EX-99.1
2
a20211028_wrerptfieldprog.htm
PRESS RELEASE DATED OCTOBER 28, 2021
a20211028_wrerptfieldprog
Exhibit 99.1
Denison Mines
Corp.
1100 – 40
University Ave
Toronto, ON M5J
1T1
www.denisonmines.com
PRESS
RELEASE
DENISON ANNOUNCES COMPLETION OF HIGHLY SUCCESSFUL
PHOENIX ISR FIELD TEST PROGRAM
Toronto, ON – Oct. 28,
2021. Denison Mines Corp. (“Denison” or the
“Company”) (TSX: DML, NYSE American: DNN) is pleased to
announce the initial results of a highly successful In-Situ
Recovery (“ISR”) field test program (“2021 ISR
Field Test”) completed within the commercial-scale ISR test
pattern installed in the Phase 1 area of the high-grade Phoenix
uranium deposit (“Phoenix”) at the Company’s 95%
owned Wheeler River Uranium Project (“Wheeler River” or
the “Project”) in northern
Saskatchewan.
●
Achieved the commercial-scale production flowrate assumed in the
Pre-Feasibility Study (“PFS”) prepared for the Project
in 2018.
●
Demonstrated hydraulic control of injected solution during ion
tracer test – reporting no elevated values of the tracer
element in the monitoring wells surrounding the commercial-scale
test pattern.
●
Established breakthrough times between injection and recovery
wells, spaced 5 to 10 meters apart, that are consistent with
previous ‘Proof of Concept’ hydrogeological modelling
conducted by Petrotek Corporation ("Petrotek").
●
Completed ‘clean-up phase’ following tracer test
demonstrating ability to remediate the test pattern –
reducing tracer concentrations to as low as 4% of peak test levels
within eight days of remediation.
David Cates, Denison’s President & CEO,
commented, “We
are pleased to have safely and successfully completed another
significant ISR field program at Phoenix. Our evaluation team and
field staff have worked diligently over an eight-month period to
expertly carry out a complex project execution plan that has
delivered the data and results necessary for our Company to
continue our industry-leading efforts to further de-risk the
application of the ISR mining method in the Athabasca Basin
region.
While our previous test work has provided considerable support for
the use of ISR at Phoenix, the achievement of the targeted flowrate
from the PFS in a commercial-scale well pattern located within
Phase 1 of Phoenix, and the tangible demonstration of our ability
to control fluid flows during the tracer test, together mark
another highly significant de-risking milestone for the
Project.
With the field test completed and the Company well capitalized, our
technical team is moving full-steam ahead with the development of
our field plans for 2022 while also supporting the recent launch of
the formal feasibility study process.”
The
2021 ISR Field Test program was designed to further increase
confidence and reduce risk in the application of the ISR mining
method at Phoenix – with the detailed results providing the
necessary datasets for the permitting and preparation of a planned
lixiviant test in 2022, which is expected to support the completion
of the recently announced Feasibility Study (or “FS”)
for the Project (see press release dated September 22,
2021).
This press release constitutes a "designated news release" for the
purposes of the Company's prospectus supplement dated September 28,
2021, to its short form base shelf prospectus dated September 16,
2021.
Test Pattern Installation
A test pattern
consisting of five commercial-scale wells ("CSWs"), including
GWR-038 to GWR-042, and 10 additional small diameter monitoring
wells (“MWs”) (together described as the “Test
Pattern”), was successfully installed within the Phase 1 area
of the Phoenix deposit (see Figure 1) during the summer months (see
press release dated July 29, 2021).
Three methods of
permeability enhancement were successfully evaluated on the five
CSWs, with post permeability enhancement testing resulting in
observed improvement in hydraulic responses and inter-well
connectivity within the Test Pattern. These results exhibit and
confirm the ability to engineer additional access to the natural
permeability within the deposit. Permeability enhancement methods
included the use of the MaxPERF drilling tool as well as
wireline-conveyed tools designed to perforate and stimulate well
production using a controlled propellant. The wireline tools can
effectively “clean out” restricted pathways within the
well screen, well bore, and the geological formation and provide
increased flow rates in the wells by intersecting and connecting to
the naturally occurring fractures within the ore zone.
