Depleted zinc oxide (DZO) is a zinc oxide depleted in the zinc isotope with the atomic mass 64, and used as a corrosion inhibitor in nuclear pressurized water reactors.
The depletion of <sup>64</sup>Zn is necessary, because this isotope is transformed into <sup>65</sup>Zn by neutron capture. <sup>65</sup>Zn with a half-life of 244.26 days emits gamma radiation with 1.115 MeV. <sup>64</sup>Zn has a natural abundance of 48.6%, but in DZO it is reduced below 1%. Adding zinc oxide to the primary water loop of a boiling water reactor or pressurized water nuclear reactor reduces corrosion and therefore minimizes the amount of dissolved materials, especially <sup>60</sup>Co.
The isotope separation of zinc is done by gas centrifugation of diethylzinc.