Low level cleaning of a fusion target chamber

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.