Neutron radiography of a grid-type subassembly

The examination and performance evaluation of grid-type subassemblies irradiated in EBR-II required neutron radiography prior to disassembly. This operation required that the subassembly be shielded, contained, and cooled in a package small enough to allow location of the radiography foil close to the grid detail for sharp resolution of the structure. A sealed can with static helium as the heat transfer medium provided satisfactory containment and cooling for the subassemblies; the can contained cadmium targets for precise rotational alignment of subassemblies during radiography