TY CONF TI On conditional "safety grades" of power units of NPPs of the Russian Federation KW nuclear power plants KW nuclear power plants KW federal norms and rules KW safety deficiencies KW equipment and pipelines of systems important to safety KW non-destructive testing of the state of metal KW non-destructive testing systems KW certification testing of non-destructive testing systems KW the concept of leak before destruction JO International Conference "Computing for Physics and Technology - CPT2020" AU Arzhaev, A.I. PY 2024 PB ANO "Scientific and Research Center for Information in Physics and Technique"