The enhanced numbers, following last month's resource update, show the junior will need A$176 million to cover the total development costs, up from $75 million due to the addition of $90 million in ramp-up costs to deliver a much larger development that can produce more at lower costs for longer.
The enhanced DFS, based on a uranium price averaging $64 per pound, suggests the mine will produce 22.5Mlb over 16 years at all-in sustaining costs of $28.70/lb.
That compares to the 2021 estimate of 12.1Mlb produced over 15 years at $29.80/lb based on a $60/lb price.
Financials show post-tax net present value and internal rate of return have increased from $80 million and 22% respectively to $226 million and 28%.
Free cashflow has more than doubled from $265 million to $554 million.
Aura ran upside numbers based on a $79/lb price that increases the NPV to $347 million and the IRR to 35% and adds about $20 million per annum in earnings.
The big change in cost comes from the additional capital investment needed to increase production by 150%, from 800,000lbpa to 2Mlbpa, with plans to add additional beneficiation and leaching in the ramp-up phase from 2025.
Initial capex is $88 million, a rise of about 10%.
Despite the extra spending, payback as increased less than a year to 4.5 years.
Managing director Dave Woodall said the results showed Tiris had a "low capital intensity, low operating costs (and) competitive all-in-sustaining cost", and was primed for a rapid start with key regulatory approvals in place.
Tiris is fairly unique as it allows free-dig shallow open pit mining.
Aura is hoping to take a final investment decision as early as September, allowing commissioning in late 2024, and steady state production at 4.2Mtpa by 2027 after its ramp-up investment.
Life of mine production has increased 110% to 25.5Mlb with Aura keen to add to resources with further exploration work and resource definition drilling given the total resource is 59Mlb.
Front-end engineering and design work has started.
Aura, which has been working on Tiris since 2008, has A$6 million in cash remaining.
Shares in the company were last traded at 31c, valuing it at $173 million.
