ML19322A157
| ML19322A157 | |
| Person / Time | |
|---|---|
| Site: | Waterford  |
| Issue date: | 12/27/1978 |
| From: | ARKANSAS POWER & LIGHT CO. |
| To: | |
| Shared Package | |
| ML19322A154 | List: |
| References | |
| NUDOCS 7901030065 | |
| Download: ML19322A157 (1) | |
Text
Y b
LOUISIANA POWER & LICliT COMPANY WATERFORD SES - UNIT NO 3 FINAL REPORT OF SIGNIFICANT CONSTRUCTION DEFICIENCY NO 8 CONTAlta!ENT ELECTRICAL PENETRATION BOLTING FAILURE l
(
DECE11BER 27,1978 l
7901030066
FINAL REPORT SIGNIFICANT DEFICIENCY NO 8 CONTAINMENT ELECTRICAL PENETRATION BOLTING FAILURE INTRODUCTION This report is submitted pursuant to 10CFR50.55(c)(3).
It describes deficiencies in gontainment electrical penetrations at Waterford Unit 3.
BACKCROUND A.
Synopsis of Incident electri-During the installation of Conax Corporation containment cal penetrations, at the Waterford Unit 3 project, it was noted that the bolted connections that connect the horizontal channel sections of the termination subassembly to the header mounting brackets were loose or disengaged.
Conax Corporation has confirmed that this method of attachment was employed in 32 low voltage control and in-strumentation penetrations.
B.
Resolution Conax Corporation has modified their design for Waterford 3 such that the pemnuts are welded in place, in IIeu of the pressed connections in question.
DISCUSSION The "pemnuts" were installed by Conax Corporation (manuf acturers drawings 7320-10001, Ebasco No 1564-2332 R3).
The problem identified at Waterford 3 cast doubt on the scismic capabilitics of the "pemnuts" although further A
investigations would be necessary to make a conclusive statement.
management decision was made to modify the design rather than undertake an extensive evaluation program to justif y the acceptability of the design.
We have been informed by Conax Corporation that. the " press fit" pemnut de-sign has been utilized in electrical penetration terminal block mounting brackets delivered to Millstone Nuclear Power Station Unit 3, North Anna Units 3 and 4, St Lucie Plant Unit 2 and LaSalle County Station Unit 1.
CORRECTIVE ACTION The termination sub-assembly connections have been redesigned to utilize welded pemnuts. The modified connections have now been received at the Waterford 3 project and the modification procedure has been approved.the Work to change out the connections will be accomplished to support construction plan.
O O
O WW Ju 6
_ L,J
. A
.:2
_