ML19273B936

LER 79-059/03L-0 on 790517:unsealed Hole Discovered in Fire Barrier Floor.Caused by Uncompleted Survey of Work Items.Gap Sealed & Training Meeting Held W/Maint & Const Supervisors

ML19273B936
Person / Time
Site:	Davis Besse
Issue date:	06/13/1979
From:	Naylor R TOLEDO EDISON CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML19273B935	List: ML19273B934 ML19273B936
References
LER-79-059-03L, LER-79-59-3L, NUDOCS 7906180551
Download: ML19273B936 (3)

Text

U.S. NUCLEAR REGULATORY COMMISSION lRC F ORM 366 77)

- LICENSEE EVENT REPORT (PLEASE PRINT OR TYPE ALL REQUIRED INFORMATION)

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.o 2 l On May 17, 1979, a hole was discovered through a fire barrier floor which had not beerl I

Technical Specification 3.7.10 requires all penetration fire barriers to be

,o 3 l sesled.

The hole was through the floor of essential low voltage i io 4 l functional at all times.

l fo s l switchgear room 428. Conduit filled most of the hole, but the gap between the hole There was no danger to the healtn and safety of 1 o ls l l and the conduit had not been sealed.

l o 7 l the public or station personnel. The gap was no wider than 3/8 inch,and there were l

(NP-33-79-61) 80 o a l no combustible materials in the immediate area.

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N l X lgyg l35Z lg l42Nl@ 44 33 34 l36Zl@ 31 40 41 43 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS h i Station personnel did not complete a survey of all previous 1v completed work items lilO l l  ;

li ;i j l since this hole was drilled on 10/2/78, and a similar occurrence was reported on 11/24/78. The gap was sealed within one hour of notification by QC personnel.

ST 5016.11 is being conducted to verify no further such violations exist. A trainingj

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meeting was held with maintenance and construction supervisors. 80 1 8 9 015 O FY DISCOVERY OESCRIPTION

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1 6 HELE ASED@OF RELE ASE@l 8 9 10 11 44 45 PERSONNEL EXPOSURES NUVBER TYPE DESCRIPTION 1 7 l0l0l0 NA PERSONNE L INJUT IES NUYBE R D ESCRIP TION l i s 8 9 10l0l0l@l NA 11 12 80 7

LOSS OF OR DAMAGE TO FACILITY TYPE D E SC HIP TION l i 9 W @l10 NA 80 7 H 9 NRC USE ONLY '

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Richard W. Naylor PHONE: 419-259-5000. Fvt_ 2Q

TOLEDO EDISON COMPANY DAVIS-BESSE NUCLEAR POWER STATION UNIT ONE SUPPLEMENTAL INFORMATION FOR LER NP-33-79-61 DATE OF EVENT: May 17, 1979 FACILITY: Davis-Besse Unit 1 IDENTIFICATION OF OCCURRENCE: Failure to fire block a core drill through a fire barrier, Conditions Prior to occurrence: The unit was in Mode 5, with Power (MWT) = 0, and Load (Gross MWE) = 0.

Description of occurrence: On May 17, 1979, it was discovered that during the imple-mentation of Facility Change Request (FCR)78-373, which was the installation of several new electrical system feeders, a core drill had been made through the floor of essential low voltage switchge4 r room 428. Technical Specifcation 3.7.10 requires all penetration fire barriers protecting safety related areas shall be functional at all times. The Action Statement requires that if a fire barrier is not functional, a continuous fire watch be established on at least one side of the affected penetration within one hour.

This penetration remained unblocked from approximately October 2,1978 until May 17, 1979.

This report is being submitted in accordance with Technical Specification 6.9.1.9c.

Designation of Apparent Cause of Occurrence: The instructions for the implementation of FCR 78-373 did not identify the significance of a fire wall and also failed to state any requirements of the Technical Specification 3.7.10. When a previous similar occurrence was discovered (see Licensee Event Report NP-33-78-137), the Facility Change Request was modified to assure all subsequent work was performed in accor-dance with technical specifications. However, plant personnel did not complete a comprehensive survey of all previously completed work items to insure that the re-quirements were met.

Analysis of Occurrence: There was no danger to the health and safety of the public or to station personnel. The fire barrier affected only provides protection for one of two separate essential buses. The only open path was the gap between the conduit and the hole in the floor which was not wider than 3/8 inch. There were no combus-tible materials in the immediate area.

LER #79-059 2353 302

TOLEDO EDISON COMPANY DAVIS-BESSE NUCLEAR POWER STATION UNIT ONE SUPPLEMENTAL INFORMATION FOR LER NP-33-79-61 PAGE 2 Corrective Action: Within one hour of notification from station Quality Control personnel, the penetration was blocked. Surveillance Test ST 5016.11 is being con-ducted to identify any further unblocked fire barrier penetrations. An information meeting was conducted with maintenance and construction supervisory personnel instructing them on fire barrier requirements and of the station procedures pertain-ing to the proper method of working on fire barriers.

Failure Data: There has been one previously reported similar occurrence, see Licensee Event Report NP-33-78-137.

LER #79-059 .