ML20054L241

Forwards Revised Response to Question 421.09 Per . Single Failure from Blockage in Instrument Line Will Not Affect Protective Sys

ML20054L241
Person / Time
Site:	Clinch River
Issue date:	06/30/1982
From:	Longenecker J ENERGY, DEPT. OF
To:	Check P Office of Nuclear Reactor Regulation
References
HQ:S:82:062, HQ:S:82:62, NUDOCS 8207070300
Download: ML20054L241 (2)

Text

.

Department of Energy Washington, D.C. 20545 Docket No. 50-537 HQ:S:82:062 JUN 3 01982 Mr. Paul S. Check, Director CRBR Program Office Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C. 20555

Dear Mr. Check:

REVISED RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION

Reference:

Letter HQ:S:82:046, J. R. Longenecker to P. S. Check, " Responses to Request for Additional Information," dated June 14, 1982 Enclosed is a revised response to Question 421.09. Please delete the previous two-page response to this question submitted by the reference letter and replace it by the one-page enclosure.

Sincerely,

rb .

npithW hhnR.Longenggker Acting DirectoV, Office of the Clinch River Breeder Reactor Plant Project Office of Nuclear Energy Enclosure cc: Service List Standard Distribution Licensing Distribution i

~

r207070300 820630 PDR ADOCK 05000537 A pop

82-0260

, , , Page 13 [8,22]i25 OUESTICN CS 421.09 Identify where instrument sensors or transmitters supplying information to more than one protection channel, to both a protection channel and control channel, or to more than one control channel, are located in a ccmuco .

instrument line or connected to a ccanon instrument tap. % e intent of this iten is to verify that a single failure in a canon instrument line or tap (such as break or blockage) cannot defeat required protection systen redundancy.

RESPCNSE Instrumentation sensors or transmitters located in instrument lines or connected to instrument taps do not supply more than one protection channel or control channel. %erefore, the required protection action will not be defeated by a blockage or breakage of an instrument line or instrument tap.

However, there are instrument sensors and transmitters located in instrument lines or connected to instrument taps which provide signals to both a protection channel and a control channel. In all cases, both the protection and control function has a three channel inp1t redundancy. %ese rechndant channels use separate instrument lines and taps. For example, the superheater steam ficw Venturi provides three separate taps located 1200 apart for the redundant sensors. Bus, a single failure resulting frcm a blockage or a breakage in an instrument line or tap will not defeat the required protective 4

action.

CCS421.09-1 Ar.cnd. 69

-