Despite the significant progress achieved in the nuclear data uncertainties quantification techniques for neutron transport calculations, some parts of the nuclear data uncertainties are still not investigated in sufficient details. Particularly, the impact of the neutron scattering angular distributions in application to the fast neutron fluence (FNF) assessment for light water reactor pressure vessels can be named. At present time not only the calculation techniques need further developments for such investigations, but also the nuclear data libraries in general lack the uncertainty information which should be associated with the angular distributions of the scattered neutrons. At such circumstances it is not really possible to accurately evaluate the uncertainties associated with the differential neutron scattering cross-sections and commonly only the uncertainties of the angular integrated scattering cross-sections can be propagated in the neutronic calculations. However, at the same time it can be seen that the neutron scattering angular distributions can differ significantly between different evaluations and thus should be actually quite uncertain in the modern nuclear data libraries. Therefore, it is proposed in the given paper to make a preliminary quantitative assessment of importance of the neutron scattering angular distributions, e.g. with respect to the FNF predictions, before moving towards more sophisticated studies. Results of such an assessment are presented in the paper, underlying some noticeable differences particularly between the ENDF/B-VII.1 and JENDL-4.0 libraries and specifically for the elastic scattering angular distributions of emitted neutrons for O-16 isotope.