ML20095L335
| ML20095L335 | |
| Person / Time | |
|---|---|
| Site: | Fermi  |
| Issue date: | 08/15/1984 |
| From: | Jens W DETROIT EDISON CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| 74, EF2-69672, NUDOCS 8408300209 | |
| Download: ML20095L335 (2) | |
Text
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'. Wayne H. Jens y--") -
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. Veo Pasadent
' Nuclear Operat:ons l7
' 6400 North Oxie HP.way F wms-2 l
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August 15, 1984
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EF2-69672 i
Mr. James G.
Keppler Regional Administrator r
(=
Region III L-U.
S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, Illinois 60137
Dear Mr. Keppler:
l Reference (1) Fermi 2 NRC Docket No. 50-341 (2) Letter, D. A. Wells to J.
G.
- Keppler, July 30, 1982, EF2-59383 (3) Letter, D. A. Wells to J.
G.
- Keppler, November 2 4, 1982, EF2-612 01 l
Subject:
Final Report of 10CFR50. 55(e) Item 74 l
" Sway Strut Paddles Clamped Rigid" This is Detroit Edison's final report concerning item 74,
" Sway Strut Paddles Clamped Rigid."
Item 74 was originally reported as a potential deficiency on July 2, 1982, and was subsequently documented in References (2) and (3).
Description of Deficiency i
During the installation of various Power Piping Co. power sway struts, problems were encountered with the fitup of the strut paddle to the support clamp.
The problem was attributed to non-compatibility of Power Piping model M-3 50 sway struts and Power Piping SK 500 and SK 1000 pipe clamps when they are used in off angle ( < 9 0* ) load configurations.
Specifically, the squared corners of the clamp would not permit rotation'of the sway strut to the proper load angle.
During installation, the paddle and strut were forced into the clamp, thereby locking the sway strut at a single
. position.
Subsequent investigations identified additional Power Piping model M-350 sway struts with the same install-ation problem.
8408300209 840815 PDR ADOCM 05000341 S
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.Mr. James G.
Keppler August 15, 1984 CF2-69672 Page 2 Analysis of Safety Implications Failure of the sway struts to allow the designed pipe movement would induce stresses not considered in the piping design analysis of a safety related system.
Corrective Action Upon identification of the problem, installation of this type strut assembly was placed on hold while the problem was resolved.
Detroit Edison conducted an inspection of the 280 Power Piping model M-350 sway strut installations.
The walkdown inspection identified sway struts with clamp interference problems.
These deficiencies were documented on DDRs in accordance with the Detroit Edison Quality Assurance Program.
Hanger Engineering, in conjunction with the vendor, developed corrective modifications for various-installation conditions encountered.
Modifications were processed on approved DDRs and included:
1)
Using extended end paddles; 2)
Rounding interfering clamp corners; or, 3)
Relocating load pin holes to allow corner clearance.
In addition to the component modifications, the contractors were required to conduct training sessions with craft supervisory and-quality control personnel in t.he proper techniques to be used during construction and inspection of this type installation.
This is Detroit Edison's final report on this item.
If you have questions concerning this matter, please contact Mr. Lewis P.
Bregni at (313) 586-5083.
Sincerely,
/
cc:
Mr.
P. M. Byron Mr.
R.
C.
DeYoung Mr.
R.
C. Knop
.