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The following information was provided by … The following information was provided by the licensee via phone and email:</br>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. </br>This event is reportable to the NRC under AFRRI Technical Specifications (T.S.) 6.5.2.b. and 6.5.2.c. </br>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.</br>The NRC Project Manager will be notified.
The NRC Project Manager will be notified. +
04:00:00, 22 May 2025 +
57,730 +
00:00:00, 22 May 2025 +
04:00:00, 22 May 2025 +
The following information was provided by … The following information was provided by the licensee via phone and email:</br>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. </br>This event is reportable to the NRC under AFRRI Technical Specifications (T.S.) 6.5.2.b. and 6.5.2.c. </br>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.</br>The NRC Project Manager will be notified.
The NRC Project Manager will be notified. +
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00:00:00, 22 May 2025 +
R-84 +
Modification date"Modification date" is a predefined property that corresponds to the date of the last modification of a subject and is provided by <a rel="nofollow" class="external text" href="https://www.semantic-mediawiki.org/wiki/Help:Special_properties">Semantic MediaWiki</a>.
11:20:22, 25 May 2025 +
00:00:00, 22 May 2025 +
-0.167 d (-4 hours, -0.0238 weeks, -0.00548 months) +
04:00:00, 22 May 2025 +
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