ML20096E151
| ML20096E151 | |
| Person / Time | |
|---|---|
| Site: | Bellefonte  |
| Issue date: | 08/14/1984 |
| From: | Mills L TENNESSEE VALLEY AUTHORITY |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| NUDOCS 8409060428 | |
| Download: ML20096E151 (2) | |
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TENNESSEE VALLEY AUTHORITY c
CH ATTANOOGA. TENNESSEE 374ot 400 Chestnut Street Tower II 34 AUG 2028st31423984 BLRD-50-438/83-25 BLRD-50-439/83-20 U.S. Nuclear Regulatory Commission Region II Attn:
Mr. James P. O'Reilly, Regional Administrator 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323
Dear Mr. O'Reilly:
BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 - MANUAL ADJUSTMENT OF DIESEL GENERATOR SETPOINTS - BLBD-50-438/83-25, BLRD-50-439/83 FINAL REPORT The subject deficiency was initially reported to NRC-0IE Inspector P. E. Fredrickson on March 9,1983 in accordance with 10 CFR 50.55(e) as NCR BLN EEB 8302. This was followed by our interim reports dated April 6 and October 26, 1983 and February 23, 1984. Enclosed is our final report.
If you have any questions, please get in touch with R. H. Shell at FTS 858-2688.
Very truly yours, TENNESSEE VALLEY AUTHORITY 4
L. M. Mills, Fanager Nuclear Licensing Enclosure cc:
Mr. Richard C. DeYoung, Director (Enclosure)
Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, D.C.
20555 Records Center (Enclosure)
Institute of Nuolear Power Operations 1100 Circle 75 Parkway, Suite 1500 Atlanta, Georgia 30339 8409060428 840814 PDR ADDCK 05000438 S
PDR UFFICIAL GOPY An Equal Opportunity Employer
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ENCLOSURE i
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_..#4 BELLEFONTE NUCLEAR PLANT UNITS 1' AND 2 MANUAL. ADJUSTMENT OF DIESEL GENERATOR SETPOINTS BLRD-50-438/83-25, BLRD-50-439/83-20 2
NCR BLN. EEB 8302 FINAL' REPORT Descriptioniof Deficiency.
For the star 41byLdiesel" generators at Bellefonte, - them are manual voltage and frequency controls in the main control room which can adjust the voltage and/or frequency levels of one or more diesel generators to values below the ready-to-load set points used during the automatic start-automatic -load sequence. -. Because the diesel generators lack an automatic -
reset capability for output voltage and frequency during automatic starts, low manuel setting would prevent the misadjusted generator (s) from
' initiating the automatic load sequence. ' Also, since adjustments away from.
acceptable values are not. alarmed, the misadjustment(s) could go undetected until after an automatic start is initiated.
This' situation was caused by a fa'ilure on the part of TVA' to anticipate that operators would be adjusting the generators to values below the ready-to-load set points and a. subaequent failure to mquire an automatic mset of voltage and.frequenc,y. capability in the procurement documents concerning the diesel gmerator controls.
Safety Implications Because the standby diesel generator systems lack the automatic reset capability for voltage and frequency, misadjustment of voltage and/or frequency levels could delay ce prevent the generation of sufficient on-site standby power to rerve necessary safety-related systems. This situation could adversely affect safe operation of the plant.
Corrective Action TVA has purchased th'e necessary equipment from Transamerica Delaval to modify the diesel generator control circuits for an automatic voltage and frequency reset capability and is mvising the control circuit drawings through engineering change, notice (ECN) 2458. All necessary design and construction ' work is expected to be completed by June 3,1986.
To nrevent a recurrence of this deficiency, the TVA standard diesel generator specification No.: 3887 now contains the requirement for automatic reset of voltage and frequency to mady-to-load set' points upon receipt of an emergency start signal. '
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