The article presents the results of research on a new method of restoration by means of electrospark alloying (ESA) of X10CrNiTi18-10 steel details, which operates under radiation conditions. The method can be used to repair machine details of nuclear power plants. The technology includes coating the worn surface of the detail with an ESA electrode, which is made of steel X10CrNiTi18-10 or nickel, which does not contain special additives of cobalt and other elements that form long-lived isotopes in the active working environment. ESA is carried out in two stages. Before the first stage, a layer of graphite electrode coating is applied to the worn steel surface by the ESA method—a tool with a discharge energy $Wp$ = 0.02 J and a productivity 0.3 sm$^{2}$/min. At ESA by the electrode tool from steel X10CrNiTi18-10 the first and second stages are carried out, accordingly at $Wp$ = 0.20 J with productivity 1.6 sm$^{2}$/min; and $Wp$ = 0.55 J with a productivity 2.5 sm$^{2}$/min. As a result, the coating thickness is $\Delta H$ = 0.19 mm, the continuity is $S$ = 100% and the roughness is $Rz$ = 57 $\mu$m. During ESA the first and second stages are carried out by nickel electrode tool respectively at $Wp$ = 0.55 J with a capacity 2.5 sm$^{2}$/min and $Wp$ = 0.90 J with a capacity 3.4 sm$^{2}$/min. As a result, $\Delta H$ = 0.20 mm, $S$ = 100 % and $Rz$ = 38 $\mu$m. The increase in discharge energy in ESA is accompanied by a decrease in yield strength and tensile strength and an increase in the relative elongation and relative narrowing of the sample. During the ESA of the sample with $Wp$ = 0.90 J, compared with the undoped sample, the yield strength and tensile strength decrease with alloying by steel X10CrNiTi18-10, respectively, to 11.7% and 8.3%, and the relative elongation and relative narrowing increases, respectively, to 15% and 14.7%. During the ESA by nickel yield strength and tensile strength decreases to 13.3% and 8.6%, respectively, and the relative elongation and relative narrowing increase to 14.7% and 16.7%, respectively.