METHODOLOGY AND RESULTS OF INVESTIGATION OF RADIATION CREEP IN LARGE-GRAIN URANIUM DIOXIDE BASED FUEL

摘要

Three series of investigations of the radiation creep of modified uranium dioxide with grain size ≥25 μm were conducted, using methods and experimental means developed in this work, for reactor conditions at fission density 1.2·10~(13) sec~(-1)-cm~(-3). Diagrams of radiation creep in the stress interval 10-40 MPa were obtained for three temperatures. At 747℃, the results are identical to the radiation creep of standard uranium dioxide. At this temperature, the deformation is controlled by radiation creep, which is confirmed by the linear dependence on the stress. The creep rates at 927 and 1028℃ are higher than for standard uranium dioxide. The stress dependence of the creep rate can be represented by a power-law function or a combination of linear and power-law functions.