The following information was provided by the licensee via phone and email:
Minimum staffing [was] not met under Missouri University of Science and Technology Reactor (MSTR) Technical Specification (TS) 6.1.3.1(a) [for approximately one hour].
At 1400 CDT, on July 24, 2024, the MSTR conducted a planned shutdown from 40 kW in support of a thermal power calibration. At approximately 1410, the control room operator left the control room for the reactor bay to perform additional power calibration data collection. At approximately 1510, the radiation safety officer (RSO) passed by the control room and observed that the magnet key remained in the console. The operator was promptly notified and secured the key. The operator notified the reactor manager and senior reactor operator on duty (shift supervisor) by approximately 1530, who discussed the issue with the facility director.
During the time period of 1410 to 1510, the MSTR did not meet the TS definition for reactor secured, as the magnet key remained in the console. As such, without an operator in the control room, the minimum staffing requirements of TS 6.1.3.1(a) were not met, as this specification states: `1. The minimum staffing when the reactor is not secured shall be: a) A certified reactor operator in the control room.' It is noted that the reactor was shut down and the control rods remained inserted for the duration of the event.
The event has been entered into the facility corrective action program as CAP-2024-001, and the NRC project manager will be notified.