It is extensively used as a moderator in nuclear reactors and in exchange reactions for the study of reaction mechanisms.
It can be prepared by exhaustive electrolysis of water or as a by-product in some fertilizer industries. It is used for the preparation of other deuterium compounds, for example:
CaC2 + 2D2O → C2D2 + Ca(OD)2
SO3 + D2O → D2SO4
Al4C3 + 12D2O → 3CD4 + 4Al(OD)3