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Fusion experiments involving a deuterium–tritium compound can be considered in the near future at CEA/DAM/Cesta using the laser integration line facility (LIL; prototype of the laser mega joule (LMJ), under construction). Nevertheless, non-contaminated materials are currently favoured in order to minimise exploitation constraints. Hence, as it presented low but significant levels of contamination (tritium and beryllium), the LIL target chamber was cleaned up before being installed. A comparison of selected decontamination methods has been made based on their ability to reach very low levels of contamination (i.e. the lowest contamination threshold in transportation regulations and beryllium public limit), their efficiency and compatibility with vacuum objectives. The process was thereby performed at CEA/DAM/Cesta in 2001, using an acid foam technique in a dedicated installation. Its implementation and effectiveness are further discussed in this paper.

In the framework of research on inertial fusion, experiments on a reduced-scale prototype of the future Laser MegaJoule (LMJ) are planned in the ‘Laser Integration Line’ at CEA/DAM/CESTA. By 2005, part of these experiments will involve Deuterium–Tritium targets in which fusion reaction will result in radiation—mainly in the form of neutron flux and photon radiation from activated materials—that constitute a source of radiological exposure at the workplace. At the conception stage, an evaluation of the radiological exposures of occupational workers was performed. Different options for reducing these exposures have been studied. Results show that by modifying the composition of the staff or delaying the interventions, a reduction of the individual doses to the most exposed categories of employees from 2 to 50% to a factor 4 can be achieved, without increasing the total collective dose which can be further reduced by 10–25%. This study is a good illustration of how the ALARA principle can be implemented at the conception stage of an installation. Due to the low individual and collective exposures, the different options to reduce doses are more closely associated with staff and planning re-organisations. These options are characterised by a rather low cost and limited constraints of implementation.