It is estimated that between one-half to two-thirds of the value of all U.S. currency in circulation is outside of the U.S. In 1934, the $100,000 Gold Certificate became the highest denomination ever issued. It was never intended for public use. Instead, it was meant solely for official transactions between Federal Reserve Banks.
Enriched uranium. Enriched uranium is a type of uranium in which the percent composition of uranium-235 has been increased through the process of isotope separation. Natural uranium is 99.284% 238U isotope, with 235U only constituting about 0.711% of its weight. 235U is the only nuclide existing in nature that is fissile with thermal neutrons.
Using uranium as a fuel in the types of nuclear reactors common in the United States requires that the uranium be enriched so that the percentage of the uranium-235 isotope is increased, typically to 3 to 5%.fter gaseous diffusion, the enriched uranium hexafluoride is subjected to further processing, while the depleted UF 6 is generally stored. The uranium enrichment process was first developed in the 1940s as part of the Manhattan Project.