The objective of this Safety Guide is to provide up-to-date guidance and recommendations on the design@ safe operation and assessment of safety for the different types of spent nuclear fuel storage facility (wet and dry)@ by considering different types of spent nuclear fuel from nuclear reactors@ including research reactors@ and different storage periods@ including storage beyond the original design lifetime of the storage facility. This Safety Guide presents guidance and recommendations on how to meet the requirements established in the following IAEA Safety Requirements publications: Predisposal Management of Radioactive Waste [1]@ Safety of Nuclear Fuel Cycle Facilities [3]@ Safety Assessment for Facilities and Activities [4] and The Management System for Facilities and Activities [5].