05000344/LER-1981-006, Forwards LER 81-006/03L-0.Detailed Event Analysis Encl

Forwards LER 81-006/03L-0.Detailed Event Analysis Encl

ML19345G806
Person / Time
Site:	Trojan File:Portland General Electric icon.png
Issue date:	04/13/1981
From:	Yundt C PORTLAND GENERAL ELECTRIC CO.
To:	Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV), NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
Shared Package
ML19345G807	List: 05000344/LER-1981-006, Forwards LER 81-006/03L-0.Detailed Event Analysis Encl 05000344/LER-1981-006-03, /03L-0:on 810316,erratic Trip Setpoint Found on Engineered Safeguards Feature Steamline Pressure Channel 516.Caused by Failed Capacitator.Capacitator Replaced & Channel Calibr
References
CPY-321-81, NUDOCS 8104220413
Download: ML19345G806 (2)

LER-1981-006, Forwards LER 81-006/03L-0.Detailed Event Analysis Encl

Event date:
Report date:
3441981006R00 - NRC Website

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April 13, 1981 CPY-321-81 Mr. R. H. Engelken, Director U. S. Nuclear Regulatory Co=nission 1990 North California Blvd.

'a'alnut Creek, California 94596

Dear Sir:

In accordance with the Trojan Plant Operating License, Appendix A, US NRC Technical Specifications, Paragraph 6.9.1.9.b, attached is Licensee Event Report No. 81-06.

This report describes an event where an erratic trip setpoint was found on one ESF steamline pressure channel.

Sincerely, ff C.

. Yundt General Manager CPY S:na Attachments i

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REPORTABLE OCCURRENCE l.

Report No.:

81-06 2.

a.

Report Date:

April 13, 1981 b.

Occurrence Date: March 16, 1981 3.

Facility: Trojan Nuclear Plant, PO Box 439, Rainier, OR 97048 4.

Identification of Occurrence:

Routine instrument calibration found that steamline pressure channel 516 had an erratic trip setpoint.

This channel provides an input to the Engineered Safeguards Feature (ESF) Actuation System tofinitiate a safety injection. Due to its erratic behavior, its trip setpoint could not be verified as being within the Technical Specification limit specified in.

Section 3.3.2.1.

i 5.

Conditions Prior to Occurrence:

The plant was in Mode 1 at 100% power.

6.

Description of Occurrence:

Routine instrument calibrations performed on steamline pressure channel 516 discovered that the instrument had an erratic trip setpoint. This channel provides an input to the ESF actuation system to generate a Safety Injection under conditions of high steam flow coincident with low steam pressure. Because of its errat.c behavior, the trip setpoint of channel 516 for low steamline pressute could not be' accurately determined.

l Based on observations of the channel, it is likely that the low pressure trip setpoint was below the minimum Technical Specification limit.

7.

Designation of Apparent Cause of Occurrence:

The apparent cause of this evenc is attributed to component failure.

+

Troubleshooting of the channel identified a failed capacitor as the cause of the channel's erratic. behavior. There is no previous history 5

of failures of this type of capacitor and this event is attributed to random failure.

8.

Significance of Occurrence:

This avent had no effect on either plant or public safety. Three other channels of steamline pressure were available to provide ESF actuation signals if required. Technical Specifications permit continued plant operation with one channel inoperable.

9.

Corrective Action

The defective capacitor was replaced, and the Caannel calibrations were satisfactorily completed.