Neutronics analysis of a spherical torus based volumetric neutron source

A spherical torus based volumetric neutron source (ST-VNS) concept has been developed as a possible intermediate step to develop the necessary technology for reactor components of future fusion power plants. Such a VNS would complement ITER in testing, developing and qualifying nuclear technology components. Two recently design concepts for a spherical torus based VNS have been investigated. The initial design operated at 39 MW fusion power with a 0.8 m major radius yielding an average neutron wall loading of 1 MW/m². A higher fusion power (326 MW) ST-VNS design was conceived by increasing the major radius to 1.07 m yielding an average neutron wall loading of 5 MW/m². In this paper, we report the results of the neutronics analyses of this high power design along with several design modifications including the effects of using ITER materials in the key components. The results of a feasibility study of using the ST-VNS with suitably designed blankets to provide an intense neutron source for neutron science applications is also reported