The following is a summary received from the University of
New Mexico Reactor Facility via email:
At 1330 MST, February 25, 2020, a pre-operational checkout was being performed on the reactor while it was shutdown. The pre-operational checkout includes confirming operation of the rod interlocks, scram systems, and control rods. The interlock check was performed and all requirements were fulfilled. During the manual scram test, Operators determined that only Safety Rod #2 and the Coarse Control Rod scrammed. Safety Rod #1 was still attached to the magnet and was being driven out along with the drive motor. As a result, the licensee was not in compliance with Limiting Conditions for Operations, Section 3.2a, which requires the fine control rod, coarse control rod, and the two safety rods be operable and the carriage position of the fine and coarse control rods be displayed at the console whenever any rod is above its lower limit.
Operators performed a series of tests to determine the cause of the problem. Operators determined that the rod and plate were sticking to the magnet, but could not be separated when the rod was subject to downward force. Corrective actions included cleaning the plate and magnet, and breaking any potential air seals at the plate. After a series of satisfactory tests, Safety Rod #1 was returned to operable condition and reinstalled in the reactor. The rod was tested to reassure it would scram in its original configuration. The issue with Safety Rod #1 did not affect the shutdown margin of the reactor, and at no time was the reactor operated when Safety Rod #1 was not in operable condition.
This notification is required per Technical Specification 6.9.
The licensee notified the
NRR Project Manager (Helvenston).