Radiological Safety Training for Uranium Facilities
Module 101 Properties of Uranium
radionuclides results in an increased risk of cancer, typically in the bones,
kidney, and lungs, since these are the organs where uranium is deposited.
3. Chemical Reactivity
The chemistry of uranium is complicated. For example, uranium forms several
oxides: UO, UO2, UO3, and UO4. In general, a sample of uranium oxide will
include a mixture of several of these. For example, U3O8 is sometimes written
The lower oxidation states, UO2 and U3O8, tend to be dark brown or black. The
higher oxidation states, UO3 and UO4, are generally orange or yellow,
especially in solution or if water or crystallization are present (e.g., (UO4)·
2H2O). Furthermore, the higher oxides usually flake off more easily and are
usually more soluble in water. Being flaky, they are more easily inhaled. Being
more soluble, they are more easily absorbed into the body.
Uranyl compounds, such as uranyl nitrate, or UO2(NO3)2, are chemical forms of
uranium that are often found in solution with water. They are generally yellow
in color and are used in criticality experiments.
Uranium reacts readily with air and water. For example, when uranium is
machined, small chips catch fire from the heat of the machining process.
Shavings placed in water react to produce hydrogen gas. The surfaces quickly
oxidize to a hard black coating that is at first protective; however, under adverse
conditions, it corrodes and flakes.
Uranium also reacts with hydrogen or tritium gas to form uranium hydride
(UH3). Uranium "beds" are commonly used to store tritium. Uranium
hexafluoride (UF6) reacts in moist air to produce hydrogen fluoride (HF) gas,