Thermo-mechanical behavior of all the metallic fuel rods in a sodium-cooled fast reactor

A detailed analysis of neutronics, core thermal-hydraulics, and fuel performance has been developed to predict the thermo-mechanical failures of all the metallic fuel rods in a sodium-cooled fast reactor. The neutronics analysis provides a reload pattern for fuel assemblies and power/flux spatial distributions for each fuel rod. The core thermal-hydraulics allows the calculation of the cladding temperatures via subchannel analysis. The fuel performance analysis evaluates the thermo-mechanical integrity of all the fuel rods by considering the detailed spatial and temporal variations of the thermal power, neutron flux, and cladding temperature during the in-core lifetime of each fuel assembly. This analysis leads to improved computational accuracy and provides more comprehensive physical information for each code than a conventional one-dimensional fuel performance calculation. It is evident that, compared with a simple conservative one-dimensional analysis, the present method will improve plant performance while maintaining the thermal margin. The developed analysis has been applied to evaluate the fuel performance of a Prototype Gen IV sodium-cooled fast reactor candidate core by considering the uncertainties of the design parameters.