Code

EU Code

Category

Subcategory

Prohibited Supply To

Authority

Document

Notes

• Uranium oxidation systems (Chemical exchange) Especially designed or prepared systems for oxidation of U +3 to U +4 for return to the uranium isotope separation cascade in the chemical exchange enrichment process. EXPLANATORY NOTE These systems may incorporate equipment such as: (a) Equipment for contacting chlorine and oxygen with the aqueous effluent from the isotope separation equipment and extracting the resultant U +4 into the stripped organic stream returning from the product end of the cascade, (b) Equipment that separates water from hydrochloric acid so that the water and the concentrated hydrochloric acid may be reintroduced to the process at the proper locations.
• Liquid-liquid centrifugal contactors (Chemical exchange) Liquid-liquid centrifugal contactors especially designed or prepared for uranium enrichment using the chemical exchange process. Such contactors use rotation to achieve dispersion of the organic and aqueous streams and then centrifugal force to separate the phases. For corrosion resistance to concentrated hydrochloric acid solutions, the contactors are normally made of or protected by suitable plastic materials (such as fluorinated hydrocarbon polymers) or glass. The stage residence time of the centrifugal contactors is normally designed to be 30 seconds or less.
• Uranium reduction systems and equipment (Chemical exchange) (a) Especially designed or prepared electrochemical reduction cells to reduce uranium from one valence state to another for uranium enrichment using the chemical exchange process. The cell materials in contact with process solutions must be corrosion resistant to concentrated hydrochloric acid solutions. EXPLANATORY NOTE The cell cathodic compartment must be designed to prevent re-oxidation of uranium to its higher valence state. To keep the uranium in the cathodic compartment, the cell may have an impervious diaphragm membrane constructed of special cation exchange material. The cathode consists of a suitable solid conductor such as graphite.
• (b) Especially designed or prepared systems at the product end of the cascade for taking the U +4 out of the organic stream, adjusting the acid concentration and feeding to the electrochemical reduction cells. EXPLANATORY NOTE These systems consist of solvent extraction equipment for stripping the U +4 from the organic stream into an aqueous solution, evaporation and/or other equipment to accomplish solution pH adjustment and control, and pumps or other transfer devices for feeding to the electrochemical reduction cells. A major design concern is to avoid contamination of the aqueous stream with certain metal ions. Consequently, for those parts in contact with the process stream, the system is constructed of equipment made of or protected by suitable materials (such as glass, fluorocarbon polymers, polyphenyl sulfate, polyether sulfone, and resinimpregnated graphite).
• Feed preparation systems (Chemical exchange) Especially designed or prepared systems for producing high-purity uranium chloride feed solutions for chemical exchange uranium isotope separation plants. EXPLANATORY NOTE These systems consist of dissolution, solvent extraction and/or ion exchange equipment for purification and electrolytic cells for reducing the uranium U +6 or U +4 to U +3 . These systems produce uranium chloride solutions having only a few parts per million of metallic impurities such as chromium, iron, vanadium, molybdenum and other bivalent or higher multi-valent cations. Materials of construction for portions of the system processing high-purity U +3 include glass, fluorinated hydrocarbon polymers, polyphenyl sulfate or polyether sulfone plastic-lined and resin-impregnated graphite. NSG Part 1 June 2013 - 39 - 5.6.5. Uranium
• Liquid-liquid exchange columns (Chemical exchange) Countercurrent liquid-liquid exchange columns having mechanical power input, especially designed or prepared for uranium enrichment using the chemical exchange process. For corrosion resistance to concentrated hydrochloric acid solutions, these columns and their internals are normally made of or protected by suitable plastic materials (such as fluorinated hydrocarbon polymers) or glass. The stage residence time of the columns is normally designed to be 30 seconds or less.