NexGen Announces Highest-Grade Assay to Date from Patterson Corridor East
NexGen Announces Highest-Grade Assay to Date from Patterson Corridor East
• RK-25-256 returns 5.5 m at 21.4% U3O8, including 2.5 m at 46.1% U3O8 and including
0.5 m at 74.8% U3O8,
• Rook I developing a multi-generational portfolio of uranium projects in the southwest
Athabasca Basin, Saskatchewan, Canada.
Vancouver, BC, December 1, 2025 - NexGen Energy Ltd. ("NexGen" or the "Company") ( TSX: NXE)
(NYSE: NXE) (ASX: NXG) is pleased to announce its highest-grade assay results to date at the Company’s
100%-owned Patterson Corridor East (“PCE”) with drill hole RK-25-256. Assays returned 5.5 meters (“m”)
at 21.4% U3O8 between 590.0 and 595.5 m depth, including 2.5 m at 46.1% U3O8 and 0.5 m at 74.8% U3O8
(Figures 1 and 2; Table 1) as well as a separate and adjacent intercept of 1.5 m at 5.28% U3O8.
Significantly, this high-grade uranium intersection in RK-25-256 is 119 m down-dip of drill hole RK-25-232,
and an additional 51 m down-dip of recently reported (see news release dated November 12, 2025) RK-25-
254 (Figure 1 and 3). Overall, intense high-grade uranium mineralization is currently interpreted along a
minimum of 215 m of dip extent from RK-25-254 to RK-24-222.
Leigh Curyer, Founder & Chief Executive Officer, commented : “RK-25-256 high-grade assay results,
consisting of ultra-high grade 0.5 m 74.8% U3O8 takes PCE into a rare mineralized category on a world scale
for uranium deposits. This type of basement -hosted mineralization is synonymous with Arrow, only 3.5 km
to the west.
It is clear, the frequency of this ultra -high grade category of intercepts at Arrow and now PCE, is evidence
of a very significant mineralizing event occurring at Rook I and in the surrounding region of the southwest
Athabasca Basin in Saskatchewan.
NexGen, with Arrow as the inaugural deposit, is developing a uranium project portfolio which is focused on
multi-generational nuclear fuel supply and providing economic, environmental , and social outcomes on a
scale not previously witnessed in the industry. NexGen is a central component of delivering Canada’s and
the world’s key critical mineral demand.”
Jason Craven, Vice President, Exploration, commented: “These exceptional grades significantly elevate
our understanding of PCE and offer a glimpse at the growing basement-hosted uranium prospectivity in the
southwest Athabasca Basin, where NexGen controls the most prospective portfolio of over 190,000
hectares across 140 km of the southwest Athabasca Basin.”
Figure 1: Interpreted PCE long section (as of August 28, 2025 release) with notable assays collected since discovery
and new results outlined in red; view is a long section that looks perpendicular to the primary mineralized plane; total
mineralized footprint in orange and the high-grade subdomains in red
Figure 2: Core photo with select assays from RK-25-256, grades are shown as % U3O8
Figure 3: Interpreted 3D model of PCE shown looking northwest (across strike) and northeast (along strike);
previously reported in August 28 release, now with RK-25-256 intersection shown as purple outline for reference
Table 1: Assays received since November 12, 2025 news release
Drillhole
Unconformity
Depth (m)
SRC Geoanalytical Results
(Cutoff 0.01%)
Hole ID Azimuth Dip
Total
Depth
(m)
From (m) To (m) Width
(m)
U3O8
(wt%)
RK-25-256 292 -65.5 696.0 116.9 521 521.5 0.5 0.01
525.5 527 1.5 0.01
587.5 589.5 2 0.12
590 595.5 5.5 21.4
incl. 592 594.5 2.5 46.1
incl. 593 593.5 0.5 74.8
596 597.5 1.5 5.28
incl. 596 596.5 0.5 15.8
600 600.5 0.5 0.03
602.5 603 0.5 0.07
603.5 604 0.5 0.05
607.5 608 0.5 0.02
608.5 614 5.5 0.13
615 616.5 1.5 0.10
617.5 618 0.5 0.11
626.5 630 3.5 0.03
• 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.
• * Denotes results that correlate to high-grade levels of radioactivity (>10,000 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 environmental and social governance standards. The Rook I
Project is supported by an N.I. 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, fina ncing,
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 under the ticker symbol
"NXE," and on the Australian Securities Exchange under the ticker symbol "NXG," 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.
Contact Information
Leigh Curyer
Chief Executive Officer
NexGen Energy Ltd.
+1 604 428 4112
www.nexgenenergy.ca
Travis McPherson
Chief Commercial Officer
NexGen Energy Ltd.
+1 604 428 4112
www.nexgenenergy.ca
Monica Kras
Vice President, Corporate Development
NexGen Energy Ltd.
+44 7307 191933
www.nexgenenergy.ca
Technical Disclosure*
All technical information in this news release has been reviewed and approved by Jason Craven, NexGen's
Vice President, 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.
A technical report in respect of the FS is filed on SEDAR ( www.sedar.com ) and EDGAR
(www.sec.gov/edgar.shtml ) and is available for review on NexGen Energy's website
(www.nexgenenergy.ca ).