Twenty
single-well injection tests were completed on the Test Pattern to
evaluate natural permeability and the efficiency of permeability
enhancement methods deployed in the CSWs. Nine single-well pump
tests were completed amongst the five CSWs and four of the MWs to
evaluate permeability, sustainable pumping rates, hydraulic
connectivity, and baseline groundwater conditions. Importantly,
testing showed good hydraulic connection between the CSWs in the
ore zone horizon and no significant responses in any of the MWs in
overlying or underlying horizons (see Figure 2). One step-rate
injection test was conducted on the center CSW (GWR-040) to
evaluate hydraulic connectivity, maximum injection rates and
injection pressures.
Full-Scale Well Pattern Pump and Injection Test
A full-scale well
pattern injection and pumping test was conducted to determine
hydraulic connectivity for the Test Pattern as a whole, and to
evaluate potential production rates for the pattern. The test was
run as a modified 4-spot pattern as there was an unanticipated
failure of the submersible pump in GWR-042. During the test,
injection rates were matched to pumping extraction rates for
balanced flow in the Test Pattern. Pumped groundwater from each of
the outer wells (GWR-038, GWR-039, and GWR-041) was recycled for
injection in the center well (GWR-040) to create a closed system.
Production rates for the Test Pattern achieved a sustainable rate
of 45.3 litres per minute (“L/min”) injection in
GWR-040 with minimal pressure on surface balanced with 15.1 L/min
extraction at each GWR-038, GWR-039 and GWR-041. This test
fundamentally achieved the 50 L/min flow rate assumed in the PFS
for an operating well pattern. Hydraulic control of the Test
Pattern was confirmed by no significant hydrologic responses
observed in any of the overlying or underlying monitoring
wells.
Ion Tracer Test
Following the
full-scale injection and pumping test, an ion tracer test was
completed using the 4 functional CSWs in the Test Pattern. Flow
rates were run at the same levels as the full-scale well pattern
test with 45.3 L/min injection at the center well and a balanced
extraction flow of 15.1 L/min at each of the three outer wells. The
ion tracer, consisting of a 15% concentration of potassium chloride
(KCl) by weight, was injected as an initial slug into the Test
Pattern at GWR-040, followed by a chase phase involving the
recirculation of water extracted from the three outer wells (closed
system). The chase phase continued until peak concentrations of the
ion tracer, measured in total dissolved solids (“TDS”),
were observed at the three extraction wells (GWR-038, GWR-039 and
GWR-041), followed by a decline in TDS prior to commencement of a
remediation test.
Breakthrough of
the ion tracer, as observed by an increase in the TDS, occurred at
the three extraction wells within 9 hours (GWR-039), 12 hours
(GWR-041), and 14 hours (GWR-038). These breakthrough times
observed during the field test are consistent with previous
hydrogeological modelling conducted by Petrotek (see press release dated
June 4,
2020).
Remediation Test
After completion
of the ion tracer test, a “clean-up” remediation test
was conducted to simulate the ability to remove injected fluid from
the Test Pattern. For this test, injection was halted at the center
well (GWR-040) and the three extraction wells were pumped to remove
the remaining injected ion tracer. Tracer concentrations measured
during the eight-day clean-up simulation, as observed by field TDS
measurements, declined to as low as 13% of the peak TDS value in
GWR-038, 11% of the peak TDS value in GWR-041, and 4% of the peak
TDS value in GWR-039.
Hydrogeological Monitoring
Monitoring during
the ion tracer test and subsequent clean-up test included: 376
field measurements of TDS from the CSW extraction wells to identify
tracer concentrations; logging of water levels in each of the CSWs
along with all of the surrounding MWs at five-minute intervals;
logging of TDS values at five-minute intervals in the three
overlying MWs to confirm the absence of any tracer concentrations
in the overlying horizons; and daily groundwater sampling to send
for lab analysis to confirm TDS values measured in the field and
the exact concentration of the KCl tracer.
The ability to
maintain hydraulic control was established by sampling the three
overlying MWs for TDS values before and after the ion tracer test.
No elevated values in TDS were observed during the test, thus
confirming there was no migration of the tracer to overlying
horizons.
Data collected as
part of the 2021 field program will be utilized to update the
Phoenix hydrogeological model, and will provide the necessary data for the permitting and
preparation of a lixiviant test planned for the Test Pattern in
2022.
Ongoing Permeameter Analysis
In addition to
the hydrogeological tests described above, over 1,000 drill core
samples were collected from historic holes, re-logged for
hydrogeologic characteristics, and analyzed for permeability
utilizing the permeameter on-site. Samples were selected to ensure
the database of on-core permeability results included
representative samples from all of the planned mining phases at
Phoenix.
