Am phases in the matrix of a U–Pu–Zr alloy with Np, Am, and rare-earth elements

Journal Article · Thu Jan 01 04:00:00 EST 2015 · Journal of Nuclear Materials

DOI:https://doi.org/10.1016/j.jnucmat.2014.08.051· OSTI ID:1162218

Janney, Dawn E. ^[1]; Kennedy, J. Rory ^[1]; Madden, James W. ^[1]; O’Holleran, Thomas P. ^[1]

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1. Idaho National Lab. (INL), Idaho Falls, ID (United States)

Phases and microstructures in the matrix of an as-cast U-Pu-Zr alloy with 3 wt% Am, 2% Np, and 8% rare-earth elements were characterized by scanning and transmission electron microscopy. The matrix consists primarily of two phases, both of which contain Am: ζ-(U, Np, Pu, Am) (~70 at% U, 5% Np, 14% Pu, 1% Am, and 10% Zr) and δ-(U, Np, Pu, Am)Zr₂ (~25% U, 2% Np, 10-15% Pu, 1-2% Am, and 55-60 at% Zr). These phases are similar to those in U-Pu-Zr alloys, although the Zr content in ζ-(U, Np, Pu, Am) is higher than that in ζ-(U, Pu) and the Zr content in δ-(U, Np, Pu, Am)Zr₂ is lower than that in δ-UZr₂. Nanocrystalline actinide oxides with structures similar to UO2 occurred in some areas, but may have formed by reactions with the atmosphere during sample handling. Planar features consisting of a central zone of ζ-(U, Np, Pu, Am) bracketed by zones of δ-(U, Np, Pu, Am)Zr₂ bound irregular polygons ranging in size from a few micrometers to a few tens of micrometers across. The rest of the matrix consists of elongated domains of ζ-(U, Np, Pu, Am) and δ-(U, Np, Pu, Am)Zr₂. Each of these domains is a few tens of nanometers across and a few hundred nanometers long. The domains display strong preferred orientations involving areas a few hundred nanometers to a few micrometers across.

• Research Organization: Idaho National Laboratory (INL), Idaho Falls, ID (United States)
• Sponsoring Organization: USDOE Office of Nuclear Energy (NE)
• DOE Contract Number: AC07-05ID14517
• OSTI ID: 1162218
• Report Number(s): INL/JOU--14-31715
• Journal Information: Journal of Nuclear Materials, Journal Name: Journal of Nuclear Materials Journal Issue: C Vol. 456; ISSN 0022-3115
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
36 MATERIALS SCIENCE
ACTINIDE COMPOUNDS
AMERICIUM ALLOYS
DOMAIN STRUCTURE
GRAIN ORIENTATION
NANOSTRUCTURES
NEPTUNIUM ALLOYS
NUCLEAR MATERIALS
OXIDES
PHASE STUDIES
PLUTONIUM ALLOYS
RARE EARTH ALLOYS
SCANNING ELECTRON MICROSCOPY
TRANSMISSION ELECTRON MICROSCOPY
URANIUM BASE ALLOYS
ZIRCONIUM ALLOYS
ZONES