Signature-based safeguards (SBS) is currently being investigated to assist traditional nuclear material accountancy in tracking special nuclear material (SNM) within a fuel cycle facility. SBS involves the identification and detection of signatures from process monitoring data for off-normal operation scenarios that involve the loss or improper movement of SNM. To determine possible realistic signatures, the electrorefiner (ER) process is modeled using the code Enhanced REFIN with Anodic Deposition (ERAD), and the JCC-31 Neutron Coincidence Counter, a nondestructive assay detector, is simulated using MCNPx-POLIMI. The ERAD model is used to determine the elemental composition of the ER cathode deposit, while the MCNPx model is developed to determine the single and double count rates expected for this deposition using ft8 tallies. For the determination of signatures, changes were made in the ER model for current density and diffusion layer thickness. The signatures in terms of both modeled ER and detector output demonstrate distinct signatures to be expected for off-normal operations. The detector response in particular shows significant changes registered in count rates when plutonium is deposited at the cathode, due to the changes in the simulated ER operating conditions.