This publication is a new edition of Technical Reports Series No. 240, Guidebook on Spent Fuel Storage (1991). It aims to provide guidance on spent fuel storage options, describing the history and observed trends of spent fuel storage technologies, gathering operational experiences and lessons learned. The evolving aspects related to higher burnup and mixed oxide (MOX) spent fuel, and the extension of storage timeframes are detailed. It also includes information on the distribution of the current global inventory of spent fuel by storage systems, a description of (and terminology relating to) available spent fuel storage technologies and different storage facility locations.