Peninsula Energy Advances Lance Project with Mine Unit 4 Acidification Milestone

• Header House 14 within Mine Unit 4 has commenced acidification following regulatory approval from Wyoming Department of Environmental Quality
• Optimised wellfield design targets recovery of 80% of uranium within 13 to 14 months per header house
• Mine Unit 4 pump test flow rates exceed assumptions used in the August 2025 production reset plan
• Central Processing Plant pipework replacement with fibre-reinforced plastic scheduled for January 2026 completion
• Company maintains production guidance of 0.4 to 0.5 million pounds of uranium for calendar year 2026

Peninsula Energy Limited (ASX: PEN) is an Australian-based uranium mining company that operates the Lance Uranium Project in Wyoming, United States. The company restarted yellowcake production in September 2025 under a revised operational plan announced in August 2025, which includes low-pH operations, revised wellfield design and optimised production sequencing. Lance is one of the largest independent uranium projects in the United States.

Mine Unit 4 Acidification Commencement and Production Milestone

The Wyoming Department of Environmental Quality's Uranium Recovery Program has authorised Peninsula Energy to commence acidification at Header House 14. The acidification process is expected to continue for approximately three months, after which flows from this header house will be redirected to the Central Processing Plant for production. The process lowers the pH level to approximately 2 standard units to mobilise uranium from the ore zone.

Mine Unit 4 accounts for approximately 60% of the company's uranium production forecast for 2026 and 2027. The unit comprises six header houses, with Header House 16 construction nearing completion and acidification to commence in the coming weeks. Header House 15 construction is also advanced, with acidification expected during the March 2026 quarter following completion of Header House 14's acidification.

The development follows the acidification of wells for header houses 11 and 12 in Mine Unit 3, which were the first header houses developed for low-pH operations under the production reset plan implemented in August 2025.

Managing Director George Bauk stated:

"The commencement of acidification within Mine Unit 4 is a significant milestone to conclude the year. Mine Unit 4 incorporates the optimised wellfield design within a mining area that is demonstrating strong flow rates, which we expect to be representative of the broader Kendrick mining area."

Wellfield Design Optimisation and Flow Rate Improvements

Peninsula has implemented revised wellfield designs following a review conducted earlier in 2025. Under the revised design for Mine Unit 4, each header house consists of approximately 30 production wells, with 60-foot spacing between production and injection wells. The configuration is intended to reduce the time required to reach the targeted acidification pH level of approximately 2 standard units.

The revised design is expected to result in approximately 80% of recoverable uranium within each header house pattern being recovered within a 13 to 14-month period. This represents a change from the design used in Mine Unit 3, as part of the company's revised wellfield maintenance plans and optimised design patterns aimed at improving production rates.

Pump tests conducted within Mine Unit 4 for the wellfield data package submission to the Wyoming Department of Environmental Quality indicate that flow rates are expected to be significantly better than those experienced in Mine Unit 3. The pump test flow rates exceed the more conservative flow rate assumptions used in the reset plan announced on 22 August 2025. Managing Director George Bauk noted: "Mine Unit 4 continues to progress well, with three header houses expected to be in acidification over the coming months, after which the focus will shift to the remaining three header houses in this mine unit."

Central Processing Plant Commissioning Progress

The Central Processing Plant continues commissioning activities, with ongoing refinement of elution, precipitation, filtration and drying processes. The company is implementing a water purification system for process water, aimed at reducing sodium levels in the final dried yellowcake product.

Work is progressing on the replacement of corrosion-affected piping in Phase 1 of the Central Processing Plant, with materials received on site and installation crews commenced. The company has elected to replace the affected pipework with fibre-reinforced plastic material. This material has demonstrated performance at other facilities operating under acidic and corrosive conditions.

Installation of the permanent pipework solution is targeted for completion in January 2026, ahead of production flows from Header House 14 being directed to the Central Processing Plant. The timing aligns with the expected completion of the three-month acidification period at Header House 14.

Next Steps and Production Outlook

Peninsula Energy has outlined near-term development milestones for Mine Unit 4. Header House 16 acidification is scheduled to commence in the coming weeks following construction completion. Header House 15 acidification is expected to commence in the March 2026 quarter after Header House 14 completes its acidification cycle. Following these three header houses, the focus will shift to the remaining three header houses within Mine Unit 4.

The company maintains its forecast uranium production guidance for calendar year 2026 of 0.4 to 0.5 million pounds. Mine Unit 4 represents approximately 60% of the uranium production forecast for both 2026 and 2027 outlined in the reset plan.

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