First wall risk analysis for a loss of coolant accident in an experimental fusion reactor

One of the most vulnerable components in a fusion reactor may be the first wall, which is facing the plasma and which must be water cooled. Using statistical failure rate values from french fission facilities, it is a calculated probability of an accident induced by pipe break inside the first wall. It has been found an occurence probability of about 4 E-4 per year to contaminate reactor hall, taking into account each prospective existing barrier. Then, occupational and environmental impacts are evaluated, considering all radioactive products which may be released. First conclusions point out that if consequences on the reactor itself may be serious, induced doses on the public remain always low enough to be achievable. An analysis of protection options which may decrease the risk is performed