Neutronic and thermal mechanical analyses of ITER-FEAT breeding blanket innovative design

International Thermonuclear Experimental Reactor-Fusion Energy Advanced Tokamak (ITER-FEAT) Breeding Blanket (BB) will be different from the design defined by the released version named ‘ITER-98’ from the size as well as the neutron wall loading (NWL) point of view. In fact global dimensions and output power of ITER-FEAT have been approximately reduced by a factor of 3. The BB under study corresponds to the main solutions of ITER-98 project [1] [2], that is: breeder in tube, consisting of pellets of a Lithium compound; neutron multiplier made of a pebble bed of Beryllium; cooling plates (using pressurized water as coolant) as basic cell boundaries; stainless steel as structural material. This paper deals with the neutronic as well as the thermal mechanical analyses of the envisaged BB in order to assess its performances in terms of Tritium production and thermal mechanical resistance. The code MCNP version 4B [3] has been used for the neutronic analyses while the thermal-mechanical analyses have been performed by means of the FEM codes MARC and ANSYS. The preliminary analyses demonstrated that the proposed BB verifies the temperature constraints for the Breeder (temperature contained in the ‘thermal window’) as well as for the multiplier (Be temperature lower than 500 °C), but the configuration of the breeder and multiplier in the basic cell have to be modified in order to obtain a Tritium Breeder Ratio larger than 1.