ML20086C450
| ML20086C450 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 12/19/1974 |
| From: | Schwalje E Public Service Enterprise Group |
| To: | Knuth D US ATOMIC ENERGY COMMISSION (AEC) |
| Shared Package | |
| ML20086C448 | List: |
| References | |
| 10CFR-050.55E, NUDOCS 8311280013 | |
| Download: ML20086C450 (3) | |
Text
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Public Service Electric and Gas Company 80 Park Place Newark. N.J. 07101 Phone 201/622-7000 M..
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$Y ;h December 19, 197h N** J -
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Dr. Donald F. Knuth, Director k j..s.3 {
Directorate of Regulatory Operations yeu i. ti 7920 Norfolk Avenue Bethesda, Maryland 2001h
Dear Dr. Knuth:
l hKV VITAL SWITCHGEAR FAILURE - UNUSUAL WEATHER CONDITION L
NO. 1 AND 2 UNITS SALEM NUCLEAR GENERATING STATION DOCKETS NO. 50-272 AND 50-311-l On December 2, 197h a verbal report was made'to Re6 on 1, 1
Directorate of Re6ulatory. Operations advising of the failure of No. 1 Unit 4KV Vital Switchgear due to vettin6 as a result of adverse vcather conditions.
This report.vas in accordance With provisions of 10CFR50 55(e).
The Conditions Which Led To The Damage
~
storm on December 1,'1974 caused an A severe northeast unanticipated high water condition in the Delavare River.
This condition, coupled with the fact that a 2h" overboard line, in the sump pump system at Elevation 88' of No. 2 Unit Turbine' Generator Building, was incomplete and allowed the river water to enter the building at this point.
o The water filled No. 2 Unit condenser sump and flowed across the floor of Elevation 88' to a point in the AA line vall, where a construction blockout permitted the water to flov into the Auxiliary Building at Elevation 8h'.
The water' flowed across the floor on Elevation Bh' and entered the nR$ switchgear rooms of both No. 1 and No. 2 Units.
These Rg1 rooms house the h60 Volt and 230 Volt Vital Busses.
The
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oo vater found paths through cable and conduit connections in
$O the lover portions of the h60 Volt'and 230 Volt Busses and O
n splashed onto the hkV Vital Switchgear, located below in g$
the switch 6 ear rooms at Elevation 6h'.
oO At the time of this occurrence, No. lA and No. 1B hkV Busses Og vere energized.
The No. 1C and all the vital busses on Unit
@@m N 2 vere not, energized.
As a result of the water dripping and splashing on this energized equipment, a series of hkV and 13ky. breaker trips occurred between the hours of 2230 on December 1, 197h and 0310 on December 2, 1974, resulting in a loss of all station. AC' power.
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n Dr. D.F. Knuth ",
12-19-Th i
.The hkV Group Busses and station lighting vere returned to service on December 2, 197h at 1335 hrs.
l The Extent Of The Damage The 1A hkV Vital Bus and two hkV breakers, one of which was located on the 1A hkV Vital Bus and one on the 1B hkV Vital Bus, were damaged as a result of the arcing which took place.
This damage has been investigated by the sponsor engineers in the Engineering Department and Production Department personnel in conjunction with the manufacturer's representative and.
t cleanup procedures are in progress.
The completion date for these repairs is estimated to be April 1, 1975, however it is dependent upon scheduled delivery of the necessary replace-ment components.
li The extent of the damage caused by water is still under invectigition.
1.11 the relays and breakers have toen removed for inspection and cleanup.
Any and all equipment which became vet in both No. 1 and 2 Units during the incident vill be cleaned, inspected, and restored to its original c6ndition before being placed back into service.
i Corrective Action To Prevent Recurrence O
The 2h" cuerboard' line and the. penetration in the vall' between the Turbine Building and the Auxiliary. Building have been sealed.
L j
This incident occurred as a result of temporary conditions necessitated by construction.
A. survey was'made of all.
i areas to determine if any.other similar conditions exist u.
l at this time.
The switchgear rooms and the associated areas ~are being.reviewedi to ensure that a similar condition could not occur as a result-of water leakage originating within the areas.
The detail results of our findings and the repairs which were made,.
will be available for your future review at. Salem Nuclent ~ Generatin@
Station.
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O O-Dr. D.F. Knuth 12-19-7h It should be noted that a't the time of the subject damage that the construction of No. 1 and 2 Units respectively was 89 and h8 percent completed.
If you require additional information ve vill be pleased to confer with you.
Very truly yours,
/-
.WMa
E.
N.
Schwaljee Manager of-Quality Assurance
- Engineering & Construction Department dC:
Mr., J. P.
O'Reilly King of Prussia, Pa.
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