Report issued by the Brookhaven National Laboratory discussing a hazards report on replacing the research center's current fuel elements with new highly enriched elements. As stated in the introduction, "this report is a summary of the studies, both theoretical and experimental, which have been made so far of the nuclear properties of the "new" pile, of the stability of the new fuel elements, and of the safety and practicability of operation of the "new" pile" (p. 2). This report includes tables, and illustrations.