ML20112D342
| ML20112D342 | |
| Person / Time | |
|---|---|
| Site: | Harris  |
| Issue date: | 12/18/1984 |
| From: | Parsons R CAROLINA POWER & LIGHT CO. |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| CON-NRC-308, REF-PT21-84, REF-PT21-85-023-000 186, PT21-85-023-000, PT21-85-23, NUDOCS 8501140223 | |
| Download: ML20112D342 (5) | |
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P.O. Box 101, New Hill, NC 27562 December 18,1984 Mr. James P. O'Reilly NRC-308 United States Nuclear Regulatory Commission Region 11 101 Marietta Street, Northwest (Suite 2900)
Atlanta, Georgia 30323 CAROLINA POWER & LIGHT COMPANY SHEARON HARRIS NUCLEAR POWER PLANT 1986 - 900,000 KW - UNIT 1 6.9 KV SWITCHGEAR CIRCUIT BREAKERS, ITEM 186
Dear Mr. O'Reilly:
Attached is an interim report on the subject item which was deemed reportable per the provisions of 10CFR50.55 (e) and 10CFR, Part 21, on November 30,1984. CP&L is pursuing this matter, and it is currently projected that corrective action and submission of the final report will be accomplished by February 15;1985.
Thank you for your consideration in this matter.
Yours very truly, fppp?kie :=
R. M. Parsons Project General Manager Completion Assurance Shearon Harris Nuclear Power Plant RMP/das cc:
Messrs. G. Maxwell /R. Prevatte (NRC-SHNPP)
Mr. R. C. DeYoung (NRC) 8501140223 841218 PDR ADOCK 05000400 S
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CAROLINA POWER & LIGHT COMPANY SHEARON HARRIS NUCLEAR POWER PLANT UNIT 1 INTERIM REPORT SECONDARY DISCONNECT LUGS ANTI-PUMP RELAY JUMPER ITEM 186 c
DECEMBER 14, 1984 REPORTABLE UNDER 10CFR50.55(e) AND 10CFR21 s
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SUBJECT:
Shearon Harris Nuclear Power Plant Unit No. 1 10CFR50.55(e) and 10CFR Part 21 Reportable Deficiencies 1.
Lugs on the secondary disconnect of circuit breakers are bent 90* or more upon installation.
Many show signs of metal fat ;ue.
2.
Internal wiring to the anti-pump relay in some instances rests on a rotating shaft of the charging spring motor. Failure of these leads could rendor the anti-pump relay inoperative.
ITEM:
6.9kV Switchgear Circuit Breakers SUPPLIED Tif:
Siemens-Allis, Inc., Sanford, North Carolina NATURE OF DEFICIENCIES:
1.
The terminals on the secondary disconnects of the subject breakers are aesigned such that_when straight lugs are installed they are bent approximately 90* co accommodate internal wiring l-exiting the side _of the breakers and to clear' the contact scrfaces when the breakers are racked into cubicles.
In some cases, this bend results in metal fatigue to_the point of-cracking of'the lug. -Operation of the breaker could cause a cracked lug to break and result in breaker failure.
2.
The location of theranti-pumpirelay within the breakeriis above the rotating shaft of-the spring charging motor.- In certain instances, leads to the~ relay are in contact with the:
rotating shaft. Rotation of the shaft, in time, could wear through the lead insulation and result in a short circuit, causing the anti-pump.
relay-to fail under a fault. condition.
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i DATE PROBLEM IDENTIFIED:
1.
The secondary disconnect lug problem was first identified in a QA receipt inspection leading to issuance of NCR-84-0573 (March 20, 1984).
Though originally thought to be an isolated problem, further inspection by site and vendor personnel detected many cracked lugs randomly among safety and nonsafety-related breakers.
This item was identified by RPES on August 23, 1984.
2.
The leads to the anti-pump relay resting on the rotating shaft within the circuit breaker were identified by Operations personnel on August 23, 1984.
DATE PROBLEM REPORTED:
On September 7, 1984, CP&L (N. J. Chiangi) notified the NRC (Mr. A. Hardin) that the above items were potentially reportable under 10CFR50 55(e) and 10CFR, Part 21.
On November 30, 1984, CP&L (K. V. Hate') notified the NRC (Mr. D. Verrelli) that the above items were reportable under 10CFR50.55(e) and 10CFR, Part 21.
SCOPE OF PROBLEM:
The two items outlined could occur in any of the safety and nonsafety breakers supplied by
- Siemens-Allis under Ebas<a Purchase Orders NY-435112 and NY-435113 (25 safety creakers and 57 nonsafety breakers).
SAFETY IMPLICATIONS:
1.
Control and indication power for each 6.9kV circuit breaker is wired'through the secondary disconnect. Broken lugs at the disconnect could-cause problems, such as faulty indication of breaker condition; failure of breaker to trip; failure of breaker to reclose; or loss'of-control of the breaker preventing the breaker from performing its safety function.
2.
A short in the jumpers to the anti-pump relay will result in failure of the relay. This may.
result in the breaker inadvertently opening and-closing rapidly under fault conditions.
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REASON DEFICIENCIES ARE REPORTABLE:
The deficiencies are reportable because the switchgear breakers could be inoperable during a plant emergency condition and compromise safety system redundancy and adversely reduce the degree of protection to public health by contributing to the exceeding of reactor safety limits.
CORRECTIVE ACTION:
Reportable items have been discussed with Siemens-Allis for their review. Secondary disconnect lugs are being replaced and wiring will be retrained in the breaker.
FINAL REPORT: CP&L will complete final evaluation upon completion of work on the breakers. This is scheduled for January 31, 1985.
It is currently projected that the final report will be issued by February 15, 1985.
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