Abstract: A composite structure suitable for use used for structural applications, as well as for sheathing and finishes, and packaging and crating materials, comprising layers of foamed core material, alternating with layers of material designed to absorb shear stresses, such as rigid structural membrane, and one or more external protective layers, thereby preventing damage to the foamed core material and increasing the strength and integrity of the overall assembly. The resulting structure is a panel resistant to shear, tension, and impact forces, as well as having resistance to vermin, fire, and aging. In some variations, the assembly comprises materials that are environmentally safe to produce and to dispose. The properties of the panels, including, for example, permeability, organic composition, absorption, and strength are tailorable to specific applications by using appropriate foamed material and protective layers.

Abstract: The present invention is directed to a process for reducing the volume of low level radioactive and mixed waste to enable the waste to be more economically stored in a suitable repository, and for placing the waste into a form suitable for permanent disposal. The invention involves a process for preparing radioactive, hazardous, or mixed waste for storage by contacting the waste starting material containing at least one organic carbon-containing compound and at least one radioactive or hazardous waste component with nitric acid and phosphoric acid simultaneously at a contacting temperature in the range of about 140.degree. C. to about 210 .degree. C.