METHODOLOGIES AND RELATED ISSUES - UNIVERSITY OF FLORIDA HEU TO LEU FUEL CONVERSION PROJECT

A core conversion from highly-enriched uranium (HEU) to low-enriched uranium (LEU) fuel was conducted at the University of Florida (UF) between May 2005 and September 2006. The UF Nuclear & Radiological Engineering Department with support from the Reduced Enrichment for Research and Test Reactors (RERTR) Program at Argonne National Laboratory prepared the conversion Safety Analysis Report for the Nuclear Regulatory Commission (NRC), resolved questions raised by NRC, and proceeded to refuel the core all, within a record time of 15 months. This paper presents a summary of the various analyses performed in support of the conversion process, including; i) core physics analyses with experimental benchmarking, ii) thermalhydraulics methodology and analysis, iii) accident analyses of various reactivity insertions, hypothetical accident assessment and estimation of radiation dose due to radioactive release, and iv) determination of the Limiting Safety System Settings and the Safety Limits.