The development and qualification of advanced cladding materials (including advanced zirconium cladding alloys, advanced steels, silicon carbide composite) and fuel materials (such as doped uranium dioxide, high density fuels) have made significant progress in the last decade, since the initiation of various national research and development and industry projects launched after the accident at the Fukushima Daiichi nuclear power plant. Written for operators and regulators of nuclear power plants and those involved in the development and qualification of advanced fuels, the aim of this publication is to review the status of development, qualification and licensing of some advanced fuel technologies for Water Cooled Reactors (WCRs); and to consider the applicability of the current IAEA Safety Requirements and Safety Guides in addressing the safety of advanced fuels in design and operation, identifying specific aspects that might evolve into recommendations in the future. The objective is primarily to identify and collect the status of knowledge in Member States on the applicability to advanced fuels of regulatory requirements, acceptance criteria and regulatory guidance documents that have been developed for the licensing of current nuclear fuel systems. It also aims to review the status of development, qualification, and licensing of some advanced fuel technologies for WCRs, with a focus on evolutionary as well as revolutionary technologies.