Peaks up to 4,400 cps are the highest radioactivity to date on the PLN Project outside the JR and Tetra Zones

F3 Uranium Corp. (TSX-V: FUU) (OTCQB: FUUFF) is pleased to provide an update on three drill holes completed as part of its 2026 summer exploration program at the 100% owned Patterson Lake North Project in the Western Athabasca Basin. The three holes are located between 1 km to 1.6 km to the east, southeast and south of the Tetra Zone “Tetra” discovery on the Broach Lake property (see Map 1). While all three holes intersected hydrothermal alteration associated with the Athabasca Unconformity, hole PLN26-232 encountered several discrete intervals of anomalous radioactivity, with a peak of 4,400 cps from 610.5m to 611.0m alongside broad intervals of intermittently moderate to strong alteration within the basement lithology. The radioactivity in PLN26-232 is the highest recorded on a handheld spectrometer to date on the PLN Project in an exploration hole outside the JR and Tetra Zones.

Highlights

• PLN26-232 intersected five discrete intervals of radioactivity ranging from 0.5m to 1.0m each, between 352.0m and 649.5m depth, with a peak radioactivity of 4,400 cps at 610.5m to 611.0m in strongly altered basement lithology
• A 2^nd drill rig will be added to the program, dedicated to following up the results of PLN26-232

Ray Ashley, P.Geo., President and VP Exploration, commented:

“This is an encouraging progression from the strong alteration intersected in PLN26-229, with follow-up drill hole PLN26-232 now intersecting more extensive basement bleaching and clay alteration and now for the first time in a 1km stepout to the east from the Tetra Zone, associated anomalous radioactivity, with a maximum of 4400 cps. This radioactivity is the highest handheld spectrometer reading intersected to date in an exploration hole on the PLN Project outside of the JR and Tetra Zones. In addition, with drill hole PLN26-232 being located approximately one kilometer east of Tetra, the combination of radioactivity and widespread visually comparable alteration in the hole supports the potential for a larger system in the Broach area and strengthens our confidence in the surrounding exploration target areas and interpretation of a mineralized trend that could strike east north-east from Tetra Zone. Driven by these encouraging results, the Company is expanding its drilling capacity with the addition of a second diamond drill rig for the remainder of the year, reinforcing the momentum of its ongoing exploration campaign. The 2nd drill will allow for the follow-up drill testing around PLN26-232 as we continue testing other regional targets on the Broach Property.”

Details of Drill Holes PLN26-230, 231A and 232

Holes PLN25-230, 231A and 232 are located approximately 1,600m south, 1,300m southeast and 1,000m east of the Tetra Zone discovery, respectively. (See Map 1).

Hole PLN26-232 was drilled approximately 1 km east of the Tetra Zone discovery, testing Target Area 1, as a follow-up of prospective alteration observed in hole PLN26-229 (See Map 1 and news release dated August 25, 2026). PLN26-232 intersected strong bleaching and clay alteration throughout the basement rocks, as well as five distinct intervals of anomalous radioactivity. These included a 1.0 m interval from 610.5 to 611.5 m, with a peak handheld reading of 4,400 cps recorded between 610.5 to 611.0 m: the highest radioactivity on a handheld spectrometer recorded to date on the PLN Project in an exploration hole outside the JR and Tetra Zones (see Photo 1 below). Assay results for PLN26-232 are pending.

Holes PLN26-230 and PLN26-231A tested modelled electromagnetic “(EM)” conductors and gravity-low anomalies in Broach Target Area 2. Both holes encountered strong alteration near the unconformity but no radioactivity above 300 cps.

Table 1. Drill Hole Summary and Handheld Spectrometer Results

Handheld spectrometer composite parameters:
1: Minimum Thickness of 0.5m
2: CPS Cut-Off of 300 counts per second
3: Maximum Internal Dilution of 2.0m

 Map 1. Broach Property — Summer 2026 Drill Holes 

 Photo 1. Basement Alteration and Radioactivity in PLN26-232

Winter 2026 Drilling Geochem:

The Company also reports assay and geochemical results from its approximately 3,350 m winter 2026 drill program, which tested extensions of the Tetra Zone along strike and down plunge. PLN26-225 returned 0.5 m at 0.06% U₃O₈ from 418.5 to 419.0m, while the other completed holes returned no uranium assay intervals meeting the reporting criteria summarized below. PLN26-225 tested approximately 40 m down plunge of PLN25-217 and intersected a narrow uranium-bearing interval. Previously reported results from PLN25-217 included 3.5 m at 0.30% U₃O₈ from 400.0 to 403.5 m, including 0.5 m at 1.04% U₃O₈ (see news release dated December 15, 2025).

