ML19257B892
| ML19257B892 | |
| Person / Time | |
|---|---|
| Site: | Fort Saint Vrain  |
| Issue date: | 12/12/1979 |
| From: | Swart F PUBLIC SERVICE CO. OF COLORADO |
| To: | Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| References | |
| IEB-79-02, IEB-79-2, NUDOCS 8001210172 | |
| Download: ML19257B892 (2) | |
Text
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STATE December 12, 1979 Fort St. Vrain Unit No.1 P-79297 o
GED I 7 E9 6
Mr. Karl V. Seyfrit, Director Nuclear Regulatory Commission Region IV 611 Ryan Drive, Suite 1000 Arlington, Texas 76011 Docket #50-267 Subject-I&E Bulletin 79-02 Revision 2 Base Plate Designs Using Concrete Expansion Anchor Bolt Gentlemen:
The following is in response to the items in IE Sulletin 79-02, Revision 2, dated November 8,1979, not addressed in our previous response to IE Bulletin 79-02.
ITEM 1 Answered in our letter Swart / Seyfrit dated July 3,1979 ITEM 2 Reduced Factor of Safety Using Factored Load Approach Based on the calculations performed in our random sample audit, no reduction in the factor of safety was required to design for the SSE condition.
The following interaction formula was used with the appropriate minimum factor of safety as recommended by the expansion anchor manufacture:
Tension Actual Shear Actual 1.0 Tension Allowable Shear Allowable ITEM 3,4 Answered in our letter Swart /Seyfrit dated July 3,1979 ITEM 5 Expansion Anchors in Masonry Concrete Block Walls This item is not applicable at Fort St. Vrain since no concrete expansion anchors were used to support Class I Pipe Hangers in concrete masonry block walls.
This statement is based on information gathered during the 100". Solt Torquing Program.
1774 060 hsoo1310/%
IIr. Karl V. Seyfrit, Director December 12, 1979 Page 2 ITEti 6 Structural Steel Shapes in Place of Base Plates In our random sample audit of Class I Hangers attached to concrete, we identified that structural shapes, such as, angles and tees were used in about 35% of the hangers for direct attachment to concrete.
Proper design considerations, such as distribution of bolt loads and prying action were taken into account in the analysis and no deficiencies were noted.
ITEM 7 Completion Dates PSC intends to be complete with all items by January 11, 1979.
The 100%
bolt torquing program for 21/2 inch and larger pipe hanger concrete anchor bolts is complete.
The sample bolt torquing program for the 2 inch and under concrete anchor bolts shall be complete by January 11, 1979.
This will include field work and engineering evaluation of the data from the sample audit.
The following discrepancies were noted and evaluated under our sample program to answer IE Bulletin 79-02:
1)
Improper Bolt Size 2)
Improper Bolt Spacing 3)
Base Plate Configuration 4)
Edge Distance Between Edge of Bolt and Edge of Base Plate None of the discrepancies identified were significant so no hanger impairment or system impairment was declared.
This conclusion is based on the results of our random sample audit and on our 100% bolt torquing program.
PSC intends to evaluate, correct if necessary, and properly document each discrepancy found under the, I&E Bulletin 79-14 program.
Therefore, we believe we meet the requirements of IE Bulletin 79-02.
Sincerely, f
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Frederic E. Swart Nuclear Project Manager FES/ RAG:pa 1774 061