ML19276H539

Forwards LER 79-028/03L-0

ML19276H539
Person / Time
Site:	Cooper
Issue date:	11/05/1979
From:	Lessor L NEBRASKA PUBLIC POWER DISTRICT
To:	Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML19276H540	List: ML19276H539 ML19276H542
References
NUDOCS 7911290383
Download: ML19276H539 (2)

Text

o COOPER NUCLEAR STATION

,,0. Box 98, BROWNVILLE. NEBR ASKA 68 321 Nebraska Publ.ic Power D. is tr.

ic t 1 ELE -o~E i.o2> .2s.3.i t CNSS790554 November 5, 1979 Mr. K. V. Seyfrit U.S. Nuclear Regulatory Commission Office of Inspection and Enforcement Region IV 611 Ryan Plaza Suite 1000 Arlington, Texas 76011

Dear Sir:

This report is submitted in accordance with Section 6.7.2.B.2 of the Technical Specifications for Cooper Nuclear Station and discusses a reportable occurrence that was discovered on October 8, 1979. A li-censee event report form is also enclosed.

Report No.: 50-298-79-28 Report Date: November 5, 1970 Occurrence Date: October 8, 1979 Facility: Cooper Nuclear Station Brownville, Nebraska 68321 Identification of Occurrence:

A condition which lead to operation in a degraded mode permitted by a limiting condition for operation established in Section 3.19.B of the Technical Specifications.

Conditions Prior to Occurrence:

The reactor was at a steady state power level of approximately 95%

of rated thermal power.

Description of Occurrence:

While inspecting the cable spreading room it was noted that a four inch diameter pipe sleeve in the fire wall between the cable spreading room and the cable expansion room was not properly sealed. ') } } Designatio5 cf Apparent Cause of Occurrence: Inadequate control of installation of fire seals during a microwave communications system installation in December 1978. y/ Vw\ 7911200 231s*35

_ _v Mr. K. V. Seyfrit November 5, 1979 Page 2. Analysis of Occurrence: The four inch sleeve, located in the wall between the cable spread-ing room and the cable expansion room, carries two 1 inch conduits through it. One conduit contains control cable for reactor re-circulation motor generator set ventilation flow indication. The other conduit contains cable for microwave communication. The space inside the four inch sleeve and outside of the two one inch conduits was not adequately sealed. The possibility of a fire starting in this area is minimal because no combustible material was present. The cable spreading room is equipped with an auto-matic sprinkler system which could extinguish a fire if one started. The possibility of a fire spreading through the unsealed sleeve was remote because the sleeve contained no combustible material. This occurrence presented no adverse effect to public health and safety. Corrective Action: The four inch sleeve was immediately sealed and an adequate fire barrier established. All remaining sleeves in this area were inspected and verified to be properly sealed. The Technical Spec-ifications also require that the penetrations in the cable spread-ing room be inspected every 18 months. This event was discussed with the appropriate personnel. Sincerely,

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a' - 4-se- , L. C. Lessor Station Juperintendent Cooper Nuclear Station LCL:cg Attach. 1421 ?21}}