ML18086A560
| ML18086A560 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 04/28/1981 |
| From: | Schneider F Public Service Enterprise Group |
| To: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| IEB-79-02, IEB-79-2, NUDOCS 8105290147 | |
| Download: ML18086A560 (3) | |
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Frederick W. Schneider Vice President Public Service Electric and Gas Company 80 Park Plaza Newark, N.J. 07101 201/430-7373 Production April 28, 1981 Mr. Boyce H. Grier, Director U.S. Nuclear Regulatory Commission Off ice of Inspection and Enforcement Region 1 631 Park Avenue King of Prussia, Pennsylvania 19406
Dear Mr. Grier:
SUPPLEMENTAL RESPONSE NO. 3 TO NRC IE BULLETIN NO. 79-02, Rev. 2 PIPE SUPPORT BASE PLATE DESIGN USING CONCRETE EXPANSION ANCHOR BOLTS SALEM GENERATING STATION UNIT NOS. 1 AND 2 On January 23, 1981, we submitted Supplemental Response No. 2 to NRC IE Bulletin No. 79-02, Rev. 2.
Following additional reviews for the use of concrete expansion anchor bolts in concrete block walls with respect to Item 5, we are providing this Supplemental Response No~ 3.
If you have any further questions, we will be pleased to discuss them with you.
Sincerely, CC NRC Off ice of Inspection and Enforcement Division of Reactor Operations Inspection Washington, D.C. 20555 Q
Item S Response to NRC IE Bulletin 79-02 Rev. 2 Additional Information No. 1 and 2 Units Salem Nuclear Generating Station The determination of the extent to which concrete expansion anchor bolts were used in concrete block (masonry) walls to attach piping supports in Seismic Category I systems is as follows:
Unit 1 Unit 2 Item Sa No. of Supports 1
3 Anchor 1-Anchor 2-Guides The information required for this item is as follows:
Bolt Line Support No.
Unit system Size Type Qty.* s*ize CTAA-1120 1
Control Air l" O.D.
Hilti 2
2" 2A-CTAA-1033 2
Control Air 1/2" O.D. Hilti 4
2" 2A-CTAG-1034 2
Control Air 1/2" O.D. Hilti 4
2" 2A-CTAG-1006 2
Control Air 1/2" O.D. Hilti 4
2" Item Sb Acc-ess.
yes yes Yes yes The design consideration or philosophy used in the installation of Seismic Class I Supports on block (masonry} walls was to not use such walls as the supporting structure except in a few isolated cases where it could not practically be avoided.
In the few cases where block walls were used as the support structure, they involve only small bore piping with relatively low design loadings.
Item Sc The evaluation of the Concrete Anchor Bolt loads was initiated by first computing the design tension and shear bolt loads for the specific support configurations utilizing forces and moments at the support point, developed from the seismic and thermal stress analysis of the system.
These developed bolt loads were then compared against the allowable tension and shear bolt loads in order to determine acceptance.
Based.on Hilti Kwik-Bolt published values for ultimate tension and shear loads in various strength concretes, a conservative linear interpolation was made to determine the ultimate tension and shear bolt loads in 1200 psi concrete.
The assumption of 1200 psi concrete for masonry block walls is consistent with the allowable stress values used in the design of the walls.
The details of this design are documented in the response to NRC IE Bulletin 80-11.
The adequacy of grouting of the concrete block walls has been addressed as response to IE Bulletin 80-11.
The ultimate tension and shear bolt loads, as determined above, were then divided by a safety factor of 4 in order to determine the allowable bolt loads.
These loads were then compared to the calculated design loads in order to determine the adequacy of the bolting for the intended service.
The results of thse analyses are as follows:
Support No.
CTAA-1120 2A-CTAA-1033 2A-CTAG-1034 2A-CTAG-1006 Tension *(lbs)
Design Allowable 506 750 263 843 116 750 9
750 Shear (lbs).
Design Allowable 433 938 228 600 87 600 5
600 The adequacy of the block wall itself to resist the loads imposed by these pipe supports is addressed in detail in the response to NRC IE Bulletin 80-11.
Item 5d Ultrasonic examination to determine embedment of bolts was performed and the results of this testing are as follows:
Support No.
Bolt No.
Embedment Depth (in)
CTAA-1120 1
4 2
4 2A-CTAA-1033 1
6 2
6 3
6 4
6 2A-CTAG-1034 1
5-1/4 2
5-1/2 3
5-3/4 4
5-1/2 2A-CTAG-1006 1
6 2
5-15/16 3
5-15/16 4
5-7/8 The investigation is complete and acceptable results have been obtained.
No further testing or investigations are pla-,ed.