1,000 to 1 x 10 6 Ci/yr, respectively, for each 1,000 MW of electrical power.
release about 1 x 10 6 Ci/yr. Thus, tritium facilities operate within a background
of tritium from a variety of sources.
The Relative Abundance of Tritium . The isotopes of elemental hydrogen
have long been recognized as being special-- so special, in fact, that each has
been given its own chemical name and symbol. Protium, for example, is the
name given to the hydrogen isotope of mass-1, and the chemical symbol for
protium is H. Deuterium is the name given to the hydrogen isotope of mass-2;
the chemical symbol for deuterium is D. Tritium is the name given to the
hydrogen isotope of mass-3. Its chemical symbol is T.
Protium is by far the most abundant of the hydrogen isotopes. Deuterium
follows next with a relative abundance of about 1 atom of deuterium for every
6,600 atoms of protium; that is, the D to H ratio (D:H) is about 1:6,600. Tritium
is the least common hydrogen isotope. The relative abundance of naturally
occurring tritium (i.e., tritium produced in the upper atmosphere and tritium
injected directly by the sun) has been estimated to be on the order of 1 tritium
atom for every 1018 protium atoms. The introduction of man-made tritium into
the environment, particularly as a result of atmospheric testing, has raised this
level approximately one order of magnitude so that the ambient T to H ratio is
now approximately 1:10 17.