[en] A multipurpose testing SS vessel is made up of multiple cylinders with flanges. simulated fuel assemblies, control element assemblies, control rod guide tubes, and control rod drive mechanism are housed, supported and installed in this vessel. every section of the vessel is composed of the same connection flange and 'O' sealing washer. The axial dimension of the vessel can be extended or reduced so as to meet test requirements. The baffler, which forms the plenum of the vessel, can be replaced in accordance with the type of fuel assemblies. The vessel features a top eccentric structure that enables researchers to adjust the control rod drive line (CRDL). The distance between the CRDL and the shaft of an eccentric ring in the structure is 8 mm. The largest offset of 16 mm can be attained when an eccentric ring revolves 180 degrees. The vessel with multiple sections is a very important facility for cold testing and research of CRDL. The test results will be used as the basis in the design and analysis for every component of reactor CRDL