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.
Depleted uranium (DU; also referred to in the past as Q-metal, depletalloy or D-38) is uranium with a lower content of the fissile isotope U-235 than natural uranium.(Natural uranium contains about 0.72% of its fissile isotope U-235, while the DU used by the U.S. Department of Defense contain 0.3% U-235 or less).he Nuclear Regulatory Commission (NRC) defines depleted uranium as uranium with a percentage of the 235 U isotope that is less than 0.711% by weight (see 10 CFR 40.4). The military specifications designate that the DU used by the U.S. Department of Defense (DoD) contain less than 0.3% 235 U (AEPI, 1995).