F3 - Hits 2.5m of 10.2% U3O8 Within 3.4% over 8.5m at JR Zone

Rhea-AI Summary

F3 Uranium (TSXV: FUU; OTCQB: FUUFF) released final assays from the 2025 JR Zone program. Key JR result: PLN25-200 — 8.5m @ 3.4% U3O8 (234.0–242.5m) including 2.5m @ 10.2% U3O8 and 1.0m @ 20.7% U3O8. At the Tetra Zone PLN25-217 returned a 3.5m composite averaging 0.30% U3O8 (400.0–403.5m) that includes 0.5m @ 1.04% U3O8, and a total of 26.5m of mineralization between 340.5–406.5m. A deep intercept PLN25-207 hit 0.06% U3O8 at 621.0–621.5m, interpreted as the same shear system ~200m from Tetra. All depths are down-hole; true thicknesses are yet to be determined.

Positive

• PLN25-200: 8.5m @ 3.4% U3O8 (234.0–242.5m)
• High-grade core: 2.5m @ 10.2% U3O8 within PLN25-200
• Ultra-high intercept: 1.0m @ 20.7% U3O8 in PLN25-200
• Tetra composite: 26.5m of mineralization between 340.5–406.5m
• PLN25-217 includes 0.5m @ 1.04% U3O8 ~55m along strike from discovery

Negative

• True thicknesses not determined, all reported as down-hole depths
• Multiple drill holes returned no mineralization above 0.05% U3O8, indicating variable continuity

Tetra Assays: 26.5m of mineralization including 1.04% over 0.5m

Kelowna, British Columbia--(Newsfile Corp. - December 15, 2025) - F3 Uranium Corp. (TSXV: FUU) (OTCQB: FUUFF) ("F3" or "the Company") is pleased to announce final assay results of the 2025 JR Zone drill program on the PLN Property including PLN25-200 (See NR March 18, 2025) which returned 8.5m of 3.4% U₃O₈, including a high grade core with 2.5m of 10.2% U₃O₈. At the Tetra Zone, assays confirm the presence of high grade uranium mineralization 55m along strike from discovery hole PLN25-205 with PLN25-217 returning a 0.5m high grade interval with 1.04% U₃O₈ within a 3.50m mineralized interval averaging 0.30% U₃O₈ from 400.0m to 403.5m. Total composite mineralization of 26.5m was intersected between 340.5 to 406.5m.

Exploration focused mainly on the area around Tetra Zone with PLN25-207 intersecting 0.06% U₃O₈ between 621.0 to 621.5m. This deep intersect is interpreted to be associated with the same shear system which hosts the Tetra Zone over 200m to the west.

Sam Hartmann, Vice President Exploration, Comment:

"We are pleased to release the final assays for JR Zone, where the last two holes for inclusion into the upcoming maiden resource estimate were completed earlier this spring. At the Tetra Zone, we are releasing the second batch of assays since the initial high grade discovery hole (PLN25-205) assays, including an interval with high grade mineralization with 1.04% over 0.5m, confirmation of additional high-grade uranium mineralization at the Tetra Zone, 55m along strike from the discovery hole. Exploration geochemistry around the Tetra Zone continues to return strongly anomalous uranium values with 0.06% U₃O₈ at depth in PLN25-217, approximately 200m away from Tetra Zone highlighting the prospectivity and size potential of the mineralized system."

PLN Property JR Zone Assay Highlights:
PLN25-200 (line 045S):

• 8.5m @ 3.4% U₃O₈ (234.0m to 242.5m), including
  • 2.5m @ 10.2% U₃O₈ (236.0m to 238.5m), further including
  • 1.0m @ 20.7% U₃O₈ (237.5m to 238.5m), and
• 5.5m @ 0.05% U₃O₈ (246.5m to 252.0m)

Broach Property Tetra Zone Assay Highlights:
PLN25-217 (line 11280S):

