Impact of Advanced Fuel Cycle Scenarios on Geological Disposal

The impact of advanced nuclear fuel cycles on radioactive waste management and geological disposal has been evaluated within the Red-Impact project. Five representative fuel cycles, which were considered in equilibrium, were identified. After a 50 years cooling time, the heat generated in the high-level radioactive waste arising from advanced fuel cycles is significantly lower than that in spent fuel from the "once through" fuel cycle. This would allow the dimensions of a geological repository to be reduced. The impact of advanced fuel cycles on the radiological consequences in the case of the expected evolution or reference scenario is rather limited. This is because the maximum dose in this scenario, which is calculated to occur a few tens of thousands of years after the disposal of the waste is essentially due to mobile fission and activation products; as geological disposal systems are very effective at retarding the migration of actinides, the contribution of the actinides to the effective dose is limited. On the other hand, calculated doses to a geotechnical worker resulting from inadvertent intrusion into a high-level waste repository are significantly reduced in the case of advanced fuel cycles, because of the much lower actinide content of the waste.