Stereochemistry of hydrogenation with Raney nickel
The hydrogenation of alkenes using heterogenous catalysts such as Raney nickel is syn-stereospecific; i.e. both hydrogen atoms are added to the same face of the double bond.

Therefore, the hydrogenation of (2​E)-(2,3-2H2)but-2-ene yields 
(2​R,3​R)-(2,3-2H2)butane and
(2​S,3​S)-(2,3-2H2)butane.