NioCorp Project to Expand Production to 8 Made-in-USA Critical Minerals Over a 40-Year Mine Life with an Estimated $4.1 Billion Pre-Tax NPV8%

• New Feasibility Study Shows Project Economics Including an Average Annual EBITDA² of $608 Million, Life-of-Mine Revenue of $37.4 Billion with a Pre-Tax NPV_8% of $4.1 Billion (After-Tax NPV8% of $3.4 Billion) and Pre-Tax IRR of 24% (After-Tax IRR of 22.8%)

• Expanded Product Mix is Expected to Generate Revenue of $815/Ton of Ore Against Average Operating Costs of $255/Ton, Creating a More Robust and Diversified Revenue Profile

• Proven and Probable Mineral Reserves of 45.9 Million Tons Support a 40-Year Operating Mine Life, with Additional Mineral Resources Providing Potential for Future Expansion

• NioCorp's Integrated Mine and Processing Plant in Nebraska Expected to Reduce U.S. Import Reliance on Eight Different Imported Critical Minerals: Ferroniobium, Scandium Trioxide, Titanium Tetrachloride, Terbium Oxide, Dysprosium Oxide, NdPr Oxide, SEG Carbonate, and Heavy Rare Earth Carbonate

• Diversified Revenue Stream Expected to Reduce NioCorp's Exposure to Market Concentration, Export Controls, and Pricing Volatility Associated with China-Dominated Supply Chains

• Upfront Capital Estimate of $1.85 Billion Reflects a Substantially Redesigned Processing Plant and Mining Operation Producing Eight Critical Minerals and Significant Inflationary Impacts Since the Previous Feasibility Study

• Completion of NioCorp's Feasibility Study Will Satisfy a Key U.S. Export-Import ("EXIM") Bank Due Diligence Requirement; Company Now Expects to Advance to the Next Step of Detailed Engineering and Engineering, Procurement and Construction ("EPC") Contracting

• NioCorp to Host Live Investor Webcast on Tuesday, August 11 at 10:00 AM ET. Register Here to Participate.

CENTENNIAL, CO / ACCESS Newswire / August 10, 2026 / NioCorp Developments Ltd. ("NioCorp" or the "Company") (NASDAQ:NB) is pleased to report the results of an updated Feasibility Study (the "2026 Feasibility Study") for its Elk Creek Critical Minerals Project (the "Elk Creek Project") outlining the project's evolution into a 40-year, integrated U.S. operation with a Net Present Value exceeding $4 billion that is expected to produce eight critical-mineral products from a single ore body.

The 2026 Feasibility Study estimates a pre-tax net present value at an 8% discount ("NPV_8%") of $4.1 billion, an after-tax NPV_8% of $3.4 billion, a pre-tax Internal Rate of Return ("IRR") of 24% and an after-tax IRR of 22.8%. Over the projected mine life, the Elk Creek Project is projected to generate approximately $37.4 billion in life-of-mine ("LoM") revenue, $608 million in average annual EBITDA², and $519 million in average annual operating cash flow.

The Elk Creek Project is expected to produce eight products, all designated by the U.S. Government as critical minerals: ferroniobium ("FeNb"), scandium trioxide ("Sc₂O₃"), titanium tetrachloride ("TiCl₄"), and several rare earth oxide products, including neodymium-praseodymium oxide ("NdPr"), dysprosium oxide ("Dy") and terbium oxide ("Tb"), samarium-europium-gadolinium ("SEG") carbonate, and heavy rare earth carbonate. This expanded product suite creates a more diversified revenue profile while positioning the Elk Creek Project to serve multiple U.S. critical-mineral and defense supply chains from an integrated mine and processing facility that has secured its major construction-related permits.

A technical report summarizing the 2026 Feasibility Study (the "2026 Technical Report") was prepared in accordance with National Instrument 43-101 - Standards of Disclosure for Mineral Projects ("NI 43-101") for the Company by Dahrouge Geological Consulting Ltd. and the other Qualified Persons and has been filed on SEDAR+. The 2026 Technical Report can be accessed here.

"Our 2026 Feasibility Study transforms the Elk Creek Project into the kind of critical minerals project the United States needs to have online as soon as possible," said Mark A. Smith, CEO and Executive Chairman of NioCorp. "Few critical minerals projects in the U.S. can match the Elk Creek Project's combination of a 40-year mine life, all major construction-related permits already in hand, and the planned production of eight critical mineral products from a single ore body."

"The United States is heavily reliant on imports for every single one of the products that NioCorp plans to manufacture," Mr. Smith said. "NioCorp offers an American-made solution: secure, long-term domestic production of materials essential to national defense, advanced manufacturing, energy resilience, and the technologies that will power the U.S. economy for decades to come."

