22:26 Jul 21, 2021
Automatic Reactor SCRAM
At 1826 EDT on July 21, 2021, Susquehanna Steam Electric Station Unit 1 reactor automatically scrammed due to a trip of the Main Turbine.
Unit 1 reactor was operating at 100 percent reactor power with no evolutions in progress. The Control Room received indication of a Main Turbine trip with both divisions of RPS [Reactor Protection System] actuated and all control rods inserted. The Reactor Recirculation Pumps tripped on EOC-RPT [end of cycle recirculation pump trip]. Reactor water level lowered to +8 inches causing Level 3 (+13 inches) isolations. No ECCS [Emergency Core Cooling Systems] or RCIC [Reactor Core Isolation Cooling system] actuations occurred. The Operations crew subsequently maintained reactor water level at the normal operating band using Reactor Feed Water.
The NRC Resident Inspector was notified. A voluntary notification to PEMA will be made.This event requires a 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> ENS notification in accordance with 10CFR50.72(b)(2)(iv)(B) and an 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> ENS notification in accordance with 10CFR50.72(b)(3)(iv)(A) and 10CFR50.72(b)(3)(iv)(B).
Pennsylvania (NRC Region 1)
|10 CFR 50.72(b)(2)(iv)(B), RPS Actuation|
|Time - Person (Reporting Time:+-1.6 h-0.0667 days <br />-0.00952 weeks <br />-0.00219 months <br />)|
20:50 Jul 21, 2021
|NRC Officer:||Ossy Font|
|Last Updated:||Jul 21, 2021|
|55370 - NRC Website|