ENS 41446
ENS Event | |
|---|---|
03:34 Feb 27, 2005 | |
| Title | Plant Had a Reactor Trip from 16.1% Power Due to a Loss of Turbine Load Signal |
| Event Description | The following information, in addition to the phone report, was obtained from the licensee via facsimile:
Fort Calhoun Station Unit 1 experienced a reactor trip from 16.1% Reactor Power on a Loss of Turbine Load during a scheduled plant shutdown for a refueling outage. The turbine generator was tripped offline at 2101 per refueling outage schedule. A feedwater transient occurred [cause being investigated] during turbine testing, resulting in power rising rapidly from 12.6% to 16.1% . At which point the reactor tripped on loss of load due to being greater than 15% power with all turbine stop valves closed. All plant equipment functioned as designed. A Reactor Coolant System (RCS) cooldown resulted due to a feedwater transient. Main Feedwater was isolated, which terminated the cooldown. Auxiliary Feedwater (AFW) was established with the diesel driven auxiliary feed pump. Emergency Boration was manually initiated due to the RCS cooldown and secured after shutdown margin verification. Plant is currently stable in mode 3. This report is being made pursuant to 10 CFR 50.72(b)(2)(iv)(B) for an event that resulted in an event that resulted in an unplanned RPS actuation while the reactor was critical. All rods fully inserted, no ECCS actuation and no relief valves lifted. Steam generators are being used for heat sink. The NRC resident Inspector was notified |
| Where | |
|---|---|
Ft Calhoun  Nebraska (NRC Region 4) | |
| Reporting | |
| 10 CFR 50.72(b)(2)(iv)(B), RPS Actuation | |
| Time - Person (Reporting Time:+-2.13 h-0.0888 days <br />-0.0127 weeks <br />-0.00292 months <br />) | |
| Opened: | Rich Lowery 01:26 Feb 27, 2005 |
| NRC Officer: | Chauncey Gould |
| Last Updated: | Feb 27, 2005 |
| 41446 - NRC Website
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Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | A/R |
| Before | Power Operation (12 %) |
| After | Hot Standby (0 %) |
WEEKMONTHYEARENS 520332016-06-22T13:41:00022 June 2016 13:41:00
[Table view]10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Trip Due to Turbine Trip ENS 506882014-12-17T16:14:00017 December 2014 16:14:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Trip Due to Loss of Load ENS 499262014-03-17T17:02:00017 March 2014 17:02:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Trip Due to Turbine Trip Initiated by Loss of Stator Cooling Water ENS 497172014-01-12T09:23:00012 January 2014 09:23:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Reactor Trip Following Control Rod Position Deviation ENS 465062010-12-23T16:50:00023 December 2010 16:50:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Uncomplicated Reactor Trip from 100% Power ENS 458282010-04-08T21:22:0008 April 2010 21:22:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition, 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown Technical Specification Required Shutdown Due to Inoperable Steam Generator Inlet Isolation Valve ENS 440662008-03-15T13:33:00015 March 2008 13:33:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Reactor Trip Due to Turbine Trip ENS 414462005-02-27T03:34:00027 February 2005 03:34:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Plant Had a Reactor Trip from 16.1% Power Due to a Loss of Turbine Load Signal ENS 401562003-09-13T01:55:00013 September 2003 01:55:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Manual Reactor Trip Due to Unanticipated Negative Axial Shape Index (Asi). 2016-06-22T13:41:00 | |