Variable temperature H-2 NMR T-1 measurements have been performed on perdeuterated atactic 1,2-polybutadiene (1,2-PB) at two Larmor frequencies in five solvents : toluene, dodecane, hexadecane, cis-decalin, and squalene. a model independent correlation time for C-D vector reorientation, [sigma], is determined from the T-1 data. The hydrodynamic Kramers’ equation in the high friction limit cannot describe the viscosity and temperature dependence of [sigma]. In contrast, [sigma] has an apparent power law viscosity dependence with an exponent of 0.43. Accounting for this viscosity dependence, the average potential energy barrier between conformational states is determined to be 14 kJ/mol. T-1 data have also been fitted to various relaxation time distributions. Unimodal distributions cannot fit the data while bimodal distributions are successful. This indicates that the orientational relaxation of C-D vectors occurs on two well separated time scales. These two features of the relaxation time distribution are presumably caused by librations and conformational transitions. The modification of solvent dynamics caused by the addition of 1,2-PB is also discussed.