ML20204D687

Forwards Electrical,Instrumentation & Control Sys Branch Safety Evaluation Accepting Util 840925 Analysis Re Lesser Separation Between Class 1E & Certain non-Class 1E Circuits

ML20204D687
Person / Time
Site:	Comanche Peak
Issue date:	12/19/1985
From:	Knight J Office of Nuclear Reactor Regulation
To:	Burwell S Office of Nuclear Reactor Regulation
Shared Package
ML20204D619	List: ML20204D614 ML20204D687 ML20204D789
References
FOIA-87-62 NUDOCS 8703250545
Download: ML20204D687 (2)

Text

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,7 'o,, UNITED STATES i e o NUCLEAR REGULATORY COMMISSION a g rp WASHINGTON, D. C. 20555

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.MC 191985 MEMORANDUM FOR: Spotswood Burwell, Senior Project Manager PWR Project Directorate No. 5 FROM: James P. Knight, Assistant Director for PWR-A

SUBJECT:

SAFETY EVALUATION OF LESSER SEPARATION BETWEEN CLASS 1E AND CERTAIN NON-CLASS 1E CIRCUITS FOR COMANCHE PEAK UNIT 1 In accordance with your request, the Electrical, Instrumentation and Control Systems Branch has evaluated the lesser separation provided between Class IE $

and certain non-Class IE circuits for Comanche Peak Unit 1. These circuits were identified in the applicant's letter of September 25, 1984. We conclude that the analysis provided by the applicant to justify lesser separation between the above circuits is acceptable. 'Our safety evaluation of this subject is enclosed.

Y.

James P. nigh , A N ~istant Director

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for PPR-A

Enclosure:

As stated cc: B. Sheron D. Crutchfield G. Lainas V. Noonan F. Rosa J. E. Knight S. Weiss J. Calvo

-OcChopra

Contact:

0. Chopra x28528 8703250545 870319 PDR FOIA BAUMAN87-62 PDR '

, ENCLOSURE LESSER SEPARATION BETWEEN CLASS IE AND CERTAIN NON-CLASS 1E CIRCUITS COMANCHE PEAK UNIT 1 By letter September 25, 1984, the Texas Utilities Generating Company identified the non-Class IE public address system speaker cables and area radiation monitoring detector cables in the plant that are not separated from the Class IE wiring as recommended by IEEE-384 as endorsed by R.G. 1.75. For the cables identified, the applicant performed an analysis to demonstrate that the non-Class IE cables will not cause the failure of the adjacent Class IE cables.

Testing and/or analysis are acceptable methods for demonstrating adequate separation in accordance with the requirements of IEEE Standard 384 and the recomendation of P.G.1.75.

We have reviewed the analysis of the typical cases presented by the applicant and conclude that the area radiation monitoring detectors and the public address system speaker cables are . low energy level circuits which are designed to provide a maximum of 5 watts and 12 watts respectively under fault condi-l tion. Therefore, with this level of power, it is highly unlikely that any adjacent cables would be affected under a fault condition. Moreover, the Class l 1E circuits are nn in conduits which provide a barrier between the Class IE l circuits and the above low energy level circuits. This lesser separation is j provided only for short runs (18" for speaker cables and 6' for radiation l monitoring detector cables) when the cables come out of the conduits to be l connected to their respective devices. Therefore, any damage in the non-Chss IE circuits will be limited to the non-Class 1E and will not be propagated to i

nearby Class IE circuits. Based on the above, the staff finds there is reason-able assurance that electrical faults in the subject non-Class IE cables will not degrade Class 1E circuits. Therefore, the staff finds this concern accept-ably resolved.

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