Use of thermal insulation on the equipment that processes uranium
solutions of high enrichment should be minimized because it absorbs the
solution in the event a leak occurs. The uranium-impregnated insulation
would be subject to scrap recovery operations. Because the insulation is
considered a "full reflector," the equipment together with the insulation
may not be geometrically favorable for highly enriched uranium solutions.
Storage tanks for aqueous solution of enriched uranium should be
designed to ensure favorable geometry with respect to nuclear criticality
safety. Where there is a tendency for solids to precipitate, vessels should
be instrumented to detect settling of solids and be designed to facilitate
periodic removal of solids.
Airborne radioactive wastes typically associated with UCRFs that should
be considered during the design include but are not limited to airborne
particulate material generated during processing (e.g., airborne grinding
dust) and vapors and gases used or generated during the processing.
Nuclear criticality safety should be considered in the design of the
airborne effluent system.
Uranium Conversion Facilities . Piping systems, surge vessels, and control
instruments with associated piping that carry UF 6 gas should be equipped with
heat tracing or heated enclosures wherever necessary to prevent solidification of
UF6. Steam may be used as the primary heating agent where low-enrichment
material (less than or equal to 2 percent
U) is involved. At higher enrichments,
a dry radiant heat source should be the preferred means of supplying the heating
Uranium Recovery Facilities . The design of a uranium recovery facility should
be approached on a case-by-case basis, considering possible forms of scrap
and different assays of material that could be received for processing and
possible methods that could be used for enriched uranium recovery. The
following design features should be considered: