The temperature dependence of 1-dimensional motion of interstitial clusters and void growth in Fe and Ni was studied up to a dose of 0.3dpa. Two criteria were used to detect the 1-dimensional motion of interstitial clusters. One was the formation of interstitial-type dislocation loops near to the dilatational side of edge dislocations. The other was zero formation of interstitial-type dislocation loops near to grain boundaries. In neutron-irradiated Ni with improved temperature control at 573K, the 1-dimensional motion of interstitial clusters occurred. However no evidence for 1-dimensional motion was found for conventional temperature controlled irradiation, where the specimen temperature changed with reactor power. This suggested that there was little 1-dimensional motion of interstitial clusters at lower temperatures during the start-up of the reactor. In neutron-irradiated Fe, the 1-dimensional motion of interstitial clusters occurred at 473 and 623K, judging from the criteria. A good correlation existed between the 1-dimensional motion of interstitial clusters and void growth. These results were analyzed on the basis of the temperature dependence of the interaction between impurities and interstitial clusters.

Temperature Dependence of One-Dimensional Motion of Interstitial Clusters in Fe and Ni. T.Yoshiie, M.Horiki, Q.Xu, K.Sato: Journal of Nuclear Materials, 2007, 367-370[1], 322-6