Discussion on Optimization of Protection Effect of Shielding Doors in High Level Waste Treatment Facilities

Due to the special nature of the radiation sources involved (high radioactivity and high penetration) in high discharge waste treatment facilities, several shielding doors are installed in the facilities to ensure staff safety. In the analysis of the radiation protection design of shielding doors, it is found that the type of radiation source, the relative position of the radiation source and the door, and the structure of the door all have an impact on the radiation shielding effect. In this paper, the shielding door of a hot room in a high discharge waste treatment facility is used as the research object, and the dose rate outside the shielding door is analyzed with the characteristics of radiation sources and their different locations, and with respect to the existing shielding door structure. The analysis results show that, under the premise of meeting the shielding requirements, when the radiation emitted by the source has a certain angle of incidence relative to the shielding door, the dose rate at a specific location outside the door will be significantly increased due to the scattering leakage of the door slit and the effect of the oblique penetration of the radiation. In addition, the characteristics of the radiation source, such as the type of nuclide, and the geometry can also influence the safety design of the shielded door. Therefore, in order to optimize the protection effect of shielded doors, considering that the characteristics of radiation sources are generally difficult to optimize, this paper proposes several solutions from two perspectives: door slit scattering and overlap length, and combining other influencing factors from different aspects. The optimization effects of each solution are also compared, and the corresponding adaptation sites are also outlined through their respective advantages and disadvantages. Through the analysis and research of this paper, the safety and effectiveness of the shielding door is improved, the safety of personnel is guaranteed, and the foundation for the future design of the shield door is laid.