ML20105C897
| ML20105C897 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 09/16/1992 |
| From: | Shelton D CENTERIOR ENERGY |
| To: | NRC OFFICE OF ADMINISTRATION (ADM) |
| References | |
| FRN-57FR36680, RULE-PR-50 57FR36680, NUDOCS 9209240052 | |
| Download: ML20105C897 (2) | |
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@ cruremon rpxmo 16Wn Donald C. Shelton 330 Maison Avenue Vce President Nadear 10edo, OH 436520]01
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Docket Number 50-346 3
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Serial Number 2091 2n September 16, 1992 y
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Chiet, Rules and Directives Reviev Branch United States Nuclear Regulatory Commission Vashington, D.C.
20555
Subject:
Comments On Proposed Generie Communication NRC Generic Letter! Analog-to-Digital Replacements Under the 10 CFR 50.59 Rule, 57 FR 36680, Dated August 14, 1992 i
Gentlemen Toledo Edison (TE), a subsidiary of Centerior Energy, is partial owner i
of and is responsible for operation of the Davis-Besse Nuclear Pover Station (DBNPS).
Toledo Edison has been authorized for power operation of the DBNPS since April 1977.
As a 10 CFR 50 licensee, TE has a vested interest in any policies the NRC may adopt which can affect the i
management and operation of a commercial nuclear power plant.
t Toledo Edison has reviewed the proposed NRC Generic Letter, published in the Federal Register on August 14, 1992 (57 FR 36680), entitled
" Analog-to-Digital Replacements Under the 10 CFR 50.59 Rule" and has the following comments regarding this issue.
The proposed generic letter vill prove to be counterproductive to industry efforts to upgrade existing analog systems. The generic letter suggests.a lack of confidence in licensees' ability to thoroughly consider some aspects of analog-to-digital upgrades when performing unreviewed safety question determinations.
As a result, the Staff considers all digital upgrade modification of safety related l
systems to be unreviewed safety questions, but offers.no definition or cciteria by which the industry or the NRC can reach a conclusion. This appears to circumvent the rulemaking process by denying licensees the option of following the existing 10 CFR 50.59 regulation.
9209240052 920916 PDR PR i
50.5957FR36680 PDR l
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o Docket Number $0-346 License Number NPF-3 Serial Number 2091 Page 2 In the proposed generic letter, the Staff raises a number of concerns.
As stated in the Federal Register notice, the most notable of these concerns involves the use of softvare.
Digital technology is fundamentally no more complex than existing hardvired technology.
Vhereas existing analog systems are typically modified via hardware changes, digital technology provides flexibility through the ability to modify systems by software changes.
The challenge is to control and validate software changes with the same degree of formality as hardware changes are currently controlled.
Existing design controls have been effectively adapted to the contrni of software.
There is ample evidence of successful integration of digital technology outside the nuclear industry in the aerospace, defense, and chemical industries.
Toledo Edison believes that rather than publishing the proposed generic letter, the Staff should consider publishing specific criteria concerning such issues as diversity, commercial dedication of digital electronics, administrative requirements for software verification, validation, end installation, pre-operational and post-maintenance testing, etc. to be used in the design of digital systems.
Digital systems which meet the NRC's criteria should not require further NRC review.
If the proposed generic letter is pursued, the NRC should clarify that it is only applicable to protection systems that are required to meet IEEE 279, such as_the Reactor Protection System and the Safety Features Actuation System.
Please refer any questions regarding these comments to Mr. Robert V. Schrauder, Manager - Nuclear Licensing, at (419) 249-2366.
Very truly yours,
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/ /- nt)c NC T/ c A. B. Davis, Regional Administrator, NRC Region III ect J. B. Hopkins, NRC Senior Project Manager V. Levis, DB-1 NRC Senior Resident Inspector C.- Y. Shiraki, USNRC USNRC Document Control Desk Utility Radiological Safety Board
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