Manager, General Electric Company, Sunnyvale, Calif.
Metallurgist, General Electric Company, Pleasanton, Calif.
Pages: 15 Published: Jan 1973
Results are described from the investigation of swelling caused by fast-neutron-induced void formation in stainless steel fuel cladding and high-nickel alloys irradiated in fast flux (EBR-II) to fluences up to 7.3 × 1022 n/cm2, E > 0.1 MeV. Immersion density measurements of swelling gave results ranging from a volume increase of 10 percent in solution-annealed Type 347 stainless steel to a small densification in Inconel-625. Transmission electron microscopy investigations revealed that the extent of void formation in Types 316 and 347 stainless steels, Incoloy-800, and Hastelloy-X was related to the degree of intragranular precipitation (principally carbides), whereas the Ni3 Cb precipitation in Inconel-625 had apparently inhibited void formation altogether. It is concluded that precipitate particles can play a major role in determining the extent of void formation in austenitic alloys during neutron irradiation, and in the optimum morphology (a high concentration of closely spaced, small and possibly coherent particles) they offer promise of largely inhibiting void formation and swelling.
radiation effects, neutron irradiation, nuclear fuel claddings, austenitic alloys, swelling, voids, second phase particles, precipitates, morphology, electron microscopy, fast reactors (nuclear)
Paper ID: STP35441S