عنوان مقاله [English]
One of the significant phenomena in the operational conditions of the enrichment cascades is the sudden crash of a number of separating machines along the cascade. In order to investigate the effect of gas centrifuge crash on cascade performance, separation of cascade in a transient condition should be modeled. In this paper, the performance of two-component symmetric enrichment cascades was modeled, using partial mass balance equations in the transient condition. Nonlinear equations of the model were also discriminated using Crank Nicholson's finite difference method and q iteration method was used to solve the equations. The results of the computer simulation of the model cascade for the enrichment of uranium 235 showed that if the crash of gas centrifuge machines occurs at the end of the enrichment part of cascade, the product concentration will decrease more and more, and it takes a longer time to reach new steady state condition. It was also observed that the cascade performance of machines with a higher separation factor is less affected by crash of machines. The results showed that the gas hold up has a small effect on variation of the 235 isotope concentration in the product stream and only affects the time to reach equilibrium in the cascade.