[en] A finite-element model was developed to assess the ability of a pool-type LMFBR head closure to sustain an energetic HCDA. From a conceptual representation of an expanded EBR-II type deck, it was determined that there is a reasonable amount of symmetry in the structure that an initial model would consist of a 12⁰ sector. This model accounts for the main structural elements of the closure head: beams, plates, inner ring, in-tank component nozzle and concrete shielding. The mass of the in-tank component was treated as a concentrated mass located at its attachment to the structural members. The ANL-developed SADCAT code was used in this study. The code is an explicit, three-dimensional finite-element code developed for analyzing transient, nonlinear, structural problems. The code has a triangular plate element and a three-dimensional continuum element. The above model was used to study the effect of several design variations on the structural response of the deck to an energetic HCDA. Two types of outer boundary conditions were considered to determine their effect on the closure head's displacements and stress levels. In addition to the above study, an analysis was conducted to determine the structural condition of the concrete shielding. Based upon the above preliminary calculations of pool-type LMFBR head closures, it is indicated that the shield-deck can be designed to survive the given HCDA loads without failure