Event Notification Report for March 21, 2024
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
03/20/2024 - 03/21/2024
Agreement State
Event Number: 57027
Rep Org: Minnesota Department of Health
Licensee: Northshore Mining Company
Region: 3
City: Silver Bay State: MN
County:
License #: 1080
Agreement: Y
Docket:
NRC Notified By: Tyler Kruse
HQ OPS Officer: Kerby Scales
Notification Date: 03/13/2024
Notification Time: 10:42 [ET]
Event Date: 03/12/2024
Event Time: 14:20 [CDT]
Last Update Date: 03/13/2024
Emergency Class: Non Emergency
10 CFR Section:
Agreement State
Person (Organization):
Hills, David (R3DO)
NMSS_EVENTS_NOTIFICATION (EMAIL)
Event Text
AGREEMENT STATE REPORT - MISSING SHUTTER
The following information was received by the Minnesota Department of Health (MDH) via email:
"On March 12, 2024, at 1539 CDT, the licensee contacted MDH to report a gauge with a missing shutter. During their routine semiannual inventory and shutter check, the licensee discovered a Texas Nuclear model 5190 fixed gauge that was missing its shutter. The gauge contained a 100 mCi Cs-137 source (decayed to 35 mCi). The gauge was equipped with a removable shutter, and the licensee assumes that it had become loose and detached from the device due to normal operating vibration. The event was discovered at approximately 1420 on March 12, 2024.
"The licensee stated that they had a spare shutter and were able to install it on the gauge. The gauge was installed and operating when the missing shutter was discovered. Therefore, no abnormal radiation field or exposure occurred due to the missing shutter. At the time of the call, the licensee had not yet located the missing shutter. This gauge is used for density measurements on their tailings clarifier underflow pump."
Minnesota State Event Report Number: MN240002
Power Reactor
Event Number: 57036
Facility: Browns Ferry
Region: 2 State: AL
Unit: [2] [] []
RX Type: [1] GE-4,[2] GE-4,[3] GE-4
NRC Notified By: Alex Neumann
HQ OPS Officer: Ossy Font
Notification Date: 03/19/2024
Notification Time: 18:19 [ET]
Event Date: 03/19/2024
Event Time: 10:30 [CDT]
Last Update Date: 03/19/2024
Emergency Class: Non Emergency
10 CFR Section:
50.72(b)(3)(v)(D) - Accident Mitigation
Person (Organization):
Miller, Mark (R2DO)
Power Reactor Unit Info
| Unit |
SCRAM Code |
RX Crit |
Initial PWR |
Initial RX Mode |
Current PWR |
Current RX Mode |
| 2 |
N |
Y |
100 |
Power Operation |
100 |
Power Operation |
Event Text
HIGH PRESSURE COOLANT INJECTION ISOLATION
The following information was provided by the licensee via fax or email:
"While performing a planned high pressure coolant injection (HPCI) system surveillance, an isolation signal was received based upon an exhaust rupture disc high pressure signal. This resulted in an unplanned inoperability of the HPCI system. All systems responded as expected, and the event is under investigation. No other systems were affected by this condition.
"This event is reportable as an 8-hour non-emergency notification under 10CFR50.72(b)(3)(v) as HPCI is a single train safety system. There was no impact to plant personnel or the public as a result of this condition. The NRC resident has been notified of this condition."