Effect on the Tritium Breeding Ratio for a distributed ICRF antenna in a DEMO reactor

This thesis reports results of MCNP-5 calculations, with the nuclear data library FENDL-2.1, to assess the effect on the Tritium Breeding Ratio (TBR) when integrating a distributed Ion Cyclotron Range of Frequencies (ICRF) antenna in the blanket of a DEMO fusion power reactor. Apart from a representative final configuration of both the antenna and the DEMO reactor, a parametric analysis is done on the parameters which most strongly affect the TBR. These are the type of breeding blanket (Helium Cooled Pebble Bed, Helium Cooled Lithium Lead and Water Cooled Lithium Lead), the covering ratio of the straps of the antenna (0.49, 0.72 and 0.94), the depth of the antenna (20 cm and 40 cm), the thickness of the straps (2 cm, 4 cm and a double layer of 0.2 cm plus 2.5 cm with the composition of the First Wall), and finally the poloidal position of the antenna (0º, which is the equatorial port, 40º and 90º, which is the upper port). For an antenna with a full toroidal circumference of 360º, located poloidally at 40º with a poloidal extension of 1 m and a total First Wall surface of 67 m2, the reduction of the TBR is 0.35% for a HCPB blanket concept, 0.53% for a HCLL blanket concept and 0.51% for a WCLL blanket concept. In all cases, including the parametric analysis, the loss of TBR remains below 0.61%, and the antenna is thus shown to have only a marginal effect on the TBR for a DEMO reactor.