Table 2. Winter 2026 Drill Hole Summary and Uranium Assay Results:

Assay composite parameters:
1: Minimum Thickness of 0.5 m
2: Assay Grade Cut-Off: 0.05% U3O8 (weight %)
3. Maximum Internal Dilution: 2.0 m

The natural gamma radiation detected in the drill core, as detailed in this news release, was measured in counts per second (cps) using a handheld Radiation Solutions RS-125 spectrometer which has been calibrated by Radiation Solutions Inc. The Company designates readings exceeding 300 cps on the handheld spectrometer (occasionally referred to as a scintillometer in industry terminology; this stems from historical naming conventions and the shared functionality of detecting gamma radiation between a spectrometer and a scintillometer) as “anomalous”, readings above 10,000 cps as “highly radioactive”, and readings surpassing 65,535 cps as “off scale”.

Readers are cautioned that handheld spectrometer (scintillometer) readings are preliminary in nature, are not directly or consistently correlated to uranium grades determined by chemical assay and should not be relied upon as a substitute for analytical results. All radiometric readings are subject to confirmation by laboratory assay.

Samples from the drill core are split into half sections on site. Where possible, samples are standardized at 0.5 m downhole intervals. One-half of the split sample is sent to an independent laboratory SRC Geoanalytical Laboratories (an SCC ISO/IEC 17025: 2005 Accredited Facility) in Saskatoon, SK, while the other half remains on site for reference. Analysis includes a 63-element suite including boron by ICP-OES, uranium by ICP-MS and gold analysis by ICP-OES and/or AAS.

The Company considers uranium mineralization with assay results of greater than 1.0 weight % U₃O₈ as “high grade” and results greater than 20.0 weight % U₃O₈ as “ultra-high grade”.

All depth measurements reported are downhole and true thicknesses are yet to be determined.

About the Patterson Lake North Project:

The Company’s 42,960-hectare 100% owned Patterson Lake North Project (PLN) is located just within the south-western edge of the Athabasca Basin in proximity to Paladin’s Triple R and NexGen Energy’s Arrow high-grade uranium deposits, an area poised to become the next major area of development for new uranium operations in northern Saskatchewan. The PLN Project consists of the 4,074-hectare Patterson Lake North Property hosting the JR Zone uranium discovery approximately 23 km northwest of Paladin’s Triple R deposit, the 19,864-hectare Minto Property, and the 19,022-hectare Broach Property hosting the Tetra Zone, F3’s newest discovery 13 km south of the JR Zone. All three properties comprising the PLN Project are accessed by Provincial Highway 955.

Qualified Person:

The technical information in this news release has been prepared in accordance with the Canadian regulatory requirements set out in National Instrument 43-101 and approved on behalf of the Company by Raymond Ashley, P.Geo., President & VP Exploration of F3 Uranium Corp., a Qualified Person as defined by National Instrument 43-101. Mr. Ashley is not independent of the Company. Mr. Ashley has reviewed and approved the technical information disclosed in this news release.

This news release also refers to neighbouring properties in which F3 Uranium has no interest, and the Qualified Person has been unable to verify the information from those properties. Mineralization on those neighbouring properties is not necessarily indicative of mineralization on the PLN Project.

For additional information on the PLN Project, including the current mineral resource estimate for F3 Uranium’s JR Zone uranium deposit, please refer to the report titled “NI 43-101 Technical Report, Patterson Lake North Project, Northern Saskatchewan, Canada” dated January 20, 2026, available at www.sedarplus.ca.

About F3 Uranium Corp.:

F3 is a uranium exploration company, focusing on the high-grade JR Zone and new Tetra Zone discovery 13 km to the south in the Patterson West area on its Patterson Lake North (PLN) Project in the Western Athabasca Basin. F3 currently has three properties in the Athabasca Basin: Patterson Lake North, Minto, and Broach. The western side of the Athabasca Basin, Saskatchewan, is home to some of the world’s largest high-grade uranium deposits including Paladin’s Triple R project and NexGen’s Arrow project.