NexGen Energy Ltd. (TSX: NXE) (NYSE: NXE) (ASX: NXG) is pleased to announce the mineralized zone at Patterson Corridor East has materially expanded since the original discovery in the 2024 Winter Program (see NexGen News Release dated March 11, 2024). The Summer Drill Program commenced May 21st, with eight out of twelve drillholes intersecting mineralization to date (Figures 1 and 2, Table 1). Extensive mineralization plunges to the east with a span of 540 m along strike and 600 m vertical extent, showing wide intervals of elevated radioactivity that remain open at depth and along strike. In comparison, previously reported holes from PCE had identified two mineralized holes, 275 m apart.

Off-scale (>61,000 cps) high-grade uranium mineralization has been intersected in four drillholes to date, including RK-24-183, -197, -202, and -207. The most recent intersection in RK-24-207 contains the first instance of massive replacement by uraninite, a key indicator of a strongly mineralized system (Figures 3 and 4, Table 1) with 1.5 m >10,000 cps (including 0.3 m >61,000 cps) within cumulative interval mineralization of 26.2 m > 500 cps (Table 2).

Results include the best and most recent intercept in RK-24-207, that confirms continuity of mineralization, massive replacement uranium and significant high grade at PCE (Table 1). The high-intensity style mineralization is indicative of exceptional formation conditions linked to significant orebodies within the Athabasca Basin and most notably the Arrow Deposit 3.5 km to the west. In addition, this zone of high-intensity mineralization in RK-24-207 is at a similar depth to Arrow’s A2 high-grade heart. PCE, like Arrow, is contained solely in the competent basement rock which is the ideal underground setting. The mineralized signature is expressed as very analogous to Arrow, localized veins (up to off-scale >61,000 cps) within elevated radioactivity that extends over more than 100 m.

Summer drilling to date totals 10,045.5 m of the planned 22,000 m from 12 completed drillholes. Assays from disclosed mineralized intersections are pending and due in Q4 2024.

As a consequence of these results, the focus of the summer program has substantially elevated with two primary objectives:

• continue to test the extent of the mineralized system through bold step outs, and
• vector in on the high-grade zones within the broader mineralized system.

Leigh Curyer, Chief Executive Officer, commented: “In the first two months of the summer program, the results have rapidly indicated an expansive, mineralized footprint with remarkable continuity. Geological characteristics are very analogous to Arrow indicating a large, pervasive and high-grade system. The summer program has been purposely bold with very large drill step outs and has intersected mineralization in an additional 8 of the 12 holes drilled. Important to note, PCE has currently hit 4 holes with intense mineralization >61,000 cps, with this occurring at Arrow for the first time in the 15^th hole – which led to subsequently delineating broad ultra-high grade zones in the A2 shear of Arrow.

Discoveries of the calibre of Arrow all take their own path in terms of time and extent of drilling to fully define. PCE is now commencing its path showing all the characteristics of Arrow at the same stage. PCE validates the continued prospectivity of the NexGen land package is immense and underpins the southwest Athabasca Basin as the future of Canada’s uranium industry growth over the balance of this century.

NexGen is at an incredibly exciting stage, focused on concluding the Federal Environmental Assessment for the Rook I Project, construction readiness on receipt of final approvals and in parallel drilling a newly discovered zone of mineralization.”

Mineralization is hosted as semi-massive to massive pitchblende veins, fracture coatings, and disseminations. Structures focus the mineralization via reactivated shears and faults while competent wall rock (silicified orthogneiss) acts as a physical trap. The mineralization and alteration patterns depict a well-developed hydrothermal fluid system. Typical alteration associated with the mineralization includes the formation of iron-rich minerals (hydrothermal hematite), iron oxide (limonite), clay, and chlorite. These characteristics combined with the size of the mineralized footprint, as well as the presence of >61,000 cps, demonstrates the similarities between PCE and Arrow at the same stage.

Table 1: 2024 Summer program spectrometer results to date

• All depths and intervals are meters downhole, true thicknesses are yet to be determined.
• “Off-scale” refers to >61,000 cps total readings by gamma spectrometer type RS-125.
• Unconformity of ‘N/A’ denotes a lack of visible contact between Athabasca sandstone and basement rock.
• Maximum internal dilution 2.0 m downhole.
• Minimum thickness of 0.5 m downhole.
• All depths and intervals are metres downhole, true thicknesses are yet to be determined. Resource modelling in conjunction with an updated mineral resource estimate is required before true thicknesses can be determined.

Table 2: Cumulative mineralization from 2024 summer program to date

• All depths and intervals are meters downhole, true thicknesses are yet to be determined.
• Radioactivity measured by gamma scintillometer type RS-120 and gamma spectrometer type RS-125.
• Maximum readings stated as ‘N/A’ had no radioactivity >500 cps.

About NexGen

NexGen Energy is a Canadian company focused on delivering clean energy fuel for the future. The Company’s flagship Rook I Project is being optimally developed into the largest low cost producing uranium mine globally, incorporating the most elite standards in environmental and social governance. The Rook I Project is supported by a NI 43-101 compliant Feasibility Study which outlines the elite environmental performance and industry leading economics. NexGen is led by a team of experienced uranium and mining industry professionals with expertise across the entire mining life cycle, including exploration, financing, project engineering and construction, operations, and closure.  NexGen is leveraging its proven experience to deliver a Project that leads the entire mining industry socially, technically, and environmentally. The Project and prospective portfolio in northern Saskatchewan will provide generational long-term economic, environmental, and social benefits for Saskatchewan, Canada, and the world.

Figure 1: Schematic plan view of mineralized footprint at Arrow and PCE at the same stage of drilling; gravity as background with low values in blue (CNW Group/NexGen Energy Ltd.)

Figure 2: Schematic long section of mineralized footprint at Arrow and PCE at the same stage of drilling (CNW Group/NexGen Energy Ltd.)

Figure 3: Core photo from RK-24-207; high grade mineralization is hosted across 7.1 m from 523.9 to 531 m with outer low grade disseminated uranium extending above to 519.4 and below to 534.4 m; Narrow secondary veins are hosted nearby in the footwall below (CNW Group/NexGen Energy Ltd.)

Figure 4: RK-24-207 close-up of off-scale (>61,000 cps) massive replacement by uraninite at 525.1 m (CNW Group/NexGen Energy Ltd.)

Figure 5: RK-24-202 uraninite as blebs along foliation and fracture coating at 934.4 m, max peak of >61,000 cps (CNW Group/NexGen Energy Ltd.)

Figure 6: RK-24-202 mineral replacement by uraninite within shear zone at 967.5 m, max peak of 49,000 cps (CNW Group/NexGen Energy Ltd.)