Radiation detection systems
Uranium Ore Discriminator (Automatic system with the load size correction)
Uranium Ore Discriminator (UOD-ASLSC)
Automatic system with the load size correction
The Uranium Ore Discriminator measures the gamma radiation emitted by a uranium ore truck load and establishes the average uranium ore grade on the truck so uranium ore could be stockpiled more accurately within a required uranium ore grade range.
As truck load tonnage differs from truck to truck the distance monitoring probe is used to correct the measured gamma count rate for the distance between the gamma detector and the top surface of the uranium ore load. Therefore, the UOD-ASLSC is more accurate than conventional UODs.
General operation:
The RDS uranium ore discriminator (UOD) is based on the detection of the gamma radiation emitted by the truck load of uranium ore. The gamma detection system consists of eight independent gamma detection units (four left GDUs and four right GDUs). The gamma detectors in each GDU are shielded by lead to minimize the local gamma background.
The Discriminator Control Panel (DCP) displays the gamma count of the four left and four right GDUs in 10s, 20s or 30s counting windows and the measured average U3O8 concentration. The ore grade is calculated from the net truck gamma count (the left GDU and the right GDU background counts that are programmed into the DCP memory are automatically subtracted from the left GDU and the right GDU 'truck' signal counts).
Trucks haul different loads of U-ore and thus the distance from the top of the U-ore load to the GDUs is different from truck to truck ie the measured gamma count rate is affected by the distance of the top of the load from GDUs. The computer modeling was used to obtain the function describing the dependence of the gamma count rate on the distance of the load from the GDUs. The ultrasonic distance monitoring probe, which is incorporated into the system, measures the distance between the top surface of the U-ore load and the GDUs so the measured count can be corrected and the uranium ore grade on each truck could be estimated more accurately.
When the truck parks on the pad under the GDUs the truck driver pushes the button on a panel inside the truck cabin. This initiates the gamma counting. When the counting is finished the DCP displays the total left and right count as well as the estimated ore grade. The truck number, the ore grade (%U3O8) and the ore grade cut-off are reported via radio connectivity to the operator room and to the truck driver.
Technical parameters:
Operational parameters of the UOD with 16 GRDs:
- Lowest limit of detection (depends on the gamma background of the UOD pad) typically 20 ppm U3O8
- Maximum measured ore grade about 90,000 ppm U3O8
- Accuracy of the measured ore grade 1 better than +/- 5 %
- The RDS UOD is nearly temperature independent between -10 Co and + 50 Co.