Study of the homogeneous and heterogeneous Am transmutation in an ELFR-like reactor loaded with nitride fuel

Abstract

In this paper a neutronic study of the homogeneous and heterogeneous core configuration for americium transmutation in an ELFR-like reactor loaded with nitride fuel was performed by using the reactor physics code Serpent. For this, the initial Am content was range as follows: 1, 3, 5, 7 and 9 wt%, and some neutronic and safety parameters, such as the Doppler constant, the coolant void worth and the effective delayed neutron fraction were analyzed. Based on these parameters, the maximum allowable Am content at BoC was 7 wt% for the homogeneous core due to penalties in the coolant void worth. In the heterogeneous core no safety penalties were found but a lowest Am consumption was obtained compared to the homogeneous configuration due to changes in the neutron spectrum. In addition, the axial and the radial power profiles were obtained at three different burnup steps: BoC, MoC and EoC. The homogeneous configuration showed a quite smooth radial and axial power distributions, while an increment in the radial power form factor was observed at the center of the core in the heterogeneous fuel configuration, that deserves further studies.