Boss Energy Withdraws 2021 Feasibility Study, Eyes Cost Cuts with New Wellfield Design

Context and Review Outcome

Boss Energy Limited has announced a pivotal update on its Honeymoon uranium project, revealing that its 2021 Enhanced Feasibility Study (EFS) no longer reflects the current understanding of the deposit. The recently concluded Honeymoon Review identified material and significant deviations from the assumptions underpinning the EFS, primarily due to less continuity of higher-grade uranium mineralisation, non-overlapping mineral lenses, reduced leachability, and smaller wellfields than previously anticipated. These factors are expected to impact production and costs from fiscal year 2027 onwards.

As a result, Boss Energy has formally withdrawn the 2021 EFS, advising investors and stakeholders that it should no longer be relied upon for future operational guidance. This marks a significant recalibration in the company’s medium to long-term planning for Honeymoon.

New Feasibility Study and Wide-Spaced Wellfield Design

In response to these findings, Boss has initiated a New Feasibility Study centered on an alternative wide-spaced wellfield design concept. This design proposes wider spacing between injection and extraction wells, fewer pore volume exchanges, and longer lixiviant residence times. The anticipated benefits include lower capital and operating costs per pound of uranium produced, improved leachate grades, and the ability to economically extract lower-grade uranium mineralisation that was previously excluded.

The wide-spaced wellfield design is still at a conceptual stage, but initial technical observations suggest that the Honeymoon deposit’s characteristics, such as hydraulic connectivity, favourable mineralogy, and good permeability, make it amenable to this approach. Boss plans to provide an initial update in the first quarter of calendar year 2026, with a scoping study targeted for the second quarter and completion of the New Feasibility Study by the third quarter.

Organic Growth via Satellite Deposits

Beyond Honeymoon, Boss is advancing work programs to integrate its satellite deposits, Gould’s Dam and Jason’s Deposit, into the production profile. These deposits are believed to be well suited to the wide-spaced wellfield design, potentially enhancing recoverability and reducing costs. An updated resource model and development timeline for these deposits are expected in early 2026.

Financial Position and Near-Term Outlook

Boss Energy remains financially robust, with A$212 million in cash and liquid assets as of September 2025, enabling it to self-fund the New Feasibility Study and potential early development of satellite deposits. The company maintains its fiscal year 2026 production guidance of 1.6 million pounds of uranium drummed, with C1 cash costs between US$27-28 per pound and all-in sustaining costs (AISC) of US$41-45 per pound.

Looking ahead to fiscal year 2027, production and costs are expected to be broadly in line with 2026, though AISC may rise by approximately 15% due to a higher proportion of sustaining capital expenditure. This outlook remains subject to revision following the New Feasibility Study’s completion.

Technical and Operational Insights

The Honeymoon Review incorporated extensive delineation drilling, hydrogeological testing, and mineralogical analysis. Early results indicate that higher-grade mineralisation is more pod-like and less continuous than previously modeled, while lower-grade mineralisation is extensive but not captured by current wellfield designs. The wide-spaced wellfield concept aims to leverage longer lixiviant contact times and reduced reagent use to economically extract this lower-grade resource.

Boss’s technical team, including international experts in in-situ recovery (ISR) mining, is conducting accelerated work programs to validate the new design’s feasibility. Key milestones include completion of drilling programs, updated resource models, regulatory engagement, and financial modeling, all scheduled through 2026.