• 0.5m @ 0.06% U₃O₈ (340.5m to 341.0m), and
• 3.5m @ 0.07% U₃O₈ (355.0m to 358.5m), and
• 1.5m @ 0.05% U₃O₈ (361.5m to 363.0m), and
• 1.0m @ 0.07% U₃O₈ (365.0m to 366.0m), and
• 5.5m @ 0.19% U₃O₈ (369.5m to 375.0m), and
• 6.5m @ 0.14% U₃O₈ (377.5m to 384.0m), and
• 3.5m @ 0.41% U₃O₈ (388.5m to 392.0m), and
• 0.5m @ 0.11% U₃O₈ (395.5m to 396.0m), and
• 3.5m @ 0.30% U₃O₈ (400.0m to 403.5m), including
  • 0.5m @ 1.04% U₃O₈ (400.5m to 401.0m)
• 0.5m @ 0.07% U₃O₈ (406.0m to 406.5m), and

Table 1. Drill Hole Summary and Uranium Assay Results

Collar Information							Assay Results
Hole ID	Grid Line	Easting	Northing	Elevation	Az	Dip	From  (m)	To  (m)	Interval  (m)	U3O8  weight %
PLN24-195	4140S	590029	6407318	543	57	-61	B1 Exploration; no mineralization >0.05
PLN25-196	2835S	589265	6408368	538	54	-67	A1 Exploration; no mineralization >0.05
PLN25-197	030S	587776	6410760	546	55	-71	207.0	208.5	1.50	1.08
							211.0	211.5	0.50	0.07
PLN25-198	090S	587843	6410645	546	9	-65	215.5	223.0	7.50	0.26
						inc.	220.5	221.0	0.50	1.33
PLN25-199	010N	587693	6410748	545	55	-66	242.0	243.5	1.50	0.29
PLN25-200	045S	587731	6410712	545	53	-66	234.0	236.0	2.00	0.27
						inc.	236.0	238.5	2.50	10.2
						and	237.5	238.5	1.00	20.7
							238.5	242.5	4.00	0.76
							246.5	252.0	5.50	0.05
PLN25-201	12510S	590064	6397264	569	46	-70	PW Exploration; no mineralization >0.05
PLN25-202	11325S	589353	6397967	583	46	-63	PW Exploration; no mineralization >0.05
PLN25-203B	11340S	589229	6397842	587	48	-63	PW Exploration; no mineralization >0.05
PLN25-204	11295S	589389	6398003	583	47	-63	PW Exploration; no mineralization >0.05
PLN25-206	11325S	589315	6397929	584	48	-65	PW Exploration; no mineralization >0.05
PLN25-207	11505S	589481	6397809	587	46	-66	621.0	621.5	0.50	0.06
PLN25-208	11205S	589824	6398440	579	43	-70	PW Exploration; no mineralization >0.05
PLN25-209	11280S	589344	6398000	583	44	-70	PW Exploration; no mineralization >0.05
PLN25-209A	11280S	589343	6397999	583	47	-71	PW Exploration; no mineralization >0.05
PLN25-210	11280S	589341	6397997	583	47	-73	357.0	357.5	0.50	0.18
							364.0	364.5	0.50	0.13
							369.5	370.0	0.50	0.06
							382.5	383.0	0.50	0.08
							388.5	394.5	6.00	0.14
PLN25-211	11340S	589409	6397962	586	46	-75	PW Exploration; no mineralization >0.05
PLN25-212	11310S	589368	6397970	584	40	-72	364.0	375.0	11.00	0.10
							378.0	388.0	10.00	0.12
							394.0	400.0	6.00	0.12
PLN25-213	11325S	589359	6397959	584	46	-73	Pilot hole for wedged hole below
PLN25-213W1	11325S	589359	6397959	584	46	-73	279.0	279.5	0.50	0.08
							326.0	326.5	0.50	0.07
PLN25-214	11340S	589404	6397978	584	46	-75	PW Exploration; no mineralization >0.05
PLN25-215	090S	587849	6410603	546	348	-59	249.5	250.0	0.50	0.08
PLN25-216	075S	587778	6410712	546	55	-64	211.5	212.0	0.50	0.12
PLN25-217	11280S	589393	6398026	584	34	-85	340.5	341.0	0.50	0.06
							355.0	358.5	3.50	0.07
							361.5	363.0	1.50	0.05
							365.0	366.0	1.00	0.07
							369.5	375.0	5.50	0.19
							377.5	384.0	6.50	0.14
							388.5	392.0	3.50	0.41
							395.5	396.0	0.50	0.11
							400.0	403.5	3.50	0.30
						inc.	400.5	401.0	0.50	1.04
							406.0	406.5	0.50	0.07

 

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

Map 1. Tetra Zone Drill Holes with Assay Results

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Map 2. Tetra Zone Exploration Drill Holes with Assay Results

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Map 3. JR Zone Drill Holes with Assay Results

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Map 4. A1/B1 Exploration Drillholes

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Samples from the drill core are split into half sections on site. Where possible, samples are standardized at 0.5m down-hole intervals. One-half of the split sample is sent to 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 down-hole and true thicknesses are yet to be determined.

