Out-of-pile and postirradiated examination of lanthanide and lanthanide-palladium interactions for metallic fuel

JOURNAL OF NUCLEAR MATERIALS

卷:544

Article

Benson, Michael T.¹  Harp, Jason M.²  Xie, Yi³  Yao, Tiankai¹  Tolman, Kevin R.¹  Wright, Karen E.¹  King, James A.¹  Hawari, Ayman I.⁴  Cai, Qingsheng⁴ 

[1] Idaho Natl Lab, POB 1625,MS 6188, Idaho Falls, ID 83415 USA

[2] Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA

[3] Purdue Univ, 516 Northwestern Ave, W Lafayette, IN 47906 USA

[4] North Carolina State Univ, POB 7909, Raleigh, NC 27695 USA

关键词: Metallic nuclear fuel;    Fuel-cladding chemical interaction;    Neutron diffraction;    Lanthanide compound;   

DOI  :  10.1016/j.jnucmat.2020.152727

来源: Elsevier

【 摘 要 】

Palladium is being investigated as a fuel additive to bind with and potentially immobilize lanthanide fission products. A primary cause of fuel-cladding chemical interaction (FCCI) is the lanthanide fission products migrating to the fuel periphery and interacting with the cladding. This interaction will lead to wastage of the cladding and eventually to a cladding breach. Palladium has previously been identified as a promising additive used to prevent or decrease FCCI by reacting with the lanthanide fission products. In the current study, an alloy cast from the four highest abundant lanthanides found in irradiated metallic fuel, Nd, Ce, Pr, and La, with and without Pd, has been characterized using neutron diffraction, scanning electron microscopy, and electron probe microanalysis. In the lanthanide-Pd intermetallic compounds, all of the constituent compounds, i.e. Nd-Pd, Ce-Pd, La-Pd and Pr-Pd are known. There is very good agreement, both structurally and compositionally, between the out-of-pile lanthanide alloy and lanthanide fission products characterized in irradiated fuels. In both cases, the lanthanide elements form a solid solution in a hexagonal crystal structure. The out-of-pile lanthanide alloy follows Vegard's Law, with the measured and calculated (weighted average of constituents) lattice parameters being within 1% for both the a and c parameters. Pd bonds with the lanthanides (Ln) forming the phases LnPd and Ln(7)Pd(3). The results indicate the properties of lanthanide compounds in irradiated metallic fuel can be reliably simulated in out-of-pile experiments. (C) 2020 Elsevier B.V. All rights reserved.

【 授权许可】

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