ANALYSIS OF THE EFFECT OF THE STRESS-STRAIN STATE OF IRRADIATED ZIRCONIUM-ALLOY FUEL-ELEMENT CLADDING ON HYDRIDE ORIENTATION

摘要

The effect of the stress distribution on the hydride distribution in zirconium cladding of fuel elements with dispersion fuel is analyzed. It is shown that reorientation of zirconium hydrides can occur in fuel-element cladding under the action of tensile stresses, which can result in the appearance of radially oriented hydrides and plasticity reduction in the cladding upon cool-down of the fuel elements. The threshold tensile stresses are determined in the cladding in the unirradiated and irradiated states, in which hydride reorientation from tangential to radial occurs.