Liquid-cooled nuclear reactor especially a boiling-water reactor

Boiling-water reactor having a reactor pressure vessel and a reactor core of fuel assemblies received therein, the fuel assemblies being grouped into core cells each having a control rod containing absorber material and connected to a drive mechanism, comprising a plurality of sheetmetal shafts respectively associated with the core cells, each of said sheetmetal shafts extending beyond the length of the reactor core by a length at least equal to that of the respective control rod and having a cross section substantially equal to that of the respective core cell, intermediate metal sheets subdividing said sheetmetal shaft into longitudinal channels through which the fuel assemblies are loadable and unloadable, said channels having respective cross-subsections each substantially equal in size to the cross section of a respective fuel assembly, each of said sheet metal shafts enclosing and carrying the drive mechanism for the respective control rod, and the respective control rod being guidable on and along said intermediate metal sheets, and said sheetmetal shafts having mutually adjacent sides, and means attached to the outside of said sheetmetal shafts through which said sheetmetal shafts are braced against one another and against a core enclosure.