An Innovative Non-Destructive and Computational Method for Uranium Activity and Enrichment Verification of UF₆ Cylinder

Verification of ²³⁵U enrichment in uranium hexaflouride (UF₆) cylinders is often achieved by destructive and non-destructive assay techniques. These techniques are time consuming, need suitable and similar standard, in addition to loss of the nuclear material in the case of destructive analysis. This paper introduce an innovative approach for verifying of ²³⁵U enrichment in UF₆ cylinder. The approach is based on measuring dose rate (μSv/h) resulted from the emmitted gamma rays of ²³⁵U at the surface of the cylinder and then calculating the activity of uranium and enrichment percentage inside the cylinder by a three dimensional model. Attenuation of the main ²³⁵U gamma transitions due to the cylinder wall (5A Type of Ni alloy) was also caculated and corrected for. The method was applied on UF6 cylinders enriched with 19.75% of ²³⁵U. The calculated enrichment was found to be 18% with 9% uncertainty. By the suggested method, the calculated total uranium activity inside one of the investigated UF₆ cylinder was found close to the target (certified) value (5.6 GBq) with 9% uncertainty. The method is being developed by taking into consideration other parameters.