Acid Rock Drainage / Acid Mine Drainage (ARD/AMD) - refers to the outflow of acidic water from natural rock formations and metal or coal mines that have minerals containing sulphur.  When these sulphur minerals are exposed to oxygen and water over time, it can create sulphuric acid. Without proper management of this acid, acid rock/mine drainage can happen. A typical way to fix the problem is to keep the sulphur-containing material under water where oxygen cannot react with it.

Acid Leaching – a chemical process that uses acid to extract valuable minerals from ore during the milling process. 

Adit – a horizontal opening dug to reach a mineral deposit, usually in the side of a hill or mountain. 

ALARA - means As Low As Reasonably Achievable. This is a radiation safety principle that means making every reasonable effort to maintain exposures to radiation as far below the dose limits as is practical, taking into account technology, economics and social factors. ALARA is not only an accepted safety principle, it is a regulatory requirement for all radiation safety programs.

Alpha Radiation – one of three forms of energy that may be emitted when a radioactive element, such as uranium, changes naturally (or decays) into another element. The movement of alpha particles can be stopped by light barriers, such as skin or a sheet of paper.

Assay - A chemical test done on a sample of ores or minerals to find out the amount and type of valuable elements (metals) it contains.

Background Radiation - naturally occurring radiation that we are exposed to from natural sources all around us, such as soil, water, rays from the sun, etc.  

Base Metal - any non-precious metal (eg. copper, lead, zinc, nickel, etc.).

Baseline Studies (Environmental) - a description of existing conditions to provide a starting point against which comparisons can be made following some development

Beta Radiation – one of three forms of energy that may be emitted when a radioactive element, such as uranium, changes naturally (or decays) into another element. The movement of beta particles can be stopped by barriers, such as aluminum foil or a few centimetres of wood.

Canadian Nuclear Safety Commission (CNSC) - an agency of the Government of Canada that regulates the use of nuclear materials, including uranium and uranium mining, and the production of electricity from nuclear substances (uranium).  The mandate of the CNSC is to protect the health, safety and security of Canadians and the environment; and to ensure Canada's international commitments on the peaceful use of nuclear energy are followed.

Cut-off Grade - the lowest grade of metal in an ore that can be mined at specified cost.  It is usually measured in percent, or ounces, pounds or grams per tonne.

Decommissioning – rehabilitation of affected areas and the removal of infrastructure such as buildings and roads after the closure of an industrial site, carried out and completed according to standards set by government regulators.  The objective is to make the site safe and to minimize ongoing environmental effects.

Effluent – treated waste water from an industrial process.  Typically, the amount and contents of effluents are regulated by government licenses based on legislated standards or local water quality protection.

Enriched Uranium - uranium in which the percent of 235U isotope has been increased to greater than its natural concentration. This increases the energy potential of the uranium and allows it to be used in processes such as generating electricity in nuclear reactors.

Environmental Assessment (EA) - the process of identifying and evaluating the environmental effects of proposed projects before development is allowed to be carried out. Identified negative effects are reduced and managed through changes to the project. Public input is an important part of the Environmental Assessment process.

Exploration Drilling - Drilling done in search of new mineral deposits, on parts of known ore deposits, or around known deposits until the company has determined there are enough ore resources to have an economically feasible mining operation.

Feasibility Study – in the mining industry, it is a comprehensive study of a mineral deposit where all geological, engineering, legal, operating, economic, social, environmental and other relevant factors are described in detail. It usually will be the basis for a decision by the company to develop the deposit. It can also be used by financial institutions to decide whether or not to finance a project.

Gamma Radiation - one of three forms of energy that may be emitted when a radioactive element, such as uranium, changes naturally (or decays) into another element. Gamma rays are high-energy, short wave-length rays (or waves) similar to x-rays and can be stopped or shielded by dense materials like concrete, rock, or water. 

Groundwater – water that exists beneath the earth's surface.

Heavy Metals – some metals, such as nickel, arsenic, beryllium, cadmium, chromium, lead, manganese, mercury, and selenium are called “heavy” because of their high mass.  They are naturally occurring, but can be harmful to health and the environment in high quantities or if they are not properly managed.

In-fill Drilling – drilling between existing drill holes, used to provide greater detail about a deposit and to help establish resource estimates.

International Atomic Energy Agency (IAEA) – an international organization with 151 member states, including Canada, that works worldwide to promote safe, secure and peaceful nuclear technologies. Policy and regulations for the nuclear industry in countries around the world are commonly based on standards developed by the IAEA. The IAEA reports annually to the UN General Assembly and, when appropriate, to the Security Council. 

Jaw Crusher - a machine which breaks rock by the action of steel plates pressing together.

Lime – a combination of calcium and oxygen (CaO).  Lime is commonly used in industrial processes to neutralize acid.

Limestone – a naturally occurring rock formation that can be used to make lime. 

Metallurgy - the science and technology of metals.  

Milling - the process of physically and chemically breaking down ore from underground or open pit mines, to separate the valuable metals from the remainder of the rock.

Milli-Sievert – a unit for measuring small radiation doses of the type typically encountered in uranium mining.

Mineral - a naturally occurring substance having distinct physical and chemical properties that make it easy to identify.

