9 septembre 2013
Mise à l’arrêt du réacteur suite à la perte de refroidissement de son système de pilotage électrique. Un compresseur assurant la climatisation des armoires électriques est tombé en panne.
Première divergence : mai 1985 - Type : PWR - Puissance 3565 MWth
Available in english only.
Event Number : 49339 Facility : WOLF CREEK - State : KS - Unit : [1] - RX Type : [1] W-4-LP
Event Date : 09/11/2013 - Event Time : 17:31
Emergency Class : NON EMERGENCY 10 CFR Section : 50.72(b)(2)(i) - PLANT S/D REQD BY TS 50.72(b)(3)(iv)(A) - VALID SPECIF SYS ACTUATION - Initial PWR 100 % - Current PWR 50 %
Event Text
TECHNICAL SPECIFICATION REQUIRED SHUTDOWN DUE TO LOSS OF COOLING TO SWITCHGEAR ROOMS
"Wolf Creek has commenced a plant shutdown in accordance with Technical Specifications. The A Train Class 1E Electrical Equipment Air Conditioning unit was declared non-functional due to a possible failed compressor cylinder, as indicated by increased vibration. This failure could prevent the unit from performing its required function over its required mission time, as required by Technical Specifications 3.8.4, 3.8.7, and 3.8.9. The following safety related electrical equipment was declared inoperable : 4.16KV Bus NB01 ; 480 Volt AC buses NG01 and NG03 ; 120 Volt Instrument AC inverters and buses NN11, NN13, NN01 and NN03 ; 125 VDC chargers and buses NK11, NK13, NN01 and NN03.
"Technical Specification 3.0.3 was entered at 1645 CDT on 9/11/2013 from Technical Specification 3.8.7 due to two out of four 120 VAC inverters (NN11 and NN13) being inoperable. Plant shutdown to Mode 5 commenced at 1731 CDT. The unit is currently at approximately 50% power.
"All electrical systems listed above remain available but are declared inoperable due to inadequate room cooling capability.
"No major equipment is out of service.
"The NRC Resident Inspector has been notified."
No switchgear room temperature limits were challenged.
See EN #49008 (May 6, 2013) and EN #49126 (June 17, 2013) for similar events.
* * * UPDATE ON 9/12/13 AT 0215 EDT FROM MARCY BLOW TO HUFFMAN * * *
"At 00:36 CDT 9/12/13, Wolf Creek had an Auxiliary Feedwater Actuation during a plant shutdown in accordance with Technical Specifications. The plant was in Mode 3, all control rods inserted, with reactor trip breakers closed when low steam generator levels prompted a manual reactor trip. A Valid Auxiliary Feed Actuation signal was received due to low steam generator levels. All Auxiliary Feedwater pumps started and operated as expected."
The licensee has informed the NRC Resident Inspector. R4DO (Hay) notified.
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