RADIATION EFFECTS IN CERAMICS .1. STUDY OF DYNAMIC IRRADIATION EFFECTS ON ELECTRICAL-CONDUCTIVITY IN JMTR - IN COMPARISON WITH RESULTS OBTAINED WITH OTHER IRRADIATION SOURCES

In the Oarai Branch, Institute for Materials Research, Tohoku Universi ty, we have been studying radiation effects in materials, using mainly a water-cooled fission reactor, JMTR. Comparing a fission reactor irr adiation with other irradiation sources such as ion-beams, we can poin t out many attracting features of a fission reactor irradiation. Espec ially in the course of development of fusion reactor materials, import ance of the fission reactor irradiation has bee stressed repeatedly. C eramic materials are expected to play very important roles in heavy ir radiation environments in fusion reactors. Extensive studies have been accumulated and now we will move from the materials science phase to the engineering phase. Here, we will summarized the accumulated date o n radiation effects on ceramic materials, focusing on their irradiatio n effects of dependence on irradiation sources. In the first paper, we will summarize results on dynamic radiation effects on electrical pro perties on which we are actively devoting our efforts currently using JMTR. In the second paper, we will summarize the fundamental aspects, dimensional stability and dielectric properties.