About the Patterson Lake North Project:

The Company's 44,613-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 23km northwest of Paladin's Triple R deposit, the 19,864-hectare Minto Property, and the 20,675-hectare Broach Property hosting the Tetra Zone, F3's newest discovery 13km 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 & COO of F3 Uranium Corp, a Qualified Person. Mr. Ashley has reviewed and approved the data disclosed.

This news release may refer to neighboring 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 neighboring properties is not necessarily indicative of mineralization on the PLN Project. For additional information on the PLN Project, please refer to the report titled "Technical Report on the Patterson Lake North Project, Northern Saskatchewan, Canada" prepared by SLR International Corporation with a signing date of January 25, 2023and an effective date of November 20, 2023 available at www.sedarplus.ca, and prepared in accordance with NI 43-101.

About F3 Uranium Corp.:

F3 is a uranium exploration company, focusing on the high-grade JR Zone and new Tetra Zone discovery 13km to the south in the PW area on its Patterson Lake North (PLN) Project in the Western Athabasca Basin. F3 currently has 3 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.

Forward-Looking Statements

This news release contains certain forward-looking statements within the meaning of applicable securities laws. All statements that are not historical facts, including without limitation, statements regarding future estimates, plans, programs, forecasts, projections, objectives, assumptions, expectations or beliefs of future performance, including statements regarding the suitability of the Properties for mining exploration, future payments, issuance of shares and work commitment funds, entry into of a definitive option agreement respecting the Properties, are "forward-looking statements." These forward-looking statements reflect the expectations or beliefs of management of the Company based on information currently available to it. Forward-looking statements are subject to a number of risks and uncertainties, including those detailed from time to time in filings made by the Company with securities regulatory authorities, which may cause actual outcomes to differ materially from those discussed in the forward-looking statements. These factors should be considered carefully and readers are cautioned not to place undue reliance on such forward-looking statements. The forward-looking statements and information contained in this news release are made as of the date hereof and the Company undertakes no obligation to update publicly or revise any forward-looking statements or information, whether as a result of new information, future events or otherwise, unless so required by applicable securities laws.

The TSX Venture Exchange and the Canadian Securities Exchange have not reviewed, approved or disapproved the contents of this press release, and do not accept responsibility for the adequacy or accuracy of this release.

F3 Uranium Corp.
750-1620 Dickson Avenue
Kelowna, BC V1Y9Y2
Contact Information
Investor Relations
Telephone: 778 484 8030
Email: ir@f3uranium.com

ON BEHALF OF THE BOARD,
"Dev Randhawa"
Dev Randhawa, CEO

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FAQ

What did F3 Uranium (FUUFF) report on December 15, 2025 for PLN25-200?

PLN25-200 returned 8.5m @ 3.4% U3O8 (234.0–242.5m), including 2.5m @ 10.2% U3O8 and 1.0m @ 20.7% U3O8.

What high-grade result did FUUFF record at the Tetra Zone in 2025?

PLN25-217 produced a 3.5m composite @ 0.30% U3O8 (400.0–403.5m) that includes 0.5m @ 1.04% U3O8.

How much total mineralization was reported at Tetra Zone by F3 on December 15, 2025?

The company reported 26.5m of composite mineralization intersected between 340.5–406.5m at Tetra Zone.

Are the reported depths for FUUFF drill results true thicknesses?

No, all depths are reported as down-hole and true thicknesses are yet to be determined.

Did F3 report any deep uranium intersections in the 2025 JR program?

Yes, PLN25-207 intersected 0.06% U3O8 at 621.0–621.5m, interpreted as related to the Tetra shear system ~200m away.

Will the PLN JR Zone drilling be used for a resource estimate for FUUFF?

Yes, the release notes the last two holes were completed for inclusion in the upcoming maiden resource estimate.