standpoint, however, experience has shown that, regardless of the tritiated
compound that enters into the reaction, an HTO (i.e., a tritiated water vapor)
component can be expected to come out. Presumably, this is due to catalytic
effects and/or exchange effects that derive from the outward migration of the
tritiated species through molecular layers of water vapor that are bound to the
surface of the material.
Exchange Reactions . Driven primarily by isotope effects, exchange reactions
involving tritium can be expected to occur at a relatively rapid pace. Moreover,
the speed at which reactions of this type can occur can be further enhanced by
the addition of energy from radioactive decay. For tritium, therefore, reactions
similar to the following can be expected, and they can be expected to reach
equilibrium in time frames that range from seconds to hours:
CH4 + 2T2 W! CT4 + 2H2 ,
2H2O + T2 W 2HTO + H2 .
Equation (5) describes the preferential form of tritium as it exists in nature in
the earth' upper atmosphere. Equation (6) describes the preferential form of
tritium as it exists in nature in the earth' lower atmosphere (i.e., in a terrestrial
Equation (6) is particularly important because it describes the formation of
tritiated water vapor (i.e., HTO) without the involvement of free oxygen (i.e.,
with no O2). A comparable reaction that would involve free oxygen would take
the form of a classic inorganic chemical reaction, such as
H2 + T2 + O2 6 2HTO .