COVID-19
The Company is
committed to ensuring that the Wheeler River site is a safe
operating environment for its staff and contractors and that the
Company's field activities do not compromise the health and safety
of the residents of northern Saskatchewan. In 2020, the
Company's Occupational Health and Safety Committee
in Saskatoon developed a comprehensive guide for the safe
resumption of work at Wheeler River. The protocols consider
the unique health and safety risks associated with operating a
remote work camp amidst the ongoing COVID-19 pandemic. Public
health guidelines and best practices (including testing) have been
incorporated into the Company's protocols.
The 2021 ISR
Field Test was completed over an eight-month period and involved
the on-site support of over 100 different staff and contractors.
COVID-19 rapid testing was completed regularly at the site, with no
positive cases reported during the entire program. These results
demonstrate the effectiveness of the Company’s COVID-19
protocols and helped to ensure that the extensive scope of the 2021
ISR Field Test was completed on schedule.
Groundwater Measurement and Sampling Procedures
Individual wells
are monitored and logged at five-minute intervals utilizing In-Situ
LevelTROLL 700 Data Logger transducers installed on cables below
the water table, providing water level, water pressure, and
temperature data based on factory calibrations. Manual water level
readings are recorded using a Heron Instruments Inc. water level
tape upon commencement and completion of each log. Flow rates and
cumulative flow volumes are measured ‘in-line’ on
injection and extraction hose lines and recorded at four-hour
minimum intervals, using Great Plains Industries Inc. FLOMEC
Turbine Stainless Steel Flowmeters calibrated to factory
specifications. Total dissolved solids (“TDS”)
measurements from individual wells are monitored and logged at
five-minute intervals utilizing In-Situ AquaTROLL 200 Data Logger
transducers installed on cables below the water table and in flow
cells on surface ‘in-line’ with the extraction hose
lines. The AquaTROLLs provide water level, water pressure,
temperature, and conductivity data based on factory
calibration.
TDS is calculated
from conductivity measurements via the AquaTROLLs based on factory
calibration formulas as well as field calibrations using standard
solutions of known conductivity. The data from LevelTROLL and
AquaTROLL transducers are downloaded using Win-Situ 5 software.
Manual field measurements of TDS, conductivity, pH, and dissolved
oxygen are taken from samples collected from extraction wellhead
sample ports, at 4 hour intervals during active testing, using an
YSI ProDSS Handheld Multiparameter Water Quality Meter. The Water
Quality Meter is field calibrated at a minimum of once per week,
based on manufacturer specifications, using solutions of known pH
and conductivity. Groundwater samples for lab analysis are
collected from wells following the Company’s standard
Groundwater Sampling Procedure for Wheeler River and are sent to
Saskatchewan Research Council ("SRC") Environmental Analytical
Laboratories located in Saskatoon. Samples are collected from the
sample port of the wellhead for extraction wells, during pumping of
MWs and after wells are purged. Quality control groundwater samples
for lab analysis included the collection of field duplicate and
field blank samples at a rate of 1 in 20, or a minimum of 1 per
month.
For a description
of the data verification, assay procedures and the quality
assurance program and quality control measures applied by Denison,
please see Denison's Annual Information Form dated March 26,
2021 filed under the Company's profile on SEDAR
at www.sedar.com.
About Phoenix Phase 1
As outlined in the Company's news release dated December 1, 2020,
Denison has decided to adapt its plans for the Project to use a
phased mining approach, which is expected to allow for the targeted
extraction of the least capital-intensive reserves first, based on
the grade and distribution of ore in various areas of the deposit.
The supporting trade-off study provides for mining to occur over 5
phases.
Phase 1 of the deposit is estimated to contain approximately 22.2
million pounds U3O8 (37,242 tonnes at
27.1% U3O8, above a cut-off
grade of 0.8% U3O8) in Probable
mineral reserves. Based on current designs, the Company estimates
approximately 6.6 million pounds U3O8 (7,717 tonnes at
39.2% U3O8, above a cut-off
grade of 0.8% U3O8) in Probable
mineral reserves are contained within the expected operating
perimeter of the CSWs in the Test Pattern (see Figure 1). These
estimates are derived as a direct subset of those reported in the
Technical Report titled "Pre-feasibility Study for the Wheeler
River Uranium Project, Saskatchewan, Canada" dated October 30, 2018
with an effective date of September 24, 2018. The key assumptions,
parameters and methods used to estimate the mineral reserves herein
remain unchanged.
