Renovation of DOT specification 21PF-1 protective shipping packages

Protective shipping packages for isotopically enriched uranium hexafluoride show deterioration with extended service, principally, structural damage from rough handling, and rust damage from exposure to weather and from storage practices which may promote absorption of water by the insulating foam. This report summarizes and/or references work which has been done to evaluate the integrity of the phenolic foam insulation in used shipping packages and outlines the process developed for drying the foam prior to rework of the containers. Mechanical and thermal properties of the foam are not adversely affected by the presence of limited amounts of water, nor are they degraded by the removal process. Rework of the packages, however, must be preceded by moisture removal to slow or avoid continuing rust damage, and tests have shown that drying can be effected by heating at 1900F and above for periods of three days or more. Drying progress is monitored by weight loss and/or by use of a moisture meter