ML20003C056

Interim Deficiency Rept Re Flammability of Suspended Ceiling Tile in Control Rooms at Facilities.Util Evaluating Ceiling Sys Design & Available Alternatives.Next Rept Will Be Transmitted by 810403

ML20003C056
Person / Time
Site:	Browns Ferry
Issue date:	02/20/1981
From:	Mills L TENNESSEE VALLEY AUTHORITY
To:
References
NUDOCS 8102260527
Download: ML20003C056 (2)

Text

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~. 'N F5 0' TENNESSEE VALLEY AUTHORITY Y9- N .' CH ATTANOOGA. TENNESSEE ? '4o1

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f3 February 20, 1981 L.

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t-Director of Nuclear. Reactor Regulation Attention: Mr. R. L. Tedesco, Assistant Director of Licensing Division of Licensing i U.S. Nuclear Regulatory Commission Washington, DC 20555

Dear Mr. Tedesco:

In the Matter of the .) Docket Nos. 50-259 Tennessee Valley Authority ) 50-260 ,

50-296 j In your. letter to H. G. Parris dated November 4, 1980, TVA was requested to provide information regarding the flammability of suspended ceiling tile in the control rooms at TVA nuclear plants.

An interim report was provided'to you for the Browns Ferry Nuclear l Plant on January 14, 1981.- Enclosed are the results of our investigations to date. We anticipate transmitting another report on this subject on or.before April 3, 1981.

Very truly yours, TENNESSEE VALLEY AUTHORITY I

.. L. M. Mills, Manager Nuclear Regulation and Safety Subscribed an' day sworn to p '

of ' --h '1981. I me this .

Y Notary Public

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, l My Commission Expires -

Enclosure I stossee ya7 o ~~e4 #, m-v-

e ENCLOSURE CONTROL ROOM CEILING TILE FLAMMABILITY BROWNS FERRY NUCLEAR PLANT The results of our evaluation of the control room ceiling tile at our Browns Ferry Nuclear Plant are provided below.

The suspended ceiling in the main control room at Browns Ferry is constructed of molded prismatic acrylic plastic panels. TVA has identified the acrylic plaatic used in the manufacturing process for these panels as being identical to Plexiglas G, as manufactured by Rohm and Haas, Incorporated. Plexiglas G is listed as a slow burning plastic material by Underwriters Laboratory (UL) as designated on UL cards M44933A and 3, and guide QLZQ2 dated March 18, 1971.

Thsse panels have not been tested under ASTM E84 test and are not listed by the UL in the Building Materials Directory. However, the following test results are known and are based on tests conducted on the acrylic plastic panel material according to the designated standards:

1. Minimum self-ignition temperature of 450 degrees C in accordance with ASTM D 1929-68.

2. Maximum smoke density rating of 10 in accordance with ASTM test D 2843-70.

3 Deflection temperature of 75 degrees C in accordance with ASTM test D 648-56.

4. Flar.mability rate of 1.9 inches per minute in accordance with ASTM D 635.

In response to recent NRC concerns we are evaluating the ceiling system designs and the alternatives available. Several alternatives which are under consideration are:-(1) removing all ceiling tiles, (2) modifying the ceiling with a combination of nontranslucent panels and new light fixtures, and (3) locating approved translucent material. Problems with each of the options have been

. raised which affect the ability to resolve this issue. These

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include glare problems when all panels are removed, potential HVAC problems due to the ceiling design acting as an air plenum, and l control board illumination problems if nontranslucent panels are

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( We do not have a final resolution of the problems at this time, but we are doing everything possible to devise the best acceptable solution. ./

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