ML20027A623
| ML20027A623 | |
| Person / Time | |
|---|---|
| Site: | Crystal River  |
| Issue date: | 10/08/1980 |
| From: | Ornstein H NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD) |
| To: | Michelson C NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD) |
| References | |
| TASK-AE, TASK-E014, TASK-E14 AEOD-E014, AEOD-E14, NUDOCS 8010230435 | |
| Download: ML20027A623 (3) | |
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I OCT 8 1980 AE00/E014 i
This is an intemal, pre-decisional document not i
necessarily representing a
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!*IMORANDUM FOR:
Carlyle Michelson, Director position of AE00 or NRC.
l Office for Analysis and Evaluation of Operational Data l
FROM:
Harold L.~0rnstein Office for Analysis and Evaluation of l
Operational Data
SUBJECT:
TRANSIENT AT CRYSTAL RIVER 3 - SEPTEMBER 30,1980 1
Per our discussion tcday, enclosed are the pertinent facts that I ha e learned
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i about this event. ghemostrecentinformationwasreceivedduringanOctober6, 1980 conference call with IE (G. Schwink, HQ, N. Villalva, HQ, R. Martin, R-II, L
T. Stetka, CR-3 site) and H. Ornstein, AEOD,.]
f Original Signed by i
i HaroldL. Ornstein Harold 1..OrnsteiN*
0ffice'for Analysis and Evaluation l
of Operational Data l
Enclosure:
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Crystal River 3 Alligator l
Clip Event Q*h3 b l
cc w/ enclosure:
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AEOD Members H. Denton, NRR E. Adensam, NRR S. Hanauer, NRR
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J. McKinley, ACRS l
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n Crystal River 3 Alligator Clip Event E
On September 30,1980, at 13:04 while at 100% power, Crysiial RNer 3 experienced a reactor trip (the Incident Response Center was notified
. 19 minutes later).
The event was initiated when a technician was performing a nuclear instrumentation calibration (procedure SC 113). He had attached spring clips (alligator clips) to the x-y recorder on the back panel housing RPS Channel A.
The clip fell off the equipment and struck another terminal causing a short, thereby losing RPS Channel A (15 Volt de).
The loss of this power supply caused the loss of the following instrumentation:e "NI-5" power range - Channel A
'"NT-1" source range - Channel A 4
Reactor Coolant Flow (both loops - hot leg flows and total flow).
Reactor Coolant Pressure- (narrow range recorder for loop A; however, wide range and low level instrumentation remained
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available).
The most significant item that was lost was the Reactor Coolant Flow signal which feeds into.the ICS.
Sensing z~ero Reactor Coolant System flow, the ICS initiated a.feedwater runback at the maximum rate of 60% per minute and an insertion of the control rods. Within 17 seconds of the initial short, th'e 3 remainin.g RPS channels scramed the reactor on high primary system pressure.
About 2 minutes after the reactor trip, the emergency feedwater initiated upon low steam generator level (SG - A 18",
SG'-B 33",
neither steam generator went dry).
The primary system relief and safety valves remained closed.throughout the event.
Plant cooldown and cooldown rate were within the tech spec values. Throughout the transient, the primary system remained subcooled by 80-1000F. Minimum pressurizer level was 55".
One makeup pump (HPI line) was initiated manually, and the RCS pumps remained on during.the event. The pressurizer heater controls can be placed on either RPS Channels A or B.
During this event; they happened to haye been on Channel B and, therefore, were not lost.
All. instrumentation, panel meters, and chart recorders, other than those listed above, worked properly. The data logger / computer was overloaded and did not.
print out all pertinent information (computer / data logger replacement is a long-term item believed to be scheduled for next year).
The plant was restored to power in about 5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br />.
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- )I 2-At first glance, IE. Region II.(Bob Martin) indicated that no LER.would be required for this even,t; however, upon subsequent discussion in view of the initiating event and the degraded conditions that exi.sted,, a 30 day LER appears to be appropriate.
The licensee has issembled a " Lessons Learned - Reactor Trip Task Force" which is preparing a report on this ' incident (expected out very shortly).
It was agreed that IE and AEOD will wait for that report prior to request-ing additional information about this event from the licensee. Subsequently, NRR (J. T. Beard) agreed to this approach.
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