5. Conclusion

The phenomena involved in the transfer of radio-nuclides into the air, soil and waterways are complex, as are the most advanced modelling techniques, most of which are not presented in this article because they are not used in operational radioecology. In fact, these models call on parameters for which the available values are rare and highly dependent on the conditions under which they were obtained during experiments that are otherwise difficult to carry out; their use also requires a great deal of information characteristic of the environment, which is also difficult to acquire, notably because it varies greatly in time and space. Calculations to estimate the transfer of radionuclides in these environments are therefore based on simplifications, which are possible under certain conditions and depend on the objectives of the studies, the means of calculation and the input data available....