Influence of control rods on the radiation and shielding characteristics of a megawatt nuclear-powered spacecraft
This study analyzes the full-field radiation shielding characteristics of a nuclear-powered spacecraft when the control rod and its guide tube penetrate a shadow shield and proposes an optimization plan for local shielding.The Monte Carlo method is used to complete the transport of neutrons and photons within the entire field of a nucle-ar-powered spacecraft,obtaining the neutron fluence rate and photon dose distribution at various positions of the control rod absorber.The influence of the control rod and its guide tube on the shielding characteristics of the shad-ow shield and the full-field radiation characteristics of the spacecraft is analyzed.Furthermore,a local shielding op-timization scheme is proposed for the radiation of weak points,and the optimized scheme is calculated and verified.The results show that if the guide tube of the control rod vertically penetrates the shielding body,the radiation dose of the instrument platform will exceed the limit value.In extreme cases,the photon dose and the neutron fluence will reach tenfold and 1.8-fold the limiting value,respectively.The arrangement of local shields can effectively eliminate the problem of the radiation dose exceeding the limit due to the guide tube of the control rod and ensure the radiation safety of the area where the instrument platform is located while controlling the mass increase.
万方数据
维普
