Packing material environmental considerations

The radioactive level in most chemical processing equipment is such as to preclude nearly all types of organic compounds for structural or packing materials. Thus, the use of plastics for these functions is not recommended. The selection of metals and ceramic materials can be made on the basis of corrosion resistance under ordinary environmental circumstances, provided due allowance is made for the heat effects caused by absorption of radioactivity in the material under consideration. 

Another class of equations subsumes kinetic and phase transformations of all involved reactants. Such equations describe how the reactants molecules are transformed and distributed in the reactor depending on time and other environmental parameters. Depending on the kind of chemical processes under consideration, both classes of equations are of varying importance for modelling. E.g. for catalytic packed-bed reactors the chemicals reaction rates heavily depend on local physical conditions at the (solid) catalyst material. The precise modelling of the local physical conditions and the mixture of chemicals flowing is important and complex in this case. In contrast, for classic stirred-tank reactors kinetic and phase transformations are comparatively easy to model. 

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