ML20113E643
| ML20113E643 | |
| Person / Time | |
|---|---|
| Site: | Harris  |
| Issue date: | 03/21/1985 |
| From: | Parsons R, Parsons Rm CAROLINA POWER & LIGHT CO. |
| To: | Grace J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| CON-NRC-336 207, NUDOCS 8504160563 | |
| Download: ML20113E643 (4) | |
Text
'J.g 4 Cp&L Carolina Power & Light Company
____m ew 11, C.
27562 P. O. g Dr. J. Nelson Grace NRC-336 United States Nuclear Regulatory Commission Region II 101 Marietta Street, Northwest (Suite 2900)
Atlanta, Georgia 30323 CAROLINA POWER & LIGHT COMPANY SHEARON HARRIS NUCLEAR POWER PLANT 1986 - 900,000 KW - UNIT 1 CABLE SIZING DEFICIENCY, ITEM 207
Dear Dr. Grace:
Attached is an interim report on the subject item which was deemed reportable per the provisions of 10CFR50.55(e) on February 19, 1985. CP&L is pursuing this matter, and it is currently projected that corrective action and submission of the final report will be accomplished by April 30, 1985.
Thank you for your consideration in this matter.
Yours very truly, g
22: e h M. Parsons Project General Manager Completion Assurance Shearon Harris Nuclear Power Plant RMP/bc Attachment cc: Messrs. G. Maxwell /R. Prevatte (NRC-SHNPP)
Mr. R. C. DeYoung (NRC) 8504160563 850321 PDR ADOCK 05000400 S
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CAROLINA POWER & LIGHT COMPANY SHEARON HARRIS NUCLEAR POWER PLANT UNIT 1 INTERIM REPORT PROTECTING # 10 AWG CONDUCTOR WITH A 100 AMP BREAKER NCR 85-279 ITEM 207 MARCH 18, 1985
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REPORTABLE UNDER 10CFR 50.55(e) t 4
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SUBJECT:
Shearon Harris Nuclear Power Plant Unit'No. 1 10CFR50.55(e) reportable deficiency involving the use of a 100 amp circuit breaker with a
- 10 AWG conductor cable.
ITEM:
Auxiliary Transfer Panel Power Feeder Design.
NATURE OF DEFICIENCY:
The breaker-conductor interface is such that in
-w the event of a severe circuit overload or a relatively high resistance short circuit, sufficient current would be co. ducted by the
- 10 AWG conductor to damage the conductor insulation and this current would not be sufficient to trip the breaker.
DATE PROBLEM IDENTIFIED:
This item was discovered on January 28, 1985, and identified via NCR 85-279 on February 4, 1985.
DATE PROBLEM REPORTED:
On Februar'y 19, 1985, CP&L (Mr. N. J. Chiangi) notified the NRC (Mr. A. Hardin) that the item was reportable por the provisions of 10 CFR 50.55(e).
A
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,S' COPE OF PROBLEM:
This problem was discovered to occur at each of 3
two redundant auxiliary transfer panels.
,w SAFETY
- ~
IMPLICATIONS:
Should the. control room become uninhabitable r
during a fire or similiar emergency, the auxiliary
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transfer panels are required to allow controlled shutdown from the remote shutdown panels. The N-inability of the breaker to preclude or even mitigate conductor damage compromises the reliability of the power feed to the auxiliary transfer panel.
REASON DEFICIENCIES ARE REPORTABLE:
As damaging current levels are believed creditable for the originally designed and/cr installed. power feed conductors, the ability of the auxiliary transfer panels to perform their safety function of allowing remote controlled shutdown is compromised.
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CORRECTIVE ACTION:
The subject i 10 AWG conductor was replaced with a # 2 AWG conductor per FCR-E-4052. An administrative action has been taken to more closely-monitor and control cable size design in HPES electrical. Cable sizing and re-sizing verification at SHNPP is to be f
controlled with consideration given to load L
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and circuit length.
FINAL REPORT:
The final report on this item is pending review and verification of the corrective actions taken. It is currently projected that the final report will be issued by
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April 30, 1985.
IBMD-RHS001-OS4
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