Deformation of Experimental Fuel Pins with Improved Zirconium-Alloy Cladding in Reactor Tests

A stand for inspecting experimental fuel pins in the cooling pool of the MIR.M1 reactor and methodological approaches to measuring the height and diameter of experimental fuel pins are described. The basic characteristics of the equipment used for performing measurements are described. The structural features of an experimental FA (EFA) and the test parameters of experimental fuel pins in an assembly in one of the loop facilities of the MIR reactor are presented. The results of a series of measurements of the diameter and height of irradiated fuel pins with cladding made from different zirconium alloys with different average fuel burnup over the EFA are shown.