50 Years Environmental Tritium Transfer Review in the Vicinity of French Research Centre

The objective of this document is to describe the behavior of tritium in the environment from the survey data of the site of a French research centre.

Since the late 60's, the nuclear site of Valduc, has been discharging tritium gas and tritiated water to the atmosphere. Those discharges have lead to a transfer to the nearby groundwater and rivers. A balance of the tritium migrating through the hydrogeological system is presented for the 1969-2009 period.

Surface survey data bring also quite a lot of information about transfers by the air pathway. This concerns the different compartments: air, rain, soil, vegetable and animals. Ratios between the different compartment concentration show that air-leaves transfer is important, that rain and air deposition are of the same order of magnitude, and that a relatively good equilibrium exist between free and organic material water of the vegetable.

Some outdoor experiments confirm, in agreement with literature, the level of incorporation in organic materials.

Outside the centre, water always remained below the present WHO limit of quality for drinkable water. Radiological impact has been assessed and is presently less than 1 Sv.y^-1 for individual of the nearby population.

Tritium appears to be a very good indicator of the site specific characteristics.