Spacer grids for laterally supporting and spacing rod -like or tube-like elements and methods of spacing and laterally supporting fuel rods within spacer grids of nuclear fuel rod assemblies

New designs of spacer grids for laterally supporting and spacing rod-like or tube-like elements and methods of spacing and laterally supporting fuel rods within spacer grids of nuclear fuel rod assemblies are described. The invention consists of efficient, economical apparatus and method for inserting fuel rods into cells of a grid plate lattice that utilize protrusions to positively space and support the fuel elements or rods without marring the fuel surfaces of the elements or rods and a versatile grid plate design adaptable for supporting the tubes of vapor generators, shell and tube heat exchangers and the like. (U.K.)