Nuclear characteristics analysis method and engineering application of fuel assembly reconstitution with dummy rods

During normal operation of nuclear power plants, some fuel assemblies were discharged ahead of schedule as a few fuel rods damaged due to debris in the primary circuit or maloperation of fuel handling. Reconstituted fuel assemblies which used dummy rod to replace the broken rod could re-use in the core to avoid reducing operation economy. The purpose of this article is to simulate operation of fuel reconstitution with dummy rods made of stainless steel and Zr alloy, analyze the neutronic characteristics and the mechanism of impacting fuel assembly and core operation physical parameters due to fuel reconstitution, evaluate the nuclear safety of core operation with reconstituted fuel assemblies, then establish the whole analysis method and flow of nuclear design. This work can be widely applied for fuel reconstitution with dummy rods, and can support reload design with reconstituted fuel assemblies. It is the first domestic work to establish the whole analysis method and procedure of nuclear design for fuel reconstitution and has been utilized in the engineering practice of reload design in CHASNUPP. (authors)