"This project aims to reduce the key uncertainties pertaining to zirconolite ceramic/glass-ceramic waste form dissolution. The key objectives are to: 1. Understand the effects of relevant geochemical parameters on the kinetics of HIP-ed ceramic/glass-ceramic zirconolite materials, using Ce and U as surrogates for Pu; 2. Develop an understanding of the dissolution mechanisms of HIP-ed ceramic/glass-ceramic zirconolite materials; 3. Perform selected experiments to understand the dissolution of 239Pu-doped ceramic/glass-ceramics, fabricated by University of Sheffield PhD student Steph Thornber at ANSTO in 2017; 4. Establish a series of long-term (1 – 3y) dissolution experiments with 239Pu-doped samples, to be periodically sampled."