ARISING PROBLEMS WHEN USING LEU AND HEU FUEL ELEMENTS TOGETHER IN A RESEARCH REACTOR

摘要

Concerning of nuclear material safety, some research reactors are advised to shift from HEU (%93 U-235) to LEU (%20 U-235) fuel elements. When mixed fuel elements are used together, some design problems are encountered. Therefore, detailed neutronic and thermohydraulic analyses of the research reactor must be done before loading the core with LEU and HEU fuel elements.