Phason sinks of radiation defects in quasicrystals are considered as partial point defects. The kinetics of point defect absorption by single phasons is studied. A model of the dislocation loop with the phason fault under irradiation is developed. The capture efficiency of the dislocation loop for point defects is derived. The dependence of the dislocation loop bias on the loop radius is obtained. It is shown that the phason defects decrease the total bias in a quasicrystal as compared to an ordinary crystal.