Event Notification Report for February 23, 2026
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
02/22/2026 - 02/23/2026
EVENT NUMBERS
58160
58160
!!!!! THIS EVENT HAS BEEN RETRACTED !!!!!
!!!!! THIS EVENT HAS BEEN RETRACTED !!!!!
Non-Power Reactor
Event Number: 58160
Rep Org: Univ Of New Mexico (NEWM)
Licensee: University Of New Mexico
Region: 0
City: Albuquerque State: NM
County: Bernalillo
License #: R-102
Agreement: Y
Docket: 05000252
NRC Notified By: Rowdy Davis
HQ OPS Officer: Adam Koziol
Licensee: University Of New Mexico
Region: 0
City: Albuquerque State: NM
County: Bernalillo
License #: R-102
Agreement: Y
Docket: 05000252
NRC Notified By: Rowdy Davis
HQ OPS Officer: Adam Koziol
Notification Date: 02/10/2026
Notification Time: 16:48 [ET]
Event Date: 01/21/2026
Event Time: 14:00 [MST]
Last Update Date: 02/20/2026
Notification Time: 16:48 [ET]
Event Date: 01/21/2026
Event Time: 14:00 [MST]
Last Update Date: 02/20/2026
Emergency Class: Non Emergency
10 CFR Section:
10 CFR Section:
Person (Organization):
Helvenston, Edward (PM)
Waugh, Andrew (DANU)
Lin, Brian (DANU)
Farahmandfar, Zeinab (PM)
Helvenston, Edward (PM)
Waugh, Andrew (DANU)
Lin, Brian (DANU)
Farahmandfar, Zeinab (PM)
EN Revision Imported Date: 2/23/2026
EN Revision Text: TECHNICAL SPECIFICATION VIOLATION
The following information was provided by the licensee via phone:
On January 21, 2026, a technical specification (TS) violation was discovered per TS 3.4.d due to improper shielding during operation. The TS requires that the thermal column be filled with water or graphite, however, the thermal column contained water and lead. Since lead is not identified in the TS as a permissible shield, this was identified as a violation. The site will file a license amendment to add lead to the TS as an approved shielding material for the thermal column.
The licensee notified the NRC Project Manager and Inspector.
* * * RETRACTION ON FEBRUARY 20, 2026, AT 0751 EDT FROM ROWDY DAVIS TO SAMUEL COLVARD * * *
"Following further discussion and investigation, the licensee has determined that no technical specification violation occurred under TS 3.4.d. Specifically, the licensee's position is that the thermal column is not filled with lead but rather constructed with lead as a fixed structural base, above which sits a water tank filled solely with water.
"Aerojet General Nucleonics (AGN) documentation states that the reactor core is surrounded on all sides by 10 cm of lead, and that the 'thermal column' may be outfitted with either a graphite thermal column or a water-filled thermal water tank. This language supports the conclusion that the lead comprising the thermal column base serves to satisfy the design requirement that the core be surrounded by 10 cm of lead on all sides, rather than representing a fill material within the column itself.
"This interpretation is further corroborated by drawings contained within the safety analysis report and AGN design documentation, which depict a secondary containment boundary around the water within the thermal column. Taken together, the available evidence demonstrates that the thermal column is constructed with lead as a structural and shielding element - not filled with it - and therefore does not constitute a violation of the applicable technical specifications.
"Based on the foregoing, the licensee respectfully requests that license amendment request number 9 and Event Notification 58160 be withdrawn accordingly."
ADAMS ML26050A279
Notified NRC PM (Helvenston), PM (Farahmandfar), DANU (Waugh), DANU (Lin), and DANU (Brown).
EN Revision Text: TECHNICAL SPECIFICATION VIOLATION
The following information was provided by the licensee via phone:
On January 21, 2026, a technical specification (TS) violation was discovered per TS 3.4.d due to improper shielding during operation. The TS requires that the thermal column be filled with water or graphite, however, the thermal column contained water and lead. Since lead is not identified in the TS as a permissible shield, this was identified as a violation. The site will file a license amendment to add lead to the TS as an approved shielding material for the thermal column.
The licensee notified the NRC Project Manager and Inspector.
* * * RETRACTION ON FEBRUARY 20, 2026, AT 0751 EDT FROM ROWDY DAVIS TO SAMUEL COLVARD * * *
"Following further discussion and investigation, the licensee has determined that no technical specification violation occurred under TS 3.4.d. Specifically, the licensee's position is that the thermal column is not filled with lead but rather constructed with lead as a fixed structural base, above which sits a water tank filled solely with water.
"Aerojet General Nucleonics (AGN) documentation states that the reactor core is surrounded on all sides by 10 cm of lead, and that the 'thermal column' may be outfitted with either a graphite thermal column or a water-filled thermal water tank. This language supports the conclusion that the lead comprising the thermal column base serves to satisfy the design requirement that the core be surrounded by 10 cm of lead on all sides, rather than representing a fill material within the column itself.
"This interpretation is further corroborated by drawings contained within the safety analysis report and AGN design documentation, which depict a secondary containment boundary around the water within the thermal column. Taken together, the available evidence demonstrates that the thermal column is constructed with lead as a structural and shielding element - not filled with it - and therefore does not constitute a violation of the applicable technical specifications.
"Based on the foregoing, the licensee respectfully requests that license amendment request number 9 and Event Notification 58160 be withdrawn accordingly."
ADAMS ML26050A279
Notified NRC PM (Helvenston), PM (Farahmandfar), DANU (Waugh), DANU (Lin), and DANU (Brown).