ML19319E426
| ML19319E426 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 03/06/1974 |
| From: | Phillips J ARKANSAS POWER & LIGHT CO. |
| To: | Moseley N NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| Shared Package | |
| ML19319E427 | List: |
| References | |
| NUDOCS 8004100705 | |
| Download: ML19319E426 (3) | |
Text
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H EL PIN G BUILO A R o< A N S A k
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v ARKANS AS POWER & LIGHT COMPANY i
AVENUE AND PIN..TAEET
- PINE OLUFF, ARKAN.A9 71601 e (5011534-1330 STH March 6, 1974 Norman C. Moseley, Director United States Atomic Energy Commission 71 rectorate of Regulatory Operations Region II - Suite 818 230 Peachtree Street, Northwest Atlanta, Georgia 30303 SUBJFCT: ARKANSAS POWER & LIGHT COMPANY ARKANSAS NUCLEAR ONE - UNIT 1 DOCKET NO. 50-313 INVERTER QUESTIONS RO:II:MSK 50-313/73-19
Dear Mr. Moseley:
In reply to your letter dated January 21, 1974, (
Reference:
RO:II:
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MSK 50-313/73-19) you raised two questions with regard to the loose
[V inverter connections reported in our report of October 31, 1973. The following is our answer to each of the two questions:
Question 1: "The exact cause of loose connections".
Reply: As reported by Solidstate Controls Inc., the vendor for the plant inverters, the problem of loose connections was localized to a defect in the solidity of the connections between the stripped ends of certain wires and the terminal lugs crimped thereon. After thorough investigation by the vendor it became apparent that a wrong setting was used on the crimping tool. Although the lugs had been crimped tight enough to withstand the visual and mechanical checks normally provided, evidently the crimp was not tight enough to withstand possible metal flow in the field over a period of time.
Question 2:
"A discussion of how your quality assurance program per-mitted the deficiency to occur. In particular, please discuss those actions planned or taken to improve the effectiveness of your quality assurance program in preventing such failures".
Reply: This question is answered in two parts. First, how the Quality All terminal Assurance program permitted this deficiency to occur.
connections were visually and mechanically checked. Crimping tools have been checked on a periodic basis. In this case, it is apparent O
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R Mr. Norman C. Moseley March 6, 1974 that the workman selected the wrong setting inadvertently and the setting was not far enough off to be caught by the inspection procedure. In answer to the second part of this question as to what plans or actions within ours as well as vendor's Quality Assurance program were taken.to prevent such failures in the future. All parties: AP&L, Bechtel and the vendor have been alerted to this problem and to its seriousness. The vendor has taken an action in making their production people aware of this problem its seriousness and to re-educate them in the use of the automatic crimping tool. The second safeguard which is instigated by the vendor requires a 100% inspection of equipment connections prior to being shipped with a more intense mechanical stress type inspection along with the visual inspection. This more intense mechanical stress type inspection eliminates the possibility of sbnilar deficiency.
Finally it should be recorded that in view of this deficiency, all inverters of our plant have been totally re-inspected by this re-inspection and we are assured that no further deficiency exists.
Very truly yours,
%s. D. Phillips Senior Vice President JDP: NAM:bw i
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' Letter from Arkansas Power and Light Company, J. D. Phillips' MM 25 M 50-313/73-19 dated March 6, 1974 i
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