ENS 52469
ENS Event | |
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18:05 Dec 30, 2016 | |
Title | Manual Reactor Trip Due to Control Rod Not Withdrawing as Expected |
Event Description | On 12/30/16 at 1302 EST, Unit 1 began withdrawing control bank rods for an approach to criticality following a refueling outage. At 1305 EST, operators observed that control rod H-6 did not withdraw. Operators entered the applicable Abnormal Operating Procedure. Operators tripped the reactor as required by plant procedures and entered applicable Emergency Operating Procedures. The act of manually tripping the reactor generated a valid trip signal in the plant Reactor Protection System.
Following the reactor trip, all safety related equipment operated as designed. Auxiliary feedwater was already supplying the Steam Generators; a Feedwater Isolation occurred due to plant conditions. Unit 1 is currently being maintained in Mode 3 at NOT/NOP, approximately 548 degrees F and 2235 psig, with auxiliary feedwater supplying the steam generators, and decay heat removal via the steam dumps. Method of decay heat removal is Steam Generators via the steam dumps. Current reactor coolant system conditions: Temperature at 548 degrees F and stable, pressure 2235 psig and stable. All control and shutdown banks are inserted. Electrical alignment is normal, supplied by offsite power. No impact to Unit 2, Unit 2 is in Mode 1 at 100 percent power. The licensee notified the NRC Resident Inspector. |
Where | |
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Sequoyah Tennessee (NRC Region 2) | |
Reporting | |
10 CFR 50.72(b)(3)(iv)(A), System Actuation | |
Time - Person (Reporting Time:+-1.47 h-0.0613 days <br />-0.00875 weeks <br />-0.00201 months <br />) | |
Opened: | Theodore Doukas 16:37 Dec 30, 2016 |
NRC Officer: | Donald Norwood |
Last Updated: | Dec 30, 2016 |
52469 - NRC Website
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Unit 1 | |
---|---|
Reactor critical | Not Critical |
Scram | Yes, Manual Scram |
Before | Hot Standby (0 %) |
After | Hot Standby (0 %) |
WEEKMONTHYEARENS 573512024-09-29T09:56:00029 September 2024 09:56:00
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