of unit operations in refining and petrochemical plants by leveraging heat input from nuclear heat transfer fluids rather than from combustion. ARPA-E seeks information regarding transformative and implementable technologies to facilitate this integration. ARPA-E previously issued an RFI on Nuclear Hybrid and Non-Electricity Energy Systems, DE-FOA-0003011, in February 2023. Questions in this RFI reflect the refined scope of the potential program. ARPA-E has identified three areas of interest for using nuclear energy to decarbonize process heating demands in refineries and petrochemical plants: 1. Development of process-intensified reactors for endothermic processes; 2. Novel heat transfer and heat augmentation technologies; and 3. Process dynamics of incorporating a traditionally firm (nuclear) heat source with volatile demands. Coupling nuclear with oil and gas operations will require both technical and commercial innovation in areas such as process co-design and co-optimization, sensors, controls, and thermal buffering interface-component development while meeting reliability, availability, and durability metrics cost effectively. This RFI aims to gather information from interested and relevant stakeholders about opportunities and challenges in the technical, technology-to-market, and safety aspects of coupling of nuclear heat and/or power to industrial processes beyond pure power and/or steam production. The questions posed in the section below are based on the following program-level assumptions: • Nuclear heat or combined heat and power (CHP) is a viable route to decarbonizing industrial processes; • Regulatory approvals can be obtained on a predictable basis; • The associated nuclear fuel cycle (including waste processing and geologic disposal) can be reliably and economically defined and implemented; and • Warranty protection and insurability can be established. To view the RFI in its entirety please visit https://arpa-e-foa.energy.gov.