ML20034D505
| ML20034D505 | |
| Person / Time | |
|---|---|
| Issue date: | 12/09/1992 |
| From: | Taylor J NRC OFFICE OF THE EXECUTIVE DIRECTOR FOR OPERATIONS (EDO) |
| To: | Beard P FLORIDA POWER CORP. |
| References | |
| FRN-57FR36680, RULE-PR-50 NUDOCS 9212180031 | |
| Download: ML20034D505 (2) | |
Text
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^t UNITED STATES 3
.i NUCLEAR REGULATORY COMMISSION I
WASHINGTON, D.C. 20566
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December 9, 1992 Mr. P. M. Beard, Jr.
Senior Vice President Nuclear Operations Florida Power Corporation Post Office Box 219 Crystal River, Florida 32623-0219
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Dear Mr. Beard:
SUBJECT:
COMMENTS RELATED TO 10 CFR 50.59 AS APPLIED TO ANALOG TO DIGITAL REPLACEMENTS Your letter of October 23, 1992, to Chairman Selin, provided comments regarding the proposed generic letter (GL) on 10 CFR 50.59 as applied to l
l analog to digital safety system modifications. The proposed generic letter identified a number of substantive safety concerns and regulatory issues that l
are associated with the design and installation of digitally-based safety i
systems.
Resolution of these concerns may require prior NRC approval pursuant to 10 CFR 50.59. We also believe that digitally-based modifications can improve the reliability and safety of some existing analog instrumentation and control systems. However, such improvements can only be obtained by proper system implementation that includes careful consideration of the differences in design between analog and digital systems (e.g., software, plant environ-l ments, architecture), plant and operator interfaces, and the licensing bases.
We agree that the draft generic letter could be interpreted such that all analog to digital replacements' constitute an unreviewed safety question.
This was not the intent. We expect to work with the industry through NUMARC and l
EPRI in developing appropriate guidance for-licensee 50.59 reviews which specifically addresses the concerns described in the proposed' generic letter.
We are currently considering your comments along with all other comments we received on this proposed generic letter in accordance with NRC procedures for developing and issuing generic communications. The NRC staff will continue to meet with representatives from NUMARC and the industry to discuss guidance which would better define the scope of.a licensee's. review pursuant to 10 CFR 50.59 to determine whether a modification does not constitute an unreviewed i
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P. M. Beard, Jr. safety question. The next public meeting with NUMARC is scheduled for December 9, 1992, at NRC Headquarters.
Sincerely, Original Signed Bb James M. Taylor James M. Taylor Executive Director for Operations cc:
W. Rasin, NUMARC J. Taylor, EPRI DISTRIBUTION:
Central File HICB R/F GGarten, NRR JMauck, NRR i
SNewberry, NRR CThomas, NRR BBoger, NRR WRussell, NRR FMiraglia, NRR TMurley, NRR JTaylor, EDO JSniezek, EDO HThompson, EDO JBlaha, EDO PNorry, ADM EDO R/F' EDO (GT 0008243)
NRR Hailroom (GT 000B243)
, PORI
- See previous concurrence 0FC HICB:DRCH HICB:DRCH Tech. Ed.
C:HICB:DRCH DD:DRCH NAME GGarten:ng JMauck SNewberry CThomas 11 11/23/92*
. /23/92*
DATE 11/20/92*
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m NAME BBoger WRussell FMirig$a kurley JTa [
DATE 11/23/92*
11/30/92*
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/ 2/ @92 0FFICIAL RECORD COPY Document Name: gt8243. sam
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