b'4.2 SUMMARY OF I-LOOP STATUS AND ACCOMPLISHMENTSSummary of I-Loop Status and AccomplishmentsPrincipal Investigators: Nate OldhamTeam Members/ Collaborators: Kendell Horman, Vince Tonc, Josh Tonks, Kelly Ellis, Carlos Estrada-Perez, Brian Durtschi,Cody Race, Thomas Berti, R Dale Kepler, and Darrin StefflerThe I-Loop will expandE xpand access and capabilityand other equipment. In order to to the Advanced Test Reactorprovide the neutronics to approxi-(ATR) Medium-I position with amate prototypic LWR heating rates, fuel testing capacity,flowing water loop, allowing testingnuclear grade Zr-2.5Nb will be address LWR fuelof fuels and materials in prototypicused for the experiment tubes. The irradiation testinglight water reactor (LWR) conditions. improvements will enable advanced capability gaps leftfuel qualification to continue at the by the HBWR closureProject Description: Idaho National Laboratory (INL) and enhance testingThe closure of the Halden Boilingand support the industry and DOEs capabilities includingWater Reactor (HBWR) and growingdesire for these capabilities in the ramp testing.demand for extending LWR fuelUnited States, support the continued performance limits, has createdsafe use of existing LWR reactors, urgency to find a testing solutionand provide for future fuel testing to support near-term fuel testingfor next generation reactors.needs. This need comes at a time when industry, via Electric PowerAccomplishments: Research Institute (EPRI), and theAfter a brief funding hiatus, the Department of Energy (DOE), viaI-Loop project restarted in March the Accident Tolerant Fuels (ATF)2022. The project team replanned Program, are pushing for perfor- the entire work baseline structure to mance and capability increases foraccount for newly discovered scope new fuels. The I-Loop project aimsand additional cost due to supply to fill the gap created by HBWRschain uncertainty. The project closure and provide a similarexpected completion of an operational capability at ATR, by installing aI-Loop in ATR is early 2026. The flowing water loop in one Medium-Idesign team was reassembled with position and providing access to thethe addition of ATR project engi-other Medium-I positions for futureneers. ATR project engineering is experiments. In order to providefresh off of an extensive ATR project better access to the I-positionsthat occurs every couple of decades of ATR, a new Top Head Closurecalled ATR Core Internal Changeout Plate (Mark II) has been installed,(CIC). The I-Loop project is excited expanding the capabilities of theto have the expertise of this talented ATR for continued fuel and materialsdesign group. The success of the testing. To support the flowing waterI-Loop project requires a team with loop, the refurbishment of the 1Aexperience in modifying a complex cubicle will be required includingtest reactor such as ATR.new pumps, piping, heat exchangers, 144 2022|AFC ACCOMPLISHMENTS'