[en] The interim storage is for producing an adjustable time period of the fuel reprocessing. Japanese utilities have plans to start interim storage by 2010. The interim facilities are off site of the reactors and will have no hot-cell. Therefore, it should be important to confirm integrity of cask during storage and transport after storage. NUPEC has been conducting the dual-purpose metal cask verification test since 1999 under sponsorship of the Ministry of Economic, Trade and Industry (METI). The purpose of this verification test is to confirm integrity of safety functions during interim storage and under transport conditions after the storage. The test is subdivided into two categories, material property tests and system verification tests. The first is to verify degradation of materials of which cask consists. The second is to confirm the integrity of safety functions during storage and transport. Seal ability of cask lid system during transport after the storage should especially be focused on. Based on 3D-analysis and the results of 1/3-scaled model test, sliding and opening between cask lids and their flanges will be slightly occurred. Thus cask seal ability with aging metal seal should be confirmed by full-scale test. Criteria for opening and sliding distance of metal seal that is assumed degradation should also be established. This paper presents the general plan and the current status of this verification test. Test name, its goals and current status are summarized. Evaluation for 3D-analysis based on the results of scale model test and establishment of the criteria for seal system will be also discussed in the paper