Table B.1. Theoretical densities of uranium oxides

DOE-STD-3028-2000

Table B.1. Theoretical densities of uranium oxides

Uranium

Theoretical Density

(g/cm3) [lbm/ft3]

oxide

UO2

10.970 [685]

U3O8

8.380 [523]

UO3

7.300 [456]

For ideal gases, the pressure of a mixture of gases can be determined as the sum of the partial

pressures of the individual gases. Four gases that require consideration in a 233U storage

container:

(1) the container fill gas, Pf;

(2) any gases evolved through radiolysis, chemical reactions, or desorption, PH2;

(3) helium generated by alpha decay of the contained radioactive species, PHe, and

(4) radon generated in the decay chains of any 232U and 238U, which may be stored with the

233

B.1

CONTAINER FILL GAS

The appropriate equation is simply the gas law at constant volume:

(P0 )( T1 )

Pf =

(B.5)

where P0 is the pressure at which the container was loaded (usually atmospheric), and T0 is the

temperature of the fill gas when the container was sealed.

B.2

EVOLVED GASES

There are two significant sources of evolved gases in 233U containers, water and plastics. As

described in section A.6.1.2.1 water may react with stoichiometric UO2 to form hydrogen. Water

may also undergo radiolysis, forming a variety of compounds and radicals. However, this is a

reversible process, and thermodynamics favors the reverse reactions. Metal oxides, including

uranium oxides may also act as a sink for oxygen and hydrogen. Therefore, the number of