Well, ~75 tons of fuel per three units fully loaded plus a few times that for the spent nuclear fuel pools. Also bear in mind that fuel being melted with concre

Well, ~75 tons of fuel per three units fully loaded plus a few times that for the spent nuclear fuel pools. Also bear in mind that fuel being melted with concrete and metal becomes one, so you can add a hefty multiplier to the above figure. So it seems like 800 tons is in the ballpark of the fuel assemblies plus molten metal structures of the lower part of the reactors vessels.