Mineral Reserve – the part of a mineral resource that can be mined profitably.

The technical definition of a Reserve, as used by the Canadian mining industry for official reporting of exploration information, can be found on the Canadian Institute of Mining and Metallurgy’s website at:

Mineral Resource - the calculated amount of material in a mineral deposit, classified as measured, indicated, or inferred, based on the density of drill hole information used. Measured mineral resources would have the higher density of drill holes, followed by indicated, then inferred.

The technical definition of Mineral Resources, as used by the Canadian mining industry for official reporting of exploration information, can be found on the Canadian Institute of Mining and Metallurgy’s website at:

Mineralization - a presence of economically important minerals in the form of ore bodies.

Multiple Accounts Analysis (MAA) a decision-making tool based on a number-ranking system that compares many aspects of a development project (environmental, socio-economic, technical, financial, etc.) and produces a set of options for moving ahead. Through MAA, options can be ranked using a clear and logical framework that tracks how a decision was reached and on what factors.

Nuclear Electric Power - generated by an electric power plant whose turbines are driven by steam produced by the heat from the nuclear fuel in a reactor.

Nuclear Non-Proliferation Agreement (also known as the Treaty on the Non-Proliferation of Nuclear Weapons) - a treaty finalized in 1968 which aims to prevent the spread of nuclear weapons and weapons technology, to foster the peaceful uses of nuclear energy, and to further the goal of disarmament. Almost 190 nations participate in the agreement, including Canada.

Nuclear Reactor – a device where a nuclear reaction can be initiated, controlled, and maintained at a specific rate. A reactor includes fuel (usually uranium), material to control the rate of the reaction, a heavy-walled pressure vessel to contain the parts of the reactor, shielding to protect personnel, a system to carry heat away from the reactor, and instruments for monitoring and controlling the reactor’s systems.

Open-pit - a mine that is designed to extract minerals only at the surface of the land. Also referred to as open-cut or open-cast mine.

Ore - a mixture of metal-containing minerals and non-valuable minerals from which at least one of the metals can be extracted at a profit.

Ore Body - a natural concentration of ore in a specific location.  

Person Year - one whole year worked by one employee.

Pilot Plant – a smaller-scale version of a mill where the milling process can be tested and refined before a full-scale mill is built.

Preliminary Feasibility Study (PFS) – an assessment of the technical and economic viability of a proposed project. Different approaches to elements of the project are compared, and the most suitable options for each element is recommended for further analysis. Costs of development and operations are estimated. Anticipated benefits are assessed so that some preliminary economic criteria for evaluation can be calculated.

The technical definition of a Pre-feasibility Study, as used by the Canadian mining industry for official reporting of exploration information, can be found on the Canadian Institute of Mining and Metallurgy’s website at:

Preliminary Economic Assessment (PEA) - a study that includes an economic analysis of the potential viability of mineral resources taken at an early stage of the project, prior to completing a preliminary feasibility study.

Radiation - energy that exists or moves by way of electromagnetic waves or particles.  Radiation types range from cosmic radiation to sunlight to radio waves.  A substance that emits radiation is said to be radioactive.

Some elements, like uranium, emit radiation as they change, or decay, into other elements over long periods of time. The natural decay of uranium produces three kinds of radiation: alpha, beta and gamma.

Radium – a naturally occurring element that is a radioactive decay product of uranium found in uranium ore. Radium is itself radioactive.

Radon – a naturally occurring element that is heavy radioactive gas given off by rocks containing radium (or thorium) as they decay.

Reclamation – returning the land affected by a mining operation to an acceptable use, or to its former use in cases where that is practical.

Regulatory Process – a process designed and overseen by regulators in regional, provincial and federal governments to evaluate development projects and decide whether or not they may go ahead. Their evaluation and decision are based on factors such as safety, environmental impact, and economic benefits.

The main parts of the regulatory process for a mine are an Environmental Assessment, permitting, licensing and monitoring. The process is examines projects in great detail and includes participants from governments, the project proponent, specialists who have expertise related to the project, and the public.

Sample - a small portion of rock taken so that its mineral content can be determined by assaying.

Slurry – a mixture of water and the ground particles of rock from a mining operation.

Sulphur – a naturally occurring yellow granular element that can be used to produce sulphuric acid.

Tailings - the finely ground rock left over after a desired mineral or metal has been removed from the ore at the mill.  

Thermo Luminescent Dosimeter (TLD) - a measuring device worn by a person to monitor the amount of radiation they receive. TLD badges are analyzed and the results recorded by Health Canada.

Uranium - a heavy, naturally radioactive, metallic element. It is found all over the earth in rocks, soil, water, animals and plants.

Uranium Deposit - a concentration of uranium mineralization in the ground that is of possible economic interest.

Waste Rock – un-mineralized, or sometimes mineralized, rock that is not minable at a profit.

Waste Water – water that is no longer of use in a process and which, after treatment to remove contaminants, can be discharged to the environment.

Watershed – an area drained by a river or stream which discharges to the ocean. A sub-watershed is an area within a watershed that drains into a particular stream or lake.

Yellowcake - uranium concentrate that takes its name from its color and texture. It is used as feed for uranium fuel enrichment and to make fuel pellets for use in nuclear electricity generating plants.