[en] In accordance with the amended Nuclear Energy Act, Imatran Voima Oy will make provisions for the storage and direct disposal of the spent nuclear fuel from units l and 2 of the Loviisa power plant in Finland. The fuel storage system was originally designed for the fuel volume generated during some five years of operation. Today, the changing situation requires that the storage capacity for spent fuel must be increased to cover the whole of the remaining operating life. The study covers all the options of increasing the storage capacity that are known and used throughout the world. In total nine options of various types have been designed and studied. (4 refs., 41 figs., 6 tabs.)