With the upcoming Run 3 of LHC, FASERv and SND@LHC detectors will start a new era neutrino physics using far-forward high-energy beam produced in collisions at ATLAS. This emerging LHC program requires reliable estimates LHC's forward fluxes their uncertainties. In this paper we provide fast-neutrino flux simulation, implemented as RIVET module, to address issue. We present expected energy dist...