Floating Nuclear Power Plants (FNPPs) pose a challenge to conventional safeguards inspections due to their mobility and unique design features. Space-based remote sensing and open-source geospatial data can assist in filling this information gap by providing insights unavailable from other sources. This paper identifies specific observable imagery signatures associated with activity at FNPPs across the facility life cycle, including construction, fuel loading, transit, operation, refueling, and decommissioning. It rates their detectability via three types of commercial satellite imagery which are available to the International Atomic Energy Agency: very high-resolution optical, high-resolution optical, and high-resolution synthetic aperture radar (SAR). It also identifies open-source geospatial data other than imagery that can improve the accuracy of observations made about FNPPs. The list of observable signatures is applied to a study of the only operational FNPP, the Akademik Lomonosov, as well as selected nuclear-powered surface vessels. The results of this study generally support the conclusion that satellite imagery analysis can effectively support the implementation of safeguards on this type of facility throughout its operational life. However, other safeguards tools, such as unattended monitoring systems (UMS) and seals, will remain necessary to ensure that future FNPPs are adequately safeguarded.
