Packaging Process - std301320000051

DOE-STD-3013-2000

corrosion, etc. In the case of pressurization, this is accomplished by ensuring that

the design pressure of the container is greater than the theoretical ability of the

contained materials to pressurize with time, as determined by the bounding pressure

calculation derived in Appendix B. One way to provide this assurance is to provide

sufficient free gas volume in the container to accommodate the worst possible gas

evolution and expansion. By using the limiting conditions of a minimum design

pressure of 4927 kPa (699 psig), a gas temperature of 211C (412F), a container

heat generation rate of 19 watts, and a moisture content of 0.5 wt%, it is

straightforward to show that a minimum of 0.25 liters of free volume is required for

every kilogram of oxide in the container to keep the bounding pressure below the

design pressure (see Section B.3.3.4 in Appendix B).

A.6.3.3

Packaging Process

1. Some oxide packages may contain foreign materials such as metal items and

processing debris. These materials should be removed from the oxide prior to

packaging. Items may be removed manually or by screening the powder, and can be

removed either before or after stabilization.

2. Because the oxide (including contained impurities) will pick up atmospheric water, it

is important that the sample taken for moisture analysis be representative of the

material actually packaged into the storage container. This can be done, for

example, by controlling the glovebox atmosphere and/or packaging within a very

few minutes of sampling.

3. This Standard prohibits packaging materials that may corrode the containment

system. The primary corrosion mechanisms of interest are general corrosion and

stress corrosion cracking. A recent evaluation of both types of corrosion concludes

that neither of these mechanisms is likely to be significant under storage

environments anticipated by this Standard. [Kolman, 1999]

General corrosion is not a credible problem because the quantity of oxidizer (oxygen

or water) available to react with the thick-walled containers is too limited to be

significant. The initial amount of elemental oxygen present if an air atmosphere was

present during packaging is very small, and little or no elemental oxygen is expected