Event Notification Report for August 20, 2019

60-DAY OPTIONAL TELEPHONIC NOTIFICATION OF INVALID SPECIFIED SYSTEM ACTUATION

"This 60-day telephone notification is being made per the reporting requirements specified by 10 CFR 50.73(a)(2)(iv)(A) and 10 CFR 50.73(a)(1) to describe an invalid actuation of a general containment isolation signal affecting more than one system. On August 20, 2019, at approximately 1133 hours Central Daylight Time (CDT), Browns Ferry Nuclear Plant (BFN), Unit 2 experienced an unexpected loss of the 2A Reactor Protection System (RPS). This resulted in Primary Containment Isolation System (PCIS) groups 2, 3, 6, and 8 isolations, and initiation of Standby Gas Treatment Trains A, B, and C and Control Room Emergency Ventilation System Train A. All affected safety systems responded as expected.

"Plant conditions which initiate PCIS Group 2 actuations are Reactor Vessel Low Water Level (Level 3) or High Drywell Pressure. The PCIS Group 3 actuations are initiated by Reactor Vessel Low Water Level (Level 3) or Reactor Water Cleanup Area High Temperature. The PCIS Group 6 actuations are initiated by Reactor Vessel Low Water Level (Level 3), High Drywell Pressure, or Reactor Building Ventilation Exhaust High radiation (Reactor Zone or Refuel Zone). The PCIS Group 8 actuations are initiated by Low Reactor Vessel Water Level (Level 3) or High Drywell Pressure. At the time of the event, these conditions did not exist; therefore, the actuation of the PCIS was invalid.

"The cause of the RPS MG Set trip was dirty potentiometer windings on an Over Voltage Relay. The dirt prevented the potentiometer's wiper from contacting its windings, resulting in erratic setpoint values.

"There were no safety consequences or impact to the health and safety of the public as a result of this event.

"This event was entered into the Corrective Action Program as Condition Reports 1542603, 1542608, and 1542569.

"The NRC Resident Inspector has been notified of this event."

AGREEMENT STATE - LESS THAN PRESCRIBED DOSE RECEIVED

The following was received from the State of Kentucky via e-mail:

"The University of Kentucky reported that a patient received less dose than prescribed on 8/20/2019. The patient was prescribed to receive 429.2 MBq (11.6 mCi) of Y-90 microspheres (Sirtex Medical model SIR- Spheres). A microsphere dose of 425.5 MBq (11.5 mCi) was drawn from the unit vial into the administration vial. However, the patient only received an activity of 316.72 MBq (8.56 mCi), which is 26.2 percent less than prescribed, because some microspheres remained in the administration system. Additionally, it was difficult to draw 429.2 MBq (11.6 mCi) from the 7.13 GBq (192.6 mCi) in the unit vial as it represented only a small portion of the whole. The patient and referring physician were notified. Corrective actions included ordering a dose calibrated to more closely provide the activity needed for the date and time of administration. If the activity to be administered is low, the university will ensure that the activity drawn is 10 percent greater than prescribed. More flushes of the system will also be performed in hopes of pushing more of the residual activity into the patient."

Kentucky Incident Number - 190008.
NMED Item Number - 190442

A Medical Event may indicate potential problems in a medical facility's use of radioactive materials. It does not necessarily result in harm to the patient.