20 juin 2014
Suite à des orages, les prévisions météorologiques annoncent que le Missouri dépassera 306 m au dessus du niveau moyen de la mer le 20 juin, aux environs de 23h00, à Fort Calhoun. Le niveau étant de 304 m et augmentant de 1,27 cm à l’heure, les spécifications prévoient la mise à l’arrêt du réacteur. Après 12h de baisse de puissance, le réacteur était à 30 % de sa puissance nominale. Comme le niveau du Missouri a baissé, la puissance du réacteur a été réactivée pour remonter à 100 %.
Type : PWR - Puissance : 1 500 MWth - Première divergence : 08/1973
Available in english only.
Event Number : 50214
Facility : FORT CALHOUN - 4 State : NE - Unit : [1] - RX Type : (1) CE
Event Date : 06/20/2014 - Event Time : 00:01
Last Update Date : 06/22/2014 Emergency Class : NON EMERGENCY 10 CFR Section : 50.72(b)(2)(i) - PLANT S/D REQD BY TS
Current PWR Current RX Mode 1 N Y 100 Power Operation 0 Cold Shutdown
Event Text
TECHNICAL SPECIFICATION REQUIRED SHUTDOWN
"The National Weather Service predicts that the Missouri River level at Fort Calhoun Station will exceed 1004 feet above mean sea level on 6/20/14 at approximately 2300 CDT. Fort Calhoun Station will begin a ramp down in power to satisfy technical specification 2.16 which states, ’When the Missouri River level reaches elevation 1004 feet mean sea level, the reactor shall be in a HOT SHUTDOWN condition [Mode 3] and in Cold Shutdown [Mode 4] within 36 hours following entry into Hot Shutdown.’ The river level is currently 998 feet 3 inches and rising approximately 0.5 inches per hour. At time 0001 CDT 6/20/14 Fort Calhoun station will initiate a plant shutdown to Hot Standby and will proceed to a Cold Shutdown condition within 36 hours following entry into Hot Shutdown, as required."
The licensee notified the NRC Resident Inspector.
* * * RETRACTION PROVIDED BY SCOTT LINDQUIST TO JEFF ROTTON AT 2340 EDT ON 06/22/2014 * * *
"EN 50214 is being retracted. At 2300 [CDT] on 6/21/14, actual Missouri River level at Fort Calhoun Station peaked at 1001’ 2" mean sea level (msl) and did not reach TS 2.16 (1) shutdown criteria of 1004’ msl. Based on current Army Corps of Engineers and National Weather Service published Missouri River levels, the river upstream of Fort Calhoun Station has peaked and is trending down following the recent storms. River level is predicted to continue trending downward to normal summer navigation season levels. Plans to shutdown have been terminated. Fort Calhoun Station will continue to monitor weather and river levels. Current reactor power is 66% and Fort Calhoun Station is raising power to 100%."
The lowest reactor power achieved was 30 percent at 1200 CDT on 06/20/2014.
The licensee notified the NRC Resident Inspector.
Notified R4DO (Hay)
https://www.nrc.gov/reading-rm/doc-collections/event-status/event/2014/20140623en.html#en50214