THE ITER SAFETY APPROACH FOR EXTERNAL EVENTS

ITER will be the first large-scale tokamak to be designed as a nuclear facility to provide public protection from external hazards such as e arthquakes. The design approach for such events has been developed con sistent with ITER's moderate hazards and overall safety approach on a basis of the ITER site assumptions. Seismic design is described includ ing selection of ground motions for design purposes, seismic safety re quirements, and the seismic classification scheme. The results of prel iminary seismic assessments are summarized including the potential for seismically induced plasma vertical displacement events (VDE). Finall y, potential facility modifications available to deal with site-specif ic external hazards are suggested. At the Detailed Design Report stage of the Engineering Design Activity (EDA), it is concluded that ITER h as been designed to deal with the site design assumptions for earthqua kes and can be designed to safety cope with a range of site-specific e xternal hazards with modest changes to the facility.