The 12^th SPCA was held between 19 and 21 March 2018 in the Campus Tecnológico e Nuclear of Instituto Superior Técnico, located at Bobadela (near Lisboa), Portugal, being organized as a tutorial introductory session to the conference 48^èmes Journées des Actinides. Forty participants attended the seventeen lessons of the school, which indeed was an unique opportunity for students (and others) to gain knowledge from international expert master-classes in the various areas of different actinide science aspects. 12^th SPCA was a great success, allowing students and young researchers to meet, question and learn from experts in a relaxed and friendly environment.