05000219/LER-1981-006, Forwards LER 81-006/03L-0

Forwards LER 81-006/03L-0

ML19345F618
Person / Time
Site:	Oyster Creek
Issue date:	02/09/1981
From:	Finfrock I JERSEY CENTRAL POWER & LIGHT CO.
To:	Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML19345F619	List: 05000219/LER-1981-006, Forwards LER 81-006/03L-0 05000219/LER-1981-006-03, /03L-0:on 810115,during Surveillance Testing, Reactor Triple Low Water Level Indicator Switch RE-18B Tripped at Monometer Reading Higher than Allowed by Tech Spec Table 3.1.1.Caused by Instrument Drift.Switch Reset
References
NUDOCS 8102180615
Download: ML19345F618 (3)

LER-1981-006, Forwards LER 81-006/03L-0

Event date:
Report date:
2191981006R00 - NRC Website

text

..

f'$

~

GYSTER CREEK

, <i' NUCLEAR GENERATING STATIEN

.'Lg),L. _

L

'm..

n y re;E n. NEW JEH3EY a 08731 February 9, 1981 Mr. Boyce 11. Grier, Director Office of Inspection and Enforcatent Region I Unital States Nuclear Regulatory Comdssion 641 Park Avenue King of Prussia, Pennsylvania 19406

Dear Mr. Grier:

SUBJELT: Oyster Creek Nuclear Generating Station Docket No. 50-219 Licensee Event Report Reportable Occurrence No. 50-219/81-06/3L This letter forwards three copies of a Licensee Event Report to report Reportable Occurrence No. 50-fl9/81-06/3L in canpliance with paragraph 6.9.2.b.1 of the Technical Specifications.

Very truly yours, h Yl o Ivan R. F'

ock, r.

Vice President - JCP&L Director - Oyster Creek IRF:dh Enclosures cc: Director (40 copies)

Office of Inspection and Enforcerent United States Nuclear Regulatory Carmission Washington, D.C.

20555 Director (3)

Office of Management Information m and Program Control g

United States Nuclear Regulatory Carmission Washington, D. C. 20555

~

NRC Rasident Inspector (1)

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

r-C O

B102180(it6 I

4

OYSTER CREEK NUCLEAR GI2e'ERATING STATION Forked River, New Jersey 08731 Licensee Event Report Reportable Occurrence No. 50-219/81-06/3L Report Date February 9, 1981 Occurrence Date January 15, 1981 Identification of Occurrence During surveillance testing, the reactor triple low water level indicator switch RE-18B tripped at a value greater than the desired setpoint as given in the Technical Specifications, Table 3.1.1, item G.2.

This event is considered to be a reportable occurrence as defined in the 'Itchnic al Specifications, paragraph 6.9.2.b.l.

Cc:.liuo s Prior to Occurrence The plant was operating at steady state powr. Major plant parameters at the time of occurrence were:

Power:

Reactor 1517 FMt Generator 477 FWe l

4 Flow:

Recirculation 11.6 x 10 p FeEdWater 5.0 x 106 lb/hr Description of Occurrence On January 15 during performance of the " Reactor Triple Low Water Imvel Test and Calibration" (Procedure 619.3.006), level indicator switch RE-18B tripped at a value greater than the Technical Specification setpoint of <l26"H 0.

Testing of 2

~

the four sensors yielded the following data:

Desired Setpoint As Found As Ieft Switch Designation Manameter Reading ("H O)

("H O)

("H2O) 2 2

Channel 1 - RE-18A

<126.0 121 121 RE-18C 7126.0 122 122 Channel II-RE-18B 7126.0 129 122 RE-18D

~126.0 122.5 122.5 The "As Found" alue of 129.0 "H O corresponds to a level of 53" above the top of 2

active fuel, which is less conservative than the Technical Specification limit of 56" above TAF.

e w-w 4-

Peportable Occurrence Page 2 Report No. 50-219/81-06/3L Igrent Cause of Occurrence The cause of the occurrence was due to instru:mnt drif t.

The long-term repeatability of the sensors can be as much as 4.5"H O (approxirately 2-3% of. full range), and 2

the calibration accuracy is approx 12rately +.3"H 0, meaning the reaF.ing can vary 2

as much as 4.8"H O from its setpoint and still operate within cesign accuracy.

2 This particular sensor tripped at a value outside of the range of repeatability (the trip point was 7.8"H O above the original setpoint), so it is considered to 2

be instrt'.m. ent drif t.

Analysis of Occurrence The failure of switch RE-18B to actuate at the desired setpoint would have delayed the initiation of triple low water level protection functions frm Channel II, however, Channel I would have initiated tle required actions within the Technical Specifications limit.

Corrective Action

The triple low water level sensor RE-18B was reset to trip within the desired Technical Specification limit of between 121"H2O and 123"H2O (note the "As Inf t" values under Description of Occurrence). An engineering study into the drift problen and possible setpoint change is being made. Also, the POPC has recxmmended replacment of the switches with a nore suitable qualified nodel.

Failure Data bbnufacturer:

ITT Barton Fbdel:

288A Indicating Pressure Switch Paage:

0-150"H O 2

I l

1 I

T Te--

m

--mm-