Computed phase equilibria for burnable neutron absorbing materials for advanced pressurized heavy water reactors

Burnable neutron absorbing materials are expected to be an integral part of the new fuel design for the Advanced CANDU®[CANDU is as a registered trademark of Atomic Energy of Canada Limited.] Reactor. The neutron absorbing material is composed of gadolinia and dysprosia dissolved in an inert cubic-fluorite yttria-stabilized zirconia matrix. A thermodynamic model based on Gibbs energy minimization has been created to provide estimated phase equilibria as a function of composition and temperature. This work includes some supporting experimental studies involving X-ray diffraction.