As part of a comprehensive safety study, analyses are presented on the hydrodynamic loads and containment response of a large loop-type LMFBR subjected to an HCDA of a 1000 MJ energy release. The reference reactor consists of a primary vessel, a head cover, and various complex internals such as the upper internal structure (UIS), the core-support structure (CSS), radial shield, shield baffles, and deflector plate. Three calculations are performed with the ANL hybrid Lagrangian-Eulerian containment code, ALICE-II. They deal, respectively, with: (1) the calculation of HCDA hydrodynamics, reactor-cover loads, and forces on the UIS; (2) investigating the mitigating effect of the UIS on the cover loading as well as the containment response; and (3) the analysis of overall containment integrity, including interaction of fluids with the deformable UIS and CSS
