The revised DFS shows the Western Australian deposit has a 14% higher net present value at US$393 million, a 23% higher internal rate of return at 31%, and 22% more free cashflow of $61 million per annum.
CEO Mike Young argues Mulga Rocks, which he calls "the largest advanced uranium project in Australia", remains robust and ready for development, with low economic sensitivities and capital cost risks.
"The refresh has been transformational for the project and moves it into the middle of the uranium producer AISC cost curve and on par with the higher cost Kazakh operations and well ahead of most other uranium juniors," he said.
"It is leader of the pack in terms of the next wave of world-wide uranium projects."
The 2020 refresh follows a 2019 external review of the 2018 DFS that recommended no fundamental changes, but did flag areas were costs savings could be made, primarily workforce numbers and ancillary infrastructure, and changes to the planned owner-operating mining plan with a hybrid contract mining model.
Key savings included a decision for Vimy not to invest $90 million in buying and managing its own mining fleet, working with Piacentini & Son, which worked on the 2016 test pits at Mulga Rocks, on a hybrid ownership model for a saving of $60 million.
It can also save around $38 million on owner's costs, indirect costs, and infrastructure.
Capital costs have been hammered down 20%, and payback has been reduced by eight months to just under 30 months.
Operationally, C1 has costs are down 7% over the life of the mine to $26.02 per pound, while all-in sustaining costs are down 8% over the mine life at $31.02/lb, with even lower costs during the initial five years of the 15 year life.
The study assumed a contract price of $55/lb, down from $60/lb in 2018.
Annual production remains at 3.5Mlb, and other key aspects of the DFS such as process route were unchanged.
The only increase in costs was a $2.6 million bump in the process plant budget.
Uranium prices have been climbing in recent years, since Kazatomprom and Cameco, two of the world's largest producers, began to reduce production deemed unsustainable.
Vimy is still chasing funding, believing nuclear power plant owners globally will be attracted to Mulga Rocks' location in a proven first-world jurisdiction with low sovereign risk.
Shares in the junior were last traded at A3.4c, valuing the company at $21 million.
