The foundation of the simulation effort is the MCNP–Polimi simulation. However, a known issue with MCNP is its handling of gadolinium de-excitations. A package called GADGET was devised by the author of this work to account for the discrepancies in MCNP gadolinium by combining the trust worthy neutron propagation in MCNP with the data-driven, high-fidelity gamma-ray cascades of DICEBOX. This framework is used to estimate the NuThor detector’s response to the signal neutrons emitted from the neutrino-induced nuclear fission events and both the steady-state and beam-correlated backgrounds expected to be faced in this measurement.