ML20024D555
| ML20024D555 | |
| Person / Time | |
|---|---|
| Site: | Bellefonte  |
| Issue date: | 07/29/1983 |
| From: | Mills L TENNESSEE VALLEY AUTHORITY |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, NUDOCS 8308050240 | |
| Download: ML20024D555 (3) | |
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83 Atjc 2 A10 : 26 0.* g July 29, 1983 BLRD-50-438/83-11 U.S. Nuclear Regulatory Commission Region II Attn:
Mr. James P. O'Reilly, Regional Administrator 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30303
Dear Mr. O'Reilly:
BELLEFONTE NUCLEAR PLANT UNIT 1 - GENERAL ELECTRIC MOTORS EXCEED RATED LOAD
- BLRD-50-438/83 FINAL REPORT The subject deficiency was initially reported to NRC-0IE Inspector P. E. Fredrickson on January 10, 1983 in accordance with 10 CFR 50.55(e) as NCR 1976. This was followed by our interim report on February 8, 1983 Enclosed is our final report.
In our previous report TVA had stated that the premature motor failures documented in NCRs 2102 and 2285 (BLRD-50-438/83-02) may have been due to long-term overload. However, investigation has shown that the premature failures were not caused by this condition as there was insufficient evidence of overheating of the entire winding. Also, the failures were located in either the top coil in the stator slot at the end, or the stator core, which suggests that the failures could not have been primarily caused by the motor overheating due to the plugged air passages in the stator. Consequently, TVA no longer considers NCRs 2102 and 2285 related to NCR 1976.
TVA does not now consider the subject nonconforming condition adverse to the safe operation of the plant. Therefore, we will amend our records to delete the subject nonconformance as a 10 CFR 50.55(e) item.
t If you have any questions, please get in touch with R. H. Shell at FTS 858-2688.
Very truly yours, TENNESSEE VALLEY AUTHORITY t
L. M. Mills, Manager Nuclear Licensing Enclosure cc:
Mr. Richard C. DeYoung, Director (Enclosure)
Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, D.C.
20555 cc: See page 2
~~IO1FICIANCM 8308050240 830729 383-TVA SOTH ANNIVERSARY y
DRADOCK05000h An Equai opportunity Employer
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U.S. Nuclear Regulatory Connaission July 29, 1983 Records Center (Enclosure)
Institute of Nuolear Power Operations 1100 circle 75 Parkway, Suite 1500 Atlanta, Georgia 30339 i
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ENCLOSURE BELLEFONTE NUCLEAR PLANT UNIT 1 GENERAL ELECTRIC MOTORS EXCEED RATED LOAD BLRD-50-438/83-11 NCR 1976 10 CFR 50.55(e)
FINAL REPORT Description of Deficiency Current readings taken on two 150 hp General Electric (GE) induction motors supplied by Ingersoll Rand (I-R), Chamblee, Georgia, exceeded their nameplate value of 195 amperes. The increased current could be partially attributeg to TVA operating the comgressors at a discharge pressure of 110 lb/in instead of the 100 lb/in originally specified in the contract.
Safety Implications As specified in TVA contract 76K31-86849, the subject motors were to be operated 2
at 100 lb/in g and 720 sofm air delivery. After the compressors were delivgred TVA requested that the operating pressure be increased to 110 lb/in g.
Subsequently, I-R agreed to reset the compressor safety valves for proper operation at the increased discharge pressure. Measurements were taken in the field which have shown tgat at the design conditions of 720 sofm and a discharge pressure of 100 lb/in g, the co= pressors required 149.88 hp from the 150 hp motor instead of the 140 hp value provided to TVA by I-R.
Operation at the increased discharge pressure requires the motor to operate at approximately 110 percent of the nameplate rating. However, the subject motors are capable of electrical operation at 115 percent of the nameplate rating on a continuous basis.
Although the motors age capable of continuous operation at the increased pressure of 110 lb/in, TVA will replace the existing motors (under engineering change notice (ECN) 1916) with motors that meet ~the'present quality assurance and environmental qualification requirements. The specification for the replacement motors will not allow continuous operation within the service factor horsepower range which will ensure that the current required by the motor will not exceed the value shown on the motor nameplate during normal operation.
Inasmuch as the subject motors are capable of electrical operation at 115 percent of the nameplate horsepower rating on a continuous basis it is our conclusion that there are no conditions adverse to the safe operation of the plant concerning this specific deficiency, and we no longer consider 10 CFR 50.55(e) applicable.
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