05000237/LER-1981-052-03, /03L-0:on 810918,during Normal Operation,Ps 504-C Switch Failed.Caused by Worn Out Micro Switch.Switch Replaced

/03L-0:on 810918,during Normal Operation,Ps 504-C Switch Failed.Caused by Worn Out Micro Switch.Switch Replaced

ML20010J079
Person / Time
Site:	Dresden
Issue date:	09/18/1981
From:	Morgan W COMMONWEALTH EDISON CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML20010J064	List: 05000237/LER-1981-052, Forwards LER 81-052/03L-0 05000237/LER-1981-052-03, /03L-0:on 810918,during Normal Operation,Ps 504-C Switch Failed.Caused by Worn Out Micro Switch.Switch Replaced
References
LER-81-052-03L, LER-81-52-3L, NUDOCS 8109290573
Download: ML20010J079 (2)

LER-1981-052, /03L-0:on 810918,during Normal Operation,Ps 504-C Switch Failed.Caused by Worn Out Micro Switch.Switch Replaced

Event date:
Report date:
2371981052R03 - NRC Website

text

_.. _ _ -.. _.. _.. -. _ _ _ _. -

u.s. NUCLEAR REGULATCRY COMMISSION __

LICENSEE EVENT REPORT

. CCNTROL SLCCK:

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8 80 61 coCKET NVVS E R 68 69 EVENT oATE 74 75 REPORT oATE 40 EVENT DESCRIPTION AND PRCBABLE CCNSECUENCES O'o

. I o l 21 l During normal operation, PS 504-C was found to have failed which caused an alarm indi-Since g cating bypass of generator load reject and turbine stop valve closure scrams.

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this bypass should not occur when power was above 45%, the bypass was removed by re-I l o ! s I l m Ving Power to the bypass relay. This action restored the requirements of Tech.

J l S ec Table 3.1.

Safety significance was minimized because three remaining aw Mches P

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CAuSE

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37 40 41 42 43 44 47 CAUSE DESCRIPTION AND CCRREC IVE ACTIONS h I i l o I. l The cause of this event was attributable to a worn out micro switch in PS 504-C.

Put g i pres'sure switch was replaced with a like for like. switch.

DIS-500-7 was then per-gl fomed on the new switch to verify operability. DIS 500-7 will continue to be per-l, ; 31 l formed monthly._

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DEVIATION REPORT '

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Commonwealth Ed.ison STA UNIT YEAR N O.

D-12 81 - 95 PART 1[ Tl TLE OF DEV1AT Received Alarm [ON OCCU RRED Turbine Pressure Generator Load Reject and Stop Valve 8/23/81 2025 Bvoass" DATE TIME SYSTEM decCTED 500

PLANT CONDITIONS

TESTING C C Reactor Protecticn System Run 2343 760 E

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, LOAD (MWE)

YES NO

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DESCRIPTION OF EVENT

At 2023 received alarm 902-5 (H-4) " Turbine Pressure Generator Load Reject and Stop Valve Scram Bypass." Went to panel 902-15 and found relay 590-123C energized.

Looked at print 12E2465 and 302-15 then pulled fuse 590-726C to verify that relay 590-123C would drop out.

Relav 590-123C did (OVER)

DESCRIPTION OF CAUSE Bellave at this time pressure switch 504C has failed. Called in IM's to repair switch.

OTHER APPLICABLE INFORMATION Relays 590-123A. B, and D were de-energized as expected.

EQUIPMENT YES DR NO.

WR NO.

Gary L. Smith 8/23/81 FAILU RE R NO N/A 15331 eESPONSISLE SUPEEVISOR DATE PART 2 l OPFoATING ENGINEERS COMMENTS Bvpass txtav 590-123C placed in the conservative position upon operability verification until repair to oressure switch 504C were completed.

SAFETY-TYPE OF CEVIATION EVENT CF POTENTIAL TECH SPEC NON-REPORTABLE ANNUAL RELATED REPORTABLE OCCURRENCE PUBLIC INTEREST VIOLATION OCCURRENCE.

REPORTI NG WR ISSUED"

• I 14 DAY YES X YES X lX 30 DAY N

ON NO NO PEPORTABLE CCCURRENCE ACTION ITEM NO.

PROMPT ON-SITE NOTIFICATION NUMaER R. M. Ragan 8/24/81 0600 1 - 4X 81-52/0LC TITLE DATE TIME TITLE CATE TIME 24-HOUR NRC NOTIFICATION PROMPT OFF-SITE NOT!FICATION X

TPH Mike Jordan 24/81 0800 F. A. Palmer 8/24/81 0902 REGION III DATE TIME TI TL E

- DATE

. TIME TGM REGION III & COL CATE TIME _._

TlTLE DATE TIME

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I RESPONSI BLE CCMP ANY 0FFI CER INFORMED OF 10 C FR 21

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CATE Ith CONDI TIONS AND TWEt A PEPO AT TO NPC (John /. Wujcig/a ~ Q 8/24/81 W

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DATE IIT b RESOLUTION APPROVED AND

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DESCRIPTION OF EVENT

da-energize and the alarm 902-5 (H-4) did clear. At 2027 we left this fuse pulled allowing the unit to run as permitted by Tech. Spec. Table 3.1, which requires that we have a minimum number of operable instrument channels per Trip System for both the gsnarator load retect (>45%) and Turbine Stop Valve Closure (>45%) scrams. Fuse was taksn OOS per outage II-1425.

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