ML20134G756
| ML20134G756 | |
| Person / Time | |
|---|---|
| Site: | Bellefonte  |
| Issue date: | 08/05/1985 |
| From: | Hufham J TENNESSEE VALLEY AUTHORITY |
| To: | Grace J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| NUDOCS 8508280070 | |
| Download: ML20134G756 (2) | |
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TENNESSEE VALLEY AUTHORITY CHATTANOOGA. TENNESSEE 374o1 1630 Chestnut Street Tower II August 5, 1985 0
BLRD-50-438/85-06 BLRD-50-439/85-06 U.S. Nuclear Regulatory Commission Region II Attn:
Dr. J. Nelson Grace, Regional Administrator 101 Marietta Street,_NW, Suite 2900 Atlanta, Georgia 30323
Dear Dr. Grace:
BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 - THE VARIANCE IN THE 120V AC AU POWER SUPPLY EXCEEDS SPECIFICATION - PLRD-50-438/85-06 AND BLRD-50-439/85 SECOND INTERIM REPORT The subject deficiency was initially reported to NRC-OIE Inspector
~
Al Ignatonis on, December 20, 1984 in accordance with 10 CFR 50.55(e) as NCR BLN EEB 8419.
This was followed by our first interim report dated January 21, 1985 in which we erroneously stated that the next submittal would be June 7, 1985 instead of August 6, 1985.
Enclosed it our second interim report. We expect to submit our next report on or about August 10, 1987.
If you have r.f questions, please get in touch with R. H. Shell at FTS 858-2688.
Very truly yours, TENNESSEE VALLEY AUTHORITY J. W. Hufham, Manager Licensing and Risk Protection Enclosure Mr. James Taylor, Director (Enclosure) cc:
Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, D.C.
20555 Records Center (Enclosure)
Institute of Nuclear Power Operations 1100 circle 75 Parkway, Suite 1500 Atlanta, Georgia 30339 85082800'70 850805 PDR ADOCK 05000438 S
PDR An Equal Opportunity Employer g@9
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t BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 THE VARIANCE IN THE 120V AC AUXILIARY POWER SUPPLY EXCEEDS SPECIFICATION BLRD-50-438/85-06 AND BLRD-50-439/85-06 10 CFR 50.55(e)'
NCR BLN EEB 8419 SECOND It~TERIM REPORT Description of Deficiency The minimum possible voltage levels on the 120V ao auxiliary power system (EK), trains A and B, buses may not meet the manufacturer's voltage l specifications for class 1E' instrument loads supplied by these buses. The class 1E 6900V buses can vary minus 5 percent from nominal before operator action is required. The 6900/480V transformer regulation may exceed minus 5 percent under worst case conditions. These cumulative source regulations plus a minus 3.6-percent regulation of the 120V instrument transformer could result in system EK voltage that will not meet specification.
Interim Progress
- TVA will replace the existing nonregulated tr nsfbemers with self-regulated control transformers. TVA will submit the next report on this deficiency upon procurement of satisfactory replacement transformers.
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