 14, 1981 Occurrence Date Novenber.13, 1981 Identification of Occurrence During surveillance testing, the Isolation Condenser pipe break sensors IBllAl and IBllA2 tripped at a value greater than that.specified in the Technical Specifications Table 3.1.1 iten H.

This event is consideral to be a reportable occurrence as defined in the Technical Specifications, paragra @ 6.9.2.b.l.

Conditions Prior to Occurrence Major Plant Parameters:

Power:

Reactor 1919 W t Generator 673 W e 4

Flow:

Recirculation 15.8 x 10 gpn Feedwater 7.17.x 10 lb/hr Description of Occurrence

~

During performance of the " Isolation Condenser Isolation Test and Calibration" surveillance procedure, isolation pipe break sensors IBilAl and IBilA2 tripped at values gre 9.r than the Technical Specification limit. The desired trip point'is <27.L" H O AP.

The testing yielded the followiry data:

2 "As Found" Desired "As Inft" Sensor Value ("H2O AP)

Setpoint ("H >O AP)

Value ("H O AP) 2 IBllAl 29.4

<27.0 27.0 IBllA2 27.6 727.0 26.3 IBllB1 26.9 727.0 26.9 IR11 H2 26.5 527.0 26.5 Apparent Cause of Occurrence In the case of IBilAl, the cause is attributed to ins *mt drift.

In the case of IBllA2, the cause is attributed to instrument repeatability. The total error bandwidth due to design and calibration error is+1.18 "H 0.

The change in setpoint 2

of IBilAl was outside this range (drift) and the change in setpoint of IBilA2 was within this range (repeatability).

~

Reportable Occurrence Page 2 Report No. 50-219/81-56/3L-Analysis of Occurrence

'Ihe 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 nonnal plant operatiuns the Isolation Condensers are in'a standby condition and the condensate return lines are isolated by normally closed isolatica valves.

' There are four sensors for each Isolation condenser which will autcmatically

- isolate the condenser in the event of a persistent high flow condition (hi.gh flow beug an indication of a pipe break). Two sensors are locatal on the steam l_ine inlets (IB05Al and IB05A2 for "A" Condenser and IB05B1 and IB05B2 for "B" Condenser) and two sensors are located on the condensate return lines (IBilAl and IB11A2 for "A" Condenser and IBllB1 and IBilB2'for "B" Condenser). For each condenser, a signal frcn 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 sensors IBilAl and IBllA2 tripping at a slightly nigher value is minimized.

Corrective Action

The switches were reset to trip within the limit of <27.0" H O AP (note the "As 2

Ieft" values in the Description of Occurrence). Due to the frecpency of drift problems with these snap-action type switches, it has been reccrimended that they be replaced with a nore qualified model. Replacanent is scheduled for a future refueling outage. In nMition, IBilAl will be checked for repeatnhility and, if found to drift outside the range of +1.18 in.H 0, will be replaced.

2 Failure Data Manufacturer: ITT Barton Model:

1. 228A Indicating Pressure Switch Range:

0-60 " H O 2