ML20098D315
| ML20098D315 | |
| Person / Time | |
|---|---|
| Site: | Fermi  |
| Issue date: | 09/10/1984 |
| From: | Jens W DETROIT EDISON CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| 135, EF2-69706, NUDOCS 8409270470 | |
| Download: ML20098D315 (2) | |
Text
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Wayne H Jene
's.
ve. presseent
. wuci.ar opmnon.
DOITOI,I.
6400 North Dme Highway Newport. u,cesan 48166 -
September 10, 1984
' oth 58 9 t50 EF2-69706 Mr. James G.
Keppler Regional Administrator--
Region III U. S. Nuclear Regul'atory Commission 799 Roosevelt Road Glen Ellyn,-Illinois 60137-
Dear Mr. Keppler:
References:
(1) Fermi 2 NRC Docket No. 50-341 (2) Letter W. H. Jens_to J.
G._Keppler April 20, 1984, EF2-67809 1-
Subject:
Report of 10CFR50.55(e). Item 135 i
" Design Deficiency of Conduit Support Weld p
Details" t
On August 9, 1984, Detroit Edison's Mr. Lewis P.
Bregni,-
telephoned Mr. J. McCormick-Barger of_the NRC Region III to report that some conduit support weld details in Standard ED of Specification 3071-128 were modified by Design Change Request (DCR) E-3006 without a seismic review.-
This discrepancy was discovered during a review of conduit 4
supports relating to 10CFR50.55(e), Item 119, Reference (2).
Description of Deficiency Welds were deleted from eight conduit support standards in Edison Specification 3071-128-ED (e.g., Standard ED-25-1) by DCR-E-3006 without seismic qualification review.
This 1
deficiency was discovered by Giffels Associates, Inc. (GAI) during the review of the structural adequacy of unistrut-cross arms done to resolve 50.55(e), Item 119, Reference (2)..When the two-sided welds, shown in the current-i_
revision _(Rev. AH) of specification 3071-128-ED which connect unistrut cross-arms to main tube steel support members were_ checked, GAI noted that-they were not sufficient to. withstand design-loads by a sufficient factor.
in the worst case.
A_ subsequent review of the calculations upon which the standards were based revealed that'all-around l
welds (four sided) were originally required at these connections.
An evaluation revealed.that DCR-E-3006, issued in May_of 1980, changed the details to require only two-parallel welds.
8409270470 840910 44 b@ ~ L PDR ADOCK 05000341~
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Mr. James G. Keppler September 10, 1984 EF2-69706 Page 2 Analysis of Safety Implications The structural integrity of safety related supports built to the deficient standards could not be assured under design seismic event conditions.
Corrective Action GAI reviewed the structural adequacy of the subject weld details and provided necessary design changes to the s ta nd ard s.
DC N-105 92, Rev.
A, was issued on August 17, 1984, to revise the weld details.
Detroit Edison's Field Engineering Conduit Design Group conducted a survey of all appropriate "as-built" drawings, conduit engineering sketches, and open documents to determine the scope of the deficiency.
This survey identified 130 existing conduit supports which do rot meet the revined standards.
GAI is reviewing these supports on a case-by-case basis and identifying any which require rework.
Because of the recent discovery of conduit support standard deficie ncies, GAI has been requested to nake a comprehensive review of the three specifications for which they originally provided calculations.
These three are:
Specification 3071-128-ED (Electrical Engineering Standard-Conduit Supports), Specification 3071-185 (I&C Standards for Tube Supports), and Specification 3071-232 (I&C Sta ndards for Tube Supports-RHR Complex).
Another report of this item, either interim or final, will be sent when further information is available.
If you have questions concerning this matter, please contact Mr. Lewis P.
Breg ni, (313) 586-5083.
Sincerely, cc:
Mr.
P.
M.
Byron Mr.
R.
C.
DeYoung
/
Mr.
R.
C. K nop
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