The Uranium Ore Discriminator (UOD-SAS) measures the gamma radiation emitted by a uranium-ore truck load and establishes the average uranium-ore grade on the truck so that ore can be stockpiled more accurately within the required uranium-ore grade range.
How it works
The RDS uranium-ore discriminator detects gamma radiation using two independent Gamma Detector Units (GDUs) situated approximately 1 – 1.3 m on each side of the uranium-ore truck tray. Each GDU contains 3 – 4 pairs of lead-shielded gamma-radiation detectors (GRDs) coupled with high-voltage / amplifier boards. Computer modelling estimates that the maximum error due to incorrect parking of the truck is approximately ±6 %. If the truck parks closer to one GDU, that GDU’s higher gamma count is compensated for by the lower count of the GDU situated further from the side of the truck tray.
The Discriminator Control Panel (DCP) can process the gamma count of up to 4 left and 4 right pairs of GRDs in 10 s, 20 s or 30 s counting windows. The counts of the left and right GDUs (CL and CR respectively) are displayed separately on the bottom line of the DCP. The measured average U₃O₈ concentration is displayed on the top line and is calculated from the net left and right truck gamma counts (the left- and right-GDU background counts programmed into the DCP memory are automatically subtracted from the total “truck” signal counts).
The DCP and a PC in the control room communicate via radio. When the truck stops between GDUs, the truck driver reports by radio to the operator. The operator enters the truck number into a spreadsheet and starts counting. When the count is finished, the DCP reports the total count and the assessed ore grade to the PC. The operator then directs the truck driver where the uranium-ore load is to be dumped.
The discriminator has 10 programmable uranium-ore grade cut-offs. The DCP and two GDUs are powered by a 12 V acid-gel battery coupled with a solar panel.