Although U-Pu-Zr alloys have been investigated for more than 60 years, relatively little experimental information is available, and many of the original values are in government reports that appeared more than 40 years ago. Information about the technologically important alloy U-20Pu-10Zr (weight percent) is even more limited. Since U-Pu-Zr alloys are difficult materials to study experimentally, it is therefore important to understand what results have already been obtained, how reliable they are, and where they were reported.

This critical review provides a summary and critical assessment of the available experimental measurements of thermal and mechanical properties of U-Pu-Zr alloys. Knowledge of these properties is crucial for understanding and modeling fuel constituent redistribution, fuel swelling and creep, fission gas release under normal reactor operations, and melting or formation of liquid phases under reactor transient scenarios.

This critical review builds on a previous review that assessed experimental data about phases and phase diagrams in U-Pu-Zr alloys. Both reviews are intended as resources for fuel designers and modelers and as guides for prioritizing future experimental work.