UraniumNatural radioactive element with the atomic number 92. The n... in which the percentage of the fissionable isotopeAtoms of the same atomic number (i.e. the same chemical elem... U-235 is increased beyond the content of 0.7205% in naturally occurring uraniumNatural radioactive element with the atomic number 92. The n.... Various enrichmentProcess by which the share of a certain isotpe in an element... methods are possible: (see ‘Diffusion separation processlsotope separation procedure using the different diffusion s..., ‘Gas centrifugeSee 'gas centrifuge process'. procedure’, ‘Nozzle process’).