ML20151R685
| ML20151R685 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 01/28/1986 |
| From: | Williams J TOLEDO EDISON CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| REF-PT21-86, REF-PT21-86-042-000 1-614, PT21-86-042-000, PT21-86-42, NUDOCS 8602060188 | |
| Download: ML20151R685 (1) | |
Text
DCS TOLEDO
%s EDISON Docket No. 50-346 Log No. KA86-49 License No. NPF-3 File: RR 2 (NP-43-86-01)
Serial No. 1-614 January 28, 1986 Mr. James G. Keppler, Regional Administrator United States Nuclear Regulatory Commission Region 111 799 Roosevelt Road Glen Ellyn Illinois 60317
Dear Mr. Keppler:
Subject:
Potential 10CFR Part 21 Report Consolidated Controls Corporation Field Wire Wrap Practice This letter is to serve as the written notification of a potential 10CFR Part 21 defect which was identified by the Toledo Edison Company on January 23, 1986. This letter confirms a telephone conversation between your Mr. Nick Jackiw and Toledo Edison's Mr. Rod Cook on January 24, 1986.
Toledo Edison (TED) was observing a Consolidated Controls Corporation (CCC) field engineer performing modifications in the Steam and Feedwater Rupture Control System (SFRCS) cabinets. TED noted that the field engi-neer had the practice of sliding existing wire wrap connections down the terminal posts to make room for additional wirts. This practice was questioned, but TED was assured by CCC that this was an acceptable practice.
The TED work package instructions did not have specific criteria to pro-hibit or authorize this practice. The related criteria in the Military Standards MIL-STD-1130B and Consolidated Controls QCI-110 procedure refer to a minimum pull force to prevent the wire from being stripped from the
.je terminal, 2 pounds strip force for AWG #30 wire.
CDnc CJ o c.
wo Subsequently, TED performed pull testing on some wire wraps and detennined N
that wraps that had not been moved would not fail until 8 to 12 pounds of CD o strip force was applied, which is well above the acceptance criteria.
Ilow-cc:c ever, when the test was conducted on four wire wraps that had been applied 30 to terminal posts and then pushed down further, the strip force required 0]
was sharply reduced. One wrap pulled with 2h pounds, one with 2 pounds, o
and two with 1 pound of strip force applied. Two of these four would not
$g have met the minimum strip force criteria.
4c (D c.In Therefore, TED has identified that moving a wire wrapped connection will THE TOLEDO EDISON COMPANY EDISON PLAZA 300 MADISON AVEP'UE TOLEDO, OHIO 43652 I
3 I385 FEB
l Docket No. 50-346 License No. NPF-3 Serial No. 1-614 January 28, 1986 Page 2 require retermination to ensure the minimum pull force criteria is satisfied.
TED has written a procedure, IC 2701.20, Instruction for Installation and Removal of Wire Wrap Connections. Training has already begun.
All wire wrap connections for the logic modules and card racks in the SFRCS cabinets will be stripped and reterminated.
SFRCS is the only Nuclear Safety related system in which CCC performed wire wrapping.
Although TED does not know of other specific utilities where wire wrapping is used, it would appear to be an item of interest for all utilities who may have wire wrap terminations.
This report satisfies the requirement for written notification within five days of determination of a defect. Additional information will be provided in a 30 day Licensee Event Report (LER), per 10 CFR 50.73.
Very truly yours,
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JW:JCS:syc cc: Walt Rogers DB-1 NRC Resident Inspector USNRC Document Control Desk Washington, D.C.
20555 James Taylor, Director Office of Inspection and Enforcement USNRC Washington, D.C.
20555 6