ML17252B496

LER 78-044/03L-0 for Dresden, Unit 2 Re While Performing Dis 700-6 on Unit, APRM Channel #3 Scram Setpoint Was Found >120% Power at Core Flows >100%

ML17252B496
Person / Time
Site:	Dresden
Issue date:	08/25/1978
From:	Stephenson B Commonwealth Edison Co
To:	James Keppler NRC/RGN-III
References
BBS LTR 78-1188 LER 78-044/03L-0
Download: ML17252B496 (2)

Text

Commonwea.dison Dresden Nuclear Power Station R.R. #1 Morris, Illinois 60450 Telephone 815/942-2920 August 25, 1978

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o James G. Keppler, Regional Director ,.,,CJ .

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Directorate of Regulatory Operations - Region III U.S. Nuclear Regulatory Connnission 799 Roosevelt Road Glen Ellyn, IL 60137 Reportable Occurrence Report #78-044/03L-O, Docket s hereby submitted to your office in accordance with Dresden r Power Station Technical Specification 6.6.B.2.(a), reactor protection. system or engineered safety feature instrument settings which are found to be less conservative than those established by the*technical specifications but.which do not prevent the fulfillment of the functional requirements of affected systems.

n n Superineendent Dresden Nuclear Power Station BBS/deb Enclosure*

ccc: Director of Inspection & Enforcement Director of Management Infonnation & Program Control File/NRC AUG 2 0 1-918

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U.S. NUCLEAR REGULATORY COMMISSION (7-77.4, I

A LICENSEE EVENT REPORT.

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~ I While performing DIS 700-6 on Unit 2, APRH Channel 113 Scram setP.oint was found filIJ > 120% power at core flows> 100%. For core flow-<100%, the flow biased scram setpointl

~ was conservativ~ly below Tech Spec limits. Safety significance was minimal because

!ITIJ two instrument channels per trip system remained operable as required by-Tech Specs.

[TI[) This is the first occurrence of this t e.

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• SUBCODE COMPONENT CODE SUBCOOE SUBCODE

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Cause attributable to a broken wire and a transistor failure on Flow Control Trip _J Reference Module board. The broken wire was repaired and the. module board W.flS _J replaced. DIS 700-6 was performed on Channel 113 to verify APRM operability. APRM

[IJJJ I channels will continue to be tested monthly using DIS 700-6. No further corrective 1 o:::I3J I action deemed necessary.

7 B 9 BO FACILITY METHOD OF . ~

STATUS  % POWER OTHER STATUS DISCOVERY DISCOVERY DESCRIPTION '2,V

~ LJ!J@ I 0 I 0 I 0 lli--;;.N=A_ _ _ _ ___. ~(i!)I Surveillance Testing 8 9 10 12 11 44 45 46 80 ACTIVITY CONTENT ~

RELEASED OF RELEASE AMOUNT OF ACTIVITY~ LOCATION OF RELEASE @

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NUMBER TYPE DESCRIPTION LlI2J jO jO /oj@)~j@).___ _ _ _ _ NA_ _~--~~----------__j 8 9 11 12 13. so PERSONNEL INJURIES Q NUMBER DESCRIPTION~

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