The mineralization is known to occur at seven locations on the Rook I Property: 1) Arrow Deposit, 2) Harpoon occurrence, 3) Bow occurrence, 4) Cannon occurrence, 5) Camp East occurrence, 6) Area A occurrence, and 7) South Arrow occurrence, the most significant of which is the Arrow Deposit. All uranium mineralization discovered on the Property to date is hosted exclusively in basement lithologies below the unconformity.

ARROW DEPOSIT
Uranium was first discovered at Arrow by NexGen in February of 2014 when drill hole AR-14-01 intersected modest mineralization including 0.16% U3O8 over 9.0 m. Subsequent follow-up drilling identified a zone of extensive mineralization highlighted by drill holes AR-16-63c2, which intersected 15.20% U3O8 over 42.0 m and an additional 12.99% U3O8 over 46.5 m, AR-15-62, which intersected 6.35% U3O8 over 124.0 m, and AR-15-44b, which intersected 11.55% U3O8 over 56.5 m including 20.0 m at 20.68% U3O8 and 1.0 m at 70.0% U3O8. These drill holes intersected the mineralization at a low angle and therefore the core lengths do not represent the width of the mineralization.

Uranium mineralization at the Arrow Deposit dominantly occurs as uraninite. Other common uranium minerals include coffinite and secondary yellow coloured minerals, currently interpreted to be autunite, carnotite, and/or uranophane. A green coloured secondary uranium mineral interpreted to be torbernite has also been observed very locally. In zones of massive uraninite mineralization, blebs of a glassy black coloured phase with conchoidal fracture currently interpreted to be pyrobitumen are often observed.

Two key but contrasting types of uranium mineralization occur at Arrow:

• Open-space fillings
Open-space fillings include massive uraninite bodies interpreted to be uranium veins, and breccia bodies where the matrix is comprised nearly exclusively of massive uraninite. Uranium veins and breccias typically range in thickness from less than 0.1 m to greater than one metre and display sharp contacts with the surrounding wall rocks. Individual uranium veins usually occur at parallel to sub-parallel orientations to the regional foliation, however, at least one set of veins cross-cuts the regional foliation. Clasts present in uranium breccias at Arrow are typically fragments of the immediate wall rocks and often contain additional disseminated uraninite mineralization. Uranium breccias occur as both clast supported and matrix supported forms, with the latter typically hosting higher grades. Both styles of open-space filling mineralization are categorized by high uranium grades that can be in excess of 40% U3O8 and as high as 80% U3O8.

• Chemical replacement styles
Chemical replacement types of mineralization present at Arrow include disseminated, worm-rock and near complete to complete replacement styles. Disseminated mineralization is typically associated with strong to intense hydrothermal alteration where uraninite occurs as fine to medium grained anhedral crystals and crystal agglomerates spread throughout the host in concentrations of typically less than five modal percent. Worm-rock style mineralization is named for the wormy texture it by definition displays, which is the result of redox reactions between uranium bearing fluids and the host wall rocks. Typically, these redox fronts are less than 10 cm thick. Near to complete uraninite replacement of the host rock has also been observed at Arrow. These zones range in thickness from less than 0.1 m to greater than 1.0 m and, in contrast to open- space fillings, show gradual contacts. The presence of vugs in this style of mineralization and in some zones interpreted to be uraninite veins suggests that in at least some places, the veins may actually be the result of chemical replacement and not open-space filling. Uranium grades associated with chemical replacement styles of mineralization at Arrow range from less than 1% U3O8 in disseminated bodies to greater than 70% U3O8 in complete replacement bodies.

Hydrothermal alteration that occurs in the vicinity of Arrow is extensive and several distinct styles have been observed. In some areas, mineralization is closely associated with a pervasive quartz-sericite-sudoite-illite alteration assemblage that nearly completely replaces the host rock, although pre-alteration textures are often preserved. In other areas, mineralization is closely associated with pervasive brick red coloured hematite alteration. Another key alteration phase present at Arrow is dravite. Typically, it occurs in centimetre to decimetre wide breccia vein bodies beginning tens of metres from high grade uranium mineralization and increasing in size and frequency closer to mineralization. Carbon buttons are commonly observed in association with dravite. Centimetre sized drusy quartz veins occur ubiquitously in the vicinity of the deposit. Where proximal to high grade mineralization, these veins are often pink coloured.

The mineralization in the Arrow Deposit is sub-vertical and true width is estimated to be from 30% to 50% of reported core lengths based on currently available information.

A detailed mine plan based on conventional long-hole stope mining was engineered using Indicated Mineral Resources only. Geotechnical studies during Pre- Feasibility supported the conventional longhole stoping mining method including the use of longitudinal and transverse stopes, 30 m level spacing, and the nominal stope strike length of 15 metres to 30 metres.

The PFS mine plan, using a 0.25% U3O8 cut-off grade, includes Probable Mineral Reserves consisting of 234.1 M lbs of U3O8 contained in 3.43 M tonnes grading 3.09% U3O8 that will be extracted by underground mining in an initial nine (9) year mine life. The mine production schedule envisions a life of mine rate of 1,039 tonnes per day. The underground workings will be accessed by two shafts, the first supporting personnel movements, materials, ore, waste and fresh air. The production shaft will have divided compartments, ensuring that fresh air, and personnel entering the mine,remain isolated from ore being skipped to surface. The second shaft will be used for exhaust air and secondary egress. Mining extraction is estimated to be 95% of mineralized tonnes for both ore development and stopes. Planned dilution was included in the generation of the stope shapes, and additional backfill dilution (at zero grade) was included where appropriate. Overall rock dilution is estimated to be 31%, with additional backfill dilution applied on secondary stopes only.

