Irradiation Plan for a Mixed Thorium-Uranium Oxide Drop-In Experiment in the Advanced Test Reactor

Abstract

Clean Core Thorium Energy (CCTE), LLC is committed to the development of alternative nuclear fuels using thorium, primarily for pressurized heavy-water reactors and Canada deuterium uranium (CANDU) reactors. CCTE requested Idaho National Laboratory (INL) support to conduct irradiation testing on various mixed thorium-uranium oxide ((Th,U)O2) fuel samples to help assess fuel performance. Experiment pellets were fabricated at Texas A&M University under direction from CCTE. Over the next several years, twelve experiment capsules, each containing 18 experimental fuel pellets, are planned to be irradiated in the Inner-A and Outer-A experiment positions of the Advanced Test Reactor (ATR) at INL. Experiment pellets with varying compositions of (Th,U)O2 will be irradiated across a range of burnup targets to assess the potential benefits of the CCTE-designed “Advanced Nuclear Energy for Enriched Life” (ANEEL) fuel. The planned burnup targets are well in excess of the burnup limits for the traditional natural uranium fuel used in CANDU reactors, which means that ANEEL fuel has the potential to dramatically increase fuel utilization and extend operation for those reactors. As the experiment pellets reach their desired burnup levels, they will be removed from the ATR and sent to the INL Hot Fuels Examination Facility for post-irradiation examination. This paper outlines the irradiation plan for the CCTE-ANEEL-1A experiment including irradiation locations, test train geometry, and a summary of the experiment design analysis. ATR irradiation is expected to begin in Spring 2024, with burnup targets of 20, 40, and 60 GWd/MTU.