Effective Delayed Neutron Fraction in a Molten Salt Reactor with Circulating Fuel

摘要

Abstract In molten salt reactors (MSRs) with circulating liquid fuel, delayed neutron precursors can escape from the active core and be distributed over the entire reactor circuit. Taking into account the decrease in the effective fraction of delayed neutrons due to the motion of the emitters is important for further analysis of the reactor kinetics. A new approach is proposed to account for fuel circulation in the fuel circuit on the basis of a combined calculation by the Monte Carlo and finite volume methods. The calculation was implemented using the interface between the codes SERPENT and OpenFOAM software applications (SAs) in the form of the OFSI software. Calculations of the effective delayed neutron fraction for the 10-MWt heat power MSR reactor circuit with a cavity type cylindrical core and the Li, Be, Pu/F fuel salt mixture are performed. On the basis of the results obtained, conclusions are made about the applicability of the technique and ways of its further development are outlined.