Depleted zinc oxide

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 ⁶⁴Zn is necessary, because this isotope is transformed into ⁶⁵Zn by neutron capture. ⁶⁵Zn with a half-life of 244.26 days emits gamma radiation with 1.115 MeV. ⁶⁴Zn has a natural abundance of 48.6%, but in DZO it is reduced below 1%. The addition of zinc oxide to the primary water loop of a pressurized water nuclear reactor reduces the corrosion and therefore minimizes the amount of dissolved materials, especially the amount of ⁶⁰Co.

The isotope separation of zinc is done by gas centrifugation of diethylzinc.