ENS 57730

v t e ENS Event
04:00 May 22, 2025
Title	Technical Specification Violation
Event Description	The following information was provided by the licensee via phone and email: On May 22, 2025, at 1055 EDT, the Armed Forces Radiobiology Research Institue (AFRRI) TRIGA Mark F reactor experienced a high power scram during startup in steady-state mode under two rod automatic control. During power escalation, the log channel malfunctioned, failing to provide a period signal to the automatic control system. The reactor power level increased rapidly until high flux safety channels 1 and 2 caused an automatic scram, releasing control rods to shutdown the reactor. Due to rate of power increase, reactor power momentarily exceeded the steady-state limit of 1.1MW. All reactor protection systems functioned as designed. Reactor power was verified as decreasing; control rods were verified to be fully inserted. The safety limit, nor limiting safety system setting, were exceeded during the event. This event is reportable to the NRC under AFRRI Technical Specifications (T.S.) 6.5.2.b. and 6.5.2.c. The limiting condition of operations affected are T.S. 3.1.1. - Steady state power level exceeding 1.1MW, T.S. 3.2.1.a. - Log Channel inoperable, and T.S. 3.2.2. Table 3 - Failure of Rod Withdrawal Interlock for a period less than three (3) seconds. The NRC Project Manager will be notified.

ENS 57730 +/-
Where
Armed Forces Radiobiology Rsch Inst (Afrr) Bethesda, Maryland (NRC Region 0)
License number:	R-84
Reporting

Non
Time - Person (Reporting Time:+-4 h-0.167 days <br />-0.0238 weeks <br />-0.00548 months <br />)
Opened:	Benjamin Knibbe 00:00 May 22, 2025
NRC Officer:	Tenisha Meadows
Last Updated:	May 22, 2025
57730 - NRC Website
v • d • e

v t e Emergency Notification System
Armed Forces Radiobiology Rsch Inst (Afrr) with Non
WEEKMONTHYEAR2025-05-22T04:00:00 [Table view]
[ENS list for Armed Forces Radiobiology Rsch Inst (Afrr)]

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