Microscopic cross section calculation methodology in the Serpent 2 Monte Carlo code

•Homogenized microscopic cross sections can be calculated with Serpent.•Example simulation of structural material activation with a nodal program.•Limitations of available group constants still present. This paper describes the methodology used by the Monte Carlo particle transport code Serpent to produce homogenized microscopic cross sections. The microscopic cross sections can be used for multiple purposes for example in nodal programs. The current implementation is presented together with its features and limitations. The methodology is demonstrated by calculating the activation of structural materials in two simple test problems with Serpent and the nodal neutronics program Ants utilizing Serpent-generated group constants.