To better understand the operating limits of two emergency core-cooling systems in nuclear power plants —the Terry turbines and self-regulating mode of operation of reactor-core isolation cooling systems used in boiling-water reactors (BWRs) and turbine-driven auxiliary feedwater systems for pressurized water reactors (PWRs).
Research is being conducted to demonstrate, with a high level of confidence, the Terry turbine operational performance up to and beyond 4 to 12 hours that is normally credited these systems for safety function performance. Knowledge of the actual 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.
2022—perform safety risk assessments of a station-blackout accident scenario for generic PWR and BWR plants with credited extended operation of emergency core-cooling systems.
2023—credit Terry turbines for extended operation using the results from this completed project.
This photograph of terry turbine equipment is used to demonstrate self-regulating performance.
Terry turbopumps are an important safety system credited for providing cooling water during accident conditions, similar to those that occurred during the Fukushima Daichi event in 2011.