from shaws morning notes, page-31

That's my calc as well oze assuming that the dividend is paid in July or so. However, if they pay a dividend of say 80m in July and a further 20m or so in December, then potentially they could have enough credits after paying instalments on another 6 months of WD and royalty cash flows. It then also depends on how much they can deduct for exploration expenses, etc.

Just speculating here of course. A dividend that is 80% franked is still around 10c per share of franking credits (assuming the whole 100m is declared in one hit) and still going to be coveted by many.