Uranium Conversion Facilities

DOE-HDBK-1132-99

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

235

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

requirements.

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:

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