ML20108C973
| ML20108C973 | |
| Person / Time | |
|---|---|
| Site: | Harris  |
| Issue date: | 10/01/1984 |
| From: | Parsons R CAROLINA POWER & LIGHT CO. |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| CON-NRC-277, REF-PT21-84 168, NUDOCS 8411190158 | |
| Download: ML20108C973 (5) | |
Text
mmm an CP&L Carolina Dower & L;gnt Company N
P. O. Box 101, New Hill, NC 27562 d,
October 1,.1984 Mr. James P. O'Reilly NRC-277 United States Nuclear Regulatory Commission Region II 101 Marietta Street, Northwest (Suite 2900)
Atlanta, Georgia 30323
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CAROLINA POWER & LIGHT COMPANY
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SHEARON HARRIS NUCLEAR POWER PLANT 1986 - 900,000 KW - UNIT 1 6.9KV SWITCHGEAR CIRCUIT BREAKERS - GENERIC -
ITEM 168 7
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Dear Mr. O'Reilly:
Attached is our third interim report on the subject lem', wh[td was l.
deemed reportable per the provisions of 10CFR50.55(e) and 10CFR, Part 21 on April 20, 1984.
CP&L is pursuing this matter, and,tt is currently projected that corrective action and submission,of tb final report will be accomplished by Novedrhr 9,3984.,
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Thank you for your consideration in this matter.
Yoursverhtruly, Y
h R. M. Parsons Project General Manager s
Shearon"Earris Nuclear Power Plant RMP/j ed Attachment k
Messrs. G. Maxwell /R. Prevatte (NRC-SHNPP)-;1 cc:
Mr. R. C. DeYoung (NRC) s y.
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8411190158 841001 T-PDR ADOCK 05000400 i
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. CAROLINA-POWER & LIGHT COMPANY
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.SHEARON HARRIS NUCLEAR POWER PLANT UNIT NO. I l
. THIRD INTERIM REPORT CIRCUIT BREAKER CONTROL WIRING CONFIGURATION NCR-84-799 ITEM No. 168 OCTOBER 1, 1984 4
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f, lt REPORTABLE UNDER 10CFR50.55(e) AND 10CFR21 e
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SUBJECT:
Shearon Harris Nuclear' Power. Plant / Unit No. l' 10CFR50.55(e)'and 10CFR Part 21 reportable deficiency. Wiring for the control circuitry for 6.9kV switchgear is such.that the trip coil may.
remain energized following a trip of the breaker.
This would result in the' inability to reclose the-breaker.
ITEM:
Wiring for 6.9kV switchgear breakers SUPPLIED BY:
Siemens-Allis, Inc., Sanford, North Carolina.
' NATURE OF DEFICIENCY:
.During 1980, the switchgear. division of-
'Siemens-Allis, Inc., Sanford, North Carolina, shipped 6.9kV.switchgear breakers to the CP&L site on Purchase Orders NY-435112 and NY-435113..'As part of the. start-upitesting of these breakers, they are routinely' cycled before a breaker is put in service.
During this testing..it has been found that in some cases the trip coil will remain energized preventing the breaker from being reclosed.
The only way to restore' operability to the breaker is to disconnect the control voltage source and then reenergize.
Investigation of this problem has determined that the problem results from the control wiring of the trip-coil.
It was CP&L-Ebasco's intent to monitor the trip coil both in the-breaker closed and breaker open position. This is not a Siemens-Allis standard wiring techniquej so they were unaware that there is sufficient current through the green (open) indicator light circuit to hold the trip coil in an energized state once the breaker is tripped.
4 DATE PROBLEM OCCURRED:
Refer to above section.
DATE PROBLEM REPORTED:
On March 26, 1984, CP&L (N. J. Chiangi) notified the NRC (Mr. A. Hardin) that this item was potentially reportable under 10CFR50.55(e) and 10CFR, Part 21.
' On April 20, 1984, CP&L (K. V. Hate'). notified the NRC (Mr. A. Hardin) that this item wms reportable under 10CFR50.55(e) and 10CFR, Part 21.
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. SCOPE OF
' PROBLEM:
This problem affacts all'safaty'and nonsafety.
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breakers as' supplied by'Siemens-Allis under Ebasco Purchase Orders NY-435112-and NY-435113.
For the' nonsafety breakers, this.is not a safety concern, but~
it is an operational limitation.- This will affect 25 safety. breakers and 57.nonsafety breakers.
j SAFETY.
IMPLICATION:
Safety-related; loads during.a. loss of coolantJ accidentfand loss of off-site power will be tripped-from the' plant' electrical system and' reloaded onto the emergency _ diesels..;As_ presently wired.,some of the breakers could. fail to reclose following the-
- transfer-to the emergency diesel generators.
REASON
. DEFICIENCY IS j.
REPORTABLE:
This is reportable as.a design error since, as presently designed, the switchgear could prove-to be inoperative during a plant emergency condition,.such i
as loss of coolant accident or any other circumstance; j
- requiring the initiation of loads onto th'a plant emergency power system as supplied by the. emergency diesel generators.
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' CORRECTIVE ACTION:
1.
Rewiring of the green indicator lights to the negative side of the trip coil will eliminate the current flow through the indicator lights from holding the trip; coil in an energized state l-following the tripping of a. breaker.
2..
'Since as presently wired there is not sufficient length of wire to move the wire from the green.
j indicator light to the negative terminal of the trip coil, Siemens-Allis will supply a now wire to go from the 52b contact to the negative terminal of'the trip coil. The existing wiring from the 52b contact to the high. side of the-e trip coil will be removed and discarded.. This work will be performed'by CP&L Operations personnel. The equipment will be cycled to 1
verify proper operation prior to the. breaker-being placed back into' service.
Rewiring and-testing of all Siemens-Allis supplied breakers will complete the corrective action required for this deficiency..
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. FINAL REPORT: _All repair work on the breakers has been completed;;
however, not all circuit breakers have been cycled.-
We project that all corrective action will be,
completed and a final report issued by November 9,'
1984..
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