This work deals with the application of [MERCSF-N] computer program in calculating the macroscopic effective removal cross-section of fast neutrons, Σ_R (cm^－1), for two different boro phosphate glass systems: (0.5 - x) CdO-x Fe₂O₃-0.4 P₂O₅-0.1 B₂O₃ and (0.5 - x) B₂O₃-x Fe₂O₃-0.1 CdO-0.4 P₂O₅ (with 0.05 ≤ x ≤ 0.5 by mole), to realize from the role of iron in the attenuation process and hence the usefulness of the glass containing iron as neutrons shielding material. The effect of replacing cadmium and boron oxides by iron oxide has been analyzed which proved that iron is more efficient than cadmium in attenuating and removing fast neutrons and that the presence of small amounts of B₂O₃ at least 0.1 mole fraction, with iron is needed to aid improving the removal cross-section of iron phosphate glasses. Experimental IR results are developed and used to trace the structural change and confirm the role of iron in the removal cross section.