In Australia all uranium mining and milling operations are undertaken under the Code of Practice and Safety Guide for Radiation Protection and Radioactive Waste Management in Mining and Mineral Processing. This was drawn up by the national government in line with recommendations of the International Commission on Radiological Protection (ICRP), but it is administered by state health and mines departments. The Code, which was updated in 1995 and again in 2005, sets strict health standards for radiation and radon gas exposure, for both workers and members of the public.

In Canada the Canadian Nuclear Safety Commission is responsible for regulating uranium mining as well as other aspects of the nuclear fuel cycle. In Saskatchewan, provincial regulations also apply concurrently, and set strict health standards for both miners and local people.

Uranium itself is only slightly radioactive. However, radon, a radioactive inert gas, which is a decay product of uranium, is released to the atmosphere in very small quantities when the ore is mined and crushed. Radon occurs naturally in most rocks — minute traces of it are present in the air which we all breathe and it is a significant contributor to the natural radiation dose that we all receive. Because it is airborne, special care must be taken to ensure that mine worker exposure, especially in poorly ventilated mines, is limited.

Open cut mines are naturally well ventilated. The Olympic Dam and Canadian (as well as other) underground mines are ventilated with powerful fans. Radon levels are kept at a very low and certainly safe level in uranium mines. (Radon even in non-uranium mines also may need control by ventilation.)

Gamma radiation may also be a hazard to those working close to high-grade ores such as in Canada. It comes principally from uranium decay products in the ore, so exposure to this is regulated as required. In particular, dust is suppressed, since this represents the main potential exposure to alpha radiation as well as a gamma radiation hazard.

At the concentrations associated with uranium (and some mineral sands) mining, radioactivity is a potential health hazard. Precautions taken during the mining and milling of uranium ores to protect the health of the workers include:

• Good forced ventilation systems in underground mines to ensure that exposure to radon gas and its radioactive daughter products is as low as possible and does not exceed established safety levels.

• Efficient dust control, because the dust may contain radioactive constituents and emit radon gas.

• Limiting the radiation exposure of workers in mine, mill and tailings areas so that it is as low as possible, and in any event does not exceed the allowable dose limits set by the authorities. In Canada this means that mining in very high-grade ore is undertaken solely by remote control techniques and by fully containing the high-grade ore where practicable.

• The use of radiation detection equipment in all mines and plants, often including personal dose badges.

• Imposition of strict personal hygiene standards for workers handling uranium oxide concentrate.

At any mine, designated employees (those likely to be exposed to radiation or radioactive materials) are monitored for alpha radiation contamination and personal dosimeters are worn to measure exposure to gamma radiation. Routine monitoring of air, dust and surface contamination is undertaken.

Canadian mine and mill facilities are designed to handle safely ore grades of up to 26% U.

If uranium oxide is ingested it has a chemical toxicity similar to that of lead oxide. Similar hygiene precautions to those in a lead smelter are therefore taken when handling it in the drying and packing areas of the mill.

The usual radiation protection procedures are applied at an ISL mine, despite the fact that most of the orebody’s radioactivity remains well underground, and there is hence minimal increase in radon release and no ore dust.