ML19344D571
| ML19344D571 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 02/12/1980 |
| From: | Trimble D ARKANSAS POWER & LIGHT CO. |
| To: | Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| References | |
| IEB-79-02, IEB-79-2, NUDOCS 8004250044 | |
| Download: ML19344D571 (3) | |
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--HC AAKANSAG POWER & LIGHT COMPANY POST CFFICE SCX 55' UTTLE AOCK. ARKANSAS 72203 (501? 371-4000 States February 12, 1980 1-020-08 Mr. K. V. Seyfrit, Director Office of Inspection and Enforcement U. S. Nuclear Regulatory Commission Region IV 611 Ryan Plaza Drive, Suite 1000 Arlington, Texas 76011
Subject:
Arkansas Nuclear One - Unit 1 Docket No. 50-313 License No. DPR-51 I.E. Bulletin No. 79-02 (File: 1510)
Gentlemen:
This letter is to confirm the telephone conversation of January 31, 1980 between Messrs. Wong, Fair and Westerman of your staff and representatives of Arkansas Power & Light and Bechtel Power Corporation.
This telephone conversation pro-vided the status of the structural analysis of Unit I concrete block walls sup porting Seismic Category I pipe hangers.
As of January 31, 1980, we have completed the structural analysis of the Unit I concrete block walls supporting Seismic Cagegory I large pipe hangers. A total of only five Seismic Category I large pipe hangers were found on concrete block walls.
The analysis shows that these block walls are structurally adequate for inertia forces and hanger loads.
In order to include misce.11aneous attachment items (including small pipe) in the' analysis, an additional 10% of the wall weight was assumed in the inertial force calculations for all concrete block walls.
Based on previous analyses, we believe that the 10% assumed value is conservative, however, the total weight of all attachments will be checked to verify the validity of the 10% value.
Should the assumed 10% additional weight be found inadequate for some walls, thosn walls will be reanalyzed using the actual loads.
In the case of the block walls supporting the five Seismic Category I large pipe hangers, the analysis shows that, including the 10% additional wall weight, there is an 8*. minimum safety margin in the reinforcing steel capacity for the most critical wall.
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j Mr., K. V. Seyfrit Fcb.uary 12, 1980 In the structural analyses, cracked sections were considered in computing the moment of inertia of the walls.
Hinged-end boundary conditions were used to determine the wall frequencies and stresses.
If you have further questions concerning the above information, please con-tact me.
Very truly yours, b& $. V David C. Trimble Manager, Licensing DCT:DRH:nak 3-l e
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