Research On Preparation And Application Of Hydrogen Concentration Sensor In Nuclear Power Station

Severe challenges are put forward to the global nuclear safety in Fukushima hydrogen explosion accident. Therefore, it is very important to strengthen hydrogen concentration monitoring in the containment. In order to improve the level of nuclear safety of nuclear power plants.General technical requirements of action are improved to nuclear power plant in Fukushima nuclear accident was issued by Chinese National Nuclear Safety Administration. At present, there are two ways to monitoring hydrogen concentration in the domestic security shell. One is the withdrawable measuring method, the other is the direct measuring way. Direct measurement device has good performance on real-time and precision, Not only is it suitable for the nuclear safety regulations and improvement of nuclear power plant, but also for hydrogen monitoring of other relevant places, such as fuel plant. However, due to the limitations of environment under severe accident conditions, To research and develop the direct measurement of hydrogen sensor device is always a difficult problem in the current domestic and foreign nuclear power technology research, and no more reliable and mature products can be applied. So, to develop a reliable direct measurement hydrogen sensor has a very important significance.The resistance type hydrogen sensor was studied systematically in this paper, which includes correlative sensing theoretical modeling, developing and testing of hydrogen prototypes. Main research work and achievements are as follows.First of all, research objective and background of the paper were analysed, the current status about this topic and the advantages or disadvantages of the traditional hydrogen sensor were described. Some problems of developing hydrogen sensor were pointed out.Secondly, for fabricated for Pd-Ag alloy thin film, sputtering theoretical model was put forward, and the sputtering parameters were analysed for the ideal palladium-sliver optimal proportioning and thickness of membrane, the theoretical basis for the development of palladium silver alloy sensor was provided. At the same time, in order to overcome the defects of hydrogen embrittlement phenomenon in previous hydrogen sensor, which were based on the pure palladium, gas-sensing material which the sliver as the second component was added to the palladium was studied. Due to the addition of silver, the pure palladium microstructural characterization of the films was effectively improved.After the advantages and disadvantages of preparing Pd-Ag alloy thin films in different ways were analysed, the optimal proportioning in palladium-sliver of DC magnetron sputtering method for preparing film was given. Using photochemical etching technology to produce bent metal mask, and the mask was put on the ceramic substrate. Firstly, thin film of Ta2O5 as a transition layer grows on ceramic substrate. Then, a series of palladium silver alloy film sensors were prepared, and each performance characterization of Pd-Ag alloy film was studied.In order to testing the output of current signal, the low noise amplifier circuit, filter circuit, ADC interface circuit and microprocessor were designed. The device driver and application software were completed.Then, the hydrogen concentration value can be displayed by the detection graphical software.Finally, the performance of the hydrogen sensor inside the containment was tested, and the experimental results show that the hydrogen sensor has good performance.