Mechanical Design And Analog Electronics Design Of Gaseous Radioactive Iodine Detection Devices

Real-time monitoring of radioactive emissions from nuclear facilities is animportant aspect of nuclear safety-related radiation monitoring.131I is one of thevolatile fission products, so it’s very easy to enter the emissions from nuclear facilities.Under normal condition, the concentration of131I in the emissions is low, howeverwhen a leakage occurs, the concentration will increase sharply, and this will causeserious pollution to the surrounding environment. Once131I is absorbed into thehuman body, the health of thyroid and other organs would be threatened. Therefore,the development of gaseous radioactive iodine monitoring devices is important. In thispaper, the development process of a gaseous radioactive iodine device was describedin detail. Firstly, the detection methods were simulated by the use of Monte Carlocode (MCNP and Geant4), the detection model was determined according tosimulation results and operation conditions. Secondly, the design process of detectorcircuit was introduced. Thirdly, the adsorption of gaseous radioactive iodine wasstudied. Finally, a new design of gaseous radioactive iodine was introduced, which issmaller, lower cost and lighter.In this paper, the technical improvement and design optimization have beencarried out on the basis of the design of similar equipment. There are manyinnovations in the design: In order to achieve long distance transmission of signalswithout distortion, the signal from the preamplifier in the probe is shaped beforetransmission; The way of the detector’s structure impact on the detector weresystematically studied with Monte Carlo code, This provides a comprehensive,theoretical data for the optimization of the detector, and It’s also important to reduce the costs of equipment’s research and design, improve the quality of equipment’s R&D; in order to reduce the size and weight of the external lead shielding the probewithout sacrificing performance, a small, low cost, good performance photomultiplierwas used. A fast response, low operating voltage, small silicon photomultiplier can beused as the first choice. In this paper, the feasibility of silicon photomultiplierdetectors used in gaseous radioactive iodine has been tested and the improvementprogram has been discussed briefly. It has not been found that the study of applyingsilicon photomultipliers to gaseous radioactive iodine monitor at home, so its in-depthstudy is important.