ML19220C057
| ML19220C057 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 08/18/1976 |
| From: | Arnold R Metropolitan Edison Co |
| To: | O'Reilly J NRC Office of Inspection & Enforcement (IE Region II) |
| References | |
| GQL-1182, NUDOCS 7904280144 | |
| Download: ML19220C057 (2) | |
Text
V
}2ac#W&:ciAa
~
l l $
.~77L/
^
N Q Gdim METROPOLITAN EDISON COMPANY :ue:touayof cu.?saat rustic urittriss ccapo9Arica
/
POST OFFICE BOX 542 READING, PENNSYLVANI A 19603 TELEPHONE 215 - 329 3601 August 18, 1976 CC 1182 Office of Inspection and Enforcement, Region 1 U. S. Nuclear Regulatory Co=sission 631 Park Avenue King of Prussia, Pennsylvania 19406 Attention:
Mr. J. P. O'Reilly, Director Centlemen:
i
Subject:
Three Mile Island Nuclear Station Unit 2, Docket No. 50-320 Butt Solices on GE AKD-5 Switchaear On July 20, 1976, Mr. L. Narrow of your office was verbally notified of a situation which Metropolitan Edison Company considered to be report-able in accordance with the requirements of 10CFR50.55(e). This letter constitutes the required thirty day follow-up letter.
Descriotion While performing internal wiring changes on CE AKD-5 switchgear as directed by the engineer, several butt splices located on top of the switchgear for the unit substations pulled apart. The electricians performing the wiring changes were repairing these splices as they broke. No record was -Mntained of the nu=ber of splices which required repair.
'Jhen the problem was identified, General Electric Cocpany was contacted to inform thert of the situation and to request a remedy for the problem. GE furnished a Field Engineer to inspect each splice for adequacy. Each splice was pulled fir =ly (approx 1=ntely 10-15 lbs. force) and any that pulled apart were i==ediately repaired and re-inspected.
Out of about 1,000 splices checked by CE, only 7 splices failed. Four of the failed splices occurred in two safety related unit substations.
The butt splices on one safety related DC switchgear (Unit Substation 2-2 DC) have not been mspected to date because the switchgear cannot be de-energired at this ti=e.
6 633S W.
1 i
So-19.7 i
- 9 0 4 '2 8 0 <, a
}
i s
U o
Mr. J. P. O'Reilly August 18, 1976 G@ 1182 Analysis of Safetv 1911 cations l
Two of the unit substations exhibiting this condition were sr.iety related. Had these faulty butt splices remained undetected, it is possible that a splice could have failed under load causing the loss of power and control of those safety loads downstrean of the unit substation.
Since it is imlikely that a splice in a redundant unit substation would fail simultaneously, the redundant safety related component would be available to safely shutdown the reactor. For this reason, this inci-dent would not have cocpronised the health or safety of the public or the plant staff.
Correceive Action f
General Electric Co=pany supplied a service engineer to inspect j
and repair each splice as previously described. All inspections and repair work for safety related equipment were observed by Quality i
Control. Docu=entation associated with these repair and inspection activities are available at the site for your review. The splices in Unit Substation 2-2 DC (safety related) ra-n%ing to be inspected vill be inspected when the unit can be safely de-energized prior to fuel
}
leading.
Very truly yours, t
,~
Signed - R. C. Amou R. C. Amold a
Vice President l
RCA:=ft i
i
(
cc: Dr. Ernst Volgenau, Director j
Office of Inspection and Enforcement U. S. Nuclear Regulatory Cc= mission Washington, D. C. 20535 1
i i
I, I
f 4
e.
t 86 198 I
J
}
.