Development of coupled neutronics and fuel performance analysis capabilities between Serpent and TRANSURANUS

Monte Carlo reactor physics code Serpent is coupled with the fuel performance code TRANSURANUS for steady state analyses including fuel depletion calculations. A two-way coupling is developed, such that the codes exchange data with each other and the solution is obtained as the result of iterations between the two codes. The coupling scheme is external, based on data exchange via output files, such that no source-level modifications are needed on either of the coupled codes. A separate driver program is written to run the coupled calculation including exchange of data, monitoring and determination of convergence. Data provided by the fuel performance code includes the radial temperature distribution and the radius changes in the axial slices of a fuel pin while the reactor physics code provides the linear power and fast neutron flux along with the form of the radial power density in the corresponding axial slices of the pin. The coupling is demonstrated in a calculation case based on a fuel performance benchmark for a burnable absorber rod with gadolinium. The results compared with stand-alone fuel performance calculations demonstrate the capabilities of the coupled calculation system to enhance fuel performance analyses via higher-fidelity neutronic solver capable of providing an accurate neutron flux solution for the rod of interest.