ML18153B269
| ML18153B269 | |
| Person / Time | |
|---|---|
| Site: | Surry, North Anna  |
| Issue date: | 03/28/1995 |
| From: | Ohanlon J VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML18153B270 | List: |
| References | |
| 95-007, 95-7, GL-92-08, GL-92-8, NUDOCS 9504070321 | |
| Download: ML18153B269 (4) | |
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VIRGINIA ELECTRIC AND POWER COMPANY RICHMOND, VIRGINIA 23261 March 28, 1995 United States Nuclear Regulatory Commission Attention: Document Control Desk Washington, D. C. 20555 Gentlemen:
VIRGINIA ELECTRIC AND POWER COMPANY NORTH ANNA POWER STATION UNITS 1 AND 2 SURRY POWER STATION UNITS 1 AND 2 Serial No.
NL&P/CGL Docket Nos.
License Nos.95-007 R3 50-338 50-339 50-280 50-281 NPF-4 NPF-7 DPR-32 DPR-37 FOLLOWUP TO REQUEST FOR ADDITIONAL INFORMATION REGARDING GENERIC LETTER 92-08 PURSUANT TO 10CFR50.54(t)
- THERMO-LAG FIRE BARRIERS In a December 28, 1994 letter, the NRC formally questioned the reliability of Thermal Science, lncorporated's quality assurance program for Thermo-Lag materials, as well as the quality of Thermo-Lag materials. The NRC letter further indicated that licensees must have valid and verifiable information for the identified parameters for in-plant Thermo-Lag barriers if the licensee intends to retain, modify, or expand its Thermo-Lag installations. The enclosure to the NRC letter specifically identifies the requested information regarding tests, analyses, methodology, examinations, and inspections to verify that in-plant Thermo-Lag materials and configurations are representative of those tested or analyzed to address the Thermo-Lag issues.
Based on NRC Bulletin 92-01, NRC Bulletin 92-01 Supplement 1,
Generic Letter 92-08, and the September 19, 1994 North Anna and Surry 1 OCFR50.54(f) requests, we had interpreted the scope for the requested information to be limited to 1-hour and 3-hour rated fire barriers. Therefore, this letter identifies the actions we are taking to address the NRC's December 28, 1994 request for 1-hour and 3-hour rated fire barriers. Based on this interpretation, we did not plan to take any action to address the December 28, 1994 inquiry relative to 1 /2-hour rated in-containment radiant energy shields at North Anna and Surry. This interpretation was discussed by Mr. M. L. Bowling of my staff and Messrs. D. Matthews, L. Engle, and E. Connell of the NRC staff during a March 21, 1995 telephone conversation. During that discussion, we were advised by the NRC that radiant energy shields were intended to be addressed in the response to the December 28, 1994 request.
Therefore, our planned actions to address both applications are identified in the following paragraphs.
9504070321 950328 PDR ADOCK 05000280 P
- l-HOUR AND 3-HOUR RATED EIRE BARRIERS In order to provide the requested information for 1-hour and 3-hour Thermo-Lag applications at North Anna and Surry, destructive testing of in-plant materials would be required. In view of this, we have made the decision to eliminate the need to rely on Thermo-Lag materials for 1-hour and 3-hour rated fire barriers at both North Anna and Surry. In a December 6, 1994 letter (Serial No. 94-574/94-575), we advised you of the two remaining applications where Thermo-Lag was being credited as a 1-hour or 3-hour rated fire barrier. The two remaining applications and the actions taken to obviate the need to rely on Thermo-Lag are as follows:
- A 1-hour tire barrier on six heating/ventilation/air conditioning (HVAC) ducts that penetrate the roof of Battery Rooms 1 A, 1 B, and 2A (two ducts per room) in the Emergency Switchgear Rooms at Surry - for this application, the technical evaluation has been re-examined. Based on fire tests conducted by Southwest Research Institute, it has been determined that the HVAC duct provides sufficient fire resistance for the expected fire hazard. Therefore, Engineering Evaluation 22, provided as Attachment 1, has been developed to indicate that Thermo-Lag is not required to maintain the fire resistance rating of the ducts. Also as discussed in Engineering Evaluation 22, this position applies to four fire dampers in ventilation ducts penetrating the north wall of the Turbine Building.
This engineering evaluation became effective February 27, 1995, and will be included in the next annual update of the Surry Appendix R report.
A 1-hour fire enclosure around the Appendix R ventilation duct on elevation 259'-6" of the Auxiliary Building at North Anna used to protect the duct - for this application, the flexible Appendix R ventilation duct, which is necessary to provide forced ventilation to individual charging pumps in an emergency, will be relocated and stored in another fire area. The current enclosure will no longer be used as a staging area for the duct.
Engineering Evaluation 25 discusses the current enclosure configuration and was previously transmitted to the NRC by December 23, 1993 letter (Serial No. 92-834A).
After the duct is relocated, which is scheduled to be completed by June 1, 1995, Engineering Evaluation 25 will no longer be needed and will be subsequently deleted from the North Anna Appendix R report.
Because we will no longer rely on Thermo-Lag for any 1-hour or 3-hour rated fire barriers, we are not providing the verification data requested in the December 28, 1994 NRC letter.
IN-CONTAINMENT RADIANT ENERGY SHIELDS Thermo-Lag continues be used at both North Anna and Surry as 1 /2-hour rated radiant energy shields inside containment. The North Anna and Surry radiant energy shield applications are documented in Engineering Evaluations 24 and 16, respectively, which were previously transmitted to you for information by our December 23, 1993 letter (Serial No. 92-834A).
These engineering evaluations constitute the technical basis for the continued use of Thermo-Lag in the 1 /2-hour rated radiant energy shield application at both stations.
. Baseq on the March 21, 1995 telephone conversation between Virginia Power and the NHC, we are reassessing our current position regarding the in-containment radiant energy shield application. We will advise you of the results of our reassessment by
. June 30, 1995.
If you have questions regarding this information or require additional information, please contact us.
Very truly yours,
~?OW~
James P. O'Hanlon Senior Vice President - Nuclear Attachment - Surry Engineering Evaluation 22, entitled "Evaluation of Fire Rating for Ventilation Ducts in the Turbine Building and Battery Rooms - Surry Power Station" cc:
U. S. Nuclear Regulatory Commission Region II 101 Marietta Street, N. W.
Suite 2900 Atlanta, Georgia 30323 Mr. R. D. McWhorter NRC Senior Resident Inspector North Anna Power Station Mr. M. W. Branch NRC Senior Resident Inspector Surry Power Station Mr. R. E. Bradley Nuclear Energy Institute 1776 I Street N, Suite 400 Washington, DC 20006
COMMONWEALTH OF VIRGINIA )
)
COUNTY OF HENRICO
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The foregoing document was acknowledged before me, in and for the County and Commonwealth aforesaid, today by J. P. O'Hanlon, who is Senior Vice President -
Nuclear, of Virginia Electric and Power Company. He is duly authorized to execute and file the foregoing document in behalf of that Company, and the statements in the document are true to the best of his knowledge and belief.
Acknowledged before me this.1Jr! day of ~
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