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Event Notification Report for December 15, 2017

U.S. Nuclear Regulatory Commission
Operations Center

Event Reports For
12/13/2017 - 12/15/2017

** EVENT NUMBERS **


53051 53119

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!!!!! THIS EVENT HAS BEEN RETRACTED. THIS EVENT HAS BEEN RETRACTED !!!!!
Power Reactor Event Number: 53051
Facility: DAVIS BESSE
Region: 3 State: OH
Unit: [1] [ ] [ ]
RX Type: [1] B&W-R-LP
NRC Notified By: TOM COBBLEDICK
HQ OPS Officer: JEFF HERRERA
Notification Date: 11/03/2017
Notification Time: 14:20 [ET]
Event Date: 11/03/2017
Event Time: 10:45 [EDT]
Last Update Date: 12/14/2017
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(v)(D) - ACCIDENT MITIGATION
Person (Organization):
HIRONORI PETERSON (R3DO)

Unit SCRAM Code RX CRIT Initial PWR Initial RX Mode Current PWR Current RX Mode
1 N Y 100 Power Operation 100 Power Operation

Event Text

STATION VENT RADIATION MONITOR EFFICIENCY FACTOR NON-CONSERVATIVE

"On 11/3/17, with the unit operating in Mode 1 at approximately 100 percent power, an issue was identified with the Station Vent Radiation Monitors. The noble gas channels utilize an efficiency factor for isotope Kr-85 instead of the required Xe-133. For the normal range radiation monitors, the efficiency factor is non-conservative, resulting in both monitors being declared inoperable at 1045 hours EDT. As a result, the Normal Control Room Ventilation System was shut down and isolated, and the Control Room Emergency Ventilation System started in accordance with Technical Specification Required Actions at 1122 hours.

"The inoperability of both Station Vent Normal Range Radiation Monitors represents a condition that at the time of discovery could have prevented the fulfillment of the safety function of a system needed to mitigate the consequences of an accident. The Station Vent Accident Range Monitors also utilize an efficiency factor for Kr-85 instead of Xe-133, but for the Accident Range Monitors the efficiency factor is conservative. Because alternate means exist to determine release rate, which include use of grab samples and field surveys, this degraded capability does not represent a major loss of emergency assessment capability.

"The NRC Resident Inspector has been notified."


* * * RETRACTION FROM NICK DOWNING TO DONALD NORWOOD AT 0927 EST ON 12/14/2017 * * *

"On 11/3/2017, the efficiency factors for the Station Vent Normal and Accident Range Radiation Monitors were revised to the proper setting for the required isotope, the normal range monitors were declared Operable, and the Control Room Normal Ventilation System was returned to service.

"An evaluation of the issue with the Station Vent Normal Range Radiation Monitors was performed, which determined the Control Room Ventilation isolation setpoint is well below the point at which the dose to the Control Room Operators would exceed General Design Criteria (GDC) limits following a Design Bases Accident. The error introduced from using an incorrect efficiency value did not challenge the margin to the GDC limits; therefore, the Station Vent Normal Range Monitors remained operable, and this issue did not prevent the monitors from fulfilling their safety function to mitigate the consequences of an accident.

"The NRC Resident Inspector has been notified."

Notified R3DO (Stone).

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Power Reactor Event Number: 53119
Facility: CALLAWAY
Region: 4 State: MO
Unit: [1] [ ] [ ]
RX Type: [1] W-4-LP
NRC Notified By: SHANNON GAYDOS
HQ OPS Officer: DONALD NORWOOD
Notification Date: 12/14/2017
Notification Time: 11:29 [ET]
Event Date: 12/13/2017
Event Time: 13:28 [CST]
Last Update Date: 12/14/2017
Emergency Class: NON EMERGENCY
10 CFR Section:
26.719 - FITNESS FOR DUTY
Person (Organization):
RICK DEESE (R4DO)
FFD GROUP (EMAI)

Unit SCRAM Code RX CRIT Initial PWR Initial RX Mode Current PWR Current RX Mode
1 N N 0 Hot Shutdown 0 Hot Shutdown

Event Text

FITNESS FOR DUTY REPORT

"On December 13, 2017, Callaway determined that a violation of one provision of the site's Fitness For Duty (FFD) policy had occurred. FFD testing confirmed the use of a controlled substance. The violation was committed by a non-licensed, supervisory employee. The individual's unescorted access to the plant has been removed.

"The NRC Resident Inspector has been notified by the licensee. "

Page Last Reviewed/Updated Monday, December 18, 2017
Monday, December 18, 2017