[en] It is shown that the stress-induced interaction energy between a point defect and a dislocation is a function of both the relative orientation of the Burgers vector and the stress axis and the relative orientation of the dislocation line and the stress axis. In some circumstances the deviatoric components of the interaction energies between a point defect and dislocations with parallel Burgers vectors but orthogonal dislocation lines are of opposite sign. By including this feature of the phenomenon in calculations of irradiation creep rates it is possible to derive, from first principles, relationships between strain rates for different stress systems which are identical to those of the Soderberg formalism for thermal creep. (author)