Models used by Commissariat a l'Energie Atomique, France

TRIMOVE is a numerical model for simulating both soil moisture flow and tritium transport through a column of unsaturated soil. The model, written by Y. Belot, is intended to describe the one-dimensional vertical movement of tritium in the soil-atmosphere continuum. Implied in the choice of the simulation method is the prospect of potential uses ranging from management to research. The main purpose is to study the effects of boundary and initial conditions, soil characteristics, and weather inputs on the vertical movement of water and tritium within and from a soil column, including the exchange of tritium between the soil surface and the atmosphere. The model deals with bare or vegetated soils considered as isothermal and homogeneous over the whole extent of the soil column. The model describes the transient transport of both ordinary water and tritiated water by means of two sub-models working in parallel at space and time scales that can be changed according to the problem and / or the process to be treated. Most of the model has taken advantage of process models developed by others. (author)