Abstract. Material performance of reduced activation ferritic steels (RAFS) and their response to neutron irradiation, which have been investigated by utilizing fission reactors under the US/Japan collaborative research program (JUPITER), are summarized. Rather high resistance to neutron irradiation and helium was recognized for 9Cr-2W RAFS; irradiation hardening and helium embrittlement of RAFS were evaluated to be much less than for other candidate materials. Alloy design of high-temperature steels and the development of oxide dispersion-strengthened steels have been progressing.
IAEA 2001