ML20044G592

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Forwards Application for Amend to License DPR-6,revising TS Supporting Replacement of Reactor Protection Sys CB-RE11 Undervoltage Breakers & Rev of Release Device Trip Range
ML20044G592
Person / Time
Site: Big Rock Point File:Consumers Energy icon.png
Issue date: 05/24/1993
From: Donnelly P
CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20044G593 List:
References
NUDOCS 9306030362
Download: ML20044G592 (1)


Text

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l-l Consumers -

POWBr e.,rien u oonn.i,y Plant Manager e

w POWERING hiKN0GAN5 MtD6 MESS l

B'O Rock Point Nuclear Plant.10269 US-31 North, Charlevon, MI 49720 l

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May 24, 1993 l

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NUCLEAR REGULATORY COMMISSION DOCUMENT CONTROL DESK WASHINGTON, DC 20555 DOCKET 50-155 - LICENSE DPR BIG ROCK POINT'- TECHNICAL SPECIFICATION CHANGE REQUEST - REPLACEMENT OF REACTOR PROTECTION SYSTEM CB-REll UNDERVOLTAGE BREAKERS AND REVISION OF THE RELEASE DEVICE TRIP RANGE..

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During the 1993 Refueling Outage, a modification to replace the. original type "TE" General Electric CB-REll breakers with General Electric recommended type l.

"TED" will proceed ("TE" type are no longer available). Surveillance testing I

has demonstrated that the breakers are showing evidence of' aging, and replace-ment before failure is prudent. The replacement will enhance the mechanical and electrical properties, and the seismic and quality features will exceed the original breaker qualifications.

A Technical Specification Change is requested because the replacement breaker l

trip range is based on 35 to 70% of nominal 120 Vac on the undervoltage l

release device coil. This results in a trip. voltage of 42 - 84 Vac or a design scram setting and tolerance of 63 plus or minus 21 Vac. This differs from the-existing scram setting and tolerance.of 52 plus or-minus 20 volts.

Attachment I contains proposed new Technical Specification pages. Attachment 2 l

contains existing Technical Specification pages marked up to show the proposed a

changes.

j Patrick M Donnelly

]

Plant ~ Manager 1

cc: Administrator, Region.III, USNRC NRC Resident Inspector - Big Rock Point.

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