ML20099B955

Ro:Fire Penetration Seal Degraded & Inoperable for More than 7 Days.Caused by Voids in Seal Structure.Hourly Fire Watch Established & Mod to Seal Completed on 920720

ML20099B955
Person / Time
Site:	Point Beach
Issue date:	07/29/1992
From:	Link B WISCONSIN ELECTRIC POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
CON-NRC-92-084, CON-NRC-92-84 VPNPD-92-269, NUDOCS 9208030188
Download: ML20099B955 (2)

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VPNPD-92-269 NRC-92-C84 July 29, 1992 U. S. HUCLEAR REGULATORY COMMISSION Document-Control Desk Hall Station P1-137 Washir.gton, D. C. 20555 Gentlemen:

DOCKETS 50-266 AND 50-3Q1

, 4CEEDIliG SEVEN DAYS WITH Ali INOPERABLE FIRE BARRIER PENETBATION SEAL POINT BEACH NUCLEAR PLANT. UNITS 1 AND 2 This letter is submitted in accordance with the requirements of ,

Point Beach Nuclear Plant Technical Specification 15.3.14, ' Fire Protection System," Section C.1.b. (4), due to a fire barrier penetration seal being in a degraded condition for greater than seven days while modifications to the seal were .,oing performed.

This letter summarizes the cause of the degraded condition and the compensatory measures taken in response to the degradation of the fire barrier penetration seal at Point Beach Nuclear Plant.

Point Beach Non-Conformance Report (NCR) N-09-249 was initiated on September 29, 1989, when a technical evaluation performed by the plant fire protection engineer revealed that eight fire barrier penetration seals did not contain the optimally desired number of divider boards. Divider boards are used to subdivide one large penetration seal into several individuel seals in order to maintain the overall strength of the seal. Tlv area of each individual seal should not exceed 2330 square inches, based on the maximum overall seal size for cable tray penetrations tested for acceptance by the American Nuclear Insurers. The non-conformance report evaluation concluded that the identified seals would continue to provide full duration fire resistance pending installation of the divider boards and, therefore, were determined to remain operable.

Hodification Request, HR 90-084, was initiated in response to NCR N-89-249. This moalfication required the installation of divider h boards in eight seals. Based on their relative importance, these AO seal modifications were scheduled to be performed following the V completion of the seal modifications that were required to '#

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I et NHC Document Control Desk July 29, 1992 Page 2 support the installation of our alternate shutdown system.

Installation of the divider boards in the eight seals identified in MR 90-084 began on June 25, 1991.

During the divider board installation in seal M-7-3-23-E16, voids were found in the seal structure. A technical evaluation performed by the plant fire protection engineer determined that the seal-with the existing voids was operable. However, a decision was made to remove and reinstall the entire seal, which expanded the scope and tino duration of the repair. This seal is located on the eight-foot elevation of the control building above security door 14 leading to the 4160 Volt vital switchgear room.

Because this seal measures 9 feet by 3.5 feet, the removal and reinstallation of the seal were not completed within the seven-day time period specified in Technical Specification 15.3.14.C.1.b.(4). The modification of this seal commenced on ,

June 29, 1992, and was cce.ipleted on July 20, 1992. I Compensatory measures established during the removal and reinstallation period for M-7-3-23-E16 included the establishment of an hourly fire watch to meet the requirements of Technical Specification 15.3.14.C.1.3. Also, as part of the installation process, one-inch hotboard (a fire resistant mineral board) was used as a dataming material on one side o. the seal. While this arrangement has not been specifically fire-tested and approved as a temporary fire' seal, the hotboard can serve as a substantial thermal barrier. Additionally, the rooms on both sides of this seal are equipped with automatic fire detection and halon suppression systems.

Please contact us should you have any-questions or require additional information.

Sincerely, I

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Bob Link Vice President l Nuclear Power l-Copies to NRC Regional Administrator, Region III NRC Resident Inspector L