F3 Uranium Reports Initial Mineral Resource Estimate for JR Zone Deposit

• Indicated Mineral Resource totals 11.8 million pounds U3O8 at 4.39% grade across 121,259 tonnes at the JR Zone deposit
• High-grade domain contains 10.8 million pounds at 12.23% U3O8 grade across 39,997 tonnes
• Resource estimate based on 89 drill holes totalling 29,414 metres, with estimated 97% metallurgical recovery
• Company holds $26.1 million in treasury as of 18 December 2025
• Exploration focus shifting to Tetra Zone discovery, located 13 kilometres from JR Zone

F3 Uranium Corp. (TSX-V: FUU) is a uranium exploration company operating in Saskatchewan's Athabasca Basin. The company holds a 100% interest in the 44,613-hectare Patterson Lake North (PLN) Project, which comprises three properties: the 4,074-hectare Patterson Lake North Property containing the JR Zone deposit, the 20,675-hectare Minto Property, and the 19,022-hectare Broach Property where the Tetra Zone is located. The PLN Project is positioned near Paladin Energy's Triple R deposit and NexGen Energy's Arrow deposit. All three properties are accessible via Provincial Highway 955.

Initial Indicated Mineral Resource Estimate and High-Grade Domain

F3 Uranium has reported its initial resource estimate for the JR Zone uranium deposit, establishing an Indicated Mineral Resource of 11.8 million pounds of U3O8 at 4.39% grade across 121,259 tonnes. The estimate uses a cut-off grade of 0.255% U3O8 and assumes a 97% metallurgical recovery rate. The resource is entirely classified as Indicated, based on basement-hosted shear zone mineralisation.

The resource estimate identifies a high-grade domain containing 10.8 million pounds at 12.23% U3O8 within 39,997 tonnes. This domain accounts for approximately 91% of total resource pounds in roughly one-third of the tonnage. The high-grade material is contained within a broader mineralised envelope of 81,262 tonnes grading 0.57% U3O8, which holds an additional 1.0 million pounds.

The resource calculation uses a uranium price assumption of $90 per pound.

Raymond Ashley, President and Chief Operating Officer, stated:

"With the JR Zone resource definition phase now successfully concluded, the company will turn its attention to the recently-discovered Tetra Zone, just 13km from JR Zone. This high grade Indicated resource, in combination with the potential of Tetra, sets an exciting stage for growth in the new year."

JR Zone Deposit Resource Classification and Estimation Methodology

SLR International Corporation prepared the resource estimate using data from 89 drill holes totalling 29,414 metres, available as of 15 October 2025. The methodology employed an unrotated, sub-blocked modelling approach with one-metre composited drill data. SLR constructed two mineralised domains: a low-grade envelope using a 0.1% U3O8 cut-off and a high-grade domain with a minimum threshold of 5.0% U3O8, with the high-grade domain contained within the low-grade envelope.

Grade estimation used the inverse distance squared interpolation method following statistical and spatial analysis. SLR determined that high-grade capping was not required, as the distribution of high-grade values does not materially distort overall grade estimates. A planar ellipsoid search strategy was applied to reflect the geometry of the mineralised zones during the estimation process.

Density values were derived from 505 bulk density measurements from drill core samples averaging 0.5 metres in length. These were composited to one-metre intervals, providing 109 composite samples in the high-grade domain and 396 in the low-grade domain. All blocks received Indicated classification based on drill spacing, geological confidence, and demonstrated mineralisation continuity. Potentially mineable shape volumes were generated using Deswik Stope Optimiser software to constrain Indicated blocks to volumes considered reasonable for underground extraction. The reported resources include internal dilution within these optimised shapes.

Future Exploration Plans Including Tetra Zone Development

F3 Uranium is directing exploration focus towards the Tetra Zone discovery, located 13 kilometres south of the JR Zone deposit on the Broach Property. The company identified Tetra as a priority target within its 44,613-hectare PLN Project land package. All properties within the project are accessible via Provincial Highway 955.

The company reported $26.1 million in treasury as of 18 December 2025. Raymond Ashley stated: "We are well funded to advance drilling programs through 2026 with $26.1 million in the treasury as of December 18, 2025." The PLN Project is located within the southwestern edge of the Athabasca Basin, near existing uranium deposits including Paladin's Triple R and NexGen's Arrow projects.

F3 plans to pursue additional targets across the PLN Project portfolio following the completion of the JR Zone resource definition phase. The company will apply exploration methods including drilling at the Tetra Zone and other prospects.

Mr. Ashley stated:

"The team will pursue additional high-impact targets across our extensive PLN land package, with a priority focus on Tetra."

Looking Ahead

F3 Uranium has completed its initial Indicated Mineral Resource estimate at the JR Zone deposit, totalling 11.8 million pounds of U3O8 with a high-grade core containing 10.8 million pounds. The company will file a National Instrument 43-101 compliant technical report on SEDAR within 45 days. With the JR Zone resource definition phase complete, the company is allocating resources towards the Tetra Zone discovery and other targets across the PLN Project. The company holds $26.1 million in treasury to fund its 2026 exploration programs.

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