ML20151C153

AO 50-219/74/8:on 740117,isolation Condenser Sys Initiation Time Delay Switch Failed to Close within Tech Specs Time Limit After High Reactor Pressure Reached.Caused by Instrument Drift.Research Initiated to Clarify Requirements

ML20151C153
Person / Time
Site:	Oyster Creek
Issue date:	01/24/1974
From:	JERSEY CENTRAL POWER & LIGHT CO.
To:
References
AO-50-219-74-8, NUDOCS 8103040631
Download: ML20151C153 (3)

Text

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Y Initial Telephono Report Date:

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_ _ _ _ _ _ _ _1124L74_

. Date of Occurrencet. __

1/17/74 __

Initial Written Time of. .

Report Dato: 1/ 2 5/.74_' occurrence: . 1055 OYSTER CRUEK NUCLi?^R m!EPATING STATION '

' TORKBD RIVER NEW JERSEY 08731 Abnormal.0ccurrence Report No. 50-210/74/ g.

1D5hTIFICAT10M Violction o' f..the Technical Specifications, paragraph 2.3.5 ,

' 0F 0CCUIWENCE: which requires that isolation condenser system'-initiation occur with a tipo delay.mof f15 seconds after .a specified.high y 4 /a.s k.. '..e'.7 ,

ret;ctor preseure is reaclied.. -

This event is considered to b'e an abnormal occurrence as de, finod in the Technical Specifications paragraph '1.15A . .

C0hPITIO95PP.IOP. '

TO OCCURf1NCE: ' Steady State Power Routine Stutdown not St.andby' Operation T- Cold Shutdown ~ L. cad tCh=nner. Du an

._ Refueling Shuthwn Routine Pov V. ration

- Routine $tsttup _ Other . (S < . .

Ope ration ,

The plant was shutdown with the reactor coolant at <212*F.

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THis DOCUMEt4T.'C0t1TAltiS POOR QUAUTY PAGES IGSCRIPTI(N Khile performing a routinc surveillance test on the reactor OF '00 CUT.rJING:

high pressure isolation condenser initiation switches, contacts on three out of the four associated tima delay relays failed to close within the preset tine deIcy of 15 seconds (after each

' pressure switch was tripped and the associated relay deen 7lo3&o(s3/ lho'delny tirms of these three relcyr were found to be es

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'Abnorcal Occurrence e

Report No. 50-219/74/ 8 .

Page 2 6r9 - 20 nee.

.n.- CK11 - 16.7~socp 6K12'- 18 sec.

Each' of the involved time delay relays was irradiately reset

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to less than .157. seconds. - -

Design Procedure..

APPAPIKT CMJSE X 0F 00CURPSRCE: _ ___. Manufacture Unususi Service Condition Installation / - . .

Inc.11nvirontental -

~ Constmetion . Conponent Failure

~ Other -(Specify)

.___._ Operator Instruent ' drift. has been identified as the cause of these exccse.19e tine' delsys, ".

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ANALYSTS OF Four. pressure switches in'the reactor protection systen (RPS)

Oca)RIENCti:

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adtivate the isolittion condenser systet.when there ir a persis-

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' tent.15 second condition with s * **;

ireactor prest.ure at.or above -

. s- 's 11050psig. Tu$ of'these pressi. ire switdies witfi associated -tire deIsy relays 6K9 and 6K10 nre in one RPS channel, and the other.

two pressure switches with associated tice delay relays 6K11 and "6d2. are in the other RPS channel. High prenure signals fro two pressure switches, 'one in esch RPS channel, . ate required to setivate thficoI41on condenser systeh (coincidence of two ~ ;

. EPS channels. enth of which is tripped by one o'f two pressure sensors). Accordingly, the excessive tir:c dels'ys of these three tira delay rolsys would hm.'c resulted in an isolation condenser i

' system initiation delsy tino gronter then 15 seconds. hud ,the

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isolation pressure been reached. There is no evidence, houcver, to indicato that isolation condenser systen initiation would not

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f 'Abnornni Occurrence- >

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Report:No. 50-219/74/ 8 -

. Page 3. .

• y of the isolation condsnsers is required to set as a 5-ans of heat removal during. a postulated' loss of coolant accident, ,

The safety significance:ofithe initiation delay tir.e in excess.

- of'15 seconds is being ova'luated at this tino.

CORRECTIVE- ' Corrective Action Will be d6tervined fol10 Win 2 review of this ALTION:- . -

+ abnormal ocet..Tence by th'e Plant Operations Review Comittee. '

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... FAILV.Pf .DNrA%...

Per.Onent manufacturer.ps. are_lis.ted_below:- _ _ , , , _ _ .

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Manufactur.or: Agastat- - .

Model: , 7022 PDT- - .

Range - $ to $0' seconds

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Coil t 120V. rc '

' Serial Ntubers: 6E9 - 1712235-6K11.- 1712237 .

6K12 - 1712228' ,

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