فاطمه منصورزاده

Among the noble gases, Xenon isotopes are the most widely used. So far, no specific strategy has been published for separating all Xenon stable isotopes with the highest number of stable isotopes. In this research, a computational code, SQCAS, is prepared to determine the target isotope separation strategy in light or heavy current. The prepared code investigates the separation of the natural isotopes in proportion to the feed concentration by changing the parameters of the square cascade and modeling it at each step. All stable isotopes of natural xenon are separated using a square cascade in 32 steps for the certain feed (200kg). The proposed square cascade has 20 stages. In each stage, 10 centrifuges were used. Also, the separation factor for the unit mass difference in this research equals 1.2. Using this strategy, the enrichment of nine isotopes increases from 0.9393, 0.0009, 0.01917, 0.2644, 0.408, 0.2118, 0.2689, 0.1044, and 0.087 to 98.72%, 91.3%, 92.79%, 92.63%, 83.77%, 90.12%, 91.64%, 95.68%, and 99.04%, respectively. The results show that the highest recovery is related to the end isotopes, and the lowest recovery is related to Xe-135 isotope.

One of the important parameters in the square cascade, which has a great influence on its performance in the separation of multicomponent isotopes, is the cascade cut. In this research work, at first, the effect of cascade cut on the separation of xenon middle isotopes in a square cascade with 20 stages was studied. These studies were carried out for two cases in which the separation factor was 1.2 and 1.1. Moreover, the minimum length for creating a long cascade by changing the Z/F value and cascade cut has been determined. Based on the calculations, if the separation factor is 1.2 and 1.1, the minimum number of cascade stages will be 55 and 110, that's not simply possible. The results showed that the appropriate cascade cut in the long cascade is different from the short cascade. Using the parametric studies of the short cascade, it is possible to determine the most appropriate cascade cut in which the desired isotope concentration reaches its maximum. In order to maximize the amount of Xe-129 in a 20 stages cascade, the suitable cut is 0.2 in the separation factor of 1.2 and 0.15 in the separation factor of 1.1.

In the present study, for the first time the R cascade under normal and optimal conditions with the constant and specified total number of cascade stages, the feed flow rate to the cascade, the factor of separation based on the unit mass difference, and the maximum and optimal of the feed flow into the centrifuge machine is assessed. The algorithm used for optimization is TLBO algorithm and the objective function is considered as a function of separation work for a single machine and match abundance ratio. The results show that in the cascade with the match abundance ratio for isotopes k1 and k2 the separation work in optimal cascade is more than conventional. If the abundance ratio is adapted for two pair of components, i.e., the “first and third” and the “second and third, the separation power in the optimal mode for the first and second cases is 1% and 9% more than those of conventional, respectively. Finally, a computational code named MISCC is written to determine and analyze the parameters of the match abundance ratio cascade in optimal and normal conditions.

The theological and ontological issues are one of the most important issues in the supplications and prayers of the Imams of the Ahl al-Bayt (PBUT). Focusing on the supplication of “’Arafa” as well as narrations, this research study seeks to examine the validity and position of theological arguments from Imam Hussain (PBUH)’s point of view. The themes of prayer include three types of knowledge (empirical, rational, and intuitive). Imam (PBUH) acknowledges empirical and rational knowledge to God, but repeatedly warns that they are not enough, because these knowledge focus solely on sense and reason and are deprived of intuitive and illuminating knowledge. The basic and complete knowledge is the intuitive knowledge that God shines upon the heart of his servant. Of course, form the viewpoint of the Imam (PBUH), knowing the essence of God totally is impossible.

The management of waste produced in the reactor is an essential aspect of the nuclear fuel cycle. In this research, it has been tried to reduce the amount of reactor waste at the end of the cycle without substantial changes in the fuel dimension and the core structure of the research reactor. Minimized the heat generation. The MCNPX2.6 code is used to calculate the fuel consumption and neutronic parameters of the reactor core. The results show that without any significant change in the structure of the reference core, the amount of waste decreases only by increasing the fuel enrichment and reducing the reactor power. In this study, two core models are proposed and investigated. The waste activity at the end of the cycle in the converted reactor cores reaches 15% -19% of its original value in the reference core. Moreover, fuel burn- up has increased up to 32% -40% relative to the reference core.