ML20249B236
| ML20249B236 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 06/12/1998 |
| From: | Langenbach J GENERAL PUBLIC UTILITIES CORP. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| 1920-98-20235, NUDOCS 9806220215 | |
| Download: ML20249B236 (2) | |
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GPU Nuclear,Inc.
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Route 441 South NUCLEAR Post Office Box 480 Middletown, PA 17057-0480 TeI717 944-7621 June 12,1998 1920-98-20235 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555 Gentlemen:
Subject:
Three Mile Island Nuclear Station, Unit I (TMI-1)
Operating License No. DPR-50 Docket No. 50-289 Thermo-Lag Fire Barrier Seismic Capability As a result of a recent.NRC inspection finding at Oyster Creek Nuclear Generating Station regarding incomplete design verification of calculations, GPU Nuclear committed to review the current status of calculations to determine if the design verification of any other completed
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calculations remained open. This review identified a discrepancy with respect to the lack of O
j design verification involving a seismic analysis for Thermo-Lag installations. Due to concerns involving structural properties of Thermo-Lag material, GPU Nuclear had performed additional tests of the material properties and analysis of typical Thermo-Lag installations at TMI-l. GPU 4
Nuclear produced a calculation, based on this testing and analysis, that demonstrates that the /I 2f Thermo-Lag conduit and box configurations at TMI-l will not fall and damage safety related equipment in a postulated seismic event, as described in GPU Nuclear letter to the NRC dated October 31,1995 (C311-95-2456). This calculation was performed in October 1995; however, the design verification had not been completed and as a result the original calculation was never formally released.as a design record. This calculation is being updated to address design verification concerns and additional Thermo-Lag configurations.
At the present time, GPU Nuclear Calculation No. C-1302-814-E540-003, Revision 0, has been completed, design verified, and issued on May 28, 1998. The scope of this calculation includes Thermo-Lag configurations installed with attached steel banding to structural volumes such as cable tray and conduit and their supports, and box configurations. The results of this calculation confirm the seismic capability of these Thermo-Lag installations as originally described in GPU Nuclear's letter to the NRC dated October 31,1995 (C311-95-2456).
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l-1920-98-20235 Page 2 An additional calculation is being performed to reevaluate the seismic capability of the balance of the l
installed Thermo-Lag configurations. The scope of this calculation will include assemblies attached with wires instead of steel bands, assemblies not mounted against a structural volume such as a tray, conduit, or electrical box, box configurations around valves, conduit "T" wraps, and miscellaneous assemblies around suppons and equipment anchor plates. This calculation will be completed and design verified by July 15,1998. A limited number ofinstalled Thermo-Lag assemblies may require a walkdown assessment of seismic capability. This assessment will also be completed by July 15,1998, ifrequired. GPU Nuclear will submit a summary of the results of this work by July 31,1998.
If additional information is required, please contact Mr. David J. Distel, GPU Nuclear Licensing and Regulatory Affairs, at (973) 316-7955.
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2 Sincerely, M)0N James W. Langenbach Vice President and Director, TMI cc: Administrator, Region I TMI Senior Resident Inspector TMI-l Senior Project Manager i
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