Abstract: | In conjunction with reprocessing of nuclear fuels by electrochemical methods, the general electrochemical behaviour of titanium cathodes and the problem of their hydride embrittlement have been investigated in the absence of γ-radiation in HNO3/UO/N2H solutions of varying composition. The electrode potential of galvanostatically polarized titanium cathodes is shown to be located either in the passive range, within the passive-to-active transition, or in the regime of hydrogen absorption/hydride formation, depending on the current yield of the nitrate reduction reaction. Hydride growth was observed predominantly in the morphology of continuous layers and/or isolated platelets. Following a parabolic rate law it was restricted to the vicinity of the electrode surface, the maximum penetration for polarization times up to 1000 h being less than 100 μm. As a consequence, no significant loss of ductility of normal tensile specimens could be detected under these conditions. |