ML20211E200
| ML20211E200 | |
| Person / Time | |
|---|---|
| Site: | Susquehanna  |
| Issue date: | 09/16/1986 |
| From: | Poparad C HILTI FASTENING SYSTEMS |
| To: | Fair J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE) |
| Shared Package | |
| ML20211E206 | List: |
| References | |
| NUDOCS 8702240259 | |
| Download: ML20211E200 (4) | |
Text
,
- ctL Sf6-SE O 32s MIbTE U.S. Construction Company 4115 South 100th East Avenue
- PO. Box 470400
- Tulsa, Oklahoma 74147 (918) 627-9711
- Telex 796503 a
September 16, 1986 U.S.
Nuclear Regulatory Commission office of Inspection & Enforcement Washington, D.C.
20555 Attention:
Mr. John Fair
Dear Mr. Fair:
Subsequent to our meeting on August 28, 1986, I have reviewed in detail the Kwik-Bolt data and would like to provide you with the following information.
First, on-site Kwik-Bolt testing was conducted at Susquehanna Steam Electric Station / Emergency Diesel Generator Facility during May, 1985, and March / April, 1986 (Attachment 1).
These tests indicated some local site-specific deviations from the expected values for the 3/8, 1/2, 5/8, 3/4 and 1-1/4 inch Kwik-Bolts with deep embedments (Attachment 2).-
A preliminary review at the jobsite did not reveal a cause for the differences.
The Susquehanna Kwik-Bolt data along with other nuclear power plant on-site test data (39 test reports) 1425 data points, Attachment 4) was compared to the published values.
This analysis revealed that the on-site average ultimate tensile values met or exceeded the current published ultimate tensile values except for the 1/2 inch diameter Kwik-Bolt with embedments greater than 3-1/2 inches.
These values were 7 to 20% below published data.
Next, additional 1/2 inch Kwik-Bolt tests were conducted at the HILTI L
Test Center (Report WENT #115-86).
This test program confirmed the 1/2" ultimate tensile values reported in the nuclear power plant on-site test report data analysis.
In addition, tensile tests were conducted in a hard river gravel (Moh's hardness #9) to determine the influence of aggregate hardness on the 1/2 inch Kwik-Bolt.
For comparison, the limestone aggregate norms 11y used in our testing has a Moh's hardness equal to 4 or 5.
The test results in the river gravel concrete met or exceeded the published data by 0 to 16%.
As the aggregate hardness increases, the ultimate tensile values increase until the bolt or wedge material
(
strength is exceeded.
Thus, we have concluded that the 1/2 inch Kwik-Bolt tensile values are influenced by the coarse aggregate hardness.
l A Division of Hilti, Inc.
0702240259 860916 i
PDR ADOCK 05000307
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1 i
U.S.
Nuclear Regulatory Commission Attention:
Mr. John Fair Page 2.
September 16, 1986 We believe that aggregates commonly used in concrete mix designs more closely match the limestone aggregate used in our laboratory vs. a hard river gravel.
Therefore, after review of all the test data, we have elected to revise the 1/2 inch diameter Kwik-Bolt tensile values, (Attachment 10).
All other Kwik-Bolt values will remain as currently published.
For your review, I have calculated the factor of safety using the revised ultimate values vs. the current working load.
As you can see, even for the worst case, there remains at least a 2.9:1 factor of safety.
Practically, there would probably be at least a 3.6 to 1 factor of safety since most designs are based on a 4000 psi concrete and an embedmont of less than six (6) inches, i
In summary, the Kwik-Bolt values currently published are substantiated by the on-site field test reports.
The only exception is the 1/2 inch diameter Kwik-Bolt, which is influenced by aggregate hardness at deep embedments.
Any NRC notice deemed appropriate could be developed with the text being i
specific and narrow in scope.
Working together, HILTI can be supportive to you and to the utility owners in effectively and efficiently resolving application questions that need attention.
I am available to meet with you as required.
Sincerely, i
HILTI U.S.
CONSTRUCTION kWbd Q&M Charles Popar&d, P.E.
Director Technical Marketing Services CJP:bc Attachments cc M.
Hilti - HILTI/ Tulsa E. Hoelker - HILTI/ Tulsa R. L. Zink - HILTI/ Tulsa
ATTACHMENTS 1.
Susquehanna Test Reports - March 1985 March / April 1986 2.
Susquehanna Test Data Analysis 3.
Nuclear Power Plant On-Site Test Data Analysis Index 4.
Nuclear Power Plant On-Site Test Data Analysis 5.
Hilti Test Report WENT #115-86 6.
1/2" Kwik Bolt Detailed Data Analysis 7.
1/2" Diameter Kwik Bolt Data Analysis Excluding Susquehanna Test Reports 8.
Susquehanna Kwik Bolt Material / Dimension Analysis 9.
Concrete Mix Design 10.
Revised 1/2" Kwik Bolt Tension Values 11.
Factor of Safety Analysis 12.
Nuclear Power Plant On-Site Test Index i
l l
4
1 SUSQUEHANNA TEST REPORTS March 1985 March / April 1986 J