Study of the Technical Characteristics of Low-Enriched Uranium Hexafluoride in Long-Time Storage

Investigations of the physicochemical characteristics of low-enriched uranium hexafluoride stored for up to 12 years in 1 m 3 containers confirmed the stability of its isotopic composition and activity reduction of γ-emitting products of uranium fission. It was shown that the gas pressure in the vessels increases by 4.5%/yr due to radiolysis and hydrolysis of the product. The rate of radiolysis of uranium hexafluoride was found to be 0.009%/yr, and elemental fluorine accumulates in vessels as a result; hydrolysis at 0.001%/yr confirms very weak diffusion of atmospheric air through the seal material of a vessel. Total product losses are equal to about 0.01%/yr.