Application Of SERPENT-2 In The Neutronics Of Magnetic Confinement Fusion Reactor And Related Studies Of Tritium Breeding Rate In Blanket

In the fusion reactor,the fusion neutrons transport outward from the plasma region,and in the process of transportation,the neutron will react with the materials of blanket,divertor,vacuum vessel,superconducting magnets and other components,which will cause problems such as nuclear heat,burnup,and nuclear transmutations of materials.In fusion neutronics,by solving the particle transport equation and combining with the nuclear evaluation database,the relevant parameters(including the energy spectrum and flux of neutrons and photons,the first wall neutron wall load,tritium breeding rate,nuclear heat density,nuclear heat deposition,helium production rate,displacement damage,radiation absorbed dose and shutdown dose,etc,etc.)can be obtained.There are two methods for solving the particle transport equation:the deterministic method and the Monte Carlo method.Because of the complexity of the geometric model of the fusion reactor,the Monte Carlo particle transport code is an accurate and effective method for solving the neutron transport equation.Serpent-2,developed by VTT Technical Research Center in Finland,has the ability to import CAD based mesh models directly.This feature has a significant advantage in fusion reactor neutronics modeling compared to traditional Constructive Solid Geometiy method,but the application of Serpent-2 in fusion neutronics still lacks comprehensive verification.Therefore,this paper benchmark the application of Serpent-2 in fusion neutronics with MCNP,which is widely used and verifiedin fusion neutronics.The blanket is one of the important components in the magnetic confinement fusion reactor,which is responsible for achieving tritium self-sufficiency,generating nuclear heat and shielding neutrons for superconducting magnets.The tritium producing material is used to react with neutrons in the blanket to ensure the tritium self-sufficiency.Therefore,the study on the tritium breeding rate of blanket in this paper can provide reference for the blanket design of EU DEMO and CFETR.In this paper,the neutron transport and Monte Carlo particle transport codes are introduced and compared first,and the advantages of Serpent-2 as the neutronics analysis code for magnetic confinement fusion reactors are illustrated.Then,the significance of the study on the tritium breeding rate of breeding blanket are discussed.In addition,the particle tracking mothed of Serpent-2 and the calculation of relevant parameters in neutronics are illustrated.The application of Serpent-2 in the EU DEMO HCPB blanket has been benchmarked with MCNP.The modeling based on the CSG method,neutron sources,neutron and photon energy spectrum,nuclear heat,tritium breeding rate,global variance reduction capabilities and CAD-based modeling capabilities have been tested.The results show that Serpent-2 has the ability to replace MCNP in fusion neutronics analysis.Based on Serpent-2,this paper explored the tritium breeding rate of the water-cooled lead ceramic blanket for EU DEMO.The exploration including parameterization analysis of tritium breeding rate,sensitivity study of tritium breeding rate on the material proportion of the first wall and breeding zone,influence of the structure of the first wall and breeding zone on tritium breeding rate,and influence of lead/lead alloy on tritium breeding rate.After calculation,the influence of the material proportion in the first wall and the breeding zone on the tritium breeding rate was been clarified,and a scheme to improve the tritium breeding rate was proposed.The study of the structure of the first wall and the breeding zone and the study of the lead/lead alloy on the tritium breeding rate have also been completed.In addition,neutronics analysis of HCCB Blanket with S-shaped Lithium Zone and Cooling Plate for CFETR has been done.The analysis includes neutron wall load,tritium breeding rate,nuclear heat and shielding related performance.The HCCB blaknet with S-shaped Lithium Zone and Cooling Plate have been proved to be feasible.This neutronics analysis provides reference for the design and analysis of blanket for CFETR.