Actinide materials exhibit many unique and diverse electronic, transport, and chemical properties, due in large part to the complexity of their 5f electronic structure. This Symposium will focus on the physics, chemistry, and materials science of the actinide materials. Particular emphasis will be placed upon the 5f magnetic and electronic behaviors, surface sciences, radiation damage and Pu aging, and bulk, thin-film, and nanoparticle properties and their applications to nuclear energy and security related issues. Fundamental actinide science and its role in resolving challenges in environmental and technical issues with actinide materials will be stressed, particularly regarding energy applications, including energy generation, novel nuclear fuels and structural materials, waste remediation, and waste disposal. Both basic and applied experimental approaches, including state-of-the-art experimental techniques and synchrotron-radiation-based and neutron-based investigations, as well as theoretical modeling and numerical simulations, are parts of the Symposium. Several important issues related to non-proliferation, homeland security, nuclear forensics, and the potential renaissances in Nuclear Energy, including fuel synthesis, oxidation, corrosion, intermixing, stability in extreme environments and biological media, prediction of properties via bench-marked simulations, separation science, formulation science, environmental impact and disposal of waste products will also be discussed. This would be the 11th Actinides Symposium at the meetings of the Material Research Society. The previous ten were held in Boston, San Francisco, Phoenix, and Seattle.