[en] A series of possible variance is presented for the heavy water separation technology by isotopic H₂O-H₂S exchange at dual temperatures. The critical study of these variants, which are considered as characteristic quantities for the isotopes transport (production) and the extraction level is related to a dual temperature plant fed by liquid and cold column, which is the up-to-date technology employed in all heavy water production plants as variants of following plants are studied: dual temperature plant with double feeding; dual-temperature plant with equilibrium column (booster); dual-temperature-dual-pressure plant. Attention is paid to the variant with equilibration column (booster), executed and tested at the State Committee for Nuclear Energy and to the dual-temperature-dual pressure plant which presents the highest efficiency. (author)

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[en] The principle of uranium gaseous diffusion enrichment is briefly recalled. The present status of gaseous diffusion plants is outlined, and future trends of the market and technology are envisaged

[en] An attempt is made to describe the in-process inventory of enrichment cascades with a close separation process as a product of gas in-flow and the average holdup time of gas molecules. The holdup time is calculated on the basis of a simple random-walk model of the transients and the output response to input perturbation. Calculations are carried out for a gaseous diffusion plant producing slightly enriched uranium. Experimental determination is proposed for safeguards purposes

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[en] The Urenco Group holds a unique position within the world enrichment market with experience of developing and operating centrifuge plants, development experience of both the atomic and molecular laser enrichment processes and, prior to Urenco' s formation, experience of the commercial operation of a gaseous diffusion plant by Urenco's UK partner. This paper describes the diffusion, centrifuge and laser enrichment techniques and discusses how Urenco views their relative strengths and weaknesses. The key conclusion reached is that Urenco's advanced centrifuges represent the most cost effective enrichment technology option for the foreseeable future. (author)

[en] A brief review of the present state of commercial uranium enrichment plants in the West Europe (Eurodif Inc. and Eurenco Inc.), the USA and Japan is presented. The economical and safety problems at large gaseous diffusion plants and centrifuge enrichment plants are considered. Planned uranium isotope separation productive capacities in the mentioned countries are given and the costs of enriched uranium production using different technological processes are compared

No abstract available