ML20040B213
| ML20040B213 | |
| Person / Time | |
|---|---|
| Site: | Susquehanna  |
| Issue date: | 01/07/1982 |
| From: | Curtis N PENNSYLVANIA POWER & LIGHT CO. |
| To: | Haynes R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| REF-PT21-81 10CFR-050.55E, 10CFR-50.55E, PLA-992, NUDOCS 8201250273 | |
| Download: ML20040B213 (4) | |
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M43 Pennsylvania Power & Light Company Two North t[inth Street
- Allentown, PA 18101 + 215 / 770-5151 Norrnan W. Curtis Vice President-Engincenng & Construction-Nuclear 215 / 770-5381 January 7, 1982 Mr.
R. C. Ilaynes Director, Region I U. S. Nuclear Regu?atory Commission 631 Park Avenue King of Prussia, PA 19406 a
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SUSQUEHANNA STEAM ELECTRIC STATION INTERIM REPORT OF A DEFICIENCY INVOLVING FAILURE OF MAC ADAPT TYPE 4/0 CONNECTORS ERs 100450/100508 FILE 821-10 PLA-992
Dear Mr. If aynes :
This letter serves to provide the Commission with an interim report of a deficiency involving the failure of Mac Adapt Type MPT 4/0 electrical connectors. The failure of these connectors on the 600 volt power cable terminations was discovered during post turnover rework when cables were determinated. The factory installed stranded copper pigtail fell out of the Mac Adapt MPT 4/0 connector.
During a telephone conversation on December 7, 1981, Mr. E. C. McCabe of NRC Region I was originally advised by Mr. A. R.
Sabol of PP&L that the condition was considered to be potentially reportable under the provisions of 10 CFR 50.55(e).
The attachment to this letter contains a description of the problem, the cause of failure, an analysis of safety implications, and planned corrective action.
Bechtel NCR 8200 addresses the Mac Adapt Type MPT 4/0 connector failure.
PP&L anticipates providing the Commission with a final report in March 1982 after evaluation of radiographic pass / fail criteria and final corrective action.
Since the details of this report provide information relevant to the reporting requirements of 10 CFR 21, this correspondence is considered to also discharge any formal responsibility PP&L may have in compliance thereto.
Very truly yours, O
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kGL'Y
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N. W. Curtis Vice President-Engineering & Construction-Nuclear i
JBW:sab 8201250273 820107 PDRADOCKOS000g Attachment sf S
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o January 7, 1982 2
SSES PLA-992 ERs 100450/100508 File No. 821-10 cc:
Mr. Richard C. DeYoung (15)
Director-Office of Inspection & Enforcement U.
S. Nuclear Regulatory Commission Washington, D.C.
20555 Mr. G. Mcdonald, Director Office of Management Information & Program Control U. S. Nuclear Regulatory Commission Washington, D.C.
20555 Mr. Gary Rhoads U. S. Nuclear Regulatory Commission P. O. Box 52 Shickshinny, PA 18655
Attachment to PLA-992 Subject Mac Adapt Type MPT 4/0 electrical connectors Description of Problem The Mac Adapt Series MPT Compression Adaptors are constructed of an aluminum barrel with a tinned stranded copper conductor pigtail protruding out one end of the barrel. The other end of the barrel is open to allow installation of the connector onto the end of the cable. There is a solid aluminum barrier between the open end of the connector barrel and the end containing '.he copper pigtail.
The copper pigtail is permanently bonded to the connector by impounding the stranded copper conductor into the aluminum barrier.
The Mac Adapt Series MPT Compression Adaptors are used at Susquehanna Steam Electric Station for 600 volt power cable terminations on aluminum cables size 4/0 and larger when these cables are directly terminated in equipment having mechanical lugs which cannot be converted to accept a Burndy Compression lug due to physical or practical limitations. After the copper pigtail conductors of Mac Edapt MPT 4/0 connectors have been distorted due to mechanical termination at the equipment, the copper pigtail conductors separate from the connector barrel.
Two instances have been sighted.
1.
Cable UPIT0408D (Non-Q) in Panel IN1503.
2.
Cable EPIQ4191B (Q) in Panel 1C215A.
Cause of Failure I
i There is evidence that the stranded copper pigtail was not inserted far enough f
into the barrel during the manufacturing process. This resulted in the copper pigtail strands separating from the barrel after distortion of the original strand f
configuration during termination at the equipment.
I e
Analysis of Safety Implications Failure of Mac Adapt Type MPT connectors installed in Class lE Circuits required for the safe shutdown of the plant would render the associated equipment powered by those Class 1E Circuits inoperable.
Insufficient information concerning the number and location of possible deficient connectors installed at Susquehanna l
l Steam Electric Station currently exists for PP&L to arrive at a final determination j
on reportability; therefore, PP&L considers this condition to be potentially l
l reportable under the requirements of 10 CFR 50.55(e). Final determination on reportability will be made based on the results of the inspection of the installed i
Mac Adapt Type MPT Connectors.
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Page 1 cf 2 e
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Attachment to PLA-992 Corrective Action a
Bechtel NCR No.,8200, dated 9/30/81, documents the two instances of Mac Adapt Series MPT 4/O adaptor failures. The NCR has been forwarded to Bechtel SFHO Engineering for disposition.
The following actions have been taken to date.
1.
All Mac Adapt Series MPT Connectors in stock at Susquehanna SES have been radiographec.
2.
The connector manufacturer has been requested by Bechtel to provide pass /
fail criteria to evaluate the radiographs for proper pigtail insertion in the barrel of the connectors.
Information was subsequently provided by the manufacturer and has been forwarded to Bechtel SFHO Enginee or evaluation.
3.
Bechtel is in the process of determining the location of all Mac Adapt Series MPT Connectors installed at Susquehanna SES.
The following actions are currently planned:
1.
All Mac Adapt Series MPT Connectors installed in Class lE and affiliated circuits will be radiographed.
2.
Assistance from the manufacturer will be obtained to evaluate the radiographs.
3.
All defective connectors will be replaced.
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