ML20105C895

Comment Opposing Proposed Generic Ltr Concerning analog-to-digital Replacements Under 10CFR50.59

ML20105C895
Person / Time
Site:	Comanche Peak
Issue date:	09/14/1992
From:	William Cahill TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC)
To:	NRC
References
FRN-57FR36680, RULE-PR-50 57FR36680, TXX-92430, NUDOCS 9209240050
Download: ML20105C895 (2)

Text

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TUELECTRIC  ?

September 14, 199c, r1 Wilham J. CaMH. Jr.

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Chief, Rules and Directives Review Branch U. S. Nuclear Regulatory Commission Q Washington, OC 20555 @ q g

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SUBJECT:

7. n COMMENTS 0" PROPOSED GENERIC COMMUNICATION Ui NRC GENERit LETTER: ' ANALOG-TO-DIGITAL $ $

REPLACEMENTS UNDER 10 CFR 50.59

• 8  %

• 3 Gentlemen:

10 Electric is pleased to have the opportunity to provide comments to the proposed Generic Communication NRC Generic Letter: ' Analog to-Digital Replacements under 10CFR50.59,* published in 57 FR 36680 of the Federal Register.

The proposed generic letter sets forth the staff's position on the replacement of analog safety systems with digital microcomputer based safety systems.

The NRC is correct in believing that introducing technology to Nuclear Power Plants requires a calculated and methodical approach.

However, TU Electric believes that NRC's position that all replacements constitute an unreviewed safety question and thus cannot be performed in accordance within the guidance of 10CFR50.59 and without prior NRC approval is overly conservative.

The generic letter states that the staff's position is not meant to discourage the installation of digital systems. However, the position that all safety-related analog to digital replacements require review prior to implementation as unreviewed safety questions will create a bottleneck which will hinder the introduction of current technology into existing plants. A more appropriate position to assume is that of a partnership betwaan industry and the NRC so that the design criteria, reliability and c availability data, and the installation procedures may be jointly developed, The upgradeElectric Power Research instrumentation Institute and control (IC)(EPRI) has undertaken an initiative to systems in Nuclear Power Plants.

The initiative attempt.' to introduce current digital technology as well as advanced analog technoic,1y into several demonstration plants. EPRI, under the Integrated I ns t rumen t it i ot, and Control Upgrade Plan, is forming demonstration plant teams comprised of utility. EPRI, and vendor and equipment supplier personeel to define and address the problems with upgrading Nuclear Power Flants to current technology. Participation in the development process will provide regulatory input and allay many of the staff's concerns on dig'tal technology. NRC involvement and input into the 9209240050 920914 C FR36600 PDR

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3 development of the design processes and installation procedures will result j in licensee confidence that the upgrades can be implemented in an efficient manner and without long deloys.

The NRC should also look to the ef forts, successes, and lessons learned of i foreign utilities, and regulatory a_gencies such es the Canadian, French, and Japanese agencies in introducing current technology, h the proposed

generic letter the NRC enumerates various concerns which have the potential j to affect the safety function. Concerns, similar to those listed, affect j the installation of analog circuitry. However, the concerne affecting

) analog circuitry have been addressed through effective design reviews,

- specific industry guidance documents and administrative controls. The NRC l further singles out software as being of most notable concern. TV Electric agrees that software is the heart of the digital system. TV Electric can i but point to the successes of foreign programs in using digital safety-related systems. The EPRI initiative has a good discussion on the design reviews and controls employed by Electricite' de France as well as other foreign programs.

Current digital technology has been proven to be safe and reliable at

]' foreign utilities as well as in other segments of our society. Rather than j adopt the untimely position of the draf t generic letter, the NRC should i cooperate with the industry to facilitate the replacement of sometimes outmoded and not always supported technology with current digital technology.

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i Sincerely.

l William J. Cahill, Jr.

By l J." 5. Marshall Generic Licensing Manager i

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