Reversible expansion of gallium-stabilized δ-plutonium

• Published in: Journal of nuclear materials Vol. 359; no. 3; pp. 185 - 191
• Main Authors: Wolfer, W.G., Oudot, B., Baclet, N.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.12.2006; Elsevier
• Subjects: Applied sciences; Energy; Exact sciences and technology; Fuels; Nuclear fuels; Preparation and processing of nuclear fuels; C1200; D0300; 81.30.Bx; 61.80.Az; 89.20.Dd; P0700; 61.82.Bg; R0400; 82.60.Lf; P1100; Gallium; Alloys; Radiation effect; Plutonium; Lattice parameters; Steady state; Thermodynamic equilibrium; Transients; Nuclear reactor
• ISSN: 0022-3115; 1873-4820; 1873-4820
• DOI: 10.1016/j.jnucmat.2006.08.020

It is shown that the transient expansion of plutonium–gallium alloys observed both in the lattice parameter as well as in the dimension of a sample held at ambient temperature can be explained by assuming incipient precipitation of Pu 3Ga. However, this ordered ζ′-phase is also subject to radiation-induced disordering. As a result, the gallium-stabilized δ-phase, being metastable at ambient temperature, is driven towards thermodynamic equilibrium by radiation-enhanced diffusion of gallium and at the same time reverted back to its metastable state by radiation-induced disordering. A steady state is reached in which only a modest fraction of the gallium present is arranged in ordered ζ′-phase regions.