Cautionary Note to U.S. Investors
This news release includes Mineral Reserves and Mineral Resources classification terms that comply with
reporting standards in Canada and the Mineral Reserves and the Mineral Resources estimates are made in
accordance with NI 43 -101. NI 43-101 is a rule developed by the Canadian Securities Administrators that
establishes standards for all public disclosure an issuer makes of scientific and technical information
concerning mineral projects. These standards differ from the requirements of the Securities and Exchange
Commission ("SEC") set by the SEC's rules that are applicable to domestic United States reporting
companies. Consequently, Mineral Reserves and Mineral Resources information included in this news
release is not comparable to similar information that would generally be disclosed by domestic U.S.
reporting companies subject to the reporting and disclosure requirements of the SEC Accordingly,
information concerning mineral deposits set forth herein may not be comparable with information made
public by companies that report in accordance with U.S. standards.
Forward-Looking Information
The information contained herein contains "forward -looking statements" within the meaning of applicable
United States securities laws and regulations and "forward -looking information" within the meaning of
applicable Canadian securities legislation. "Forward -looking information" includes, but is not limited to,
statements with respect to mineral reserve and mineral resource estimates, the 2021 Arrow Deposit, Rook
I Project and estimates of uranium production, grade and long -term average uranium prices, anticipated
effects of completed drill results on the Rook I Project, planned work programs, comp letion of further site
investigations and engineering work to support basic engineering of the project and expected outcomes.
Generally, but not always, forward-looking information and statements can be identified by the use of words
such as "plans", "expects", "is expected", "budget", "scheduled", "estimates", "forecasts", "intends",
"anticipates", or "believes" or the negative connotation thereof or variations of such words and phrases or
state that certain actions, events or results "may", "could", "would", "might" or "will be taken", "occur" or "be
achieved" or the negative connotation thereof. Statements relating to "mineral resources" are deemed to
be forward-looking information, as they involve the implied assessment that, based on certain estimates and
assumptions, the mineral resources described can be profitably produced in the future.
Forward-looking information and statements are based on the then current expectations, beliefs,
assumptions, estimates and forecasts about NexGen's business and the industry and markets in which it
operates. Forward -looking information and statements are m ade based upon numerous assumptions,
including among others, that the mineral reserve and resources estimates and the key assumptions and
parameters on which such estimates are based are as set out in this news release and the technical report
for the property , the results of planned exploration activities are as anticipated, the price and market supply
of uranium, the cost of planned exploration activities, that financing will be available if and when needed
and on reasonable terms, that third party contractors, equipment, supplies and governmental and other
approvals required to conduct NexGen's planned exploration activities will be available on reasonable terms
and in a timely manner and that general business and economic conditions will not change in a material
adverse manner. Although the assumptions made by the Company in providing forward looking information
or making forward looking statements are considered reasonable by management at the time, there can be
no assurance that such assumptions will prove to be accurate in the future.
Forward-looking information and statements also involve known and unknown risks and uncertainties and
other factors, which may cause actual results, performances and achievements of NexGen to differ
materially from any projections of results, performances and achievements of NexGen expressed or implied
by such forward -looking information or statements, including, among others, the existence of negative
operating cash flow and dependence on third party financing, uncertainty of the availability of additional
financing, the risk that pending assay results will not confirm previously announced preliminary results,
conclusions of economic valuations, the risk that actual results of exploration activities will be different than
anticipated, the cost of labour, equipment or materials will increase more than expected, that the future
price of uranium will decline or otherwise not rise to an economic level, the appeal of alternate sources of
energy to uranium -produced energy, that the Canadian dollar will strengthen against the U.S. dollar, that
mineral resources and reserves are not as estimated, that actual costs or actual results of reclamation
activities are greater than expected, that changes in project parameters and plans continue to be refined
and may result in increased costs, of unexpected variations in mineral resources and reserves, grade or
recovery rates or other risks generally associated with mining, unanticipated delays in obtaining
governmental, regulatory or First Nations approvals, risks related to First Nations title and consultation,
reliance upon key management and other personnel, deficiencies in the Company's title to its properties,
uninsurable risks, failure to manage conflicts of interest, failure to obtain or maintain required permits and
licences, risks related to changes in laws, regulations, policy and public perception, as well as those factors
or other risks as more fully described in NexGen's Annual Information Form dated March 6, 2024 filed with
the securities commissions of all of the provinces of Canada except Quebec and in NexGen's 40-F filed with
the United States Securities and Exchange Commission, which are available on SEDAR
at www.sedar.com and Edgar at www.sec.gov .
Although the Company has attempted to identify important factors that could cause actual results to differ
materially from those contained in the forward -looking information or statements or implied by forward -
looking information or statements, there may be other factors that cause results not to be as anticipated,
estimated or intended. Readers are cautioned not to place undue reliance on forward-looking information
or statements due to the inherent uncertainty thereof.
There can be no assurance that forward- looking information and statements will prove to be accurate, as
actual results and future events could differ materially from those anticipated, estimated or intended.
Accordingly, readers should not place undue reli ance on forward -looking statements or information. The
Company undertakes no obligation to update or reissue forward -looking information as a result of new
information or events except as required by applicable securities laws.