An exact solution for a heterogeneous, discontinuous wide beam is developed herein having three unique boundary condition (BC) sets. These BC sets were chosen based on their relevance to plate-type–fueled reactors. This solution, with respective BC sets, contributes new insights into the field of engineering mechanics as applied within the nuclear engineering discipline. Herein, the exact solution is validated under a set of test cases. A comparison is then made against other relations that have been developed to provide similar engineering insights. Last, the solution is applied toward a presently relevant engineering problem regarding the design of a monolithic plate-type fuel. The outcome of this work provides a solution form for the computation of out-of-plane deflection of a heterogeneous, discontinuous wide beam that can be easily applied in engineering mechanics and is flexible in use.