ML20095A774
| ML20095A774 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 12/01/1995 |
| From: | George Thomas DUQUESNE LIGHT CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| GL-92-08, GL-92-8, NUDOCS 9512080010 | |
| Download: ML20095A774 (2) | |
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Beaver Valley Power Station She ping rt PA 15077 0004 (412) 643-8069 FAX December 1, 1995 GEOFIGE S. THOMAS -
les Se es j
Nuclear Power Division i
l U. S. Nuclear Regulatory Commission 4
Attention: Document Control Desk i
Washington, DC 20555-0001
Subject:
Beaver Valley Power Station, Unit No. 2 I
Docket No.56-412, License No. NPF-73 Response to Follow-up Request for l
Additional Information Regarding Generie Letter 92-08, "Thermo-Lag 330-1 Fire Barriers" a
I
References:
- 1. NRC Letter to DLC dated September 28,1995, " Responses to Requests for Additional Information Regarding NRC Generic Letter 92-08, BVPS Unit 2" (TAC No. M85517).
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- 2. DLC Letter to NRC dated March 23,1995, " Response to Follow-up to the Request for Additional Information Lgarding Generic Letter 92-08, Thenno-Lag 330-1 Fire Barriers."
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- 3. DLC Letter to NRC dated December 22,1994, " Response to 10 CFR 50.54(f) Follow-up to the Request for Additional Information Regarding Generic Letter 92-08, Thermo-Lag 330-1 Fire Barriers."
In response to the Nuclear Regulatory Commission's (NRC's) follow-up request for additional information (Reference 1) regarding Generic Letter 92-08, "Thermo-Lag 330-1 Fire Barriers," for the Beaver Valley Power Station (BVPS) Unit 2, the below l
information is provided.
A preliminary ampacity derating evaluation has been conducted of the Thermo-Lag protected raceways necessary for safe shutdown. The circuits protected with a one hour fire barrier were detennined to have adequate capability.
This is based on a j
comparison between our calculation of allowable derating factors that can be tolerated by safe shutdown circuits and the results identified in the Texas Utility Electric (TUE) safety evaluation dated June 14,1995. Additional evaluations of the TUE-tested configurations will be conducted to ensure they are representative of the configurations utilized at BVPS Unit 2. For the circuits protected with a three hour fire barrier, screening criteria will be e9.ablished using the Neher-McGrath methodology to evaluate the heat transfer characteristics of the materials in selected raceway assemblies, and individual raceway configurations will be compared against the screening criteria.
Completion of the subsequent evaluations of Thermo-Lag ampacity derating will parallel the schedule for final resolution of the Thermo-Lag fire barrier issues which is targeted for completion by j
the end of 1996.-
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Beaver Valley Power Stati:n, Unit No. 2 Response to Follow-up Request for Additional Information Regarding Generic Letter 92-08, "Thermo-Lag 330-1 Fire Barriers" Page 2 Additionally, in a letter from the NRC to the Nuclear Energy Institute (NEI) dated October 20, 1995, it was identified that plant-specific responses to the questions regarding Thermo-Lag chemical properties were needed to ensure that the Thermo-Lag -
products in use are represented by the population of samples that were tested by NEI. As noted in Reference 2, Duquesne Light Company (DLC) participated in the NEI/ industry program and provided samples from BVPS Unit 2 in-plant installations and warehouse stock material as part of this effort. The industry program concluded that the Thermo-Lag material was consistent in chemical composition. Therefore, the degree of chemical consistency with other industry samples adequately demonstrates that Unit 2 materials are 4
equivalent to the materials tested in the industry fire endurance test progrant. This should resolve concerns concerning chemical composition of Thermo-Lag fire barriers installed 4
at BVPS Unit 2.
Additional generic testing of various Thermo-Lag configurations, including boxed j
i enclosures, is scheduled to be conducted by NEl in December,1995. The results of the i
testing will be factored into our overall program for demonstrating adequacy of fire i
barriers.
Reference 2 identified a date of November 30, 1995, for completion of engineering evaluations to address fire endurance issues relative to Thermo-Lag configurations at BVPS Unit 2, and the completion of hardware modifications and final 4
resolution of the Thermo-Lag issue by the sixth refueling outage for BVPS Unit 2. In consideration of the additional generic testing specified aboved and subsequent review of i
the results, our schedule has been revised accordingly. Engineering evaluations are now scheduled to be completed by April 30,1996. The hardware modifications and final resolution of the Thermo-Lag issues at BVPS Unit 2 are now targeted for completion by the end of 1996. As noted in our previous response (Reference 2), fire watch patrols for the remaining areas will be maintained until the Thermo-Lag fire barrier issues have been resolved for those areas.
Should you have any questions conceming this response, please contact Mr. Roy K. Brosi, Manager, Nuclear Safety, at (412) 393-5210.
i Sincerely, 6fD
~3 George S. Thomas c:
Mr. L. W. Rossbach, Sr. Resident Inspector Mr. T. T. Martin, NRC Region I Administrator Mr. D. S. Brinkman, Project Manager