Comparison of correlation relations for determining the relative [sup.242]Pu content in plutonium produced in the RT-1 plant at the Industrial Association Mayak

The correlation relations for determining the [sup.242]Pu mass fraction which are used in the MGA and FRAM computer codes are compared with the relations proposed in the present article for plutonium stored in the RT-1 plant of the Industrial Association Mayak. The need to determine the [sup.242]Pu mass fraction using the correlations arises in nondestructive analysis of plutonium. The MGA and FRAM codes use correlations which are based on data on the isotopic composition of the plutonium that has accumulated in American reactors so that the possibility of using these codes for Russian plutonium must be checked. This check was based on an analysis of data obtained on more than 6000 isotopic compositions during certification of the RT-1 plutonium. A characteristic of the relation proposed in this article is that it takes account of the change in the isotopic composition of plutonium over time.