CX-270998: System Physics Advanced Reactor Criticality (SPARC)

The System Physics Advanced Reactor Criticality (SPARC) Project is a long-term, zero-power critical experiment led by Idaho National Laboratory (INL) in collaboration with Oak Ridge National Laboratory, Los Alamos National Laboratory, and Lawrence Livermore National Laboratory. The project is funded by the U.S. Department of Energy (DOE) and the Nuclear Regulatory Commission under the Collaboration for Criticality Safety. SPARC is intended to operate for multiple decades, with initial operations anticipated by mid-2028. The facility will utilize a Horizontal Split-Table (HST) machine that allows nuclear fuel and materials to be remotely combined and separated to form a zero-power reactor configuration. The reactor will not produce electricity, measurable heat, or significant radiation, and will operate at extremely low neutron flux levels for short experimental durations, typically a few hours per experiment. All experiments will use uranium fuel enriched to less than 20%, and administrative and engineered controls will limit power and operating time to prevent significant fuel activation. The HST reactor will be installed in the open basement of Building PBF-613 at INL’s Critical Infrastructure Test Range Complex (CITRC). The project will leverage existing infrastructure while modifying the facility to meet current nuclear safety and natural phenomena hazard requirements. A modular control room will be installed outdoors within the designated project area adjacent to PBF-613 and connected to the facility via a new cable trench.