WNA reported in 2017 that in most respects the environmental aspects of a uranium mine are the same as those of other metalliferous mining. Most uranium mines in Australia and Canada have ISO 14001 certification. Radioactivity associated with the uranium ore requires some special management in addition to the general environmental controls of any mine.
The uranium itself has a very low level of radioactivity, comparable with granite. Virtually all the radioactive material from the associated minerals in the ore processed ends up in the tailings dam. In many respects uranium mining is much the same as any other mining. Projects must have environmental approvals prior to commencing, and must comply with all environmental, safety and occupational health conditions applicable. Increasingly, these are governed by international standards, with external audits.
Once approved, open pits or shafts and drives are dug, waste rock and overburden is placed in engineered dumps. Tailings from the ore processing must be placed in engineered dams or underground. Finally the whole site must be rehabilitated at the end of the project. Meanwhile air and water pollution must be avoided.
These processes are common to all metalliferous mining, and are well recognized and understood. In the case of in situ leach (ISL) mining, there is much less disturbance – simply multiple boreholes, and rehabilitation is simpler. An important international conference in 2009 presented a best practice guide to ISL mining published by the International Atomic Energy Agency (IAEA).
In 2014 the OECD Nuclear Energy Agency published a 140-page report: Managing Environmental and Health Impacts of Uranium Mining. “Uranium mining and milling has evolved significantly over the years. By comparing currently leading approaches with outdated practices, this report demonstrates how uranium mining can be conducted in a way that protects workers, the public and the environment. Innovative, modern mining practices combined with strictly-enforced regulatory standards are geared towards avoiding past mistakes committed primarily during the early history of the industry when maximizing uranium production was the principal operating consideration.”
In 2017 the World Nuclear Association published an internationally standardized reporting tool to understand the sustainable development performance of uranium mining and processing sites. This checklist had been developed by its members over several years with the goal of achieving widespread agreement on a list of topics and indicators for common use in demonstrating producers’ adherence to sustainable development performance. Accompanying guidelines have also been prepared to help utilities and producers use the checklist. The voluntary checklist was developed to align with the Association’s policy document on best practice in mining.
Uranium
Uranium itself is radioactive, though with the major isotope U-238 having a half-life equal to the age of the earth, it is certainly not strongly radioactive. U-235 has a half-life one-sixth of this and emits gamma rays as well as alpha particles. Hence a lump of pure uranium would give off some gamma rays, but less than those from a lump of granite. Its alpha radioactivity in practical terms depends on whether it is as a lump (or in rock as ore), or as a dry powder. In the latter case the alpha radioactivity is a potential, though not major, hazard. It is also toxic chemically, being comparable with lead. Uranium metal is commonly handled with gloves as a sufficient precaution. Uranium concentrate is handled and contained so as to ensure that people do not inhale or ingest it.
The gamma radiation detected by exploration geologists looking for uranium actually comes from associated elements such as radium and bismuth, which over geological time have resulted from the radioactive decay of uranium.
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