Prediction of the neutrons subcritical multiplication using the diffusion hybrid equation with external neutron sources

We used the neutron diffusion hybrid equation, in cartesian geometry with external neutron sources to predict the subcritical multiplication of neutrons in a pressurized water reactor, using a 1/M curve to predict the criticality condition. A Coarse Mesh Finite Difference Method was developed for the adjoint flux calculation and to obtain the reactivity values of the reactor. The results obtained were compared with benchmark values in order to validate the methodology presented in this paper.

► We proposed a new neutron diffusion hybrid equation with external neutron source.
► A coarse mesh finite difference method for the adjoint flux and reactivity calculation was developed.
► 1/M curve to predict the criticality condition is used.