[en] Bowing was not considered a problem in EBR-II until subassembly handling problems occurred. A typical handling problem, caused by top end deflection of the bowed subassembly, is centering of the subassembly removal mechanism over the subassembly. Another problem is excess loads of up to 375 kg that have been required to remove bowed subassemblies from their grid position. All of the bowed type 304 stainless steel subassemblies that created handling difficulties were given a post-irradiation examination. Correlation of the in-core bowing phenomena with the bowing data base required both an axial and radial thermal and flux characterization, consideration of the subassembly design, interpretation of swelling and creep behavior and a simple workable model that could incorporate these factors. A thermal hydraulics code, 'CLUSTER' was used to calculate the operating temperatures at sixty radial locations for each of nineteen axial sections along the hex duct. For this analysis a simple beam method was used with postulated radial restraint bounds in simulating intersubassembly loading. The results of this analysis showed that the bow at a neutron fluence of >2.7x10²²n/cm², E>0.1 MeV, in these structurally varying subassemblies was highly thermal gradient dependent. (Auth.)