A molten salt reactor(MSR) produces large amount of tritium.While the tritium may discharge from the stack

some of the tritium may permeate through the reactor vessel

causing serious effects on mechanical properties and lifetime of the structure materials

and large impact to the environment.In this paper

we give a review on the four methods to control and reduce the permeation of tritium in an MSR

such as increasing the concentration of 7Li

adding Li or Be to the fuel salt

etc.The tritium monitoring

which is fundamental and essential in its control

can reflect the operation status of the MSR.The three methods of monitoring tritium

i.e.liquid scintillation

ionization chamber

and proportional gas counting

are discussed

and accurate tritium monitoring can be achieved by combining the ionization chamber and liquid scintillation.