Steam electrolysis experiments conducted at Idaho National Laboratory (INL) have demonstrated an efficient process to generate hydrogen using waste heat and electricity from a nuclear power plant. However, the hydrogen output was observed to decrease significantly over time. Solid oxide stack components from the INL studies were analysed at Argonne National Laboratory to elucidate the degradation mechanisms of electrolysis. After probable regions of degradation were identified by surface techniques, Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDS) were used to further characterise the causes of degradation by examining cross-sections of stack components.