Studying the Thermal Expansion of Cladding Tubes and Rods Made of Zr-1% Nb Alloy in the Temperature Range of 293–873 K (20–600°C) Using X-ray and Dilatometric Measurement Techniques

The measurements of temperature dependences of the periods a and c are carried out in the crystalline structure of α-zirconium, and the coefficients of linear thermal expansion (TLEC) are estimated for the textured cladding tubes and rods made of E110 opt alloy in the axial direction in the temperature range of 293–873 K (20–600°C). On the basis of certain integral textural parameters of Kearns obtained for cladding tubes and rods, TLEC calculations are carried out. The calculated TLEC values are significantly lower than the values measured by the dilatometric method. The simulation of the thermal expansion process of products shows that the observed differences in the calculated and measured TLEC values can be explained by the layered textural heterogeneity of the tubes and by the stresses generated between layers.