Using new strategies to produce enriched uranium from natural uranium for research reactors fuel

This paper aims to produce uranium with 20% enrichment for research reactor fuel directly from natural uranium with waste xw≤0.3% through a cascade. This purpose has utilized five strategies, including single-optimized tapered, square, 2-section squared-off, 3-section squared-off, and 4-section squared-off cascades. To design and optimize the cascades, five software codes, "STC-PSOA," "SQC-PSOA," "2SQC-PSOA," "3SQC-PSOA," and "4SQC-PSOA," have been developed, with the PSO optimization algorithm employed for optimization. In the first strategy, it is not possible to achieve uranium with a 20% enrichment level using one arrangement and one step. The maximum product enrichment level attainable is 3.73%. However, in the other four strategies, uranium with a 20% enrichment level can be produced in two separation steps with a single arrangement. Notably, when employing the strategy of using 4-section squared-off cascades, the product production is 11.1%, 3.1%, and 1.0% higher compared to square, 2-section, and 3-section squared-off cascades, respectively.