It is necessary to establish evaluation methodology of radioactivity concentrations of each radionuclide in waste packages for operation of the Near-surface Trench disposal and Sub-surface Pit disposal facility in near future, which has been preparing for low-level radioactive wastes generated from research facilities in JAEA. The radionuclides containing in waste packages generated from both JRR-2 and JRR-3, which are H-3, C-14, Cl-36, Co-60, Ni-63, Sr-90, Nb-94, Tc-99, Ag-108m, I-129, Cs-137, Eu-152, Eu-154, U-234, U-238, Pu-239+240, Pu-238+Am-241, Cm-243+244, were evaluated their density based on radiochemical analysis data, and the Evaluation Methodology of the Radioactivity Concentration such as Scaling Factor method and mean activity concentration method was studied in this report.