Denison delivers robust PEA for Waterbury Lake

Company selected ISR mining for renamed Tthe Heldeth Túé deposit in Saskatchewan.

Denison Mines announced on Tuesday the successful completion of an independent preliminary economic assessment (PEA) for the Waterbury Lake property in Saskatchewan with a potential start to pre-production activities in 2025, ahead of possible first production by 2028.

The PEA evaluated the potential use of the in-situ recovery (ISR) mining method at the Tthe Heldeth Túé (formerly named J Zone, now THT) deposit with associated processing at Denison's 22.5%-owned McClean Lake mill.

The THT ISR operation is estimated to produce a total of 9.7-million pounds U3O8 over an approximate six-year mine-life with final processing at the McClean Lake mill. The project has an average cash operating cost of US$12.23 per lb and an all-in cost of US$24.93 per lb. Initial capital costs are estimated to be US$112-million.

The company announced last week that is ready to resume the formal environmental assessment (EA) process for the Wheeler River project, poised to be Canada’s first in-situ recovery uranium mine.

Denison had paused the process in March, due to restrictions related to COVID-19. 

"The Waterbury PEA further demonstrates the potential for the ISR mining method to change Canada's global competitiveness in the uranium mining sector – without requiring the discovery and development of massive-scale uranium mines," said Denison president and CEO David Cates.

"The selection of the ISR mining method for the Tthe Heldeth Túé deposit has transformed our expectations for the project – generating robust preliminary financial results with comparatively modest upfront capital costs."

Denison's plan for the project includes a 'freeze wall' design adapted from the 'freeze dome' outlined for the Phoenix deposit in the Wheeler River prefeasibility study.

"The freeze wall design allows for the containment of a smaller area and a significant reduction in up front capital costs, as compared to the 'freeze dome.'" said David Bronkhorst, VP operations of Denison.

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