Neutronic analyses for the optimization of the advanced HCPB breeder blanket design for DEMO

Highlights: • The new CAD and MCNP models of the HCPB blanket for DEMO were developed. • The model demonstrates promising tritium breeding performances. • The optimization of the design was performed to increase the shielding performances of the blanket. • The MCNP simulations were carried out to assess main nuclear responses of the HCPB blanket and DEMO reactor. • The effect of the alternative neutron multipliers on the HCPB DEMO tritium breeding performances was investigated. - Abstract: This work gives an overview of the neutronic analyses to support and optimize the advanced HCPB blanket concept for DEMO. Full scale 3D Monte Carlo particle transport simulations were performed to this end with the MCNP5 code employing a very detailed HCPB DEMO torus sector model. The HCPB blanket was optimized to fulfil the design requirements on tritium breeding, thermal stress stability and shielding performance.