"For NioCorp, this feasibility study delivers a larger, stronger, and more highly de-risked project," he added. "Eight products give us access to more markets, create multiple and highly diversified revenue streams, and reduce our exposure to the price of any one critical mineral. Combined with stronger economics and a 40-year mine life, we are now in a much stronger position to advance detailed engineering and project financing. Our job now is to turn this highly unique and important opportunity in Nebraska into a new source of American jobs, industrial strength, and critical mineral security right here at home."

A Diversified, Long-Life, Eight-Product Operation

The 2026 Feasibility Study's updated economics incorporate the expanded product offering, revised mine and processing design, an updated Mineral Resource and Mineral Reserve and current capital and operating cost estimates. Key economic results are summarized in Table 1 below.

Table 1: Highlighted 2026 Elk Creek Project Feasibility Study Economic Results

A Diversified Domestic Source of Critical Minerals in a Bifurcated Market

The addition of five rare-earth products materially changes the Elk Creek Project's revenue profile. Based on the 2026 Feasibility Study assumptions, no single product category is expected to account for more than 39% of revenue. This broader product mix gives the Elk Creek Project exposure to multiple critical-mineral markets, reduces its dependence on the pricing of any one product, and provides greater resilience against volatility or disruption in any single market.

Figure 1: Gross Revenue Breakdown (2022 Feasibility Study vs. 2026 Feasibility Study)

Figure 2: Gross Revenue, OPEX, and Gross Margin per Ton (2022 Feasibility Study vs. 2026 Feasibility Study)

The markets and pricing for scandium and the rare-earth products to be produced at the Elk Creek Project have become increasingly bifurcated between China and the rest of the world. China dominates global production and processing of these materials, but export restrictions on scandium and several heavy rare earths have constrained the availability of Chinese material to customers outside the country, contributing to materially higher prices in non-China markets. At the same time, demand is expanding across several high-growth sectors. For example, scandium is used in solid oxide fuel cells, which are increasingly being deployed to provide reliable, on-site power for energy-intensive artificial intelligence data centers, while neodymium, praseodymium, dysprosium and terbium are essential to the high-performance permanent magnets used in critical defense systems, electric vehicles, advanced automation, and robotics. Because the Elk Creek Project is expected to produce these materials in the United States for customers seeking a secure supply outside China, the economic model prepared for the 2026 Feasibility Study reflects pricing in the non-China markets that the Elk Creek Project is designed to serve.

Such pricing projections are based on assumptions and are subject to various risks described in the 2026 Technical Report, including, but not limited to, risks that anticipated demand drivers for scandium relating to artificial intelligence are not sustainable, international trade restrictions resulting in pricing bifurcation between China and the rest of the world relax, or that supply of such products increases from other sources.

Refined Mineral Processing Strategy Features Substantial Upgrades and Improvements

The 2026 Feasibility Study incorporates 12 years of engineering, metallurgical testing and mine-planning work across the Elk Creek Project. The updated design improves processing efficiency and yield, reduces reagent requirements, simplifies access to the underground mine, and supports greater electrification of the project's operations.

The redesigned production process adds calcination and ammonium chloride leaching ahead of the acid-leach stage, removing a substantial portion of acid-consuming species in the ore ahead of the introduction of mineral acid and thus reducing reagent consumption throughout the circuit. The updated design also eliminates the dedicated sulfuric acid plant contemplated in the 2022 Feasibility Study and instead uses on-site acid neutralization for sulfuric acid and hydrochloric acid regeneration to recover and reuse reagents.

Ongoing construction of the mine portal is establishing the future access point to the Elk Creek Project underground operations. From the mine portal, twin ramps will provide access from the surface to the ore body, replacing the twin shafts contemplated in the 2022 Feasibility Study and enabling the use of the Railveyor™ system for ore movement and electric underground haulage. NioCorp also plans to develop an on-site, behind-the-meter microgrid to supply a majority of the Elk Creek Project's electricity, eliminating reliance on the regional grid, and providing a reliable source of power over the operating life. Together, these changes are expected to improve project execution and operating efficiency.

Figure 3: 2026 Elk Creek Project Underground Mine Design (Cross Section View)

Updated Mineral Reserves Support a Long-Life Operation

The 2026 Feasibility Study establishes a larger and higher-confidence Mineral Reserve that supports a long-life operation at Elk Creek. As of April 2, 2026, the Elk Creek Mineral Reserve totals 45.9 million tons, comprising 7.6 million tons of Proven and 38.4 million tons of Probable Mineral Reserves. The 2026 estimate introduces a Proven Mineral Reserve for the first time, and for the first time includes rare earth elements in the Reserve, supporting the project's expanded suite of eight critical mineral products. The Reserve now supports a mine life of 40 years.

