  High purity Zinc Selenide (ZnSe) crystals are produced starting from
elemental Zn and Se to be used for the search of the neutrinoless double beta
decay (0{\nu}DBD) of 82Se. In order to increase the number of emitting
nuclides, enriched 82Se is used. Dedicated production lines for the synthesis
and conditioning of the Zn82Se powder in order to make it suitable for crystal
growth were assembled compliant with radio-purity constraints specific to rare
event physics experiments. Besides routine check of impurities concentration,
high sensitivity measurements are made for radio-isotope concentrations in raw
materials, reactants, consumables, ancillaries and intermediary products used
for ZnSe crystals production. Indications are given on the crystals perfection
and how it is achieved. Since very expensive isotopically enriched material
(82Se) is used, a special attention is given for acquiring the maximum yield in
the mass balance of all production stages. Production and certification
protocols are presented and resulting ready-to-use Zn82Se crystals are
described.
