Characterization of a minor actinides bearing metallic fuel pin irradiated in EBR-II

• Published in: Journal of nuclear materials 2020-10, Vol.539 (N/A), p.152279, Article 152279
• Main Authors: Capriotti, Luca, Harp, Jason M.
• Format: Article
• Language: English
• Subjects: Actinides; Breeder reactors; EBR-II; Experiments; Fission products; Fuel systems; Heavy metals; Irradiation; Metal fuels; Metallic fuel; Microstructure; Microstructure characterization; Nuclear engineering; NUCLEAR FUEL CYCLE AND FUEL MATERIALS; Nuclear fuel elements; Nuclear fuels; Nuclear safety; Postirradiation examination; Reactors; Scanning electron microscopy; SEM; Thermal neutrons; Transmutation; Transmutation fuel; Zirconium
• ISSN: 0022-3115; 1873-4820
• DOI: 10.1016/j.jnucmat.2020.152279

The X501 transmutation experiment irradiated in Experimental Breeder Reactor II (EBR-II) was intended to evaluate the safety and performance of the addition of minor actinides (Am, Np) into the metallic nuclear fuel system. The irradiation of this experiment is also of paramount importance for comparisons between true fast spectrum irradiations (e.g. EBR-II) and shrouded irradiation capsules performed at the thermal neutron spectrum Idaho National Laboratory Advanced Test Reactor. The X501 experimental fuel pins were irradiated to a peak measured burnup of 6.2% fission per initial heavy metal atom. This work reports and discusses Postirradiation Examination results for one of two minor actinide bearing pins from the EBR-II X-501 experiment (X501-G591) with a focus on fuel microstructure evolution. Fuel swelling, fission product distribution, cladding strain, fission gas release, fuel microstructure and fuel cladding chemical interaction were all evaluated. The fission gas release was 79.9% and the microstructure along the fuel pin presented several characteristics very similar to other EBR-II U-Pu-Zr ternary metallic fuel experience. Minor actinides seem to not dramatically affect the overall performance of this candidate transmutation fuel. Scanning Electron Microscopy was also performed and an in-depth characterization of the different regions and phases is presented. Performance data from these irradiations can be used to inform the feasibility of minor actinide transmutation in future reactor systems. •The X501 experiment demonstrated potential alloys for minor actinide transmutation.•Performance of the X501-G591 metallic fuel pin is in line with historical experience from EBR-II driver fuel.•Fuel cladding chemical interaction (FCCI) characterization revealed Am infiltration into the cladding.