enCore’s Rosita Plant, located approximately 60 miles west from Corpus Christi, Texas, is a licensed, past-producing In-Situ Recovery (ISR) uranium plant that is completing refurbishment. enCore is on budget for a scheduled production startup in 2023 with the Rosita Plant designed to process uranium feed from multiple satellite operations, all located in the South Texas area. The Rosita Plant is 1 of 11 licensed and constructed uranium processing plants in the United States, 2 of which are owned by enCore Energy.
Rosita Central ISR Uranium Processing plant
The Rosita Central Processing Plant development underway is enCore’s key asset advancing towards production. The facility is designed to process feed from multiple satellite operations, current facility refurbishment and upgrade work projected for completion by Q3 2023.
- Completion of the installation of 43 monitoring wells, including 38 perimeter and 5 overlying monitor wells, at the Rosita Extension PAA. This marks a significant milestone towards ISR uranium production at the Rosita Project as a key source of fuel for safe, clean, reliable, and carbon-free nuclear energy in the United States;
- The Rosita Extension PAA is the first production area planned as a new source of uranium for the Rosita ISR Uranium Processing Plant;
- The Rosita Extension PAA is located within the existing Radioactive Materials License, Underground Injection Control Permit and Aquifer Exemption areas at the Rosita Project;
- Future work at the Rosita Extension PAA is now focused on the completion of five baseline wells, which in combination with the 43 monitoring wells will establish groundwater quality standards within the mineralization. The pre-production water quality standards wells are used to assure production solution controls are maintained and to establish groundwater restoration standards necessary for post-production reclamation. Following completion of baseline well testing, the installation of injection and recovery well patterns will commence.
The Texas Commission on Environmental Quality (“TCEQ”) issued Radioactive Material Licenses for both the Rosita and Kingsville Dome facilities. Both sites have Class I Non-hazardous Injection Permits authorizing the operation of waste disposal wells. The Rosita project includes four TCEQ Production Area Authorizations (“PAAs”) that should reduce costs and shorten the timeline to initial production.
Rosita Central Processing Plant, Texas
In addition to the 200-acre tract of land owned by the Company for the Rosita CPP, additional property holdings consist of mineral leases from private landowners covering approximately 3,377 acres of mineral rights. The nearby Rosita South property consists of mineral leases from private landowners covering approximately 1,479 acres of mineral rights and is partially included within the existing license and permit boundaries.
Initial production of uranium utilizing the ISR process commenced in 1990 and continued until July 1999. During that time approximately 2.64 million pounds of U3O8 were produced.
In the 2007-2008 period upgrades were made to the processing equipment and additions to the facility were installed, including revisions to the elution and precipitation circuits, and the addition of a full drying system.
The upgraded and modernized Rosita Central Processing Plant will be ready to receive uranium loaded resins from various remote South Texas satellite wellfields. enCore is acquiring and has acquired uranium mineral properties to be developed and placed into production to feed the Rosita Central Processing Plant. The Central Processing Plant currently has the infrastructure in place to increase capacity substantially.
Geology and Mineralization
Uranium mineralization at the Rosita project occurs as roll-front deposits hosted in porous and permeable sandstones of the Goliad Formation, at depths ranging from 125 to 350 feet below surface.
Kingsville Dome Plant
The Kingsville Dome CPP, 35 miles south west of Corpus Christi, was constructed in 1987 and operated intermittently from 1988 to 2009, at which point it was placed on standby. Approximately 4.2 million pounds of U3O8 was produced from the project area. The facility consists of two resin processing circuits that are constructed to receive uranium loaded resins from multiple remote satellite wellfield ionexchange facilities. The CPP has a full uranium elution and precipitation circuit that is constructed to feed a dual yellowcake drying circuits. The CPP currently has one operational yellowcake dryer.
Geology and Mineralization
Uranium mineralization at the Kingsville Dome project occurs as roll-front deposits hosted in porous and permeable sandstones of the Goliad Formation, at depths ranging from 600 to 750 feet beneath the surface. The mineralization is localized along the southwestern to northern flanks of the Kingsville Dome geological feature, which also hosts oil and gas deposits in geological units that are situated well below the Goliad Formation sandstones.
South Texas Uranium Properties
enCore is advancing several historic uranium properties toward production as satellite IX wellfield operations. These properties will supply uranium loaded IX resin, principally to feed the Rosita Central Processing Plant. The Kingsville Dome Central Processing Plant will serve to increase capacity when necessary should these projects exceed the capacity of the Rosita CPP, or to possibly receive uranium loaded resins from future producing sites in South Texas.
Rosita Project Extension, Texas – The Company is advancing wellfield development of mineral resources previously included in the former production area authorization 4 within the Rosita Project radioactive materials license and injection permit boundaries. The mineral resources in this area were never produced and present a rapid opportunity for early production.
Rosita South, Texas – The Company announced positive results from its on-going uranium delineation and exploration drill programs at its 100% owned Rosita South project. The Rosita South project is within 6 miles of the Rosita CPP providing an optimal source for satellite feed to the Plant. 32 drill holes totaling approximately 11,000 feet, include 20 delineation holes and 12 exploration holes. The exploration drilling identified 8 mineralized sands plus an additional 4 potentially mineralized sands, all within 800 feet of the surface. The discovery and identification of the 4 previously unknown deeper sands provides the potential for discovery of additional uranium resources across the entire Rosita project area.
Butler Ranch Project, Texas – TThe Company acquired the Butler Ranch project from Rio Grande Resources in 2014, as part of a larger property exchange. The property is comprised of non-contiguous fee leases covering an area of about 438 acres of mineral rights. The Butler Ranch project is located in the southwestern Karnes County uranium mining district, one of the most productive uranium producing areas in Texas. It is about 45 miles southeast of the city of San Antonio, 12 miles northwest of the town of Kenedy, and about 85 miles from enCore’s Rosita CCP.
Upper Spring Creek Project, Texas – The Company is acquiring or has acquired several additional mineral properties located in South Texas, including the area described generally as the Upper Spring Creek Project. The property is currently comprised of non-contiguous fee leases covering an area of approximately 510 acres of surface and mineral rights, and the Company is actively acquiring additional mineral properties in this area. The project includes mineral properties that were identified in the Signal Equities LLC database that the Company acquired in December 2020. These properties are intended to be developed using satellite ion-exchange (IX) plants that will provide loaded resin for further processing at the Rosita CCP.
Geology and Mineralization
Regionally, uranium mineralization is hosted in fluvial sandstones of the Eocene-age Jackson Group, the Oligocene/Miocene-age Catahoula Formation, Miocene-age Oakville Formation and Miocene/Pliocene-age Goliad Formation. Uranium deposits occur as “roll-fronts” in the more porous and permeable sandstones, and they have been localized by concentrations of organic plant debris in the sandstones, or where hydrocarbon gasses have migrated upward into the host rocks along high-angle faults.
Uranium mineralization at Butler Ranch occurs in the form of roll-front deposits hosted primarily in sandstones of the Jackson Group, including the Deweesville and Stones Switch units. Some mineralization in the area also occurs as tabular bodies associated with lignite (carbonaceous material) or in somewhat permeable units in the Conquista Clay.
Previous exploration by operators including Conoco and Kerr-McGee totaled more than 2,000 drill holes, resulting in the delineation of several deposits within the vicinity of Butler Ranch. These drill programs were limited to identifying near surface mineralization amenable to open pit mining. Thus, in many areas the potential for deeper uranium bearing sand units minable using ISR has never been tested.