Recommendations for Choosing a Model Describing the Human Exposure to Uranium Hexafluoride

Abstract

The article notes the fact that uranium hexafluoride (UHF) is the only uranium compound in a gaseous state under conditions close to normal to be used in the enrichment of natural uranium with an isotope. It is noted that during the hydrolysis of UHF in the air of a working room, this room is polluted with gases and aerosols that are carriers of uranium and fluorine atoms, which have a negative chemical and radiation effect on the human body. This, of course, poses problems when using uranium hexafluoride at the enterprises of the nuclear industry both in everyday work and, especially, in possible emergency situations. The problems lie with a need for protective measures, development of the quantitative assessment methods for the intake of toxic substances, and establishment of relationships between the amount of incorporated (ingested) substance and the measure of its effect on the body. A review of certain publications on the quantitative description of the uranium and fluorine intake in the body of employees is given. The paper notes an involvement of this article’s authors in solving this issue in their previous works too. Their calculation methods are described. The conditions under which they were carried out and the experimental results that they used were described. The article presents the calculation results both of the uranium mass intake in the body (by the time t) that characterizes the toxic effect of uranium and of the number Q of decays accumulated in the body that characterize the radiation effect. The uranium penetration through the skin (percutaneous intake) in an emergency and under normal production conditions is considered. There is given a description of two models suitable for calculations, which are distinguished by various accounting for metabolism when uranium moves from the UHF source to the exit from the human body in the natural way. It is indicated that one of the models was partially borrowed from publications of the International Commission on Radiological Protection (ICRP). The results obtained using two different models are compared and recommendations are made regarding their use depending on the tasks assigned to the researcher.