NexGen Energy Ltd.

Sampling, Analysis and Data Verification

Sample Preparation Methods

On-site sample preparation consists of geological technicians splitting cores under the supervision of geologists. All split samples (mineralized, sandstone, basement) with anomalous radioactivity (>300 cps) are assayed for U 3 O 8. Non-mineralized split samples include zones of structure, elevated cps intervals, and gold sampling. The first 3m of basement rock below any unconformity need to be split in equal 1.0m splits (e.g. if the basement rock starts at 126.4m, the basement splits will be from 126.4-127.4 m,127.4-128.4 m, and 128.4-129.4 m)

One-half of the core is placed in plastic sample bagspre-marked with the sample number, along with a sample number tag. The other half is returned to the core box and stored at the core storage area located near the logging facility on the project site. The bags containing the split samples are then placed in lidded buckets to be transported by NexGen personnel to Saskatchewan Research Council Geoanalytical Laboratories (“SRC”), a wholly independent laboratory in Saskatoon, Saskatchewan.

NexGen personnel perform full core bulk density measurements using standard laboratory techniques. In mineralized zones, average bulk density is measured from samples at 2.5 m intervals, where possible (i.e., approximately 20% of all mineralized samples). In order for density to be correlated with uranium grades across the data set, each density sample directly correlates with a sample sent to SRC for assay.

Samples are also collected for clay mineral identification using infrared spectroscopy in areas of clay alteration. Samples are typically collected at five-meter intervals and consist of centimeter-long pieces of core selected by a geologist.

Security

As each hole is being drilled, drilling contractor personnel place the core in wooden boxes at the drill site and seal core boxes with screwed-on wooden lids. Core is then delivered to the Rook I Project core processing facility by the contractor twice daily. Only the contractor and NexGen geological staff are authorized to be at drill sites and in the core processing facility. Any external entities must be escorted by NexGen staff. After logging, sampling, and shipment preparation, samples are transported directly from the project site to SRC by NexGen staff.

SRC places a large emphasis on confidentiality and data security. Appropriate steps are taken to protect the integrity of samples at all processing stages. Access to the SRC premises is restricted by an electronic security system and patrolled by security guards 24 hours a day.

After the completion of analyses, data is sent securely via electronic transmission to NexGen. These results are provided as a series of PDFs and an Excel spreadsheet.

Assaying and Analytical Procedures

SRC crushes each sample until 60% is capable of passing-10 mesh. It is then riffle-split to a 200 g sample, with the remainder retained as coarse reject. The 200 g sample is then milled to 90% passing-140 mesh.

All samples are analyzed at SRC by inductively coupled plasma optical emission spectroscopy(“ICP-OES”) or inductively coupled plasma mass spectroscopy(“ICP-MS”) for 64 elements including uranium. Samples with low radioactivity are analyzed using ICP-MS. Samples with anomalous radioactivity are analyzed using ICP-OES. Partial and total digestion runs are completed for most samples. For partial digestion, an aliquot of each sample is digested in HCI:HNO3 for one hour at 95°C, and then diluted usingde-ionized water. For the total digestion, an aliquot of each sample is heated in a mixture of HF/HNO3/HClO4 until completely dried, and the residue dissolved in dilute HNO3.

For uranium assays, an aliquot of sample pulp is completely digested in concentrated HCl:HNO3, and then dissolved in dilute HNO3 before being analyzed using ICP-OES. For boron, an aliquot of pulp is fused in a mixture of NaO2/NaCO3 in a muffle oven. The fused melt is dissolved inde-ionized water before being analyzed using ICP-OES.

Selected samples are also analyzed for gold, platinum, and palladium using traditional fire assay methods.

Quality Control Measures

NexGen’s quality assurance and quality control (QA/QC) program includes the following.

The QA/QC program used at the Arrow Deposit includes the insertion of SRMs, blanks, and duplicates into the sample stream at the frequency summarized in the table below.