The increases have come on the back of increasing the life of mine from 11.5 years to 26 years.

Initial capex has increased slightly to $333 million, though the company believes positive beneficiation testwork will deliver a reduction in downstream capital and operating costs - the latter currently at around $30 per pound.

Meanwhile the breakeven uranium price has reduced from $47/lb to $42/lb.

"Development of the Tumas project remains dependent on a suitable incentive price for uranium being achieved and the company entering acceptable long-term offtake agreements," Deep Yellow said.

The company - led by inveterate uranium bull John Borshoff - expects this could happen in the period from late-2022 to mid-2023.

Deep Yellow had cash of A$72 million at the end of the December quarter.

Shares in Deep Yellow were down 1% to 75c in late morning trade, capitalising it at $290 million.

At that price the stock is little-changed from trading levels 12 months ago.