ENS 44508: Difference between revisions

v t e ENS Event
02:35 Sep 21, 2008
Title	Unplanned Loss of Shutdown Cooling Due to Containment Isolation
Event Description	On Saturday, September 20, 2008, Monticello Nuclear Generating Plant (MNGP) experienced an actuation of the following systems: Reactor Protection System (with the reactor shutdown), Containment Isolation, and Emergency Diesel Generators. The apparent cause of the actuation was a pressure pulse in the reference leg of a Reactor level instrument that resulted when a CRD [Control Rod Drive] pump was started without the reference leg backfill system isolated from the CRD system. This notification is being made in accordance with 10CFR50.72(b)(3)(iv)(A). Due to the containment isolation, shutdown cooling was lost for approximately 90 minutes. Initial reactor temperature was ~95 degrees when the isolation occurred. When shutdown cooling was restored, reactor temperature had increased to ~120 degrees. The Emergency Diesel Generators started but did not load. The diesels have been restored to normal standby status. The licensee has notified the NRC Resident Inspector.

ENS 44508 +/-
Where
Monticello Minnesota (NRC Region 3)
Reporting

10 CFR 50.72(b)(3)(iv)(A), System Actuation
Time - Person (Reporting Time:+-0.37 h-0.0154 days <br />-0.0022 weeks <br />-5.06826e-4 months <br />)
Opened:	Matt Schillerstrom 02:13 Sep 21, 2008
NRC Officer:	Howie Crouch
Last Updated:	Sep 21, 2008
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v • d • e

v t e Emergency Notification System
Monticello with 10 CFR 50.72(b)(3)(iv)(A), System Actuation
WEEKMONTHYEAR2024-02-28T14:39:00 [Table view]
[ENS list for Monticello]

@@ Line 16: / Line 16: @@
 | event date = 09/20/2008 21:35 CDT
 | last update date = 09/21/2008
-| title = Unplanned Loss Of Shutdown Cooling Due To Containment Isolation
+| title = Unplanned Loss of Shutdown Cooling Due to Containment Isolation
 | event text = On Saturday, September 20, 2008, Monticello Nuclear Generating Plant (MNGP) experienced an actuation of the following systems:  Reactor Protection System (with the reactor shutdown), Containment Isolation, and Emergency Diesel Generators.
 The apparent cause of the actuation was a pressure pulse in the reference leg of a Reactor level instrument that resulted when a CRD [Control Rod Drive] pump was started without the reference leg backfill system isolated from the CRD system.

Latest revision as of 22:13, 1 March 2018