ML20028G119

Forwards Two Pages Inadvertently Omitted from 821214 Transmittal of Addl Info Re Control & Protection Sys Interaction.Revised PSAR Pages Will Be Incorporated in Future PSAR Amend

ML20028G119
Person / Time
Site:	Clinch River
Issue date:	02/02/1983
From:	Longenecker J ENERGY, DEPT. OF, CLINCH RIVER BREEDER REACTOR PLANT
To:	Grace J Office of Nuclear Reactor Regulation
References
HQ:S:83:206, NUDOCS 8302070420
Download: ML20028G119 (3)

Text

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Department of Energy

, Washington, D.C. 20545 Docket No. 50-537 HQ:S:83:206 FEB 0 21983 Dr. J. Nelson Grace, Director CRBR Program Office Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C. 20555

Dear Dr. Grace:

i CLINCH RIVER BREEDER REACTOR PLANT - CONTROL AND PROTECTION SYSTEM INTERACTION

Reference:

Letter HQ:S:82:147, Longenecker to Check, " Instrumentation (Chapter 7) Working Meeting - Additional Information,"

dated Decenber 14, 1982 Enclosed are two pages that were inadvertently left out of our response to November item 1 transmitted by the referenced letter. The revised Preliminary Safety Analysis Report (PSAR) pages will be incorporated into a future PSAR amendment.

Any questions regarding the information provided. or further activities can be addressed to Mr. R. Rosecky (FTS 626-6149) or Mr. A. Meller (FTS626-6355) of the Project Office Oak Ridge staff.

Sincerely, W

Jo'n R. Longene er Acting Director, Office of Breeder Demonstration Projects Office of Nuclear Energy j Enclosure cc: Service List Standard Distribution Licensing Distribution j

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8302070420 830202 PDR ADOCK 05000537 A PDR

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i ,l ENCLOSURE Hr on.,dling and Display system alerts the operator to significant deviations h tween redundant plant parameter for the RSS.

RSS analog Instrtraentation used to monitor a reactor or Centrol end Protection ~Svstem Interaction l The Reactor Shutdown System and the Plant Control System have been designed +o assure stable reactor plant operation and to protect the reactor plant in the l event of worst case postul ated Plant Control System f ail ures. The RSS is designed to protect the plant regardless of control system action or lack of action. Isolation devices will be used between protection and control functions. Where this is done, all equipment common to both the protection l and control function is classified as part of the RSS. Equipment sharing

' between protection and control is minimized. Where practical, separate equipment (sensors, signal conditioning, cabt Ing penatrations, raceways,

cabinets, monitoring etc.) is provided. [T nr-shacing of commnaa+r Le . w i-I lead to a situation where a sinnt a '

L... iniTsate, Ident through i l Pl an' rW ' 0, s e.m mal function and prevents the appropriate RS Perfcdfc Tes+fna EG!'*CE WITA {'"' 'E.h' Ik l

• l The Reactor Shutdown System is designed to permit periodic testing of its functioning including actuation devices during reactor operation. in the Primary RSS, a single Instrument channel is testod by inserting a test signal I et the sensor transnitter and verifying it at the comparator output. A logic l train is tested by inserting a very short test signal in 2 comparator inputs gg and verifying that the voltage en the scram breaker trip coils decrease, q) Because of the tirc response of the andervoltage rolay coils of the scran I breakers and very short duration of the test signal, the reactor does not j trip. In the Secondary RSS, an Instrument channel can be tested f rom sensor 1

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7.2-15a Anend. 73 Nov. 1982

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The sharing of components does not lead to a situation where a single event both initiates'an 1ncident through Plant Control System' malfunctions and-

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prev.ents reactor shutdown system action. Where such a malfunction in a shared component requires action by the shutdown systems this will take ,

place with any resulting core transient 'no greater than that associated with -

{ _ the normal operation of the shutdown systems. Also, this performance - -

'will not be affected by the removal from service of a shutdown system channs1' for testing and the simultaneous presence of a single random' failure in the

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shutdown system in addition to the malfunction which initiates the transient .

(both are assumed to occur in the particular shutdown system affected.by the ,

malfunction) . . . . .. , ,

Median select circuits are used by the plant control syst' ems for those

' instrumentation channels comon to both protection and control systems. This

' allows continued. operation of the control systems during testing of the

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r'eactor shutdown systems. These circuits will be seismically qualifie'd for" '

,an operational basis earthquake. .

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