Reactor Water Chemistry
Numerous potential and actual sources of tritium production exist in the United States,
the United Kingdom, France, and other countries. They include light-water reactors,
heavy-water reactors, fuel reprocessing facilities, and production reactors. Light-water
reactors produce between 500 and 1000 Ci/yr of tritium in their coolant for every 1000
MW(e) of power. Heavy-water reactors produce approximately 2 x 10 Ci/yr of tritium
in their coolant for every 1,000 MW(e) of power.
Atomic Weight/Hydrogen Isotopes
The atomic weights, symbols, and abundance of the three well-known isotopes of
hydrogen are given in Table 2. H and H are also known. However, because they decay
in fractions of a single second, they are not extensively studied. Unless otherwise
specified in this chapter, the term hydrogen includes protium, deuterium, and tritium. H
will be used to refer to protium; confusion with elemental hydrogen will be eliminated by
spelling out the latter.
* 12.32-years half-life
Tritium decays by emitting a weak beta particle together with an antineutrino. The
product is helium-3. Helium is a monatomic gas; therefore, the decay of 1 mole of T2
yields 2 moles of helium. This causes a pressure buildup in sealed vessels containing
diatomic tritium gas (or HT or DT gas). The following reaction is tritium disintegration.