ML20100L204

Interim Deficiency Rept,Item 141 Re Deviations from Specified Clearance Between Cable Trays & Vertical Support Members.Initially Reported on 841107.As-built Tray/Hanger Clearance for Hangers & Cable Trays Acceptable

ML20100L204
Person / Time
Site:	Fermi
Issue date:	11/30/1984
From:	Jens W DETROIT EDISON CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
141, EF2-70044, NUDOCS 8412110497
Download: ML20100L204 (2)

Text

'

W:yne H. Jens

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Vies President Nuclear Operations FermL2 6@ Nodh Dme Highway November 30, 1984 l

h @ $f d" EF2-70044 -

Mr.. James G. Keppler-Regional Administrator Region III' O. S. Nuclear Regulatory Commission 799 Roosevelt Road '

Glen Ellyn, Illinois' 60137

Reference:

Fermi 2 NRC Docket No. 50-341

Subject:

Interim Report of Potential 10CFR50.55(e)

Item 141 " Deviations from Specified Clearance between Cable Trays and Vertical Support Members" On November 7, 1984, Detroit Edison's Mr. J. E. Conen, Engineer-Licensing, telephoned Mr. R. C. Knop of NRC Region III, to report a potential deficiency concerning deviations from specified clearance between cable trays and vertical support members. This item is potentially reportable under 10CPR50.55(e) and is being tracked as Item 141.

Description of Deficiency During an area walkdown in the Residual Heat Removal-(RHR)

Building, it was identified that the cable tray location of 4 safety related hangers did not meet the requirements of Specification 3071-128 and the general notes for cable tray installation contained on drawing 6E721-2808-3. These documents require that the vertical members of Class I cable tray hangers be located 2 inches (+ 1/4 inch) clear of the outside face of the cable tray. In addition to the 4 hangers originally identified, 43 cable trays located on 37-hangers in the Reactor Building, Auxiliary Building and RHR complex have been identified as having the same deficiency and were documented on Nonconformance Report (NCR) 84-1585.

The incorrect clearance between the cable tray and the hanger may result in increased moment loading on the connections between the horizontal and vertical hanger members during a seismic event.

f~ .

Mr.. James G. Keppler November 30,.1984 EF2-70044 Page 2-Analysis of Safety Implications The increased load on the connections between horizontal and vertical members of-the hangers could result in the failure

-of. safety related electrical supports duriaq a seismic event.

Corrective Action The following actions have been taken to correct this deficiency and prevent recurrences o The as built tray / hanger clearance for each of the hangers and cable trays identified in NCR 84-1585 has been analyzed and found acceptable.

o A program is being implemented to sample and evaluate the tray / hanger clearance for safety related cable tray hangers in the Auxiliary Building and-the RHR complex. This sample will emphasize hangers expected to be most sensitive to variations of the location of the cable trays. These include hangers with large widths that could permit significant variation in the tray location, "L" shaped and cantilevered hangers,.and hangers with reduced design loads close to the actual loads.

o A review will be performed of the cable tray general notes drawings (6E721-2808-1 and 6E721-2808-3) to-identify any other possible problem areas. This review will include generic criteria that is not duplicated in

.the site specifications or on'other cable tray design t.

drawings.

Detroit Edison will~ provide another report on this item,

. either interim or final, when further-information is available. If you have questions concerning this matter, please contact Mr. Lewis Bregni, (313) 586-5083.

Sincerely, p[ h, cc: P. M. Byron ,#

i: R. C. DeYoung C R. C. Knop (

USNRC, Document Control Desk i Washington, D. C. 20555 l

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