LAUSR

Abstract A hybrid coupled strategy was proposed for a coupled neutronics and thermal-hydraulics analysis of a full PWR core, using the continuous-energy Reactor Monte Carlo code (RMC) and the sub-channel code COBRA-TF (CTF). In the code system with hybrid coupling, CTF was invoked and controlled by RMC internally, without external interface. The On-The-Fly cross sections treatment of RMC was used to reduce the complexity of the coupled code as well as to reduce the memory requirement. The domain decomposition parallel technique was developed in CTF to improve the efficiency of full core sub-channel calculations, and the PWR preprocessor of CTF can reduce the complexity of full core modeling establishment. The coupled codes were applied to steady-state simulations of the Benchmark for Evaluation And Validation of Reactor Simulations (BEAVRS) in the hot, full power condition at the full-core level to reveal the effects of the coupling on the full-core power distribution in both axial and radial directions. The influences of other important parameters including the neutron population and the boron concentration were also investigated. The results proved the effectiveness and high fidelity of the coupled system. More systematic and detailed analyses can be performed based on realistic operating conditions of PWR full core with the coupled codes system.