NexGen Energy Ltd. (TSX: NXE) (NYSE: NXE) (ASX: NXG) is pleased to announce drilling at Patterson Corridor East has intersected mineralization in RK-24-193 over 67.5 metres (m) (383.5 to 451 m) across various intervals including up to 7,500 cps over 1.5 m (Figures 1 to 4, Table 1). RK-24-193 is located 275 m southwest along strike of RK-24-183 (discovery hole) and at approximately the same depth below surface.

In addition, assays from RK-24-183 confirm high grade uranium veins across a 20 m interval with several intersections totalling 13.5 m at 0.78% U₃O₈ including 0.5 m (348.0 to 348.5 m) at 10% U₃O₈ and another 0.5 m (356.5 to 357 m) at 6.23% U₃O₈ (Table 2). For reference, the Arrow discovery hole RK-14-21 assayed 5.75 m at 0.37% U₃O₈, including 0.25 m at 5.77% U₃O₈.

Collectively, these results of multiple narrow intersections of mineralization in two holes represent a current strike length of 275 m at PCE, suggesting a potential upper edge to mineralization highly analogous to the early holes at Arrow (Figure 1). Consequently, the summer drilling program has been expanded to 4 drill rigs and targeting 22,000 m at PCE (Figure 2).

Leigh Curyer, Chief Executive Officer, commented: “Our team has assessed the geological similarities between RK-24-183 and RK-24-193 and the upper areas of Arrow, which indicates the high prospectivity of an additional mineralized system 3.5 km east of Arrow. Consequently, the growing potential of this latest discovery will drive the focus of the summer exploration program to determine the potential size and extent of mineralization. Efficient and bold testing of the overall system is the first priority.

It is an exciting time at NexGen with the Company recently advancing the Federal Environmental Assessment process for the Rook I Project through the submission of responses to the remaining Information Requests, as well as advancing detailed engineering and exploring a new discovery in parallel.”

RK-24-193

This new hole intersected elevated radioactivity over 67.5 m (Table 1) with mineralization style and alteration intensity strongly resembling up dip projections that were seen during the early discovery holes at Arrow.

In addition, drill results further south in RK-24-180, RK-24-192, and RK-24-194 indicate a possible repetition of prospective structure that correlates well with the local gravity low, a typical indicator of potential hydrothermal alteration. Numerous brittle reactivated structures and associated intense alteration within these three drillholes highlight a potential supplementary uranium-bearing trend within the same system. This has doubled the size of the system to be tested this summer with an approximate extent of 1.5 km long by 1.2 km wide (Figure 2). Potential remains in most directions within this highly prospective area.

Summer Drilling

Focus of the expanded summer program is on assessing the broad hydrothermal system at PCE (Figure 2) and expanding the mineralized footprint. Robust analysis and interpretation processes will be utilized to actively assess potential while efficiently testing priority targets.

Over 22,000 m of diamond drilling is planned for the PCE system utilizing four drill rigs. This represents a near tripling of drilling from the winter to summer program. Optionality exists with planning underway to increase the total based on drill results. Targets will primarily be tested between 400 and 700 m below surface to test potential depth extensions, as is present at Arrow. Summer drilling will significantly advance the investigation of PCE while highlighting geological relationships that can be applied elsewhere within NexGen’s exploration portfolio (Figure 5).

Table 1: 2024 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: 2024 Assay results to date

• All depths and intervals are meters downhole, true thicknesses are yet to be determined.
• 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.
• Cutoff grade 0.01% U₃O₈.
• 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.

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.

NexGen is listed on the Toronto Stock Exchange, the New York Stock Exchange and on the Australian Securities Exchange providing access to global investors to participate in NexGen’s mission of solving three major global challenges in decarbonization, energy security and access to power. The Company is headquartered in Vancouver, British Columbia, with its primary operations office in Saskatoon, Saskatchewan.

Technical Disclosure*

All technical information in this news release has been reviewed and approved by Jason Craven, NexGen’s Manager, Exploration, a qualified person under National Instrument 43-101.

Natural gamma radiation in drill core reported in this news release was measured in counts per second (cps) using a Radiation Solutions Inc. RS-125 gamma spectrometer. The reader is cautioned that total count gamma readings may not be directly or uniformly related to uranium grades of the rock sample measured; they should be used only as a preliminary indication of the presence of radioactive minerals.

Figure 1: Schematic cross-section showing early holes at Arrow and PCE with relative depths of mineralization; follow up will primarily focus on blue shaded area down dip and along strike (CNW Group/NexGen Energy Ltd.)

Figure 2: PCE showing with area of interest for further exploration outlined; 2024 drillholes shown as green dots, interpreted primary structures are represented by dashed lines (CNW Group/NexGen Energy Ltd.)

Figure 3: Elevated radioactivity from RK-24-193 with maximum values shown for mineralized veins outlined in yellow. Replacement style mineralization is similar to the discovery hole, RK-24-183, with a notable upgrade of alteration intensity that included m-scale dravitic breccia. (CNW Group/NexGen Energy Ltd.)

Figure 4: Hydrothermal hematite, argillization, and uraninite blebs at 419.7 m with a maximum of 7,500 cps (CNW Group/NexGen Energy Ltd.)

Figure 5: PCE and analogs, based on geological and geophysical similarities, shown as green shapes (CNW Group/NexGen Energy Ltd.)