Compatability of U-Pu-Fz Fuel Alloys with Potential Cladding Materials

The cladding materials tested against uranium-plutonium-fizzium alloy can be arranged in order of decreasing compatibility at 650°C as follows:

1. V-20wt%Ti
2. V-10wt%Ti
3. molybdenum
4. 304 stainless steel
5. Hastelloy-X
6. niobium and Nb-1wt%Zr.

Increasing plutonium content of the fuel decreases its compatibility with all the cladding materials investigated. The results of this study indicate that the compatibility of a given metal fuel with various claddings may be predictable, on a relative basis, by comparison of the binary phase diagrams of the major elements in the fuel and in the cladding.