About Wheeler River
Wheeler River is the largest undeveloped uranium project in the
infrastructure rich eastern portion of the Athabasca Basin region,
in northern Saskatchewan – including combined Indicated
Mineral Resources of 132.1 million pounds U3O8 (1,809,000 tonnes
at an average grade of 3.3% U3O8), plus combined
Inferred Mineral Resources of 3.0 million pounds U3O8 (82,000 tonnes at
an average grade of 1.7% U3O8). The project is
host to the high-grade Phoenix and Gryphon uranium deposits,
discovered by Denison in 2008 and 2014, respectively, and is a
joint venture between Denison (operator) and JCU (Canada)
Exploration Company Limited (“JCU”). Denison has an
effective 95% ownership interest in Wheeler River (90% directly,
and 5% indirectly through a 50% ownership in JCU).
A PFS was completed for Wheeler River in 2018, considering the
potential economic merit of developing the Phoenix deposit as an
ISR operation and the Gryphon deposit as a conventional underground
mining operation. Taken together, the project is estimated to have
mine production of 109.4 million pounds U3O8 over a 14-year
mine life, with a base case pre-tax NPV of $1.31 billion (8%
discount rate), Internal Rate of Return ("IRR") of 38.7%, and
initial pre-production capital expenditures of $322.5 million. The
Phoenix ISR operation is estimated to have a stand-alone base case
pre-tax NPV of $930.4 million (8% discount rate), IRR of 43.3%,
initial pre-production capital expenditures of $322.5 million, and
industry leading average operating costs of US$3.33/lb
U3O8.
The PFS is prepared on a project (100% ownership) and pre-tax
basis, as each of the partners to the Wheeler River Joint Venture
are subject to different tax and other obligations.
Further details regarding the PFS, including additional scientific
and technical information, as well as after-tax results
attributable to Denison's ownership interest, are described in
greater detail in the NI 43-101 Technical Report titled
"Pre-feasibility Study for the Wheeler River Uranium Project,
Saskatchewan, Canada" dated October 30, 2018 with an effective date
of September 24, 2018. A copy of this report is available on
Denison's website and under its profile on SEDAR at www.sedar.com
and on EDGAR at www.sec.gov/edgar.shtml.
Denison suspended certain activities at Wheeler River during 2020,
including the EA process, which is on the critical path to
achieving the project development schedule outlined in the PFS.
While the EA process has resumed, the Company is not currently able
to estimate the impact to the project development schedule outlined
in the PFS, and users are cautioned against relying on the
estimates provided therein regarding the start of pre-production
activities in 2021 and first production in 2024.
About Denison
Denison is a uranium exploration and development company with
interests focused in the Athabasca Basin region of northern
Saskatchewan, Canada. In addition to its effective 95% interest in
the Wheeler River project, Denison's interests in the Athabasca
Basin include a 22.5% ownership interest in the McClean Lake joint
venture, which includes several uranium deposits and the McClean
Lake uranium mill that is contracted to process the ore from the
Cigar Lake mine under a toll milling agreement, plus a 25.17%
interest in the Midwest Main and Midwest A deposits, and a 66.90%
interest in the Tthe Heldeth Túé ("THT," formerly J Zone)
and Huskie deposits on the Waterbury Lake property. The Midwest
Main, Midwest A, THT and Huskie deposits are each located within 20
kilometres of the McClean Lake mill.
Through its 50% ownership of JCU, Denison holds additional
interests in various uranium project joint ventures in Canada,
including the Millennium project (JCU 30.099%), the Kiggavik
project (JCU 33.8123%) and Christie Lake (JCU 34.4508%).
Denison’s exploration portfolio includes further interests in
properties covering ~280,000 hectares in the Athabasca Basin
region.
Denison is also engaged in mine decommissioning and environmental
services through its Closed Mines group (formerly Denison
Environmental Services), which manages Denison's Elliot Lake
reclamation projects and provides post-closure mine care and
maintenance services to a variety of third-party
clients.
For more information, please contact
David Cates
(416) 979-1991 ext
362
President and Chief Executive
Officer
Shae Frosst
(416) 979-1991 ext
228
Investor
Relations
Follow Denison on
Twitter
@DenisonMinesCo
Qualified Persons
The disclosure of scientific or technical information related to
certain hydrogeological results and interpretations (including the
hydrogeological investigations carried out as part of the 2021 ISR
Field Test and associated analysis) contained in this release has
been reviewed and approved by Mr. David Bronkhorst, P.Eng,
Denison's Vice President, Operations and Mr. Andrew Yackulic, P.
