The paper is focused on calculation of the friction forces work in the contact of nuclear fuel rods with fuel assembly spacer grid cells. This friction work is deciding factor for the prediction of the fuel rod coating abrasion. The fuel rod abrasion is caused by fuel assembly vibrations excited by pressure pulsations of the cooling liquid generated by main circulation pumps. A prediction of fuel rod coating abrasion makes use of experimentally investigated dependence of the abrasion on the friction force work in laboratory conditions. The presented original analyticalnumerical method is applied for nuclear fuel rod inside of the Russian TVSA-T fuel assembly in the WWER 1000/320 type reactor core in NPP Temelín.