The major components of the process plant are the following:
• Crushing, Milling and Classification
• Acidic Leaching
• Counter Current Decantation (CCD)
• Tailings Neutralization, Thickening, and Disposal
• Pregnant Leach Solution (PLS) Clarification
• Solvent Extraction (SX)
• Molybdenum Removal
• ADU Precipitation
• Product Drying and Packaging

Mineralized material will be crushed underground in order to facilitate handling and transportation. Crushed material will be hoisted to the surface and conveyed to a stockpile local to the processing plant. The stockpile will enable a controlled feed rate into the mill and also serve as a buffer for upstream variances during operation. Primary mill feed will be withdrawn from the mill feed stockpile using two variable speed apron feeders and discharged onto a conveyor to feed the primary mill.

Milled product will report to a conditioning tank prior to acidic leaching. This tank will serve as both a surge tank to cater for downstream variances and as a reagent conditioning and feed dilution tank. The leach circuit will be composed of six 180 m3 tanks arranged in a staggered cascade configuration enabling gravity flow between the tanks. Overflow launders will be strategically located to allow bypassing of any one tank if required during operation.

Leaching of uranium will be conducted at a controlled pH of 1.1 using diluted sulphuric acid as the lixiviant. Sulphuric acid will be diluted using raffinate enabling reduced acid consumption and improved pH control. Hydrogen peroxide, which serves as an oxidant, will be added into the leach tanks at a controlled rate to ensure target ORP levels are achieved for effective dissolution. Steam will be sourced from the sulphur burning plant and added into the leach tanks using lances to elevate the operating temperature from ambient conditions to approximately 50oC. Under these operating conditions, the leaching kinetics will be relatively rapid with the bulk of the leaching occurring within the first two tanks. Leach slurry from the last leach tank will be pumped to a CCD circuit prior to tails disposal. A uranium dissolution rate of approximately 98.3% is expected.

Leach slurry from the last leach tank will be pumped to the CCD circuit to enable recovery of uranium in solution by counter-current washing prior to disposal of the underflow as tails. The CCD circuit will be composed of seven 18 m diameter thickeners configured in series. Underflow from each thickener will be pumped to the subsequent thickener, with overflow fed into the previous thickener feed tank equipped with a pump mixer. Raffinate from the SX circuit will be used as wash water and added into the last CCD thickener in the train. Flocculant will be made-up and pumped to each thickener followed by in-line dilution using raffinate prior to addition into the respective thickener. A wash ratio falling within the range of 1.5 m3/t to 2.5 m3/t and an underflow density of 40% to 50% m/m solids will be expected based on limited testwork data. Bypass facilities are allowed on both the overflow and underflow to enable bypassing of any one thickener if required during operation.

Underflow from the last CCD thickener #7 will be pumped to the tails neutralization circuit. The objective of neutralizing tailings material is to comply with the applicable environmental legislation under enforcement in Saskatchewan. The neutralization circuit will be composed of four 55 m3 tank in a staggered configuration. Limestone and burnt lime will be added at a controlled rate in order to increase the pH to an operational band of 7 to 8. At this operating pH, major dissolved metal ions will precipitate from solution into a stable hydroxide form prior to being fed to the filtration plant. Bypass launders will be provided to enable bypassing of any one tank if required during operation. Neutralized tailings will then be pumped to the filtration circuit composed of a single 68 m2 vacuum belt filter. Dewatered tails (filter cake) will discharge onto a conveyor and then onto a tails stockpile prior to feeding the paste plant. The moisture content of the filter cake will be expected to fall within the range of 15% to 20% m/m pending testwork validation.

Overflow from CCD 1 will be pumped to a clarification circuit composed of a single 5 m diameter pin bed clarifier. Clarified PLS will be pumped to the PLS pond prior to feeding the SX circuit. The PLS pond will have a total capacity of 4,800 m3 and will be designed to allow for a 24 hour residence time to ensure stable flow into the SX plant. The SX circuit will be composed of extraction (four stages), scrub (three stages), strip (four stages), regeneration (one stage), and crud treatment. The solvent will be a combination of Armeen 380, Isodecanol, and Calumet 400-500 at 6% v/v, 3% v/v, and 91% v/v respectively.

The organic will be loaded to 6 g/L U3O8 and scrubbed in three stages using water, dilute sulphuric acid, and an ammonium sulphate scrub in sequence. The scrub stages will be included to mitigate against impurity carry over to the final product. The scrubbed organic will be stripped using ammonium sulphate to achieve a tenor of approximately 10 g/L U3O8. The pH will be controlled in each stage of stripping using a solution of ammonium hydroxide. A bleed stream of stripped organic (approximately 10%) will be regenerated using sodium carbonate with sodium hydroxide added for pH control. A crud treatment circuit will be included to recover organic and aqueous, with solid waste stockpiled in a bunker for manual disposal. A uranium recovery of 99.5% is expected for the SX circuit.

The loaded strip liquor (Odourless Kerosene liquor) from the SX circuit will be pumped to the Mo removal circuit.

OK liquor from the Mo removal circuit will be pumped to the production precipitation circuit.

Washed ADU will be pumped to a product dewatering, drying, and packaging circuit, which is a highly integrated and automated plant. The product will be dewatered using a centrifuge to achieve a solids concentration of approximately 60% to 65% m/m solids. The centrifuge solids will then be fed into an electrically heated horizontal rotary dryer to reduce the residual moisture content to less than 1% m/m. The dryer will operate at a temperature of 700oC to 750oC to produce a final U3O8 product. The 210L drums will be filled and lidded with dried product ready for dispatch.