Geo., Denison's Director, Exploration, who are Qualified Persons in
accordance with the requirements of NI 43-101.
Certain information contained in this news release constitutes
‘forward-looking information’, within the meaning of
the applicable United States and Canadian legislation, concerning
the business, operations and financial performance and condition of
Denison.
Generally, these forward-looking statements can be identified by
the use of forward-looking terminology such as ‘plans’,
‘expects’, ‘budget’,
‘scheduled’, ‘estimates’,
‘forecasts’, ‘intends’,
‘anticipates’, or ‘believes’, or the
negatives and/or variations of such words and phrases, or state
that certain actions, events or results ‘may’,
‘could’, ‘would’, ‘might’ or
‘will be taken’, ‘occur’, ‘be
achieved’ or ‘has the potential to’.
In particular, this news release contains forward-looking
information pertaining to the following: the interpretation of
results of the ISR field program, including expectations regarding
further de-risking of the ISR mining method; Denison’s
capitalization to enable further studies; the initiation of the FS
and the planned scope, elements, and objectives of the FS; other
evaluation activities, objectives and expectations, including the
permeameter analysis and the ongoing EA and related processes; the
results of the PFS and expectations with respect thereto, including
the mineral resource estimates and project designs disclosed
to-date and the ability to maintain or build upon such designs;
other development and expansion plans and objectives;
Denison’s COVID-19 and other health and safety protocols; and
expectations regarding its joint venture ownership interests and
the continuity of its agreements with its partners and third
parties.
Forward looking statements are based on the opinions and estimates
of management as of the date such statements are made, and they are
subject to known and unknown risks, uncertainties and other factors
that may cause the actual results, level of activity, performance
or achievements of Denison to be materially different from those
expressed or implied by such forward-looking statements. For
example, the modelling and assumptions upon which the work plans
are based may not be maintained after further testing or be
representative of actual conditions within the Phoenix deposit. In
addition, Denison may decide or otherwise be required to
discontinue its field test activities or other testing, evaluation
and development work at Wheeler River if it is unable to maintain
or otherwise secure the necessary resources (such as testing
facilities, capital funding, regulatory approvals, etc.) or
operations are otherwise affected by COVID-19 and its potentially
far-reaching impacts. Denison believes that the expectations
reflected in this forward-looking information are reasonable but no
assurance can be given that these expectations will prove to be
accurate and results may differ materially from those anticipated
in this forward-looking information. For a discussion in respect of
risks and other factors that could influence forward-looking
events, please refer to the factors discussed in Denison’s
Annual Information Form dated March 26, 2021 or subsequent
quarterly financial reports under the heading ‘Risk
Factors’. These factors are not, and should not be construed
as being exhaustive.
Accordingly, readers should not place undue reliance on
forward-looking statements. The forward-looking information
contained in this news release is expressly qualified by this
cautionary statement. Any forward-looking information and the
assumptions made with respect thereto speaks only as of the date of
this news release. Denison does not undertake any obligation to
publicly update or revise any forward-looking information after the
date of this news release to conform such information to actual
results or to changes in Denison's expectations except as otherwise
required by applicable legislation.
Cautionary Note to United States
Investors Concerning Estimates of Mineral Resources and Mineral
Reserves: This press release may use terms such as
“measured”, “indicated” and/or
“inferred” mineral resources and “proven”
or “probable” mineral reserves, which are terms defined
with reference to the guidelines set out in the Canadian Institute
of Mining, Metallurgy and Petroleum (“CIM”) CIM
Definition Standards on Mineral Resources and Mineral Reserves
(“CIM Standards”). The Company’s descriptions of
its projects using CIM Standards may not be comparable to similar
information made public by U.S. companies subject to the reporting
and disclosure requirements under the United States federal
securities laws and the rules and regulations thereunder. . United
States investors are cautioned not to assume that all or any part
of measured or indicated mineral resources will ever be converted
into mineral reserves. United States investors are also cautioned
not to assume that all or any part of an inferred mineral resource
exists, or is economically or legally mineable.
Figure 1: Plan Map Showing Location of Phoenix Deposit (Phase 1)
– ISR Test Pattern
Figure 2: Cross Section Showing Location of Test Pattern Wells at
Phase 1