[aBeard]

So I have this assignment in which I'm supposed to find out the amount of depleted uranium produced when 1 tone of naturally occuring uranium is enriched to about 5% 235-U. Must I not know the efficiency of enrichment in order to know how much uranium is depleted? is there an easier way to approach this problem? please help

[Enthalpy]

Welcome, aBeard!

Yes, some data is missing, but you can make almost-reasonabe assumptions, as supposedly did whoever asked this question:

• That the depleted uranium contains very little ²³⁵U (a bit stretched)
• That the process results only in depleted and enriched uranium, nothing stored in between. That's reasonable if the process is continuous and an additional 1t is input.

The enrichment process has usually no other output, and the proportion of ²³⁵U is nearly uniform among ore of varied mines.

[aBeard]

Thanks for the reply. I think I managed to solve it. It seems rather obvious now so I guess I was just tackling the problem the wrong way. What I did was to look up the composition of natural uranium, which contains 0.7% 235-U. That means that in 1 tone, there'll be 7kg of 235-U. Assuming all the 7kg are extracted (which doesn't happen in actual enrichment, but the question provided no data regarding the content of the isotope in the depleted uranium), the mass of enriched uranium must be 7/0.05=140kg.
The mass of depleted uranium will therefor be 1000-140=860kg