In the United States, in-situ recovery (ISR) uranium mining is being positioned as a flexible production approach as domestic supply lags demand. The modular development model used in ISR allows operators to add capacity incrementally rather than tying output to a single, fixed infrastructure buildout. Demand growth and declining production have increased attention on projects that can bring new output online efficiently.
ISR vs conventional mining infrastructure
Conventional hard-rock mining depends on large-scale infrastructure such as open pits, underground workings, processing plants, and tailings facilities. Once these assets are in place, production capacity is generally linked to that infrastructure until another major expansion is completed. ISR follows a different operating model focused on uranium-bearing formations underground.
Instead of excavating ore, ISR operators inject a specially prepared solution into uranium-bearing sandstone formations. The solution dissolves uranium in place and is pumped back to the surface for processing. By keeping ore underground, ISR reduces the need for large-scale excavation and lowers the mine’s surface footprint compared with conventional methods.
Demand gap and uranium supply pressure
Scalability has gained importance alongside growing global interest in nuclear energy. U.S. Energy Information Administration data through the fourth quarter of 2023 shows domestic uranium demand increasing by about 48 million pounds annually. Over the same period, U.S. production declined by roughly 200,000 pounds per year.
The widening gap between supply and demand has supported efforts to develop new uranium projects for domestic energy security. Projects using ISR technology are described as having lower capital intensity and the ability to enter production faster than many conventional operations.
How ISR extraction produces yellowcake
ISR has been commercially used in the United States for more than five decades. The process begins with injecting a lixiviant solution—typically groundwater mixed with oxygen—into uranium-bearing sandstone formations. As the solution moves through the ore body, it dissolves uranium minerals and carries them to production wells on the surface.
The uranium-bearing solution is then processed through an ion exchange system where uranium is captured onto specialized resin beads. The resin beads are transported to a central processing facility to produce uranium concentrate, commonly referred to as yellowcake. Because ore remains underground, ISR operations generally require less land disturbance and lower infrastructure costs than traditional mining.
Satellite ion exchange plants support staged expansion
A key element of ISR scalability is the use of satellite ion exchange plants near active wellfields. Rather than building a full processing facility at each production area, operators can install smaller modular IX plants close to where extraction occurs. Uranium-loaded resin produced at these satellites is transported to a centralized plant for final refining.
This configuration reduces capital expenditures while enabling multiple wellfields across a broader geographic region. Additional satellite facilities can be deployed as new wellfields come online without duplicating expensive processing infrastructure at each site.
Upper Spring Creek phase buildout and throughput targets
Upper Spring Creek is an ISR project in South Texas owned by enCore Energy. In June 2026, the company reported completion of construction for the project’s first phase. The initial satellite IX plant was built with a flow capacity of 1,600 gallons per minute (gpm), described as about half of ultimate planned throughput.
Planned capacity increases include reaching 75% of total capacity by end of June 2026. The company also scheduled 100% capacity or 3,200 gpm by end of July 2026. Infrastructure is being brought online in stages rather than as a single complete system build.
Wellfield modules and production readiness timeline
The wellfield development program follows a modular approach aligned with the processing buildout. Drilling for the first 800-gpm production module had been completed, while associated infrastructure was nearing final completion. A second module was reported as approximately 90% complete.
Development was underway on two additional 800-gpm wellfields. Each module functions as a discrete production unit contributing directly to overall project output. This staged approach supports starting revenue generation before reaching full project capacity.
Permitting requirements affecting start of extraction
Project schedules for ISR operations remain influenced by regulatory approvals after construction milestones are reached. At Upper Spring Creek, much of the physical infrastructure was already in place, but uranium extraction could not begin until necessary authorizations were secured. Production was targeted for late 2026 subject to final regulatory clearance.
The approvals described for ISR projects include aquifer exemption permits, injection well authorizations, environmental compliance approvals, and groundwater protection permits. These processes can affect development schedules even when construction work is largely complete.
Clay West district geology and resource footprint
The Upper Spring Creek project sits within the historic Clay West uranium district in South Texas. Uranium-bearing sands occur within the Oakville Formation at depths of approximately 300 to 450 feet. The broader mineralized trend extends roughly 120 miles long and 20 miles wide.
The district’s geology has supported ISR uranium mining for decades and continues to provide opportunities for additional wellfield development within the same regional setting.
Rosita central processing plant connection
A stated advantage for Upper Spring Creek is its connection to enCore’s existing Rosita Central Processing Plant (CPP). Instead of constructing a new processing facility, uranium-loaded resin from Upper Spring Creek is planned to be transported directly to Rosita for final processing. This centralized model spreads fixed processing costs across multiple projects while supporting operational efficiency.
The ability to link multiple satellite operations to an existing processing hub is cited as one reason ISR projects may achieve lower capital costs per pound of uranium produced.
enCore resource base beyond Upper Spring Creek
beyond Upper Spring Creek, enCore Energy controls a broader uranium resource portfolio. In an April 2026 corporate presentation, its projects were reported to contain approximately 30.94 million pounds of measured and indicated resources and 20.54 million pounds of inferred resources. These figures are presented as a foundation for future expansion tied to strengthening global uranium demand.
South Texas operating experience supporting execution
South Texas has served as an ISR uranium mining proving ground for more than 50 years. The region’s operational history has created technical expertise that supports modern uranium developers working on similar extraction methods. enCore’s technical advisory team includes professionals with experience at major industry operators including U.S. Steel, Cameco, Rio Algom, and General Atomics.
This experience is described as relevant to execution areas such as wellfield construction, production optimization, and operational scaling across modular ISR systems.
