Geres-A code to process MC2 II data for heterogeneous fast reactor cell calculations

This report is the user manual of the GERES code. This code has been written at ENEA-CRE-CLEMENTEL to permit a fast and accurate analysis of the effect of fast reactor cell heterogeneity. The code produces broad-group resonance cross sections for each zone of the reactor cell, utilizing ultra-fine-group cross sections and resonance integrals produced by the MC2-II code. The code sequence of which this code is a part is described in this report, as well as the input and structure of the GERES code. To show the main features of the code the analysis of a simplified reactor cell is included