ENS 53443
ENS Event | |
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14:20 Jun 4, 2018 | |
Title | Manual Reactor Trip on Lowering Steam Generator Water Level |
Event Description | At 0920 CDT, Braidwood Unit 1 reactor was manually tripped due to lowering steam generator water levels following a trip of the 1C main feedwater pump. The cause of the 1C main feedwater pump trip is unknown at this time and is under investigation.
Both trains of Braidwood Unit 1 auxiliary feedwater started automatically following the reactor trip to maintain steam generator water levels. All systems responded as expected. Steam generator power operated relief valves lifted momentarily and reseated as designed in response to the secondary transient due to the reactor trip. The main steam dump valves are in service to the main condenser to provide heat sink cooling. The plant is being maintained at normal operating pressure and temperature. AC power is being provided by offsite power with the diesel generators in standby and all safety systems available. There is no impact to Unit 2. This report is being made per 10CFR50.72(b)(2)(iv)(B) for a RPS actuation, 4-hr. notification, and per 10CFR50.72(b)(3)(iv)(A) for an automatic actuation of the auxiliary feedwater system, 8-hr. notification. All rods inserted into the core during the trip. Concerning the relief valves momentarily lifting and reseating, there is no known primary-to-secondary leakage. The licensee has notified the NRC Resident Inspector. |
Where | |
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Braidwood Illinois (NRC Region 3) | |
Reporting | |
10 CFR 50.72(b)(2)(iv)(B), RPS Actuation | |
Time - Person (Reporting Time:+-0.33 h-0.0138 days <br />-0.00196 weeks <br />-4.52034e-4 months <br />) | |
Opened: | Jacob Eilertson 14:00 Jun 4, 2018 |
NRC Officer: | Howie Crouch |
Last Updated: | Jun 4, 2018 |
53443 - NRC Website | |
Unit 1 | |
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Reactor critical | Critical |
Scram | Yes, Manual Scram |
Before | Power Operation (100 %) |
After | Hot Standby (0 %) |
Braidwood with 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation | |
WEEKMONTHYEARENS 553202021-06-21T05:51:00021 June 2021 05:51:00
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