ML20086K119
| ML20086K119 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 01/09/1984 |
| From: | Van Brunt E ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR |
| To: | Bishop T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| References | |
| REF-PT21-84 ANPP-28576-BSK, DER-83-35, NUDOCS 8401260248 | |
| Download: ML20086K119 (4) | |
Text
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crcr/ED wa' Arizona Public Service Company P.O. BOX 21666
- PHOENIX. ARIZONA 85036 I ] [ ]j { C
("!, l: l]
January 9, 1984-q;;T; *. -
- ANPP-28576-BSK/TRB U. S. Nuclear Regulatory Commission Region V Creekside Oaks Office Park 1450 Maria Lane - Suite 210 Walnut Creek, CA 94596-5368 sp 52 S Attention: Mr. T. W. Bishop, Director Division of Residect Reactor Projects and Engineering Programs Fr.bject :
Final Report - DER 83-35 A 50.55(e) Reportable Condition Relating to Inverters Supplied By Elgar Were Found To Produce Voltage Spikes on The DC Supply Bus.
File: 84-019-026; D.4.33.2
Reference:
A) Telephone Conversation between P. Narbut and R. Tucker on June 7, 1983 B) ANPP-24247, dated July 7,1983 (Interim Report)
C) ANPP-28095, dated October 26, 1983 (Time Extension)
Dear Sir:
Attached is our final written report of the Reportable Deficiency under 10CFR50.55(e), referenced above.
Very truly yours, k
cutf d'RLt \\^
E. E. Van Brunt, Jr.
APS Vice President Nuclear Projects Management ANPP Project Director EEVB/TRB:ru
-Attachment-cc:
See Page Two 8401260248 840109 ff PDR ADOCK 05000529 I
/EL l7 S
=
- Mr. T. i W. -Bishop DER-83-3 5 ~
Page Two ec:
Richard DeYoung, Director Office of Inspection and Enforcement ii U. S. Nuclear Regulatory Commission Washington, D. ~ C. 20555
. T. G. Wo od s, Jr.
J. A. Roedel D. B. Fasnacht A. C. Rogers B. S. Kaplan W.'E. Ide J. Vorees J. R. Bynum D. D. Green P. P. Klute A. C. Gehr W. J. Stubblefield W. G. Bingham R. L. Patterson R. W. Welcher H. Foster D. R. Hawkinson L. E. Vorderbrueggen G.'A.
Fiorelli S. R. Frost
. J. Self D. Canady Records Center Institute of Nuclear Power Operations 1100 Circle 75 Parkway, Suite 1500
' Atlanta, GA 30339
.i l
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f.
FINAL REPORT - DER 83-35
. DEFICIENCY EVALUATION 50.55(e)
PVNGS UNITS'1, 2; & 3 1.
Description of Deficiency Inverters supplied by' Elgar Corporation under specification 13-EM-054, were found to1 produce AC voltage spikes of 20 to 400 volts on the 125 VDC supply bus. The voltage spikes caused full scale deflection ~on the Diesel Generator RPM meter, which prevented the ' Diesel: Generator from operating properly.
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The inverters'are' identified by the following tag numbers:
1-E-PKC-N4 3 2-E-PKC-N43 3-E-PKC-N43 1-E-PKD-N44' 2-E-PKD-N44 3-E-PKD-N44 1-E-PNA-Nil 2-E-PNA-Nil 3-E-PNA-Nil
~1-E-PNB-N12
- 2-E-PNB-N12 3-E-PEB-N12 E-PNC-N13 2-E-PNC-N13 3-E-PNC-N13 1-E-PND-N14 -
2-E-PN D-N14 3-E-PND-N14 The ' Elgar service representative was called to the site to evaluate
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l the cause of this~ condition.-' Measurements were taken at.each single phase inverter for the four separation ' groups '(<A, B, C, and D) to
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determine the cause of the problem. The problem was identified to be the result of the high frequency snubber capacitor negative lead wire being run in the-same wire bundle as the unfiltered power wires. This condition-resuled in 20 to 40 volt AC spikes at~2000 Hz being superimposed on the 112VDC bus. -The negative lead wire on the
. inverters will be removed from the power wire Lundle, insulated and
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rerouted to the negative side of the incoming circuit breaker. This modification-reduces-the AC voltage spikes down to 2 to 4 volts which is an acceptable range.
II.
Analysis of Safety Implications The 125VDC vital bus is provided to power emergency equipment during l.
a design basis event (DBE). Stray or superimposed AC signals of a magnitude that would impair or render instrumentation or equipment
' inoperable.is unacceptable.
l The AC spikes generated from the inverters are being distributed to the diesel generator DC control circuits. This condition is producing 'a full scale false reading of approximately 700 RPM on the diesel generator RPM meter while the diesel generator is not running. The full scale reading of the RPM meter is above the
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shutdown setpoint of the. standby lube oil pump, which must remain operational to provide the fast starting requirements of the diesel l'
generator.
In additon, the full scale reading of the RPM meter prevents the implementation of the diesel generator air starting sequence..
L-i
r o
s Fir.al Report - DER 83-35 Page Two Based on the above, this condition is evaluated as reportable under the requirements of 10CFR50.55(e), since if this condition were to remain uncorrected it would represent a significant safety condition. In addition, this condition is also evaluated as reportable under'the requirements of 10CFR21.21(b) (3) with the' exception of sub part (vi), which requires the number and location of all defective components.
III.-
Corrective Action A.
NCR SE-1993 for Units 1, 2, & 3 will be dispositicaed as
" Rework."
B.
A copy of this report will be sent to the Elgar Corporation for their review and disposition under the requirements of 10CFR21.
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