Development of Neutronics and Thermal-Hydraulics Coupled Code for Accelerator Driven Subcritical Systems

A new neutronics and thermal-hydraulics coupled code named ARTAP is developed to analyze the steady-state and transient characteristics of accelerator driven subcritical system (ADS) in this paper. Monte Carlo simulations for spallation neutron source and deterministic calculations for the subcritical core are performed in the steady-state analysis module. The ADS core is divided into a number of nodes both along the reactor axis and the fuel pellet radius for the calculation of spatial temperature distributions. The power iteration method is adopted to solve the coupled neutronics and thermal-hydraulics problems. The transient analysis module consists of space-time neutron kinetics model and thermal-hydraulics dynamic model, which is calculated by using numerical differentiation formulas (NDFs) method. The new code is verified by comparing its predictions for both the steady-state and transient cases of the OECD/NEA ADS benchmark. Results of numerical simulations indicate that ARTAP is reliable and efficient to be applied for the ADS analysis.