Research demonstrated, with a high level of confidence, the Terry turbine operational performance up to and beyond four to 12 hours that is normally credited to these systems for safety function performance. Knowledge of the operating characteristics of these systems will provide a technical basis that may allow utilities to take credit for extended emergency core cooling. The research will provide margins on the distribution of scarce plant resources to where they are most-urgently needed and will allow more time to transition to other core-cooling equipment, such as FLEX (flexible coping strategies), to prevent core damage. The project was completed in 2021.