Determination of uranium dioxide powder and pellet performance

The chemical composition of a nuclear fuel element is extremely strict quality standards, to constitute the core and cladding of all kinds of ingredients and the content of harmful impurity must be quantitative determination. Impurity hydrogen in fuel pellet surface adsorption or internal water exists in the form of hydrogen, can make the cladding hydrogenation, namely the hydrogen embrittlement of U0₂ pellets in the total hydrogen content must be kept under strict control, for accurate determination of the high precision. Of U0₂ theory density is an important design parameter, requires a high density of pellets, make pellets when operating in pile density and small size change. Fluorine impurities of U0₂ powder preparation of pellets sintering process has adverse effect, can reduce the density of pellets, fluorine will accelerate the damage of the equipment at the same time. In this paper, the hydrogen content in pellets, fluorine content in the powder and pellets, powder and pellet density analysis methods, instruments and equipment are reviewed, and puts forward some suggestions to the inspection method. (authors)