NUCLEAR POWER PLANT EVALUATION SYSTEM AND METHOD

摘要

PROBLEM TO BE SOLVED: To respond to the necessity of highly precisely evaluating safety of a plant in a nuclear power plant evaluation system.SOLUTION: A nuclear power plant evaluation system includes: a plant system analysis part 21 which calculates a reactor pressure, a reactor core inlet enthalpy, a reactor core inlet flow rate and a reactor core inlet boron concentration as reactor core boundary conditions for a reactor core consisting of a plurality of fuel rods; a three-dimensional reactor core kinetics analysis part 22 which calculates reactor core output and a reactor core output distribution on the basis of the reactor core boundary conditions; a three-dimensional reactor core heat flow kinetics analysis part 23 which calculates distributions of fuel temperatures, coolant densities and boron concentrations on the basis of the reactor core boundary conditions and the reactor core output distribution; a first correction part 31 which calculates a corrected reactor core output distribution by increasingly correcting an uncertainty at the time of transition for the reactor core output distribution; and a second correction part 32 which calculates a corrected fuel rod output distribution by increasingly correcting an uncertainty at the time of transition for the fuel rod output distribution. The three-dimensional reactor core heat flow kinetics analysis part 23 calculates a minimum DNBR, a fuel center temperature and a cladding tube maximum temperature on the basis of the boundary conditions, the corrected reactor core output distribution and the corrected fuel rod output distribution.SELECTED DRAWING: Figure 2