The nuclear fuel cycle is the industrial process that converts the uranium ore, to its use as fuel, inside of a nuclear power station. In all steps from the nuclear cycle workers are exposure to uranium dust particles. To evaluate the risk due particles incorporation data like deposition, concentration and kinetics of the particles in the respiratory tract must be know The in vitro solubility test allows a systemic understanding about the compound solubility. Samples of DUA, TCAU e UO2 and SLF was collected in different time interval and the uranium concentration was determined by PIXE (Particle Induced X rays Emissions) technique and the uranium compounds were identified by 252 Cf-PDMS (Plasma Desorption Mass Spectrometry). The specific objectives were: (i) identifying uranium compounds in the respirable fractions of aerosol (ii) identified and determinated the uranium coumpounds solubility in simulated lung fluid (iii) determinated the solubility parameters to this uranium compounds. The solubility parameters to DUA, TCAU and UO2 are: fr, = 0,83; sr = 0,51 d -1 and ss = 0,0075 d -1; fr = 0,60; sr = 0,70 d -1 and ss = 0,00089 d -1 e fr = 0,19; sr = 0,47 d -1 e ss = 0,0019 d -1, respectively.