ML19343D410

Forwards Clarification of Conformance W/Reg Guide 1.75.FSAR Will Be Augmented Accordingly

ML19343D410
Person / Time
Site:	LaSalle
Issue date:	04/30/1981
From:	Delgeorge L COMMONWEALTH EDISON CO.
To:	Schwencer A Office of Nuclear Reactor Regulation
References
RTR-NUREG-0519, RTR-NUREG-519, RTR-REGGD-01.075, RTR-REGGD-1.075 NUDOCS 8105040432
Download: ML19343D410 (4)

Text

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s~ .O, Commonwealth Edison O One First National P!aEa, Chicago. Ilkno Accress Recly to: Post Office Box 767 Chicago, Illinois 60690 a4 c3 s  ? :-

April 30, 1981 / p# # 5; A gg -:-

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Mr. A. Schwencer, Chief - =

Licensing Branch 2 Ok- l E3'C7

' F'"?'~// t; Division of Licensing / Y U.S. Nuclear Regulatory Commission \/c-D '

Washington, DC 20555

Subject:

LaSalle County Station Unit 1 Separation Audit of Electrical Equipment NUREG-0519 Section 1.8 Item 8 NRC Occket Nos. 50-373/374 R'eferences (1): B. J. Youngblood letter to D. Louis Peoples dated May 7, 1981.

(2): L. O. DelGeorge letter to B. J. Youngblood dated March 27, 1981.

(3): L. O. DelGeorge letter to B. J. Youngblood aated February 10, 1981.

Dear Mr. Schwencer:

Cer.monwealth Edison has performed the plant wide fielo audit of installea electric equipment and systems as defined in Enclosure 2 of Reference (1). The results of that audit were submitted to the NRC Staff in Reference (2). The scope of that audit, as defined by the Staff aid not incluae the audit of separation between Class lE and non-Class lE cables and between associated anc non-Class lE cabi es.

As was discussed with the NRC Staff (J. Knox, D. Thatcher ana A. Bournia) on February 6, 1981 and as documentea in Reference (3), the LaSalle County Station design criteria was developed prior to the development of IEEE-384(1974) and Regulatory Guide 1.75.

Although Appendix B of the FSAR was modifiea after that discussion with the Staff to clarify the basis of conformance with Regulatory Guide 1.75, and the plant design criteria was thought to have been understood by the Staff.

In order to resolve this apparent misunderstanding of the critiera implemented at LaSalle County, the FSAR will be augmented as show'n in Attachment 1 to further clarify our position. These materials also incluae the technical bases which Justify the alternate approach taken which is judged to satisfy the intent of 0

the applicable section of the Regulatory Position of RG 1.75. go\5 \

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f In the event'you_have'any.further questions in this'regara,

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.Very t'ruly yours,

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. L.-0. 0e1 George Nuclear Licensing Administrator Attachment-cc: NRC_ Resident Inspector LSCS 8

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ATTACHMENT 1 REGULATORY GUIDE 1.75 Ado the following information to the bottom of Page 8.1-95a submitted with FSAR Amendment 55 dated March, 1981:

IEEE Std. 184-1974, Section 4.6, requires that Non-Class lE cable trays be separated from Class lE cable trays by the following minimum separation requirements:

a. l' horizontally ano 3' vertically in cable spreading areas.

b. 3' horizontally and 5' vertically in general plant areas.

The LaSalle County Station criteria specifies that the minimum distance between safety-relateo and non-safety-related cable trays shall be 3" horizontally and l' vertically. Cable trays at LaSalle County Station were installed to this latter criterion prior to the issuance of IEEE-384.

Although LaSalle County Station criteria is less than that perscribed by IEEE-384, the LaSalle County Station cable tray installation is considered to be adequate for the following reasons:

a. There are no non-safety-related cable trays throughout the entire Reactor Bldg. and Primary containment.

b. There are no safety-related cable trays throughout the entire Turbine Bldg. and outlying structures (Service Bldg., Screen House, etc.)

c. Non-safety-related cable trays are installed in close proximity to safety-related caole trays only at a minimal number of locations in the Auxiliary Bldg.

d. In those few instances where non-safety-related cable trays come in close proximity to safety-related trays, only one division of safety-related trays are present in the room. The lone exception to this statement is the corridor between the diesel generator rooms ano the switchgear room. However, trays in this area will be covered with a flame retardant material as a result of the Fire Hazards Analysis.

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e. All cables used to interconnect non-safety-related circuits are the same high quality as that utilized in Class lE circuits; i.e., all non-safety-related cables comply with the requirements of IEEE-383-1974.

.Therefore, this. cable has been proven to be highly fire retardant by testing.

f.- Fire stops are installed in all cable trays, including non-safety-related' cable trays, where they penetrate walls and floors.

g. All cable trays installea at LaSalle County Station are, for the most part, solid bottom cable trays.

Therefore, where vertical stacking occurs, an additional barrier is provided between each layer of cable trays beyond that recognized by Section 5.5.1.3 of IEEE 384- 1974.

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