This book contains detail information on the various reactor physics calculations for core conversion studies of Research Reactor. It provides detail information about the procedure for generating fine group and broad-group cross section libraries for the HEU and the proposed LEU fueled Nigeria Research Reactor (NIRR-1). It also provides information about various reactor models used in the generation of broad group cross section library for reactor physics calculation. In addition, detail information about the development of a 2-D RZ computational model for the HEU and the proposed LEU core...