ML20039C940

LER 81-019/01T-0:on 811210,steam Flow Channels FC-464 & FC-465 Found to Be Indicating Zero Flow Following Rephasing. Caused by Improper Zero Setting on Transmitters.Channels Placed in Trip to Provide Safeguard Signals Pending Calibr

ML20039C940
Person / Time
Site:	Point Beach
Issue date:	12/23/1981
From:	Fay C WISCONSIN ELECTRIC POWER CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML20039C920	List: ML20039C919 ML20039C940
References
LER-81-019-01T, LER-81-19-1T, NUDOCS 8112310121
Download: ML20039C940 (2)

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NRC FORM 366 ' U.S. NUCL$AR f.EGULATCflY COMMISSION 0 778

• LICENSEE EVENT REPORT CONTROL BLOCK: l 4.

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lh (PLEASE PRINT OR TYPE ALL REQUIRED INFORMATION) 0 t 7 8 9 l Wl LICENSEE I l P lCODE B l H l 1 lQ14 16 l 0 l- l 010' CENSE l 0 NUMBER l 0 ] 0 l- l 0 l 026l@264 l1LICENSE. l1 l 1l 1 l@l57 CAT TYPE JO l

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REPORT D ATE 80 EVENT DESCRIPTION AND PROBABLE CC"EQUENCES h O 2 lon 12-10-81, follow' ; cephasinct of the unit to the line at the end of l 0 3 lthe refueling outage, both steam flow channels for loop "A" were dis- l O 4 Icovered to be indicating zero flow. Technical Specifications require atl l 0 l $ 1 lleast one of the two flow channels to be operable to provide high and l 10isllhigh-high steam flow signal to safeguards logic for steam line isolation l l0l7lland reactor trip. This event is reportable in accordance with Technical l lOisiIS pecification 15.6.9.2.A.2. I DE CO E S 8C E COMPONLNT CODE S8 DE S E liTE]

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CAUSE DESCRIPTION AND CORRECTIVE ACTIONS h i O phe zero flow indications were found to be caused by an improper zero I i i ] setting on both transmitters. Flow channel FC-464 was placed in trip l c

, 7 lat 0830 hou's r and channel FC-465 was placed in trip at 1030 hours0.0119 days <br />0.286 hours <br />0.0017 weeks <br />3.91915e-4 months <br /> to l

, i 3 l provide safeguards signals. Both channels were recalibrated and the l 3

, 4 l trips removed by 1230 hours0.0142 days <br />0.342 hours <br />0.00203 weeks <br />4.68015e-4 months <br /> on 12-10-81. l 7 8 9 80 ST S M*0WER OTHER STATUS DISC RY DISCOVERY DESCRIPTION i s

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• OY PHONE: 414/277-2811 {

ATTACHMENT TO LICENSEE EVENT REPORT NO. 81-019/OlT-0 l Wisconsin-Electric Power Company Point Beach Nuclear Plant Unit 1 Docket-No. 50-266 Chi 12-10-81, following rephasing of the unit to'the line at the end of the refueling outage, both steam flow channels for loop "A" were discovered to be' indicating zero flow.

l The flow indications from FC-464 and FC-465 were noted at zero flow at approximately 0800 hours0.00926 days <br />0.222 hours <br />0.00132 weeks <br />3.044e-4 months <br /> on 12-10-81. It is not unusual for flow indications to fluctuate when the unit is first placed on line and the zero flow condition.could not be detected until the unit had reached approximately 15% power.

Following investigations into the problem, flow channel FC-464 was placed in the trip-position at 0830 hours0.00961 days <br />0.231 hours <br />0.00137 weeks <br />3.15815e-4 months <br />. This iaet the Tech-nical Specification'for limiting conditions of operation since the logic is one out of two'per loop for steam flow. With one steam flow channel in trip for the "A" loop, the high and high-high steam flow portion of the logic is already in for steam line isolation and reactor trip. Steam line isolation is initiated by a high steam flow coincident with low Tave and safety injection or a high- ,

high steam flow coincident with safety injection. A reactor trip is initiated by a steam flow / feed flow mismatch (steam flow higher than feed flow) and a low steam generator level. Following further review and discussions int'o the problem, the other flow channel FC-465 was placed in the trip position at 1030 hours0.0119 days <br />0.286 hours <br />0.0017 weeks <br />3.91915e-4 months <br /> on 12-10-81. .)

I' Placing the remaining channel in trip satisfied the Technical Specifications in providing the minimum degree of redundancy.

, The zero flow indications were a result of improper zero settings on both transmitters.- These transmitters were installed during the outage as part of TMI-required modifications and were checked out and aligned satisfactorily on 11/07/81. 'Although'the exact cause of the i

, transmitter misalignment cannot be determined, the cause is believed l to be related to contractor activity in the area; either by. move-ment of equipment in the area or by an inadvertent adjustmer,t of the exposed zero adjust screw by an unauthorized person.

l Both transmitters were realigned and put back into service by 1230 hours0.0142 days <br />0.342 hours <br />0.00203 weeks <br />4.68015e-4 months <br /> on 12/10/81. .l 1

This event-is reportable in accordance with Technical Specifi-cation 15.6.9.2.A.2. j Contractors will be reinstructed as to the caution required while working in sensitive areas.

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