Irradaition damages in structural materials

Selected results of investigations on radiation damages in structural materials of nuclear reactors are reviewed. The most important damages and their factors of influence are briefly described on the basis of the primary defects. These are: swelling, creep, embrittlement, and radiation-enhanced diffusion. Swelling is caused by void growth. Whereas the growth process is relatively well understood, the mechanism of void formation, i.e. germination, is widely unknown. The physical cause of embrittlement in thermal reactors is different from that in fast breeders and fusion reactors. The necessity of fundamental investigations for understanding radiation damages is pointed out. (author)