Glossary - T

Three Mile Island

A two-unit nuclear generating station near Harrisburg, Pennsylvania, U.S.A. In April 1979, severe core melting occurred in one of the units. The reactor was safely shut down, radiation releases were minimal, and no one was injured.

Source: AECL

Thorium-232

A naturally occuring element that will absorb neutrons and become fissile or fissionable. Thorium-232 has possibilities in replacing uranium-235 as a fuel for nuclear reactors. When thorium-232 absorbs a neutron it transforms to thorium-233 which then decays to protactinium-233 and then to the fissile material, uranium-233.

Source: AECL

Tracer

A small amount of a radioactive isotope introduced into a system in order to follow the behavior of some component of that system.

Source: AECL

Tritium

A radioactive form of hydrogen produced naturally in small amounts by cosmic radiation. Larger amounts are formed in heavy water reactors. Tritium is thus of special concern to the utilities that operate CANDU power reactors and its release is carefully monitored to keep it within acceptable levels.

Source: AECL