[en] The burn up calculations have been performed for the NEACRP fast breeder benchmark. The calculated core parameters are based on the proposal at the NEACRP meeting due to Hammer (CEA). The present calculations have been perfomed basing on JENDL-2 (Japanese Evaluated Nuclear Data Library) instead of JENDL-1 which was used for the previous international comparison calculation of a large LMFBR. The core parameters of the fresh core have been recalculated using JENDL-2 in order to enable direct comparison with those of the end-of-cycle core. The effective microscopic cross sections for fresh core elements have been obtained with use of the ESELEM5 code in 25 groups by weighting with a fundamental mode fine spectrum. Those of F.P. and Actinide nuclides have been generated by using the PROF-GROUCH-G2 code by weighting with 1/E and fission spectrum. The calculations based on the seventy group constants set (JENDL-2B-70) have been performed for a comparison. The burn up calculations have been performed in R-Z geometry by the diffusion theory code PHENIX. The irradiated fuel composition have been obtained at the end of-cycle of the inner core zone 1 by using the zero dimensional burn-up code, FPG S-3. The final report has been submitted to Hammer and intercomparison of solution will be made at NEACRP. Tables of group cross sections for Actinides and F.P. are shown in Appendixes. (author)