Nuclear design analyses of the helium cooled lithium lead blanket for a fusion power demonstration reactor

This work presents nuclear design analyses for a demonstration power reactor (DEMO) employing the HCLL (helium cooled lithium lead) blanket for the tritium breeding and the power production. The related neutronic calculations were performed with the Monte Carlo code MCNP using a dedicated 3D torus sector model of DEMO. The model has been generated by the geometry conversion tool McCad from available CAD models developed in the frame of the European DEMO study for a device with integrated HCLL blanket modules. The nuclear design analyses address the tritium breeding capability, the shielding performance and the nuclear power production taking into account various engineering design parameters. The HCLL type DEMO was shown to provide tritium self-sufficiency with a sufficient high safety margin. The shielding performance was proven to be sufficient to allow the operation of the DEMO power plant over the full-anticipated lifetime.