Table 2: Underground Mineral Reserves Estimate for Elk Creek, Effective Date April 2, 2026

See accompanying notes to this table in the Appendix of this press release.

The updated 2026 Mineral Resource estimate introduces a Measured category of 21.7 million tons, reports Indicated Mineral Resources of 187.4 million tons, and reports Inferred Mineral Resources of 169.2 million tons. The growth in the Mineral Resource, driven by additional drilling completed in 2025, suggests exploration and expansion potential that is not included in the current mine plan or economic analysis.

Table 3: Elk Creek Mineral Resource Estimate - Effective January 9, 2026

See accompanying notes to this table in the Appendix of this press release.

Potential for EXIM Financing Support

NioCorp continues to work with EXIM to advance the Elk Creek Project through EXIM's due diligence and loan application process. The completion of the 2026 Feasibility Study satisfies a key EXIM due diligence requirement reflected in the preliminary project letter that the Company received from EXIM in April 2024 (the "PPL"), and the Company now expects to advance to the next steps of the process relating to detailed engineering, procurement and construction contracting. The PPL included an indicative term sheet, which left open the total estimated amount of EXIM bank support and provided that the amount of EXIM financing that could be made available for the Elk Creek Project will be scaled based on the number of U.S. jobs supported, both during construction and over the life of EXIM's financing, subject to certain expectations regarding the ratio of debt-to-equity financing for the Elk Creek Project. The Company believes that the updated 2026 Feasibility Study, with its updated economic model, Mineral Resource and Mineral Reserve estimates, and increased job creation projections, demonstrates that the Elk Creek Project satisfies the criteria for increased EXIM financing as contemplated by the PPL. However, NioCorp is currently unable to estimate the total amount of EXIM financing, if any, as well as how long the application process, including additional project activities identified by EXIM, may take, and there can be no assurances that NioCorp will be able to successfully negotiate a final commitment of debt financing from EXIM, on acceptable terms, or at all.

TECHNICAL REPORT AND QUALIFIED PERSONS

The following 15 independent experts, each a Qualified Person as defined by NI 43-101, have reviewed, and approved the scientific and technical information and verified the data contained in this press release, which are derived from the 2026 Feasibility Study:

• Jacob Anderson, CPG, MAusIMM, Resource Geologist, Dahrouge Geological Consulting Ltd.

• Trevor Mills, P.G., SME-RM, Principal Geologist, Dahrouge Geological Consulting Ltd.

• Gareth Flitton, CPG, Pr.Sci. Nat, Mining Geologist, Dahrouge Geological Consulting Ltd.

• Eric Larochelle, B.Eng., SMH Process Innovation

• Anthony (Tony) Linton, FEC, P.Eng., IntPE (Canada), Director, Engineering & Technical Services, Dumas Contracting USA Inc.

• Scott G. Britton, P.E., Amplify Mine Planning

• Troy Meyer, P.E., Chief Geotechnical Quality Engineer, BBA Consultants International LP, Tierra Group/BBA (formerly Tierra Group International, Ltd.)

• Jason Byler, P.E., Olsson

• Adrian Brown, P.E., President, Adrian Brown Consultants, Inc.

• Patrick Andrieux, Ph.D., P.Eng., (ON, NT/NU), Eng. (QC), Principal Engineer, Andrieux & Associates Geomechanics Consulting, L.P.

• David Winters, S.E., P.E., MBA, Senior Principal Engineer, Tetra Tech

• Deepak Malhotra, Ph.D., SME (RM), DM Consulting

• Sylvain Harton, P.Eng., President, Metallurgy Concept Solutions

• Georgi Doundarov, M.Sc., P.Eng., PMP, CCP, CEO, Magemi Mining Inc.

• B. Ting, P. Eng., MASc., T Engineering

Readers are encouraged to read the 2026 Technical Report in its entirety, including all qualifications, assumptions and exclusions that relate to the Mineral Reserve and Mineral Resource declaration. The 2026 Technical Report is intended to be read as a whole, and sections should not be read or relied upon out of context. The Mineral Resource statement for the Elk Creek Project included in this press release was prepared by Jacob Anderson, CPG, MAusIMM, Resource Geologist, Dahrouge Geological Consulting Ltd. The Mineral Reserve statement for the Elk Creek Project included in this press release was prepared under the supervision of Scott G. Britton, P.E, Amplify Mine Planning.

