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Title: Microstructure evolution of T91 irradiated in the BOR60 fast reactor

In this paper, microstructures of T91 neutron irradiated in the BOR60 reactor at five temperatures between 376 °C and 524 °C to doses between 15.4 and 35.1 dpa were characterized using transmission electron microscopy (TEM), scanning transmission electron microscopy (STEM), and atom probe tomography (APT). Type a<100> dislocation loops were observed at 376–415 °C and network dislocations dominated at 460 °C and 524 °C. Cavities appeared in a bimodal distribution with a high density of small bubbles less than 2 nm at irradiation temperatures between 376 °C and 415 °C. Small bubbles were also observed at 460 °C and 524 °C but cavities greater than 2 nm were absent. Enrichment of Cr, Ni, and Si at the grain boundary was observed at all irradiation temperatures. Radiation-induced segregation (RIS) of Cr, Ni and Si appeared to saturate at 17.1 dpa and 376 °C. The temperature dependence of RIS of Cr, Ni and Si at the grain boundary, which showed a peak Cr enrichment temperature of 460 °C and a lower peak Ni and Si enrichment temperature of ~400 °C, was consistent with observations of RIS of Cr in proton irradiated T91, suggesting that the same RIS mechanism may also apply tomore » BOR60 irradiated T91. G-phase and Cu-rich precipitates were observed at 376–415 °C but were absent at 460 °C and 524 °C. Finally, the absence of G-phase at 524 °C could be related to the minimal segregation of Ni and Si in that condition.« less
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  1. Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Nuclear Engineering and Radiological Sciences
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science & Technology Division
  3. Univ. of Oxford (United Kingdom). Dept. of Materials
Publication Date:
Grant/Contract Number:
AC05-00OR22725; AC07-05ID14517; NE0000639; EP/L025817/1; EP/M022803/1
Accepted Manuscript
Journal Name:
Journal of Nuclear Materials
Additional Journal Information:
Journal Volume: 504; Journal ID: ISSN 0022-3115
Research Org:
Univ. of Michigan, Ann Arbor, MI (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Oxford (United Kingdom)
Sponsoring Org:
USDOE Office of Nuclear Energy (NE), Nuclear Reactor Technologies (NE-7); USDOE Office of Nuclear Energy (NE), Fuel Cycle Technologies (NE-5); Engineering and Physical Sciences Research Council (EPSRC)
Country of Publication:
United States
22 GENERAL STUDIES OF NUCLEAR REACTORS; 36 MATERIALS SCIENCE; microstructure; radiation-induced segregation; swelling; radiation-induced precipitates
OSTI Identifier: