This volume contains the notes of lectures given at the workshops 'Hybrid Nuclear Systems for Energy Production, Utilisation of Actinides & Transmutation of Long-lived Radioactive Waste' and 'Nuclear Data for Science and Technology: Accelerator Driven Waste Incineration', held at the Abdus Salam ICTP in September 2001. The subject of the first workshop was focused on the so-called Accelerator Driven Systems, and covered the most important physics and technological aspects of this innovative field. The second workshop was devoted to an exhaustive survey on the acquisition, evaluation, retrieval and validation of the nuclear data relevant to the design of Accelerator Driven Systems. This partial collection should represent a useful reference for researchers interested in these topics. For the benefit of potential readers who did not participate in the workshops these lecture notes will also be available from the ICTP Web-page (http://www.ictp.it/~pub_off/lectures/) for free access and consultation. (ISBN 92-95003-17-9)