ML20031H280
| ML20031H280 | |
| Person / Time | |
|---|---|
| Site: | Susquehanna  |
| Issue date: | 10/16/1981 |
| 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-945, NUDOCS 8110270320 | |
| Download: ML20031H280 (4) | |
Text
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@ Pennsylvania Power & Light Company se.n e)
Two North Ninth Street
- Allentown, PA 18101
- 215 1 770 5151 Norman W. Curtis Vice President-Engineering & Construction Nuclear 215 / 770-5381 October 16, 1981 3
Mr. R. C. Haynes Director, Region I U. S. Nuclear Regulatory Commission 631 Park Avenue
" f / qf King of Prussia, PA 19406 V/
SUSQUEHANNA STEAM ELECTRIC STATION Iftren!M REPORT OF A DEFICIENCY IN AMERICAN h
O $8De-t-
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e,ro e car INSULA'.'ED WIRE 600 VOLT CABLE ERs 100450/100508 FILES 840-4/821-10 k,
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'y, 4'N PLA-945
Dear Mr. Haynes:
This letter serves to provide the Commission with an interim report of a deficiency involting the failure of American Insulated Wire to pass qualification testing. The problem was originally reported under the provisions of 10 CFR 50.55(e) in a telephone conversation between Mr. A. Sabol of PP&L and Mr. E. McCabe of NRC Region I on September 1, 1981. The information contained in this report is submitted pursuant to the requirements of 10 CFR 50.55(e).
The attachment to this letter contains a description of the problem, its s:nuse, safetir implications and the corrective action planned. Since the details of this report provide information relevant to the reporting requirement of 10 CFR 21, this correspondence is considered to also discharge any formal responsibility PP&L may have in compliance thereto.
We expect to issue a final report on the deficiency in December,,1981.
Very truly yours, gQ)
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N. W. Curtis l
Vice President-Engineering & Construction-Nuclear l
FLWesab Attachment 8110270320 811016" PDR ADOCK 05000387 S
T Mr. R. C. Haynes October 16, 1981 cc:
Mr. Victor Stello (15)
Director-Office of Inspection & Enforcement U. S. Nuclear Regulatory Commicsior-Washington, D.C. 20555 Mr. G. Mcdonald, Director (1)
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 i
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,o ATTACHMENT TO PLA-945 Subject Failure of American Insulated Wire Corporation (AIW) 600 volt cable to pass a sequential mechanical and a
'.-383-1974 100 day environmental qualification test.
Description of Deficiency Four of six AIW 600 volt cab.
ich were subjected to 100 day environmental qualification testing per IEEE-383-1974 failed to pass the post-LOCA insulation resistance and/or dielectric strength tests.
The testing was undertaken tc determine if AIW cable known to have jacket manufacturing defects such us scrapes, pinholes, skips and bumps could with-stand the most severe environmental conditions postulated inside and outside containment at Susquehanna SES and retain suitable electrical characteristics.
Cable samples with known jacket defects were pulled through conduit to simulate as installed conditions (mechanical test) and then subjected to a 100 day environ-mental test.
On the seventh day of the 100 day test, the cables were removed from the LOCA chamber and subjected to dielectric strength and insulation resistance tests.
The cables tested sucessfully passed this part of the test.
Since the most severe environmental conditions outside of primary containment are postulated to be less severe than the seven day LOCA profile to which the cable was tested, the AIW cable was determined to be acceptable for use outside containment.
Upon completion of the 100 day environmental test, a non-destructive insulation resistance and dielectric strength test was performed on the cable. Four of the six cables tested failed the insulated resistance and/or the dielectric strength test. This sixty seven percent failure rate after the 100 day environmental test is considered to be unacceptable.
Cause of Fail;.re The cause of the failure is attributed to the gradual breakdown of the insulating material after sequential mechanical and environmental testing leading to overall failure of the insulation during a post-LOCA insulation resistance and/or dielectric stre.ngth test.
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The insulation breakdown during the post LOCA dielectric strength and insulation resistance tests could not be attributed specifically to the jacket defects, as the insulation breakdown occurred at numerous locations thoughout the cable length.
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e ATTACHMENT TO PLA-945 Analysis of Safety Implications i
The AIW 600 volt cable is used in Class lE, safety related power and control circuits inside primary containment at Susquehanna SES.
Failure of this cable on a Class lE circuit inside primary containment could adversely affect safe shutdown of the plant. Therefore, PP&L has concluded that l
d the failure of AIW 600 volt cable to successfully withstand the simulated LOCA environment is a significant deficiency, reportable under 10 CFR 50.55(e).
Corrective Action On Septemtor 4, 1981 PP&L NPE directed Bechtel to replace all AIW cable used on Class 10 circuits inside primary containment with qualified cable supplied by Boston Insulated Wire. AIW cable used on Class lE and non-Class lE circuits outside of primary containment will not be replaced.
Following the present schedule, all AIW cable used on Class lE circuits inside Unit #1 primary containment will be replaced by November 4, 1981. Only a small amount of the AIW cable scheduled for use on Class lE circuits inside Unit #,2 primary containment has been installed. This cable will be replaced and the balance of Class lE cables will be installed"following the Unit #2 cable installation schedule.
A final report on the deficiency and the corrective action undertaken will be provided in December, 1981.
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