As part of its program to produce isotopes for medical, research and industrial purposes.
the Departnient of Energy (Department) has used its unique nuclear facilities to produce
thorium-229 isotopes f'rom its inventory of uranium-233. Thorium-229 is used to create
actiniurn-225 and its progeny isotope, bismuth-213. Both actinium and bismuth are
extreniely rare isotopes that are now being used in clinical trials and cancer research at
organi~ationsu ch as the Memorial Sloan-Kettering Cancer Center in New York. Early
research results have been promising, showing improved cancer survivability rates in test
populations. Consistent with these research results, a 2001 Departmental Report to
Congress underscored the importance of maintaining a supply of these isotopes to support
promising medical research and treatment. Specifically, the report stated that "the supply
of actinium-225lbismuth-213 available as uranium-233 decay products will be inadequate
if therapeutic applications for leukemia become even moderately successful and will
become woefully inadequate if successfully applied to other types of cancer including
prostate, breast. lymphomas, and various forms of brain cancer."