San Diego, California, 17-19 June 2002

Management of Radioactive Equipments in Laser Megajoule Facility

Philippe Joyer ⁽¹⁾ and Marc Dupont ⁽²⁾

Commissariat à l’Energie Atomique

(1) Centre d’Etudes Scientifiques et Techniques d’Aquitaine (CESTA) BP 2, 33114 Le Barp, France,

joyerbordeaux.cea.fr

(2) Centre d’études Ile de France, BP 12, 91680 Bruyères le Châtel, France,

marc.dupontcea.fr

Laser Megajoule (LMJ) is the major project in France for Inertial Confinement Fusion research. 240 laser beams will generate 1.8 MJ energy required to reach ignition. High 14 MeV neutrons amounts (up to 1 10¹⁹ neutrons) will be produced with a few hundred micrograms of deuterium tritium mixture. Construction phase should begin in the course of year 2003 and operation is planned to start at the end of the decade (around 2008-2010).

High neutron levels expected (about 4 decades higher than in existing laser facilities), will induce high activation levels which is an important issue for LMJ.

Increase of tritium amounts in next steps facilities induces higher contamination levels.

All equipments introduced inside the experimental bay (target chamber area and laser beam distribution rooms) will be only activated. Activation may be reduced by a suitable choice of materials used.

In addition, in vessel equipments will also be contaminated by tritium unburned in the experiments.

Management of these radioactive equipments is based on two basic choices: reuse or elimination as radiological wastes.

Preliminary calculations have been performed to estimate, on the one hand dose rate expected for maintenance operators and, on the other hand specific activities for wastes disposal. Results will be given.

In case of reuse, maintenance prediction is needed to reduce personnel exposure, define equipments handling (hands-on or remote handled) and reduce handling time. Some elements may be stored before maintenance and if necessary, decontaminated after storage to make maintenance easier.

Preliminary analyses have been undertaken to define functionalities of post-experiments activities on radioactive equipments. These activities will be made in contiguous buildings for which design is not, at present time, done. A first estimation of equipments amounts will be shown.

Preliminary information on radiological wastes will also be given.