Hot Isostatically Pressed Zirconolite Wasteforms for Actinide Immobilisation

In order to demonstrate the deployment of Hot Isostatic Pressing (HIP) for the immobilisation of Pu stocks and residues, a series of active and inactive zirconolite formulations have been processed and characterised. In this instance, Ce, U, and Th have been applied as chemical surrogates for Pu4+. A range of formulations targeting isovalent Zr4+ site substitution (i.e. to simulate CaZr1-xPuxTi2O7) have been processed by HIP and characterised by powder Xray diffraction, and scanning electron microscopy, in order to determine surrogate partitioning between the host zirconolite phase, and accessory phases that may have formed during the HIP process.