An analysis of benchmark experiment on iron for D-T neutrons with JENDL Fusion File and FENDL/E-1.1 suggested that neutron flux above 10 MeV in iron, was underestimated monotonously with depth. Reasons of this underestimation were investigated through various analyses by DORT3.1 with JENDL Fusion Füe, FENDL/E-1.1 and FENDL/E-2.0. The followings for evaluated cross section data on iron around 15 MeV were considered to be possible origins of underestimation of neutron flux above 10 MeV.

1. JENDL Fusion File: Elastic scattering cross sections for forward angles were smaller. Angle-integrated cross section data of (n,2n) and (n,np) reactions were larger.

2. FENDL/E-1.1: Elastic scattering cross sections for forward angles were smaller.

3. FENDL/E-2.0: Angle-integrated cross section data of inelastic scattering and (n,np) reaction were larger.