ML20090M541
| ML20090M541 | |
| Person / Time | |
|---|---|
| Site: | Harris  |
| Issue date: | 05/17/1984 |
| From: | Parsons R CAROLINA POWER & LIGHT CO. |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| CON-NRC-217, REF-PT21-84-240-000 168, PT21-84-240, PT21-84-240-000, NUDOCS 8405290052 | |
| Download: ML20090M541 (5) | |
Text
Cp&L Carolina Power & Light Company
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P. O. Box 101, New Ilill, N. C. 27562 May 17,1984 Mr. James P. O'Reilly NRC-217 United States Nuclear Regulatory Commission Region II 101 Marietta Street, Northwest (Suite 2900)
Atlanta, Georgia 30303 CAROLINA POWER & LIGHT COMPANY SIIEARON IIARRIS NUCLEAR POWER PLANT 1986 - 900,000 KW - UNIT 1 6.9 Kv SWrrCHGEAR CIRCUIT BREAKERS - GENERIC -ITEM 168
Dear Mr. O'Reilly:
Attriched is an interim report on the subject item which was deemed reportable per the provisions of 10CFR50.55(e) and 10CFR, Part 21, on April 20, 1984. CP&L is pursuing this matter, and it is currently projected that corrective action and submission of the final reyrt will be accomplished by July 31,1984.
Thank you for your consideration in this matter.
1 Yours very truly, W
2 ' ^vA R. M. Parsons Project General Manager Shearon liarris Nuclear Power Plant RMP/sh Attachment ec:
Messrs. G. Maxwcll/R. Prevatte (NRC-SIINPP)
Mr. R. C. DeYoung (N RC)
OtTICIAL COPY 8405290052 840517 Od[
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CAROLIFA POWER'& LICHT COMPANY SHEARON HARRIS NUCLEAR POWER PLANT t
UNIT NO. 1 IFTERIM REPORT 6.9KV SWITCHCEAR CIRCUIT BREAKERS
~ (CIRCUIT BREAKER CONTROL WIRING CONFIGURATION)
ITEM 168 MAY 16, 1984 6
6 REPORTABLE l'NDER 10CFR50.55(e) AND 10CFR21
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SUBJECT:
Sh:2ron Harris Nuclear Pow 2r Plcnt/ Unit No. I 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.
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Wiring for 6.9kV switchgear breakers SUPPLIED BY:
Siemens-Allis, Inc., Sanford, North Carolina NATURE OF D FFICIENCY :
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-up testing 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 the breaker open position.
This is not a Siemens-Allis standard wiring technique, 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.
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 reportabic under 10CFR50.55(e) and 10CFR, Part 21.
On April 20, 1984, CP&L (K. V. Hate') notified the NPC (Fr. A. Hardin) that this item was reportable under 10CFR50.55(e) and 10CFR, Part 21.
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SCOPE OF PROBLEM:
This problem affects all safety and nonsafety 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.
SAFETY IMPLICATION:
Safety-related loads during a loss of coolant accident and 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.
R EASON DEFICIE?CY IS R FTORTAPLE:
This is reportabic as a design error since, as presently designed, the switchgear could prove to be inoperative during a plant emergency condition, such as a loss of coolant accident or any other circumstance requiring the initiation of loads onto the plant erergency power system as supplied by the emergency diesel generators.
CCRRTCTIVE 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 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 indicator light to the negative terminal of the trip coil, Siemens-Allis will supply a new 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 trip coil will be removed and discarded.
This work will be performed by CP&L Operations personnel. The equiprer.t will be cycled to 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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,,:s FINAL REPORT:.~ Based. on projected delivery and installation of the required wiring to.all breakers, the final report is projected to. be issued - by July 31, 1984.
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