SAFETY ANALYSIS AND RADIOACTIVITY CONFINEMENT FOR ITER

The paper summarizes the main results of an collaborative effort by the ITER safety group (within the Systems Project Unit). The work was done in support of ITER design and evolved in collaboration with the other ITER groups. A safety approach has been defined and radioactivity dose limits have been quantified both in terms of target numbers for the design and of estimated limits expected to be requested by the regulatory bodies. Doses due to normal operation effluents of tritium and activation products have been estimated. Accidents of significance have been identified. Emphasis of accident analysis was put on events related to plasma (vacuum) chamber and cooling system. A confinement concept has been specified and assessed in terms of effective release fractions for accidental situations involving mobilization of both tritium and activation products. The masses of decommissioning and operational radioactive waste have been estimated and broadly characterized by the potential disposal options. Overall, the safety work resulted in safety features implemented in the design, recommendations pending for the EDA, and identification of potential problems to be resolved by EDA safety work as well as by safety related R&D.