Anforderungen an LWR-brennstohp aus der sicht des betriebsverhaltens☆

Abstract UO 2 , UO 2 -PuO 2 and UO 2 -Gd 2 O 3 pellets for LWR fuel rods have to meet the following operational characteristics: (1) Behavior according to the design and performance calculations, (2) lowest possible defect rate, and (3) good performance of defective fuel rods. The fuel itself plays an important role in three possible defect types: (1) Defects by hydriding of the Zry-clad, (2) flattening of the clad due to fuel densification, and (3) mechanical and chemical pellet clad interaction (PCI). The specified properties and the interdependence between these requirements and fuel performance are discussed for four groups of properties: (1) Content of fissionable and poisson material, (2) chemical purity and stoichiometry, (3) density and microstructure, (4) dimensions and surface conditions. LWR's oxide fuel provides excellent operational behavior because of its good basic material properties and its well defined and controlled fabricational characteristics.