LD-87-051, Provides Design Info to Support Conclusion That Sys 80R in Compliance W/Atws Rule.Requests Closure of Issuance on CESSAR - F Docket.Response to NRC Evaluation of CEN-315,Sys 80R Encl

Provides Design Info to Support Conclusion That Sys 80R in Compliance W/Atws Rule.Requests Closure of Issuance on CESSAR - F Docket.Response to NRC Evaluation of CEN-315,Sys 80R Encl

ML20235G517
Person / Time
Site:	05000470
Issue date:	09/18/1987
From:	Scherer A ABB COMBUSTION ENGINEERING NUCLEAR FUEL (FORMERLY
To:	Miraglia F NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM), Office of Nuclear Reactor Regulation
Shared Package
ML20235G520	List: LD-87-051, Provides Design Info to Support Conclusion That Sys 80R in Compliance W/Atws Rule.Requests Closure of Issuance on CESSAR - F Docket.Response to NRC Evaluation of CEN-315,Sys 80R Encl ML20235G994
References
LD-87-051, LD-87-51, NUDOCS 8709300085
Download: ML20235G517 (2)

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September 18, 1987 LD-87-051 Docket No. STN 50-470F l

Mr. Frank J. Miraglia Associate Director for Projects Office of Nuclear Reactor Regulation Attn: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555 i

Subject:

Compliance With the ATWS Rule

References:

(A) NRC Letter, D. M. Crutchfield to R. W. Wells, dated, August 4,1986 (B) C-E letter LD-87-012, A. E. Scherer to F. J. Miraglia, dated February 27, 1987

Enclosure:

CEN-362, R" Response to the NRC's Evaluation of CEN-315 for System 80 ", dated September,1987

Dear Mr. Miraglia:

The purpose of this letter is to provide sufficient design information to support the conclusion that System 80Ris in compliance with the Anticipated Transient Without Scram (ATWS) Rule and to request that the issue be closed on the Combustion Engineering Standard Safety Analysis Report - FSAR (CESSAR-F) docket. >

Reference ( A) provided the Staff's evaluation of CEN-315 " Summary of the Re Diversity Between the Reactor Trip System and the Auxiliary Feedwater m e ca Actuation System". In that evaluation the Staff indicated that it was not E8' clear, from the information provided, that sufficient diversity existed R@ between the Auxiliary Feedwater Actuation System (AFAS) and the Reactor mo Trip System (RTS) for the System 80 design.

n s:

$8 Additional design information to describe System 80 compliance with the gg ATWS Rule was then submitted to NRC [ Reference (B)]. Specifically, we n described the safety systems which are designed to protect the plant and

$x mitigate the consequences of an ATWS event. Reference (B) also g described a proposed modification to CESSAR-F to reflect the addition of control grade circuitry to allow the Supplementary Protection System (SPS) to trip the Control Element Drive Mechanism motor generator output load Add'. L fo #j>N eonj esrino6 s P M8 4, [0 0 i

f Poker Systems (65 %6 1

! {* g 1000 Prospect Hdi Road Post Office Box 500 (203) 688-1911 Telex: 99297 gg NRR doe kombustion T& B Engineering, Inc. lgg . g windsor. connecticut 06095 0500 N NY

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Mr. Frank J. Miraglia ' LD-87-051 l September 18, 1987 Page 2 ]

i contactors. This design modification would establish an SPS reactor trip .l which is diverse and completely independent from the existing RTS.- Since l the SPS is also diverse and independent from the AFAS and since SPS I would also initiate a turbine trip diverse and independent of the RTS, we  :

concluded that the System 80 design described in CESSAR-F, when modified as described, will meet the ATWS Rule.

Consistent with Staff guidance, we believe that the ATWS Rule require-ments for diversity between the AFAS and RTS are satisfied if each AFAS component has a degree of diversity from its counterparts in at least one . ,

of the RTS trip paths. . The enclosed report, CEN-362, provides design j specifics in order to demonstrate, in detail, the level of diversity which l exists between the RTS and AFAS. As a result of the analysis, I summarized in this report, Combustion Engineering has confirmed that the i SPS is diverse from the AFAS and, therefore, that System 80, as modified by Reference (B), will meet the ATWS Rule. l We request the staff's prompt review and concurrence on System 80's compliance with the ATWS Rule, so that plant specific approvals may q proceed. In order to assist you in your review, we would be pleased to  !

support an early meeting with members of the Staff. If I can be of any additional assistance in this matter, please do not hesitate to call me or T. ]

L. Cameron of my staff at (203) .285-5217. I Very truly yours, COMBUSTION ENGINEERING, INC.

A. E cherer Director y Nuclear Licensing i k

AES:ss Enclosure I

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