Add this code to control.lua. It re-generates the uranium on already existing map that was played without this mod.

script.on_configuration_changed(function(event)
if event.mod_changes.Nucular.old_version == nil then
for surface_index,surface in pairs(game.surfaces) do
surface.regenerate_entity("uranium-ore")
end
end
end)

I tried this and it didn't work. I did create a new map and it was populated with Uranium.

Doesn't work. Bummer. Would love to add this to my current game.