ML20085L740
| ML20085L740 | |
| Person / Time | |
|---|---|
| Site: | Fort Saint Vrain  |
| Issue date: | 02/07/1975 |
| From: | Brey H PUBLIC SERVICE CO. OF COLORADO |
| To: | Howard E NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| References | |
| AO-50-267-75-1, NUDOCS 8311020401 | |
| Download: ML20085L740 (4) | |
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,., -i n G z-Mr. E. Morris Howard, Director
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Directorate of Regulatory Operations V. dN!?/[.['
,I Region IV, USAEC s,' f 0
P. O. Box 5039 4%)
White Settlement, Texas 76108
Dear Mr. Howard:
REF: Facility Operating License No. DPR-34 Docket No. 50-267 Enclosed please find a copy of Abnormal Occurrence Report No. 50-267/75/1, submitted per the requirements of the Technical Specifications.
Very truly yours, LW l,
H. Larry Brey Superintendent-Operations Fort St. Vrain Nuclear Generating Station FES:ll cc:
Mr. Angelo Giambusso 4
0311020401}50$67 PDR ADOCK PDR S
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.o Q,J REPORT DATE: January 28, 1975 ABNORMAL OCCURRENCE
- OCCURRENCE DATE: January 18, 1975 Subsequently determined not to be an Abnormal Occurrence l
FORT ST. VRAIN NUCLEAR GENERATING STATION PUBLIC SERVICE COMPANY OF COLORADO P. O. BOX 361 PLATTEVILLE, (DLORt.D0 80651 REPORT NO. 50-267/75/1
.?inal IDENTIFICATION OF OCCURRENCE:
The 230KV Breaker, which isolates Bus #22 and the Reserve Auxiliary Transformer from the Valment line tripped due to high winds.
This trip
- caused the "A" Standby Diesel Generator Unit to receive a start signal.
'The "A" Unit started norrally but the "B" Unit did not receive a start signal.
-CONDITIONS PRIOR TO OCCURRENCE:
Routine Shutdown Steady State Power Hot Shutdown Routine Load Change Cold Shutdown X
Other (specify)
Refueling Shutdown Reactor in Cold Shutdown condi-Routine Startup tion except R.M.S. in fuel load-ing nosition to nerform Rod Cal.
Tests.
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o The major plant para =eters at the time of the event were as follows:
- PIR, O
MWth Power
- ELECT, O
MWe Pressure O
psig Secondary Coolant Temperature N/A
'F Flow 0
i/hr.
Pressure 8
psig Primary Coolant Temperature 185
- F Core Inlet 185
- F Core Outlet Flow 0
f/hr.
DESCRIPTION OF OCCURRENCE:
'"A" Diesel Generator Unit started (both engines).
"B" Diesel Generator Unit e
.did not start.
4 APPARENT CAUSE OF OCCURRENCE:_
Design Unusual Service Cond.
Component Failure 1
Manufacture Installation /Const.
X
'Other.(specify)
The low voltage relav on the "A" Operator 480V Bus sensed a momentary low Procedure voltage due to the line trip and started the "A" Diesel Unit. The
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voltage trip was not enouch' to'be sensed on the "C" 480V Bus, there-fore a signal to start the "B" Diesel Generator was not generated.
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O ANALYSIS OF OCCURRENCE :
The relay sensing voltage of the "A" 480V Bus was found to be set to sense a very small trip in voltage and sent a start signal to the "A" diesel unit.
No failure of the "b" unit occurred since it properly did not receive a start The results of the analysis indicates that no Abnormal Occurrence signal.
existed.
CORRECTIVE ACTION:
The relays for under-voltage on the "A" 480V Bus will be recalibrated.
FAILURE DATA /SIMILAR RrPORTED OCCURRENCES:
Abnormal Occurrence #14 involved a failure of a diesel to start but this was due to a fuel system problem and is unrelated to this occurrence.
PROGRA3DIATIC IMPACT:
None CODE IS' PACT:
None I
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REC 01DIENDED )Me) _
APPROVED H.L.Brey,lSuperintbndent F7ederic E. Swart, Superintendent Operations, Fort St.\\Vrain Nuclear Production, Fort St. Vrain Nuclear Generating Station Nuclear Generating Station O
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