The Transport and Fate of Helium in Nanostructured Ferritic Alloys at Fusion Relevant He/DPA Ratios and DPA Rates

Journal Article · Wed Aug 01 04:00:00 EDT 2007 · Journal of Nuclear Materials, 367-370:399-410

DOI:https://doi.org/10.1016/j.jnucmat.2007.03.047· OSTI ID:917966

Yamamoto, Takuya; Odette, George R; Miao, Pifeng; Hoelzer, D T; Bentley, James; Hashimoto, N; Tanigawa, Hiroyasu; Kurtz, Richard J

A novel in-situ 59Ni(n,α) reaction He-implanter technique is described, that was used to characterize the effect of the He/dpa ratio on microstructural evolution and changes in the flow properties of various materials at fusion relevant conditions. Irradiations in the High Flux Isotope reactor (HFIR) resulted in α-implantation from thin 1 to 5 µm NiAl coatings on TEM discs producing a uniform He concentration of 5 to 50 appm He/dpa to a depth of 5 to 8 μm. Initial post-irradiation TEM observations of MA957 irradiated to 9 dpa and 380 appm He at 500 ºC provide strong evidence for the existence of high density of small ≤ 1 nm size bubbles trapped on nano-scale YTiO clusters. In contrast, similar irradiations of Eurofer 97, described in a companion paper, produce a lower number density of larger cavities, which may be a mixture of bubbles and voids.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 917966
• Report Number(s): PNNL-SA-55263; AT6020100
• Journal Information: Journal of Nuclear Materials, 367-370:399-410, Journal Name: Journal of Nuclear Materials, 367-370:399-410
• Country of Publication: United States
• Language: English

Related Subjects

fusion
helium
neutron irradiation
ferritic/martensitic steels