# # #

FOR MORE INFORMATION:

Jim Sims, Chief Communications Officer, NioCorp Developments Ltd., (720) 334-7066, jim.sims@niocorp.com

Alex Guthrie, Director, Investor Relations, NioCorp Developments Ltd., (647) 999-0527, aguthrie@niocorp.com

@NioCorp $NB #Niobium #Scandium #rareearth #neodymium #dysprosium #terbium #ElkCreek

ABOUT NIOCORP

NioCorp is developing the Elk Creek Project that is expected to produce niobium, scandium, and titanium and several rare earth products. Niobium is used to produce specialty alloys as well as High Strength, Low Alloy steel, which is a lighter, stronger steel used in automotive, structural, and pipeline applications. Scandium is a specialty metal that can be combined with Aluminum to make alloys with increased strength and improved corrosion resistance. Scandium is also a critical component of advanced solid oxide fuel cells. Titanium is used in various lightweight alloys and is a key component of pigments used in paper, paint and plastics and is also used for aerospace applications, armor, and medical implants. Magnetic rare earths, such as neodymium, praseodymium, terbium, and dysprosium are critical to the making of neodymium-iron-boron magnets, which are used across a wide variety of defense and civilian applications.

About Dahrouge Geological Consulting Ltd.

Dahrouge Geological Consulting Ltd. (DGC Canada), and its subsidiary, Dahrouge Geological Consulting USA Ltd. (DGC USA), advise and assist clients in identifying, exploring, and developing mineral projects. DGC manages projects of all scopes from grassroots exploration and resource delineation to pre-feasibility and feasibility level studies. Experienced project teams plan mineral projects based upon client needs, provide a detailed review of approach, and execute programs following industry-standard best practices.

FORWARD-LOOKING STATEMENTS

This press release contains forward-looking statements within the meaning of the United States Private Securities Litigation Reform Act of 1995 and forward-looking information within the meaning of applicable Canadian securities laws (collectively "forward-looking statements"). Forward-looking statements may include, but are not limited to, statements related to the expected economics for the Elk Creek Project, including NPV, IRR, payback period, CAPEX, gross revenue, gross margin, EBITDA, operating cost and effective tax rate; future commodity price volatility and any possible reductions thereto; NioCorp's expectation that the Elk Creek Project will have over a 40-year mine life; statements regarding NioCorp's Mineral Resource and Mineral Reserve estimates; NioCorp's expectations related to the development timeline of 35 months; statements related to potential future expansion of the Elk Creek Project; NioCorp's expectation that the integrated mine and processing plan will reduce U.S. import reliance; effects on and benefits to the U.S. derived from NioCorp's future operations; NioCorp's expectation that a diversified revenue stream will reduce exposure to market concentration, export controls and pricing volatility associated with China-dominated supply chains; statements related to expected pricing for niobium, scandium, titanium and the rare earth products; statements regarding NioCorp's debt financing application process with EXIM; NioCorp's expectation of producing niobium, scandium, titanium and the rare earth products at the Elk Creek Project, including estimated production totals; NioCorp's confidence in and ability to secure sufficient project financing to complete construction of the Elk Creek Project and move it to commercial operation, as well as efforts and expenditures relating to the same; statements that demand for niobium, scandium, titanium and the rare earth products is expanding across several high-growth sectors; statements that NioCorp expects to produce its products in the United States; statements related to the expected design of the mine, including the mine portal, Railveyor™ system and behind-the-meter microgrid for electricity, as well as the expectation that these will improve project execution and operating efficiency; and trends in global geopolitics and their effects on NioCorp's operations. Forward-looking statements are typically identified by words such as "plan," "believe," "expect," "anticipate," "intend," "outlook," "estimate," "forecast," "project," "continue," "could," "may," "might," "possible," "potential," "predict," "should," "would" and other similar words and expressions, but the absence of these words does not mean that a statement is not forward-looking.

The forward-looking statements are based on the current expectations of the management of NioCorp and are inherently subject to uncertainties and changes in circumstances and their potential effects and speak only as of the date of such statement. There can be no assurance that future developments will be those that have been anticipated. Forward-looking statements reflect material expectations and assumptions, including, without limitation, expectations and assumptions relating to: NioCorp's ability to receive sufficient project financing for the construction of the Elk Creek Project on acceptable terms, or at all; the future price of and demand for metals, including Al-Sc alloy; the impact that Chinese restrictions have on pricing and demand, including the existence of a bifurcated market between China and the rest of the world; and the stability of the financial and capital markets. Such expectations and assumptions are inherently subject to uncertainties and contingencies regarding future events and, as such, are subject to change. Forward-looking statements involve a number of risks, uncertainties or other factors that may cause actual results or performance to be materially different from those expressed or implied by these forward-looking statements. These risks and uncertainties include, but are not limited to, those discussed and identified in public filings made by NioCorp with the Securities and Exchange Commission and with the applicable Canadian securities regulatory auth