or carbon dioxide) is injected through a series of injection wells into the ore body to dissolve the uranium (Figure 1.10). The solution is then collected in a series of recovery lixiviant wells, from which it is pumped to a processing plant (Figure 1.11), where the uranium is extracted from the solution, usually by . The uranium extract is then further purified, concentrated, and dried to produce . Monitoring wells are checked regularly to ensure that uranium and chemicals are not escaping from the drilling area. Figure 1.10: In situ leaching/recovery (© USNRC). Figure 1.11: Hobson ISL processing in . Yellowcake produced by any method (conventional milling, Heap Leach or ISL) is transported to a facility for further processing. Table 1.1 compares the main environmental and safety regulatory issues for the three main types of milling (also known as “recovery”) facilities. Table 1.1: Characteristics of uranium milling facilities Conventional Heap Leach Feature ISL Uranium Mill Facility Physical and Physical and Chemical process chemical process to chemical process to to extract uranium extract uranium extract uranium from underground Recovery Method from ore. from mined ore deposits. that has been piled in a heap. Mill building(s), Process buildings, Well fields, header process tanks, heap pile consisting houses, Surface Features tailings of crushed ore. processing facility, impoundment, and storage or evaporation ponds. evaporation pond. Mill tailings, Heap pile remains Liquid pumps, and other in after (disposed of in process equipment processing; pipes, injection wells or that cannot be pumps, and other through an decontaminated. process equipment evaporation Generated that cannot be system), pipes, decontaminated. pumps, and other process equipment that cannot be decontaminated. Demolition of mill Demolition of site Restoration of Decommissioning and site buildings, buildings, final groundwater,
or carbon dioxide) is injected through a series of injection wells into the ore body to dissolve the uranium (Figure 1.10). The lixiviant solution is then collected in a series of recovery wells, from which it is pumped to a processing plant (Figure 1.11), where the uranium is extracted from the solution, usually by . The uranium extract is then further purified, concentrated, and dried to produce . Monitoring wells are checked regularly to ensure that uranium and chemicals are not escaping from the drilling area. Figure 1.10: In situ leaching/recovery (© USNRC). Figure 1.11: Hobson ISL processing in . Yellowcake produced by any method (conventional milling, Heap Leach or ISL) is transported to a facility for further processing. Table 1.1 compares the main environmental and safety regulatory issues for the three main types of milling (also known as “recovery”) facilities. Table 1.1: Characteristics of uranium milling facilities Feature Conventional Uranium Mill Heap Leach Facility ISL Recovery Method Physical and chemical process to extract uranium from ore. Physical and chemical process to extract uranium from mined ore that has been piled in a heap. Chemical process to extract uranium from underground deposits. Surface Features Mill building(s), process tanks, tailings impoundment, and evaporation ponds. Process buildings, heap pile consisting of crushed ore. Well fields, header houses, processing facility, storage or evaporation pond. Generated Mill tailings, pumps, and other process equipment that cannot be decontaminated. Heap pile remains in after processing; pipes, pumps, and other process equipment that cannot be decontaminated. Liquid (disposed of in injection wells or through an evaporation system), pipes, pumps, and other process equipment that cannot be decontaminated. Decommissioning Demolition of mill and site buildings, Demolition of site buildings, final Restoration of groundwater,
Module17%20Fuel%20cycle%20spent%20fuel%20management.docx