We have investigated by high resolution X-ray diffraction the change of the structural correlation length in 6H-SiC after neutron irradiation with different fluences and following different annealing procedures. Following a model of Klimanek [1] it is shown, that high fluences lead to a stronger than linear reduction of the correlation length whereas higher annealing temperatures lead to a stronger recovery of the correlation length. In addition, a reorientation of the direction of the defect structure upon annealing is observed.