ENS Event | |
|---|---|
20:40 Nov 25, 2024 | |
| Title | Technical Specification Abnormal Occurrence |
| Event Description | The following report was provided by the licensee via email:
This event is being reported as an 'Abnormal Occurrence,' per the University of Missouri Research Reactor technical specification (TS) 6.6.c, which requires 'Abnormal Occurrences,' defined by TS 1.1, be promptly reported to the NRC Operations Center within one working day. At approximately 1440 CST on 11/25/24, during the banking of all four control rods at 50 kW, the '1S3' control blade selector switch became inoperable. The control blade selector switch allows selection of the control blades for manual operation. The inability to select control blades for manual operation resulted in a violation of TS 3.2.a, which requires all control blades, including the regulating blade, be operable during reactor operation. The reactor was immediately scrammed and placed in a safe shutdown condition. All applicable safety functions were completed as expected. As a result, there was no impact on the health and safety of the public or facility staff due to this condition. Investigation determined that the internal spring of the '1S3' switch had failed, preventing the switch from selecting a specific control blade for manual control. The spring was replaced and approval to proceed per TS 6.4.c was obtained from the reactor facility director. Post-maintenance testing was completed at 1525 CST on 11/25/24, prior to returning the reactor to normal operations. The NRC project manager has been notified. |
| Where | |
|---|---|
| University Of Missouri - Columbia Columbia, Missouri (NRC Region 0) | |
| License number: | R-103 |
| Reporting | |
| Non | |
| Time - Person (Reporting Time:+17.55 h0.731 days <br />0.104 weeks <br />0.024 months <br />) | |
| Opened: | Deborah Farnsworth 14:13 Nov 26, 2024 |
| NRC Officer: | Robert A. Thompson |
| Last Updated: | Nov 27, 2024 |
| 57445 - NRC Website | |
University Of Missouri - Columbia with Non | |
WEEKMONTHYEARENS 574452024-11-25T20:40:00025 November 2024 20:40:00
[Table view]Non Technical Specification Abnormal Occurrence 2024-11-25T20:40:00 | |