Event Notification Report for January 10, 2023

EN Revision Imported Date: 1/10/2023

EN Revision Text: UNUSUAL EVENT DUE TO EXCESSIVE REACTOR COOLANT SYSTEM LEAKAGE

At 1402 EST Turkey Point Unit 3, while operating at 100 percent, declared an Unusual Event due to unidentified leakage greater than 10 gallons per minute for more than 15 minutes. The abnormal procedure for Reactor Coolant System leakage was entered. The plant remains at 100 percent power. The cause of the leakage is under investigation.

At 1446 EST it was verified that the leak had been isolated. The plant remains at 100 percent power.

Unit 4 was unaffected.

State and local authorities were notified by the licensee.

The NRC Resident Inspector has been notified.

Notified DHS SWO, FEMA Operations Center, CISA Central, FEMA NWC (email), DHS NRCC THD Dest (email), and DHS Nuclear SSA (email).


* * * UPDATE ON 12/08/22 AT 1621 (EST) FROM SZEMEI CHOI TO THOMAS HERRITY * * *

Turkey Point Unit 3 has isolated the leak. The Unusual Event was terminated at 1558 EST.

The NRC Resident Inspector has been notified.

Notified R2DO (Miller), NRR EO (Miller), and IR MOC (Crouch). Notified DHS SWO, FEMA Operations Center, CISA Central, FEMA NWC (email), DHS NRCC THD Dest (email), and DHS Nuclear SSA (email).

* * * RETRACTION FROM BRANDEN NATHE TO DONALD NORWOOD AT 1446 EST ON 1/9/2023 * * *

"Turkey Point Nuclear Unit 3 is retracting this notification based on the following additional information not available at the time of the notification, Following the event for unidentified RCS leakage on 12/8/22 at 1403 EST, additional information demonstrated that an RCS leak did not exist.

"A review of indications showed that the in-service seal water return filter D/P [Differential Pressure] rose from 1 psid to 6 psid with a corresponding rise in VCT [Volume Control Tank] level as would be seen with an increase in excess letdown flowrate. Additionally, the on-contact radiation dose rate from the excess letdown piping in the U3 Pipe and Valve Room was measured by RP [Radiation Personnel] to be significantly higher than normal with no other sources of elevated radiation levels noted.

"Following the closure of CV-3-387, RCS To Excess Letdown HX [Heat Exchanger] Control Valve, a nominal input/output flow balance was able to be restored. Containment parameters including pressure, temperature, sump level and radiation level did not change during the event. Due to the shared nature of piping between excess letdown and seal water return, a challenge to system integrity would not allow RCP [Reactor Coolant Pump] controlled bleed-off to remain in service with a normal flow balance which it has at all times subsequent to the event.

"Turkey Point Nuclear reported initially based on the available information at the time and to ensure timeliness with emergency declaration and reporting notification requirements. The NRC Resident Inspector has been notified."

Notified R2DO (Miller).