Preventing Large Radionuclide Releases During Severe Accidents in Fluoride-Salt-Cooled High-Temperature Reactors

摘要

The FHR has the unique combination of a hightemperature fuel, a high-temperature liquid coolant with a boiling point substantially above reactor vessel failure temperatures, and a large temperature margin between operating temperatures and the coolant boiling point. That combination provides over a 1000°C to drive decay heat in a BDBA from the reactor vessel to the atmosphere. Our initial assessment is that with appropriate choice of materials from the reactor vessel through the silo, it may be possible to prevent major fuel failure (thus no major radionuclide release) with a large reactor of several thousand megawatts thermal even if all conventional decay heat removal systems fail and there are large-scale structural failures. Significant work remains to determine if an economic fail-safe system can be designed to eliminate the potential for large-scale nuclear reactor accidents in large FHRs.