ML19351F401
| ML19351F401 | |
| Person / Time | |
|---|---|
| Site: | Surry, North Anna  |
| Issue date: | 12/26/1980 |
| From: | Sylvia B VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| 1005, IEB-80-11, NUDOCS 8101120519 | |
| Download: ML19351F401 (2) | |
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VIRGINIA ELzcTnIc ann Powna COMPANYd'
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Mr. James
. O'Reilly, Director Serial No. 1005 Office of Inspection & Enforcement PSE&C/RHW,III:bmt U. S. Nuclear Regulatory Coninission Docket Nos.
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Region II 50-281 101 Marietta Street, Suite 3100 50:338]
l Atlanta, Georgia 30303
. 50-339y License Nos.
Dear Mr. O'Reilly:
IE BULLETIN 80-11 ESTIMATED SCHEDULE ~
SURRY POWER STATION UNITS 1 AND 2 MRTH ANNA POWER STATION UNITS 1 AND 2 The purpose of this letter is to provide you with our estimated schedule for completing the masonry wall reevaluation program required by IE Bulletin 80-11 at Surry and North Anna Power Stations. This letter is in response to the request made by NRC I&E Inspector, Mr. J. _J. Lenahan, during his exit critique of IE Bul-i letin 80-11 activities at Surry Power Station on December 5,1980. As requested by Mr. Lenahan, this schedule consists of identifying key dates in the reevalua-tion program and stating reevaluation priorities.
The priority for evaluating masonry walls is based on the function and amount of safety-related equipment located within the proximity of the masonry walls.
i Class I walls are defined as those walls located in critical plant areas and with a high probability of striking a significant amount of safety-related equipment should wall failure occur. Class II walls are defined as those walls located in critical plant areas but with a lesser probability than Class I walls of striking a significant amount of safety-related equipment should wall failure occur. Since Surry Unit 1 is in the steam generator replacement outage, the first priority for wall reevaluation is with Class I walls at North Anna Units 1 and 2 and Surry Unit 2.
The second priority is for reevaluation of Class II walls for these units and the third priority is for Class I and Class II walls for Surry Unit 1.
As analysis continues on individual walls, some Class II walls may be given priority for evalua-tion over other Class I walls where the analysis results indicate that such action may be appropriate.
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VinotwxA Ex.acrasc AND Powra COMPANY T Mr. J. P. O'Reilly Page 2 Our schedule is developed around the multi-level format of the masonry wall reevaluation program described in our letter of November 3,1980. This program is based on utilizing conservative assumptions, simplified analysis techniques and conservative acceptance criteria with the most conservative criteria and simpli-fied analysis techniques being applied in the early phases of analysis to screen those walls where more complex analysis is not warranted. Where additional analy-sis is warranted more exact analysis techniques, which are still conservative, are applied to incorporate refined boundary conditions, more precise loading defini-tion, and computer aided analysis. The structure of the multi-level analysis pro-gram consists of two levels of analysis with Level I bei.ng an elastic analysis and Level II being an inelastic analysis; Level I consists of three Phases or sublevels which refine the assumptions, analysis techniques, and acceptance criteria used with the elastic analysis.
Walls that have not had analysis completed are in Phase II of Level I analysis in the reevaluation program.
The estimated completion dates for this level of analysis are March 15, 1981 for the Class I walls and April 15, 1981 for the Class II walls. At the end of this phase of analysis all walls which have been identified as requiring further analysis will be further evaluated in Phase III of Level I.
of the reevaluation program. As indicated in our letter of October 24, 1980, Serial No. 868, requesting an extension for completion of the reevaluation program, analy--
sis is scheduled to be completed by July 31, 1981.
Should you have any questions or require additional information, please con-tact us.
Very truly yours, C
[ R. Sylvia Manager-Nuclear 6 Operatio'ns and Maintenance cc: Mr. Victor Stello, Diroctor Office of' Inspection & Enforcement Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation w-
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