The sources and origins of internal contamination under study by UMRC are derived from artificial, technological and military applications of uranium and transuranic products. Uranium products encompass both naturally occurring and artificially produced actinides and their decay progeny. These materials are produced in a variety of ways: milled and concentrated from natural ores, separated in the uranium enrichment process, metallurgically processed, by-products and waste from nuclear reactors, waste from weapons production, purposefully synthesized by-products in nuclear reactors, and the associated decay chain products of natural and man-made fission and fusion reactions..