AbstractThe aqueous salt blanket for ITER (International Thermonuclear Experimental Reactor) has been examined with regards to accident safety. Source terms include tritium as well as dissolved and deposited activated corrosion products in the breeder salt solution and in the water coolant. Scenarios investigated in detail include a pipe break within a breeder module and a major loss of coolant accident (LOCA). The impact of varying the salt concentration in the breeder solution and of operating the salt at a lower pressure on the accident consequences was examined. Consequences of the pipe break were found to be dependent on the duration of flow after the break and the amount of spilled material that becomes airborne. Even with conservative assumptions, the offsite dose from this accident did not exceed the 10 rem passive safety target proposed for ITER. A preliminary estimate of the pipe break frequency indicated that this may occur as often as once per year, although there is some uncertainty in this value. Other impacts of the accident, such as reduced availability, may be unacceptable. Preliminary results for a conservative LOCA analysis indicated that the offsite dose consequences may exceed the proposed ITER target for passive safety, particularly if the tritium concentration in the breeder is as high as 30 Ci/l and if the system is operated at high pressure. Equipment damage and impact on facility mission may also be considerable. Two other scenarios, a loss of flow accident/loss of heat sink, and a recombiner failure were examined in less detail. To minimize the consequences of losing flow or losing the heat sink on the secondary side of the heat exchanger, the system should be designed to take advantage of natural circulation. A passive heat exchanger should also be employed to remove about 3% of reactor power, which arises from decay heat. Of the possible recombiner designs, liquid phase or free gas recombination appear to have the fewest safety concerns.