b'tube penetrations. The I-penetrations allow for all types of experiment vehicles to be inserted through the reactor top head and open the possi-bility for facilities such as I-Loop to be located in the reactors reflector Medium-I positions.The I-Loop project also completed a conceptual design of the in-vessel hardware known as an I-Loop Tube (Figure 3). The I-Loop Tube serves as the experiment facility that houses the experiment test rig and specimens. The I-Loop Tube design established a that concept is viable the following critical capabilities: LWR fuel testing in both pressurized water reactor (PWR) and boiling water reactor (BWR) environments Flux similar to Haldens central core flux (~5.2 kW/ft) Loop coolant pressure of 15.2 MPa (2,200 psi) and 320C (608F) Figure 3. I-Loop tubes in the ATRInsertion/removal of test trains using existing casksI-Loop Tube installation during an extended maintenance outageTest train of a 2x2 array of LWR fuel rods The test needs subjected to power manipulations that are decoupled from the ATR coreThe I-Loop project is in a great position to continue with design refinement and prototype activities in the next fiscal year. The following years will consist of equipment procurement, installation, and commissioning tests.Figure 4. Mark II installation team on ATR main floor138 2021|AFC ACCOMPLISHMENTS'