A method is suggested for calculating the density of single-component aqueous solutions of nitric acid and nitrate salts contained in solutions used in hydrometallurgical processes on the nuclear fuel cycle. The method uses apparent molar volumes and the water concentration. The method makes it possible to calculate the density of nitric acid solutions up to 17 M (HNO3 dihydrate) and salts to the point of formation of saturated solutions with an error not exceeding 0.2%. The values of the apparent molar volumes linearly depend on the concentration of water, and the apparent molar values approximated to the infinite dilution correspond to the Pitzer values.