Alpha particles
Positively charged particles consisting of two protons and two neutrons that are emitted by the nuclei of radioactive elements as they decay. Alpha particles are relatively large and can be stopped by skin or a sheet of paper.

Beta particles
Fast moving electrons ejected by radioactive element as they decay. Beta particles are relatively small and can penetrate up to two centimeters of water or human flesh. They can be stopped by a sheet of aluminum a few millimeters thick.

CANDU reactor
The Canadian designed nuclear power reactor that uses natural, unenriched uranium for fuel and heavy water as a moderator.

Enriched uranium
Is uranium that has been processed to increase the concentration of fissionable uranium-235 isotope to prepare it for use in some types of reactors. Natural uranium is about 0.7 per cent U-235. Enriched uranium is about three per cent U-235.

Fission
The splitting of the nucleus of an atom which is accompanied by the release of energy in the forms of heat and radiation.

Gamma rays
A wave form of ionizing radiation that is emitted from the nuclei of some radioactive elements as they decay.

Many different devices are used to detect and measure radiation to ensure the safety of nuclear energy workers

Irradiation
The use of ionizing forms of radiation to kill bacteria and pests in human food and animal feed or to slow the ripening process in fruits and vegetables after harvest.

Isotopes
Various forms of atoms of the same chemical element which are distinguished by the number of particles in the nucleus. Uranium has 16 different isotopes.

Neutron
A particle found in the nucleus of atoms with no electrical charge. Neutrons are released from the nuclei of Uranium-235 atoms during fission.

Radiation
Is energy travelling through space in the form of waves or particles including sunlight and radio waves. The type of radiation emitted by uranium is ionizing radiation which is potentially harmful or beneficial to people.

Radioisotope
Unstable atoms of various chemical elements that emit radiation. They are widely used in medicine to treat diseases such as cancer or to diagnose injuries and disease. Radioisotopes can also be used to kill pests and bacteria in food and to slow the ripening process in fruits and vegetables after harvest.

Uranium ore
Is rock that contains unusually high concentrations of natural uranium which can be extracted through the mining and milling process.

Yellowcake
Is the name given to the final product of most uranium mills including those in Canada. A common type of yellowcake is uranium oxide (U₃O₈).