ML20151A778

Deficiency Rept Re nonwater-tight Penetration Seals. Initially Reported on 880609.Investigation Incomplete.Next Rept Expected by 880818

ML20151A778
Person / Time
Site:	Vogtle
Issue date:	07/06/1988
From:	Rice P GEORGIA POWER CO.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
GN-1468, NUDOCS 8807200117
Download: ML20151A778 (1)

Text

Georgia Fbwer Company Post Off,ce Ben 282 Waynesboro. Georgia 30830 tr . Teleptee 404 554-9961 Extension 3413

, 404 724-8114 Extens+on 3413 L

P, D. Ric. Georgia Power

$eYoN July 6, 1988 * * "* * ""

U. S. Nuclear Regulatory Comission Attn: Document Control Desk File: X78G03-M145 Washington, D. C. 20555 Log: GN-1468

Reference:

Vogtle Electric Generating Plant - Unit 2; 50-425 Non-Water Tight Penetration Seals (M145)

On June 9,1988 C. W. Hayes, Vogtle Quality Assurance Manager, notified Mr. M. V. Sinkule, USNRC-Region II, of a potentially reportable condition as defined by the reporting requirements of 10CFR50.55(e). This condition involved Unit 2 penetration seals which were found not to be water tight.

These penetration seals consist of a Dow-Corning silicone foam material supplied and instelled by ICMS which is poured in place to form a fire barrier where comodities penetrate a fire rated floor slab or wall.

However, recent tests have shown that water can seep between the foam .

I and the concrete floor slab in the corners of square or rectangular penetrations.

Seepage of water has also been observed between bundled '

electrical cables penetrating the silicone foam seal. This seepage appears to be due to a slight shrinkage of the silicone foam possibl,y  !

attributable to several factors such as offgassing during the curing process or significant ambient temperature changes. The silicone material does not appear to bond very well to concrete, steel or electrical cable jacket material. Therefore, shrinkage could open a leakage path which would allow seepage of water. The effectiveness of the seal as a fire barrier is not expected to be affected since heat would cause the entrapped gasses and, thus, the seal to expand.

Georgia Power Company's investigation into this concern is not yet comgivte. A second interim report is scheduled to be submitted to the NRC prior to August 18, 1988 providing a re information.

This correspondence contains no proprietary information and may be placed in the NRC Public Document Room.

8807200117 880706 PDR S ADOCK 05000425 '

PtJu - .

P. D. Rice PDR/sem xc: USNRC - Region II Suite 2900 101 Marietta Street, N. W.

Atlanta, GA 30323 H. G. Baker, Jr. D. R. Altman L. T. Gucwa R. P. Mcdonald J. A. Bailey C. W. Hayes R. H. Pinson G. Bockhold, Jr. R. W. McManus fp E. D. Groover G. R. Frederick Sr. Resident (NRC)

C. T. Moore J. E. Swartzwelder D. H. Smith (OPC)

R. A. Thomas A. B. Gallant J. E. Joiner (TSLA)

NORMS