The primary path of production of 234U via nuclear decay is as follows: uranium-238 nuclei emit an alpha particle to become thorium-234.

Extraction of rather small amounts of 234U from natural uranium would be feasible using isotope separation, similar to that used for regular uranium-enrichment.

[1] The increased percentage of 234U in enriched natural uranium is acceptable in current nuclear reactors.

234U is converted to 235U more easily and therefore at a greater rate than 238U is to 239Pu (via neptunium-239) because 238U has a much smaller neutron-capture cross section of just 2.7 barns.

Natural uranium has an "equilibrium" concentration of 234U—the point at which an equal number of decays of 238U and 234U will occur.