
The objective of this paper is to present the results of comparative study of integral parameters for TRX and BAPL benchmark lattices of thermal reactors. The nuclear data processing code NJOY’99 was deployed for the generation of the 172-group cross-section library from the basic evaluated nuclear data files ENDFB-VII and JEF-3.1. TRX and BAPL benchmark lattices were modeled with optimized inputs, which were suggested in the final report of the WIMS Library Update Project .The inputs were the results of a detailed parametric study of the WIMS input options and also optimized for accuracy. The integral parameters (such as keff, ρ28, δ25, δ28, C*) of five uranium-fuel thermal assemblies: TRX-1 and TRX-2 and BAPL-1, BAPL-2, and BAPL-3 were calculated with the help of WIMSD-5B code based on the generated 172-group cross section library. The calculated results are compared with those of experiments and it is found that the obtained results between the two libraries are in good agreement with each other, which reflect the validation of the generated 172-group cross-section library and this library thus obtained is necessary to meet up the nuclear data for neutronics calculation of TRIGA Mark-II research reactor at CNESTEN, Rabat, Morroco.